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Sample records for antimalarial antiplatelet antiprotozoal

  1. Antiprotozoal compounds from Asparagus africanus

    DEFF Research Database (Denmark)

    Oketch-Rabah, H A; Dossaji, S F; Christensen, S B

    1997-01-01

    Two antiprotozoal compounds have been isolated from the roots of Asparagus africanus Lam. (Liliaceae), a new sapogenin, 2 beta, 12 alpha-dihydroxy-(25R)-spirosta-4,7-dien-3-one (1), which was named muzanzagenin, and the lignan (+)-nyasol (2), (Z)-(+)-4,4'-(3-ethenyl-1-propene-1,3-diyl)-bisphenol.......Two antiprotozoal compounds have been isolated from the roots of Asparagus africanus Lam. (Liliaceae), a new sapogenin, 2 beta, 12 alpha-dihydroxy-(25R)-spirosta-4,7-dien-3-one (1), which was named muzanzagenin, and the lignan (+)-nyasol (2), (Z)-(+)-4,4'-(3-ethenyl-1-propene-1,3-diyl...

  2. Antiplaquetarios Antiplatelets

    Directory of Open Access Journals (Sweden)

    Lilliana Chaves Brenes

    2012-12-01

    Full Text Available Introducción: Con el advenimiento de los antiplaquetarios se dio un gran avance en el tratamiento de los eventos tromboticos, de tal forma que se revoluciona el tratamiento del infarto y el Accidente Vascular Cerebral. Con la combinación de los antiplaquetarios se potencia el efecto antitrombotico, mejorado los resultados y la reversión de los eventos, sin embargo, aumenta los efectos secundarios como el sangrado. Aproximadamente, existe alrededor de 20 fármacos antiplaquetarios, algunos se administran oral o intravenosamente como el tirofiban,abciximab, y la eptifibatida. En la presente revisión hablaremos solamente de la terapia oral de los principales antiplaquetarios orales, sus efectos secundarios, sus indicaciones y precauciones. Aunque, muchas veces se administra los medicamentos plaquetarios en dosis correctas no siempre se puede ver la recanalización del vaso sanguíneo debido a un síndrome de resistencia a los antiplaquetarios.The advent of antiplatelet agents was a major advance in the treatment of thrombotic events, so that are revolutionizing the treatment of heart attack and stroke. The combination of antithrombotic antiplatelet gave better effect and improvement results and reverse of events. However, increases the side effects such as bleeding. Approximately exists around twenty antiplatelet drugs, some are administered orally or intravenously as Tirofiban, Abciximab and Eptifibatide. In this review we will talk only therapy of oral antiplatelet main, side effects, indications and precautions. Although often administrated the correct dose antiplatelet drugs, those can not always obtain the blood vessel recanalization due to resistance: syndrome antiplatelets.

  3. Antiprotozoal Activity of Essential Oils

    Directory of Open Access Journals (Sweden)

    Lianet Monzote

    2013-03-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} In the present scenario of protozoal infections, new drugs are urgently needed to treat and control infections such as malaria, sleeping sickness, Chagas disease, leishmaniasis and intestinal infections, which affect millions of people each year. In this review, we are focusing on articles related to antiprotozoal essential oils extracted from plants that have been published during the last 20 years. The data analyzed indicate that essential oils could be promising antiprotozoal agents, opening perspectives to the discovery of more effective drugs of vegetal origin for the treatment of diseases caused by protozoa.

  4. Evaluation of in vitro antiprotozoal activity of Ajuga laxmannii and its secondary metabolites.

    Science.gov (United States)

    Atay, Irem; Kirmizibekmez, Hasan; Kaiser, Marcel; Akaydin, Galip; Yesilada, Erdem; Tasdemir, Deniz

    2016-09-01

    Context Some Ajuga L. (Lamiaceae) species are traditionally used for the treatment of malaria, as well as fever, which is a common symptom of many parasitic diseases. Objective In the continuation of our studies on the identification of antiprotozoal secondary metabolites of Turkish Lamiaceae species, we have investigated the aerial parts of Ajuga laxmannii. Materials and methods The aerial parts of A. laxmannii were extracted with MeOH. The H2O subextract was subjected to polyamide, C18-MPLC and SiO2 CCs to yield eight metabolites. The structures of the isolates were elucidated by NMR spectroscopy and MS analyses. The extract, subextracts as well as the isolates were tested for their in vitro antiprotozoal activities against Plasmodium falciparum, Trypanasoma brucei rhodesiense, T. cruzi and Leishmania donovani at concentrations of 90-0.123 μg/mL. Results Two iridoid glycosides harpagide (1) and 8-O-acetylharpagide (2), three o-coumaric acid derivatives cis-melilotoside (3), trans-melilotoside (4) and dihydromelilotoside (5), two phenylethanoid glycosides verbascoside (6) and galactosylmartynoside (7) and a flavone-C-glycoside, isoorientin (8) were isolated. Many compounds showed moderate to good antiparasitic activity, with isoorientin (8) displaying the most significant antimalarial potential (an IC50 value of 9.7 μg/mL). Discussion and conclusion This is the first report on the antiprotozoal evaluation of A. laxmannii extracts and isolates. Furthermore, isoorientin and dihydromelilotoside are being reported for the first time from the genus Ajuga.

  5. Antiprotozoal properties of Helianthemum glomeratum.

    Science.gov (United States)

    Meckes, M; Calzada, F; Tapia-Contreras, A; Cedillo-Rivera, R

    1999-03-01

    Structure characterization and biological evaluation of the compounds isolated from Helianthemum glomeratum, particularly that of the polyphenols, has been the aim of a series of studies carried out to define the further potential use of this plant in the treatment of infectious diarrhoea in children. The flavan-3-ols, (-)-epigallocatechin and (-)-epigallocatechin gallate, isolated from Helianthemum glomeratum roots were tested for their antiamoebic and antigiardial effects in vitro. Compared with the activity determined with the leaf and the root methanol extracts, the effect of (-)-epigallocatechin against Entamoeba histolytica was of a similar potency, nevertheless, it also suppressed the growth of Giardia lamblia in axenic cultures, a parasite that proved to be resistant to the crude extracts. It might be assumed that determined biological properties are due to the presence of (-)-epigallocatechin in the plant, although the flavonoids, kaempferol and tiliroside isolated from the leaves, could account for the antiprotozoal properties of this herbal resource, used in Mayan traditional medicine for the treatment of bloody diarrhoea.

  6. Discovery and Evaluation of Thiazinoquinones as Anti-Protozoal Agents

    Directory of Open Access Journals (Sweden)

    Marcel Kaiser

    2013-09-01

    Full Text Available Pure compound screening has identified the dioxothiazino-quinoline-quinone ascidian metabolite ascidiathiazone A (2 to be a moderate growth inhibitor of Trypanosoma brucei rhodesiense (IC50 3.1 μM and Plasmodium falciparum (K1 dual drug resistant strain (IC50 3.3 μM while exhibiting low levels of cytotoxicity (L6, IC50 167 μM. A series of C-7 amide and Δ2(3 analogues were prepared that explored the influence of lipophilicity and oxidation state on observed anti-protozoal activity and selectivity. Little variation in anti-malarial potency was observed (IC50 0.62–6.5 μM, and no correlation was apparent between anti-malarial and anti-T. brucei activity. Phenethylamide 7e and Δ2(3-glycine analogue 8k exhibited similar anti-Pf activity to 2 but with slightly enhanced selectivity (SI 72 and 93, respectively, while Δ2(3-phenethylamide 8e (IC50 0.67 μM, SI 78 exhibited improved potency and selectivity towards T. brucei rhodesiense compared to the natural product hit. A second series of analogues were prepared that replaced the quinoline ring of 2 with benzofuran or benzothiophene moieties. While esters 10a/10b and 15 were once again found to exhibit cytotoxicity, carboxylic acid analogues exhibited potent anti-Pf activity (IC50 0.34–0.035 μM combined with excellent selectivity (SI 560–4000. In vivo evaluation of a furan carboxylic acid analogue against P. berghei was undertaken, demonstrating 85.7% and 47% reductions in parasitaemia with ip or oral dosing respectively.

  7. Antiplatelet therapy and exodontia

    National Research Council Canada - National Science Library

    Schreuder, Willem H; Peacock, Zachary S

    2015-01-01

    .... The authors reviewed the literature, focusing on the indications and mechanisms of antiplatelet therapy and the perioperative management of patients taking these agents who require exodontia or other...

  8. Monitoring Antiplatelet Therapy.

    Science.gov (United States)

    Orme, Rachel; Judge, Heather M; Storey, Robert F

    2017-04-01

    The increasing use of antiplatelet therapy, particularly aspirin and oral P2Y12 inhibitors, in the prevention and management of arterial thrombosis, has stimulated extensive pharmacodynamic studies and research into tailored antiplatelet regimens. Many different methodologies have been studied for monitoring antiplatelet drugs and some are now well validated and used in clinical practice. However, clinical studies of tailored antiplatelet therapy have not convincingly demonstrated a benefit of this approach in patients treated with aspirin and clopidogrel, coupled with the fact that more potent antiplatelet therapies have more consistent effects compared with clopidogrel and so may reduce the rationale for monitoring. On the other hand, the optimum timing of urgent surgery after cession of oral antiplatelet therapy may be informed by platelet function testing. This review discusses the different methodologies that have been used to monitor the effects of antiplatelet therapy and highlights the current position of platelet function testing in clinical practice. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  9. Antiprotozoal and antioxidant alkaloids from Alternanthera littoralis.

    Science.gov (United States)

    Koolen, Hector H F; Pral, Elizabeth M F; Alfieri, Silvia C; Marinho, Jane V N; Serain, Alessandra F; Hernández-Tasco, Alvaro J; Andreazza, Nathalia L; Salvador, Marcos J

    2017-02-01

    Five alkaloids, in addition to hydroxytyrosol and uridine, were isolated from aerial parts of Alternanthera littoralis P. Beauv. Among the isolated compounds, alternamide A was an unusual tricyclic alkaloid with a bridged benzoazepine core. All isolated alkaloids have a catechol moiety, indicating a possible common biosynthetic route. Their structures were established by 1D and 2D NMR spectroscopy in combination with extensive tandem MS experiments by collisional induced dissociation (CID). The antiprotozoal activity of the isolated compounds was assayed against trypomastigote forms of Trypanosoma cruzi and amastigotes of Leishmania amazonensis. Alternamine A was the most active compound, reducing markedly the viability of both parasites. Antioxidant capacities evaluated by ORACFL assay showed that the isolated alkaloids (mainly alternamide B) contributed to the high activity recorded for the ethanolic crude extract; possibly, the catechol moiety present in all structures plays a central role in this result.

  10. Advances in antiplatelet therapy

    National Research Council Canada - National Science Library

    Michelson, Alan D

    2011-01-01

    Because of the central role of platelets in cardiovascular atherothrombosis, there is a well-established therapeutic role for antiplatelet therapy that includes aspirin (a cyclooxygenase 1 [COX1] inhibitor), clopidogrel...

  11. Antiplatelet therapy and exodontia.

    Science.gov (United States)

    Schreuder, Willem H; Peacock, Zachary S

    2015-11-01

    This is a review of the management considerations regarding exodontia for patients taking antithrombotic medications that affect platelet function or aggregation. The authors reviewed the literature, focusing on the indications and mechanisms of antiplatelet therapy and the perioperative management of patients taking these agents who require exodontia or other dentoalveolar surgery. Dentists making management decisions regarding patients taking antiplatelet therapy should consider the patient's risk of experiencing perioperative hemorrhage against the risk of experiencing complications associated with thromboembolic events. The risk of perioperative bleeding complications is low for patients taking single or dual antiplatelet therapy. Intraoperative and postoperative bleeding can be controlled with local hemostatic measures. For patients taking antiplatelet medication, bleeding risk for exodontia is generally lower than the risk of experiencing thromboembolic events owing to cessation of therapy. Dentists can safely complete exodontia in patients who continue taking antiplatelet therapy. The dentist should consult the patient's prescribing physician before considering altering the patient's antiplatelet therapy regimen. Copyright © 2015 American Dental Association. Published by Elsevier Inc. All rights reserved.

  12. New prodrugs of the antiprotozoal drug pentamidine.

    Science.gov (United States)

    Kotthaus, Joscha; Kotthaus, Jürke; Schade, Dennis; Schwering, Ulrike; Hungeling, Helen; Müller-Fielitz, Helge; Raasch, Walter; Clement, Bernd

    2011-12-09

    Pentamidine is an effective antimicrobial agent that is approved for the treatment of African trypanosomiasis but suffers from poor oral bioavailability and central nervous system (CNS) penetration. This work deals with the development and systematic characterisation of new prodrugs of pentamidine. For this reason, numerous prodrugs that use different prodrug principles were synthesised and examined in vitro and in vivo. Another objective of the study was the determination of permeability of the different pentamidine prodrugs. While some of the prodrug principles applied in this study are known, such as the conversion of the amidine functions into amidoximes or the O-alkylation of amidoximes with a carboxymethyl residue, others were developed more recently and are described here for the first time. These newly developed methods aim to increase the affinity of the prodrug for the transporters and mediate an active uptake via carrier systems by conjugation of amidoximes with compounds that improve the overall solubility of the prodrug. The different principles chosen resulted in several pentamidine prodrugs with various advantages. The objective of this investigation was the systematic characterisation and evaluation of eight pentamidine prodrugs in order to identify the most appropriate strategy to improve the properties of the parent drug. For this reason, all prodrugs were examined with respect to their solubility, stability, enzymatic activation, distribution, CNS delivery, and oral bioavailability. The results of this work have allowed reliable conclusions to be drawn regarding the best prodrug principle for the antiprotozoal drug pentamidine.

  13. Determination of antiprotozoal drug mechanisms by metabolomics approaches.

    Science.gov (United States)

    Creek, Darren J; Barrett, Michael P

    2014-01-01

    The discovery, development and optimal utilization of pharmaceuticals can be greatly enhanced by knowledge of their modes of action. However, many drugs currently on the market act by unknown mechanisms. Untargeted metabolomics offers the potential to discover modes of action for drugs that perturb cellular metabolism. Development of high resolution LC-MS methods and improved data analysis software now allows rapid detection of drug-induced changes to cellular metabolism in an untargeted manner. Several studies have demonstrated the ability of untargeted metabolomics to provide unbiased target discovery for antimicrobial drugs, in particular for antiprotozoal agents. Furthermore, the utilization of targeted metabolomics techniques has enabled validation of existing hypotheses regarding antiprotozoal drug mechanisms. Metabolomics approaches are likely to assist with optimization of new drug candidates by identification of drug targets, and by allowing detailed characterization of modes of action and resistance of existing and novel antiprotozoal drugs.

  14. On peroxide antimalarials

    Directory of Open Access Journals (Sweden)

    IGOR OPSENICA

    2007-12-01

    Full Text Available Several dicyclohexylidene tetraoxanes were prepared in order to gain a further insight into structure–activity relationship of this kind of antimalarials. The tetraoxanes 2–5, obtained as a cis/trans mixture, showed pronounced antimalarial activity against Plasmodium falciparum chloroquine susceptible D6, chloroquine resistant W2 and multidrug-resistant TM91C235 (Thailand strains. They have better than or similar activity to the corresponding desmethyl dicyclohexylidene derivatives. Two chimeric endoperoxides with superior antimalarial activity to the natural product ascaridole were also synthesized.

  15. Pharmacology of antiplatelet agents.

    Science.gov (United States)

    Kalra, Kiran; Franzese, Christopher J; Gesheff, Martin G; Lev, Eli I; Pandya, Shachi; Bliden, Kevin P; Tantry, Udaya S; Gurbel, Paul A

    2013-12-01

    Pharmacotherapies with agents that inhibit platelet function have proven to be effective in the treatment of acute coronary syndromes, and in the prevention of complications during and after percutaneous coronary intervention. Because of multiple synergetic pathways of platelet activation and their close interplay with coagulation, current treatment strategies are based not only on platelet inhibition, but also on the attenuation of procoagulant activity, inhibition of thrombin generation, and enhancement of clot dissolution. Current strategies can be broadly categorized as anticoagulants, antiplatelet agents, and fibrinolytics. This review focuses on the pharmacology of current antiplatelet therapy primarily targeting the inhibition of the enzyme cyclooxygenase 1, the P2Y12 receptor, the glycoprotein IIb/IIIa receptor, and protease-activated receptor 1.

  16. Antiplatelet drugs - P2Y12 inhibitors

    Science.gov (United States)

    Blood thinners - clopidogrel; Antiplatelet therapy - clopidogrel; Thienopyridines ... daily aspirin is generally the first choice for antiplatelet therapy. Clopidogrel is prescribed instead of aspirin for patients ...

  17. Synthesis and antiprotozoal activity of pyridyl analogues of pentamidine.

    Science.gov (United States)

    Bakunova, Svetlana M; Bakunov, Stanislav A; Wenzler, Tanja; Barszcz, Todd; Werbovetz, Karl A; Brun, Reto; Tidwell, Richard R

    2009-08-13

    A series of novel pyridyl analogues 1-18 of antiprotozoal drug 1,5-bis(4-amidinophenoxy)pentane (pentamidine) has been synthesized and tested for in vitro activities against Trypanosoma brucei rhodesiense, Plasmodium falciparum, and Leishmania donovani, and for cytotoxicity against mammalian cells. Antiprotozoal properties of compounds 1-18 depended on the placement of cationic moieties on the pyridine rings as well as the nature of substituents on the amidine groups. Diamidine 6 with cationic moieties adjacent to pyridine nitrogen atoms was the most promising compound in the series showing superior in vitro activities against T. brucei rhodesiense, P. falciparum, and L. donovani compared to pentamidine. An oral prodrug of diamidine 6, diamidoxime 9, administered at 25 mg/kg daily for 4 days, exhibited excellent antitrypanosomal efficacy in vivo curing all infected animals in the STIB900 acute mouse model of trypanosomiasis.

  18. Review of triazine antiprotozoal drugs used in veterinary medicine.

    Science.gov (United States)

    Stock, M L; Elazab, S T; Hsu, W H

    2017-08-17

    Triazines are relatively new antiprotozoal drugs that have successfully controlled coccidiosis and equine protozoal myeloencephalitis. These drugs have favorably treated other protozoal diseases such as neosporosis and toxoplasmosis. In this article, we discuss the pharmacological characteristics of five triazines, toltrazuril, ponazuril, clazuril, diclazuril, and nitromezuril which are used in veterinary medicine to control protozoal diseases which include coccidiosis, equine protozoal myeloencephalitis, neosporosis, and toxoplasmosis. © 2017 John Wiley & Sons Ltd.

  19. Antiviral, antifungal and antiprotozoal agents in the cinema.

    Science.gov (United States)

    García-Sánchez, Jose Elias; García-Sánchez, E; Merino Marcos, M L

    2007-03-01

    Among the antimicrobial agents, antibacterials are the most frequently mentioned in cinematographic plots. Nevertheless, it is not uncommon to come across other antiviral agents, especially antiretrovirals and antiprotozoals. We analyzed the presence of antiviral and antifungal agents in different commercial films, both when they were merely mentioned in passing and when they played a major role in the film. This review essentially aims to address the historical portrayal of these agents in film and to list their appearances. The fictional treatments that appear in some films are not addressed.

  20. Antiprotozoal activity of the constituents of Teloxys graveolens.

    Science.gov (United States)

    Calzada, Fernando; Velázquez, Claudia; Cedillo-Rivera, Roberto; Esquivel, Baldomero

    2003-08-01

    Antiprotozoal activity-guided fractionation of a methanol extract of the aerial parts of Teloxys graveolens led to the isolation of one coumarinic acid derivative, melilotoside, and five flavonoids, pinocembrine, pinostrobin, chrysin, narcissin and rutin. Among them, melilotoside exhibited the most potent activity toward Entamoeba histolytica and Giardia lamblia (IC(50) 12.5 and 16.8 micro g/mL, respectively). Narcissin showed selectivity against E. histolytlica (IC(50) 17.2 micro g/mL). The results support data for the traditional use of T. graveolens in some gastrointestinal diseases. Copyright 2003 John Wiley & Sons, Ltd.

  1. Pharmacokinetic justification of antiprotozoal therapy. A US perspective.

    Science.gov (United States)

    Berman, J D; Fleckenstein, L

    1991-12-01

    Infections with parasitic protozoa have always been problems for the developing world and are becoming of greater importance to the developed world in this age of easy international travel. The major human protozoal diseases are summarised with an emphasis on their presentation in normal hosts and in immunocompromised individuals and current US drug treatment recommendations are discussed. Present antiprotozoal regimens are based either on a pharmacokinetic rationale or on clinical trial and error. Regimens based on trial and error include amphotericin B against leishmaniasis and arsenic against African trypanosomiasis. Regimens which are to some extent driven by pharmacokinetic or biochemical considerations include paromomycin and metronidazole against amoebiasis, sodium stibogluconate against leishmaniasis, halofantrine and mefloquine against malaria, dihydrofolate reductase (DHFR) inhibitors against Pneumocystis carinii and toxoplasmosis and aerosolised pentamidine against P. carinii pneumonia. The majority of pharmacokinetic studies have been performed only on agents which have some therapeutic activity against other diseases of the developed world. Despite the trend toward rational treatment regimens, no studies have been performed that permit optimisation of antiprotozoal treatment regimens on the basis of clinical conditions such as renal failure.

  2. 1,2-substituted 4-(1H)-quinolones: synthesis, antimalarial and antitrypanosomal activities in vitro.

    Science.gov (United States)

    Wube, Abraham; Hüfner, Antje; Seebacher, Werner; Kaiser, Marcel; Brun, Reto; Bauer, Rudolf; Bucar, Franz

    2014-09-10

    A diverse array of 4-(1H)-quinolone derivatives bearing substituents at positions 1 and 2 were synthesized and evaluated for antiprotozoal activities against Plasmodium falciparum and Trypanosoma brucei rhodesiense, and cytotoxicity against L-6 cells in vitro. Furthermore, selectivity indices were also determined for both parasites. All compounds tested showed antimalarial activity at low micromolar concentrations, with varied degrees of selectivity against L-6 cells. Compound 5a was found to be the most active against P. falciparum, with an IC50 value of 90 nM and good selectivity for the malarial parasite compared to the L-6 cells. Compound 10a, on the other hand, showed a strong antitrypanosomal effect with an IC50 value of 1.25 µM. In this study side chain diversity was explored by varying the side chain length and substitution pattern on the aliphatic group at position-2 and a structure-antiprotozoal activity study revealed that the aromatic ring introduced at C-2 contributed significantly to the antiprotozoal activities.

  3. Preoperative management of anticoagulation and antiplatelet agents.

    Science.gov (United States)

    Gleason, Lauren Jan; Friedman, Susan M

    2014-05-01

    This article describes current literature and treatment plans for managing anticoagulation and antiplatelet agents in patients presenting with hip fractures. Indications for anticoagulation and antiplatelet agents are discussed, and management techniques for when patients present with hip fractures are reviewed.

  4. What Are Anticoagulants and Antiplatelet Agents?

    Science.gov (United States)

    ... by heart Treatments + Tests What Are Anticoagulants and Antiplatelet Agents? Anticoagulants and antiplatelet agents are medicines that reduce blood clotting in an artery, a vein or the heart. Blood clots can block the ...

  5. Pharmacogenomics of oral antiplatelet drugs.

    Science.gov (United States)

    Yasmina, Alfi; de Boer, Anthonius; Klungel, Olaf H; Deneer, Vera H M

    2014-03-01

    Pharmacogenomics has been implicated in the response variability of antiplatelet drugs in coronary artery disease (CAD), particularly for aspirin and clopidogrel. A large number of studies and several meta-analyses have been published on this topic, but until recently, there have been no clear conclusions and no definite guidelines on the clinical use of pharmacogenetic testing before prescribing antiplatelet drugs for CAD. In this review, the available evidence is summarized. The most consistent results are on clopidogrel, where CYP2C19 loss-of-function alleles are associated with stent thrombosis events. We recommend to genotype for CYP2C19 loss-of-function alleles in patients with CAD who are to undergo percutaneous coronary intervention and stenting, and to adjust the antiplatelet treatment based on the genotyping results.

  6. KEUNGGULAN FARMAKODINAMIK CLOPIDOGREL SEBAGAI ANTIPLATELET DIBANDINGKAN ANTIPLATELET LAIN

    Directory of Open Access Journals (Sweden)

    I M Jawi

    2012-11-01

    Full Text Available Pada keadaan normal platelet tidak dapat beragregasi atau adhesi, namun bila terjadi gangguan fungsi platelet atau terjadi kerusakan pada endotel pembuluh darah dapat terjadi adesi dan aggregasi platelet. Agregasi platelet dapat menyebabkan kelainan yang fatal seperti acut myocardial infarction, ischaemic heart disease, stroke,dan lain-lain. Semua kelainan tersebut dapat diatasi atau dicegah dengan obat-obat antiplatelet. Hingga saat ini telah beredar puluhan jenis obat antiplatelet dengan kebaikan dan kekurangan masing-masing. Salah satu dasar pertimbangan dalam pemilihan obat yang dipakai adalah farmakodinamik dari obat-obat antiplatelet, sehingga pengetahuan tentang farmakodinamik dari obat-obat amat diperlukan. Adanya berbagai reseptor pada permukaan platelet merupakan salah satu faktor penentu farmakodinamik dari obat-obat anti platelet. Reseptor ADP( Adenosin diphosphat terutama P2Y12 merupakan peran sentral dalam aktivasi dan agregasi platelet sehingga obat yang dapat menghambat/antagonis reseptor ADP merupakan harapan baru dari obat-obat antiplatelet. Clopidogrel merupakan antagonis reseptor ADP yang baru selain ticlopidin. Clopidogrel dikatakan lebih efektif dibandingkan aspirin dan obat lain pada kasus myocardial infark, ischaemic stroke, dan vascular desease, oleh karena itu nampaknya pemahaman menganai mekanisme kerja clopidogrel perlu deketahui.

  7. Absolute configuration and antiprotozoal activity of minquartynoic acid

    DEFF Research Database (Denmark)

    Rasmussen, H B; Christensen, Søren Brøgger; Kvist, L P;

    2000-01-01

    Minquartynoic acid (1) was isolated as an antimalarial and antileishmanial constituent of the Peruvian tree Minquartia guianensis and its absolute configuration at C-17 established to be (+)-S through conversion to the known (+)-(S)-17-hydroxystearic acid (2) and confirmed using Mosher's method....

  8. Antibacterial and antiprotozoal effect of Artemisia annua extracts

    DEFF Research Database (Denmark)

    Ivarsen, E.; Fretté, X. C.; Engberg, R. M.;

    2012-01-01

    be banned in the EU. Extracts of aerial parts of Artemisia annua (AA) showed antimicrobial activity in overnight cultures of CP strains isolated from diseased broilers. The hexane extract (HEX) gave the strongest inhibition (MIC=185ppm) while the dichloromethane extract (DCM) gave a weaker inhibition (MIC......=270ppm). The dietary incorporation of HEX reduced the population of CP and the severity of the associated small intestinal lesions (P>0.05) in broilers when applying a NE disease model. The antibacterial compounds from HEX and DCM, chrysosplenol and ponticaepoxide, were isolated. This is the first...... report of activity against CP for these compounds. HEX, DCM and artemisinin were also tested against HM. The two latter showed highest antiprotozoal effect in vitro (MLC=1.0mg/ml and IC50=1.3mg/ml respectively), and were tested in vivo in infected poultry. However, no effect against HM at the given...

  9. Antiprotozoal and cytotoxic activities in vitro of Colombian Annonaceae.

    Science.gov (United States)

    Osorio, Edison; Arango, Gabriel Jaime; Jiménez, Nora; Alzate, Fernando; Ruiz, Grace; Gutiérrez, David; Paco, Marco Antonio; Giménez, Alberto; Robledo, Sara

    2007-05-22

    Ethnobotanical and chemotaxonomical studies for antiparasitic activity of Colombian Annonaceae were carried out. In vitro antiprotozoal activity of 36 extracts obtained from six different species was determined against promastigotes of three Leishmania species, epimastigotes of Trypanosoma cruzi and both chloroquine sensitive (F32) and resistant (W2) Plasmodium falciparum. Cytotoxic activity was evaluated in U-937 cells. Active extracts were selected according their selectivity index (SI). Extracts from Annona muricata, Rollinia exsucca, Rollinia pittieri and Xylopia aromatica were active against Leishmania spp. and Trypanosoma cruzi showing IC50 values lower than 25 microg/ml. Hexane extract from Rollinia pittieri leaves was the most selective against Trypanosoma cruzi and Leishmania spp. (IS=10 and 16, respectively). The extracts from Desmopsis panamensis, Pseudomalmea boyacana, Rollinia exsucca and Rollinia pittieri showed good antiplasmodial activity (IC50 Annonaceae extracts. Results presented here also demonstrate which plants and/or plant parts could be useful in the treatment of leishmaniasis, Chagas' disease and malaria.

  10. Structure-activity study of pentamidine analogues as antiprotozoal agents.

    Science.gov (United States)

    Bakunova, Svetlana M; Bakunov, Stanislav A; Patrick, Donald A; Kumar, E V K Suresh; Ohemeng, Kwasi A; Bridges, Arlene S; Wenzler, Tanja; Barszcz, Todd; Jones, Susan Kilgore; Werbovetz, Karl A; Brun, Reto; Tidwell, Richard R

    2009-04-09

    Diamidine 1 (pentamidine) and 65 analogues (2-66) have been tested for in vitro antiprotozoal activities against Trypanosoma brucei rhodesiense, Plasmodium falciparum, and Leishmania donovani, and for cytotoxicity against mammalian cells. Dications 32, 64, and 66 exhibited antitrypanosomal potencies equal or greater than melarsoprol (IC(50) = 4 nM). Nine congeners (2-4, 12, 27, 30, and 64-66) were more active against P. falciparum than artemisinin (IC(50) = 6 nM). Eight compounds (12, 32, 33, 44, 59, 62, 64, and 66) exhibited equal or better antileishmanial activities than 1 (IC(50) = 1.8 microM). Several congeners were more active than 1 in vivo, curing at least 2/4 infected animals in the acute mouse model of trypanosomiasis. The diimidazoline 66 was the most promising compound in the series, showing excellent in vitro activities and high selectivities against T. b. rhodesiense, P. falciparum, and L. donovani combined with high antitrypanosomal efficacy in vivo.

  11. Antimalarial activity of cedronin.

    Science.gov (United States)

    Moretti, C; Deharo, E; Sauvain, M; Jardel, C; David, P T; Gasquet, M

    1994-06-01

    Cedronin was isolated from Simaba cedron Planchon (Simaroubaceae), a species popularly believed in South America to have antimalarial properties. It was examined for in vitro and in vivo antimalarial activities and for cytotoxicity against KB cells. Experimental results showed that cedronin was active against chloroquine-sensitive and resistant strain, with an IC50 of 0.25 micrograms/ml (0.65 mumol/ml). It was also found to be active in vivo against Plasmodium vinkei with an IC50 of 1.8 mg/kg (4.7 nM/kg) in the classic 4-day test. Cedronin belongs to the small group of quassinoids with a C19 basic skeleton and shows a rather low cytotoxicity against KB cells (IC50 = 4 micrograms/ml, 10.4 microM) as compared with C20 biologically active quassinoids; however its toxic/therapeutic ratio (10/1.8) remains lower than chloroquine (10/0.5).

  12. Herbicidal properties of antimalarial drugs.

    Science.gov (United States)

    Corral, Maxime G; Leroux, Julie; Stubbs, Keith A; Mylne, Joshua S

    2017-03-31

    The evolutionary relationship between plants and the malarial parasite Plasmodium falciparum is well established and underscored by the P. falciparum apicoplast, an essential chloroplast-like organelle. As a result of this relationship, studies have demonstrated that herbicides active against plants are also active against P. falciparum and thus could act as antimalarial drug leads. Here we show the converse is also true; many antimalarial compounds developed for human use are highly herbicidal. We found that human antimalarial drugs (e.g. sulfadiazine, sulfadoxine, pyrimethamine, cycloguanil) were lethal to the model plant Arabidopsis thaliana at similar concentrations to market herbicides glufosinate and glyphosate. Furthermore, the physicochemical properties of these herbicidal antimalarial compounds were similar to commercially used herbicides. The implications of this finding that many antimalarial compounds are herbicidal proffers two novel applications: (i) using the genetically tractable A. thaliana to reveal mode-of-action for understudied antimalarial drugs, and (ii) co-opting antimalarial compounds as a new source for much needed herbicide lead molecules.

  13. Antimalarial activity of azadipeptide nitriles.

    Science.gov (United States)

    Löser, Reik; Gut, Jiri; Rosenthal, Philip J; Frizler, Maxim; Gütschow, Michael; Andrews, Katherine T

    2010-01-01

    Azadipeptide nitriles-novel cysteine protease inhibitors-display structure-dependent antimalarial activity against both chloroquine-sensitive and chloroquine-resistant lines of cultured Plasmodium falciparum malaria parasites. Inhibition of parasite's hemoglobin-degrading cysteine proteases was also investigated, revealing the azadipeptide nitriles as potent inhibitors of falcipain-2 and -3. A correlation between the cysteine protease-inhibiting activity and the antimalarial potential of the compounds was observed. These first generation azadipeptide nitriles represent a promising new class of compounds for antimalarial drug development. Copyright 2009 Elsevier Ltd. All rights reserved.

  14. Terpyridyl Complexes as Antimalarial Agents

    African Journals Online (AJOL)

    NICO

    suggest and refute that the parasite obtains this element from the serum, from the ... presumably others, such as copper, gold and platinum, can be mediated by .... antimalarial compounds are capable of performing this feat has been reported ...

  15. Antimalarial Activity of Azadipeptide Nitriles

    OpenAIRE

    Löser, Reik; Gut, Jiri; ROSENTHAL, Philip J.; Frizler, Maxim; Gütschow, Michael; Andrews, Katherine T.

    2009-01-01

    Azadipeptide nitriles – novel cysteine protease inhibitors – display structure-dependent antimalarial activity against both chloroquine-sensitive and chloroquine-resistant lines of cultured Plasmodium falciparum malaria parasites. Inhibition of parasite’s haemoglobin-degrading cysteine proteases was also investigated, revealing the azadipeptide nitriles as potent inhibitors of falcipain-2 and -3. A correlation between the cysteine protease-inhibiting activity and the antimalarial potential of...

  16. World Antimalarial Resistance Network I: Clinical efficacy of antimalarial drugs

    Directory of Open Access Journals (Sweden)

    Olliaro Piero

    2007-09-01

    Full Text Available Abstract The proliferation of antimalarial drug trials in the last ten years provides the opportunity to launch a concerted global surveillance effort to monitor antimalarial drug efficacy. The diversity of clinical study designs and analytical methods undermines the current ability to achieve this. The proposed World Antimalarial Resistance Network (WARN aims to establish a comprehensive clinical database from which standardised estimates of antimalarial efficacy can be derived and monitored over time from diverse geographical and endemic regions. The emphasis of this initiative is on five key variables which define the therapeutic response. Ensuring that these data are collected at the individual patient level in a consistent format will facilitate better data management and analytical practices, and ensure that clinical data can be readily collated and made amenable for pooled analyses. Such an approach, if widely adopted will permit accurate and timely recognition of trends in drug efficacy. This will guide not only appropriate interventions to deal with established multidrug resistant strains of malaria, but also facilitate prompt action when new strains of drug resistant plasmodia first emerge. A comprehensive global database incorporating the key determinants of the clinical response with in vitro, molecular and pharmacokinetic parameters will bring together relevant data on host, drug and parasite factors that are fundamental contributors to treatment efficacy. This resource will help guide rational drug policies that optimize antimalarial drug use, in the hope that the emergence and spread of resistance to new drugs can be, if not prevented, at least delayed.

  17. Additional antiprotozoal flavonol glycosides of the aerial parts of Helianthemum glomeratum.

    Science.gov (United States)

    Calzada, Fernando; Alanís, Alma Delia

    2007-01-01

    Bioassay-guided fractionation of the methanol extract of aerial parts from Helianthemum glomeratum afforded five antiprotozoal flavonol glycosides: tiliroside, kaempferol-3-O-(3'',6''di-O-E-p-coumaroyl)-betad-glucopyranoside, astragalin, quercitrin and isoquercitrin. The in vitro antiprotozoal assay showed that tiliroside was the most potent antiamoebic and antigiardial compound with IC(50) values of 17.5 microg/mL for Entamoeba histolytica and 17.4 microg/mL for G. lamblia. Isoquercitrin showed selectivity against E. histolytica (IC(50) 14.7 microg/mL) and quercitrin toward G. lamblia (IC(50) 24.3 microg/mL). All isolated compounds were less active than metronidazole and emetine, two antiprotozoal drugs used as positive controls.

  18. Newer agents in antiplatelet therapy: a review

    Directory of Open Access Journals (Sweden)

    Yeung J

    2012-06-01

    Full Text Available Jennifer Yeung, Michael HolinstatCardeza Foundation for Hematologic Research, Department of Medicine, Thomas Jefferson University, Philadelphia, PA, USAAbstract: Antiplatelet therapy remains the mainstay in preventing aberrant platelet activation in pathophysiological conditions such as myocardial infarction, ischemia, and stroke. Although there has been significant advancement in antiplatelet therapeutic approaches, aspirin still remains the gold standard treatment in the clinical setting. Limitations in safety, efficacy, and tolerability have precluded many of the antiplatelet inhibitors from use in patients. Unforeseen incidences of increased bleeding risk and recurrent arterial thrombosis observed in patients have hampered the development of superior next generation antiplatelet therapies. The pharmacokinetic and pharmacodynamic profiles have also limited the effectiveness of a number of antiplatelet inhibitors currently in use due to variability in metabolism, time to onset, and reversibility. A focused effort in the development of newer antiplatelet therapies to address some of these shortcomings has resulted in a significant number of potential antiplatelet drugs which target enzymes (phosphodiesterase, cyclooxygenase, receptors (purinergic, prostaglandins, protease-activated receptors, thromboxane, and glycoproteins (αIIbß3, GPVI, vWF, GPIb in the platelet. The validation and search for newer antiplatelet therapeutic approaches proven to be superior to aspirin is still ongoing and should yield a better pharmacodynamic profile with fewer untoward side-effects to what is currently in use today.Keywords: platelet aggregation inhibitors, blood platelets, purinergic P2Y receptor antagonists, receptor, PAR-1, platelet glycoprotein GPIIb-IIIa, thrombosis

  19. Use of antiplatelet drugs after cardiac operations.

    Science.gov (United States)

    Ferraris, Victor A; Bolanos, Michael D

    2014-01-01

    Unfortunately, venous bypass grafts still have a prominent role in operative coronary revascularization (coronary artery bypass graft [CABG]). Venous grafts develop pathologically occlusive disease that limits the effectiveness of CABG, and antiplatelet drugs following operation may limit this problem. The types and indications of antiplatelet drugs following CABG generate some controversy in the recent literature. This review surveys relevant evidence about the use of antiplatelet drugs following CABG to identify the controversial issues, define appropriate questions, and attempt to provide evidence-based interventions that may be helpful in limiting graft occlusion after CABG. Evidence suggests that, in most CABG patients, dual antiplatelet drugs (aspirin and clopidogrel), given after operation, minimizes early (within 1 year) graft failure and improves intermediate-term outcomes, better than single antiplatelet therapy with aspirin alone. There are gaps in the knowledge base that supports this contention, and future clinical trials will likely augment or alter this recommendation. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Microbial transformation of antimalarial terpenoids.

    Science.gov (United States)

    Parshikov, Igor A; Netrusov, Alexander I; Sutherland, John B

    2012-01-01

    The fungal and bacterial transformation of terpenoids derived from plant essential oils, especially the sesquiterpenoid artemisinin from Artemisia annua, has produced several new candidate drugs for the treatment of malaria. Obtaining new derivatives of terpenoids, including artemisinin derivatives with increased antimalarial activity, is an important goal of research in microbial biotechnology and medicinal chemistry.

  1. State of the art: Oral antiplatelet therapy.

    Science.gov (United States)

    Gurbel, Paul A; Myat, Aung; Kubica, Jacek; Tantry, Udaya S

    2016-01-01

    Platelet adhesion, activation, and aggregation are central to the propagation of coronary thrombosis following rupture, fissure, or erosion of an atherosclerotic plaque. This chain of deleterious events underlies the pathophysiological process leading to an acute coronary syndrome. Therefore, oral antiplatelet therapy has become the cornerstone of therapy for the management of acute coronary syndrome and the prevention of ischemic complications associated with percutaneous coronary intervention. Landmark trials have established aspirin, and the addition of clopidogrel to aspirin, as key therapeutic agents in the context of acute coronary syndrome and percutaneous coronary intervention. Dual antiplatelet therapy has been the guideline-mandated standard of care in acute coronary syndrome and percutaneous coronary intervention. Despite the proven efficacy of dual antiplatelet therapy, adverse ischemic events continue to occur and this has stimulated the development of novel, more potent antiplatelet agents. We focus this state-of-the-art review on the most recent advances in oral antiplatelet therapy, treading the tightrope of potency versus bleeding risk, the quest to determine the optimal duration of dual antiplatelet therapy and future of personalized antiplatelet therapy.

  2. Synthesis of marine-derived 3-alkylpyridinium alkaloids with potent antiprotozoal activity

    NARCIS (Netherlands)

    Rodenko, B.; Al-Salabi, M.I.; Teka, I.A.; Ho, W.; El-Sabbagh, N.; Ali, J.A.M.; Ibrahim, H.M.S.; Wanner, M.J.; Koomen, G.J.; de Koning, H.P.

    2011-01-01

    Given the pressing need for new antiprotozoal drugs without cross-resistance with current (failing) chemotherapy, we have explored 3-tridecylpyridinium alkaloids (3TPAs), derivatives of viscosamine, as antiparasitic agents. We have developed a simple synthetic route toward viscosamine and related cy

  3. Antiprotozoal Activities of Tiliroside and other Compounds from Sphaeralcea angustifolia (Cav.) G. Don

    Science.gov (United States)

    Calzada, Fernando; Basurto, Jose Correa; Barbosa, Elizabeth; Velázquez, Claudia; Hernández, Normand García; Ordoñez Razo, R. M.; Luna, David Mendez; Mulia, Lilian Yepez

    2017-01-01

    Background: Sphaeralcea angustifolia (Malvaceae) is extensively used in Mexican traditional medicine for the treatment of gastrointestinal disorders such as diarrhea and dysentery. Objective: The current study was to validate the traditional use of S. angustifolia for the treatment of diarrhea and dysentery on biological grounds using in vitro antiprotozoal activity and computational experiments. Materials and Methods: The ethanol extract, subsequent fractions, flavonoids, phenolic acids, and a sterol were evaluated on Entamoeba histolytica and Giardia lamblia trophozoites. Moreover, molecular docking studies on tiliroside were performed; it was tested for its affinity against pyruvate:ferredoxin oxidoreductase (PFOR) and fructose-1,6-bisphosphate aldolase (G/FBPA), two glycolytic enzymes of anaerobic protozoa. Results: Bioassay-guided fractionation of extract of the aerial parts of S. angustifolia gives tiliroside and apigenin, caffeic acid, protocatechuic acid, and β-sitosterol. The in vitro antiprotozoal assay showed that tiliroside was the most potent antiprotozoal compound on both protozoa with 50% inhibitory concentration values of 17.5 μg/mL for E. histolytica and 17.4 μg/mL for G. lamblia. Molecular docking studies using tiliroside showed its probable antiprotozoal mechanism with PFOR and G/FBPA. In both cases, tiliroside showed high affinity and inhibition constant theoretic for PFOR (lowest free binding energy from −9.92 kcal/mol and 53.57 μM, respectively) and G/FBPA (free binding energy from −7.17 kcal/mol and 55.5 μM, respectively), like to metronidazole, revealing its potential binding mode at molecular level. Conclusion: The results suggest that tiliroside seems to be a potential antiprotozoal compound responsible for antiamoebic and antigiardial activities of S. angustifolia. Its in vitro antiprotozoal activities are in good agreement with the traditional medicinal use of S. angustifolia in gastrointestinal disorders such as diarrhea and

  4. Modern antiplatelet agents in coronary artery disease.

    LENUS (Irish Health Repository)

    Power, Rachel F

    2012-10-01

    Dual antiplatelet therapy is well recognized in the prevention of thrombotic complications of acute coronary syndrome and percutaneous coronary interventions. Despite clinical benefits of aspirin and clopidogrel therapy, a number of limitations curtail their efficacy: slow onset of action, variability in platelet inhibitory response and potential drug-drug interactions. Furthermore, the single platelet-activation pathway targeted by these agents allows continued platelet activation via other pathways, ensuring incomplete protection against ischemic events, thus, underscoring the need for alternate antiplatelet treatment strategies. A number of novel antiplatelet agents are currently in advance development and many have established superior effects on platelet inhibition, clinical outcomes and safety profile than clopidogrel in high-risk patients. The aim of this review is to provide an overview of the current status of P2Y12 receptor inhibition and PAR-1 antagonists in determining a future strategy for individualized antiplatelet therapy.

  5. Antiplatelet and anticoagulation therapy in microlaryngeal surgery.

    Science.gov (United States)

    Francis, David O; Dang, Jennifer H; Fritz, Mark A; Garrett, C Gaelyn

    2014-04-01

    Indications for antiplatelet and anticoagulation use are expanding. There is no evidence to direct therapeutic management in patients undergoing microlaryngeal surgeries. Our aim was to compare bleeding complications between microlaryngeal surgeries performed for patients preoperatively taken off and maintained on antiplatelet and/or anticoagulation therapy. Retrospective cohort study. Patients undergoing microlaryngeal surgeries (2008-2009) on baseline antiplatelet and/or anticoagulation therapy were identified. Records were reviewed to determine whether therapy was stopped preoperatively. The primary outcome, bleeding complication, was compared between those taken off and maintained on therapy. Patient characteristics, surgical data, and outcomes were assessed. Of 287 microlaryngeal surgeries, 26% were performed for patients on antiplatelet (23%) and/or anticoagulation (3%) therapy. There was no difference in bleeding complications between patients' naïve to and on baseline antiplatelet or anticoagulation therapy [naïve: 3.8% vs. on: 5.3%, P = 0.58] and no thromboembolic events. Among surgeries performed for patients on baseline antiplatelet therapy, 35% preoperatively stopped therapy. No observed difference in bleeding complications was observed between those taken off or maintained on therapy [off: 8.0% vs. on: 4.9%, P = 0.63]. Of 3% of surgeries performed for patients on warfarin, no bleeding complications occurred, even among the 8/10 with therapeutic international normalized ratios. Perioperative management decisions regarding antiplatelet and anticoagulation therapy are becoming more common. Results suggest that antiplatelet therapy can be maintained during microlaryngeal surgery without increasing bleeding risk. Further prospective research is required to confirm findings and rigorously investigate the safety of continuing warfarin and other anticoagulation therapy in these surgeries. 4. © 2013 The American Laryngological, Rhinological and

  6. New antiplatelet drugs and new oral anticoagulants.

    Science.gov (United States)

    Koenig-Oberhuber, V; Filipovic, M

    2016-09-01

    In our daily anaesthetic practice, we are confronted with an increasing number of patients treated with either antiplatelet or anticoagulant agents. During the last decade, changes have occurred that make the handling of antithrombotic medication a challenging part of anaesthetic perioperative management. In this review, the authors discuss the most important antiplatelet and anticoagulant drugs, the perioperative management, the handling of bleeding complications, and the interpretation of some laboratory analyses related to these agents.

  7. Novel agents for anti-platelet therapy

    Directory of Open Access Journals (Sweden)

    Ji Xuebin

    2011-11-01

    Full Text Available Abstract Anti-platelet therapy plays an important role in the treatment of patients with thrombotic diseases. The most commonly used anti-platelet drugs, namely, aspirin, ticlopidine, and clopidogrel, are effective in the prevention and treatment of cardio-cerebrovascular diseases. Glycoprotein IIb/IIIa antagonists (e.g., abciximab, eptifibatide and tirofiban have demonstrated good clinical benefits and safety profiles in decreasing ischemic events in acute coronary syndrome. However, adverse events related to thrombosis or bleeding have been reported in cases of therapy with glycoprotein IIb/IIIa antagonists. Cilostazol is an anti-platelet agent used in the treatment of patients with peripheral ischemia, such as intermittent claudication. Presently, platelet adenosine diphosphate P2Y(12 receptor antagonists (e.g., clopidogrel, prasugrel, cangrelor, and ticagrelor are being used in clinical settings for their pronounced protective effects. The new protease-activated receptor antagonists, vorapaxar and atopaxar, potentially decrease the risk of ischemic events without significantly increasing the rate of bleeding. Some other new anti-platelet drugs undergoing clinical trials have also been introduced. Indeed, the number of new anti-platelet drugs is increasing. Consequently, the efficacy of these anti-platelet agents in actual patients warrants scrutiny, especially in terms of the hemorrhagic risks. Hopefully, new selective platelet inhibitors with high anti-thrombotic efficiencies and low hemorrhagic side effects can be developed.

  8. Antiprotozoal Activity of Flavonoids Isolated from Mimosa tenuiflora (Fabaceae-Mimosoideae)

    OpenAIRE

    Elihú Bautista; Fernando Calzada; Alfredo Ortega; Lilian Yépez-Mulia

    2011-01-01

    As result of the chemical study of the leaves and flowers of Mimosa tenuiflora (Willd.) Poir. (Fabaceae-Mimosoideae) eigth flavonoids were isolated: 6-methoxy-4¿-O-methylnaringenin (1), santin (2), 6-methoxynaringenin (3), tenuiflorin A (4), 5, 7, 4¿-trihydroxy-3, 6-dimethoxyflavone (5), 6-demethoxy-4¿-O-methylcapilarisine (6), 6- methoxykaempferol (7) and tenuiflorin C (8). Antiprotozoal activity of these compounds as well as the tenuiflorina B (9) and 6-desmethoxycapilarisine (10), isolated...

  9. Antimalarial natural products: a review

    Directory of Open Access Journals (Sweden)

    Faraz Mojab

    2012-03-01

    Results and Conclusion: There is an urgent need for the development of new treatments for malaria. Many countries have a vast precedence in the use of medicinal plants and the required knowledge spans many centuries. Although malaria is controlled in Iran, some researchers tend to study malaria and related subjects. In vitro biological tests for the detection of antimalarial activities in plant extracts are currently available. It is vital that the efficacy and safety of traditional medicines be validated and their active constituents be identified in order to establish reliable quality control measures.

  10. Dual antiplatelet treatment in patients candidates for abdominal surgery.

    Science.gov (United States)

    Illuminati, Giulio; Ceccanei, Gianluca; Pacilè, Maria A; Pizzardi, Giulia; Palumbo, Piergaspare; Vietri, Francesco

    2013-01-01

    With the increasing diffusion of percutaneous interventions (PCI), surgeons are often faced with the problem of operating on patients under dual antiplatelet treatment. Replacing dual antiplatelet regiment with low molecular weight heparin may expose to the abrupt thrombosis of coronary stent and massive myocardial infarction. The purpose of this study was to test the hypothesis that abdominal operations can be safely performed under dual antiplatelet treatment. Eleven patients underwent 5 colectomies, 3 nefrectomies, 2 gastrectomies and 1 hysterectomy under aspirin and plavix without any significant perioperative hemorrhage. These preliminary results show that abdominal operations can be safely performed under dual antiplatelet regimen. Abdominal surgery, Dual antiplatelet treatment.

  11. Personalized antiplatelet therapy: state of the art

    Directory of Open Access Journals (Sweden)

    Paul A Gurbel

    2012-09-01

    Full Text Available Overwhelming evidence exists that thrombus generation resulting from platelet activation and aggregation is the primary process involved in the occurrence of the myocardial infarction and stent thrombosis. Despite the proven clinical efficacy of dual antiplatelet therapy, wide antiplatelet response variability associated with clopidogrel therapy was demonstrated in pharmacodynamic studies where approximately one in three patients exhibited high on-treatment platelet reactivity (HPR. Generally, physicians do not objectively assess the intensity of the adenosine diphosphate–P2Y12 interaction in their high-risk patients treated with clopidogrel. Instead most clinicians use a non-selective or one-size-fits-all approach. HPR and CYP2C19 LoF carriage are associated with clinical outcomes in high-risk clopidogrel-treated patients who have undergone percutaneous coronary intervention (PCI. Although we do no yet have conclusive evidence from a large-scale randomized trial that personalized antiplatelet therapy improves patient outcomes, a class IIb recommendation has been given in the guidelines to perform genotyping or phenotyping in high-risk PCI patients if a change in antiplatelet therap will ensue based on the test results. It may be reasonable at this time to assess platelet function and perform genotyping in clopidogrel-treated high-risk patients and treat with more potent P2Y12 receptor therapy selectively.

  12. Oral antiplatelet therapy for acute ischaemic stroke.

    Science.gov (United States)

    Sandercock, Peter A G; Counsell, Carl; Tseng, Mei-Chiun; Cecconi, Emanuela

    2014-03-26

    In people with acute ischaemic stroke, platelets become activated and can cause blood clots to form and block an artery in the brain, resulting in damage to part of the brain. Such damage gives rise to the symptoms of stroke. Antiplatelet therapy might reduce the volume of brain damaged by ischaemia and also reduce the risk of early recurrent ischaemic stroke, thereby reducing the risk of early death and improving long-term outcomes in survivors. However, antiplatelet therapy might also increase the risk of fatal or disabling intracranial haemorrhage. To assess the efficacy and safety of immediate oral antiplatelet therapy (that is started as soon as possible and no later than two weeks after stroke onset) in people with acute presumed ischaemic stroke. We searched the Cochrane Stroke Group Trials Register (last searched 16 October 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2013), MEDLINE (June 1998 to May 2013), and EMBASE (June 1998 to May 2013). In 1998, for a previous version of this review, we searched the register of the Antiplatelet Trialists' Collaboration, MedStrategy and contacted relevant drug companies. Randomised trials comparing oral antiplatelet therapy (started within 14 days of the stroke) with control in people with definite or presumed ischaemic stroke. Two review authors independently applied the inclusion criteria and assessed trial quality. For the included trials, they extracted and cross-checked the data. We included eight trials involving 41,483 participants. No new trials have been added since the last update.Two trials testing aspirin 160 mg to 300 mg once daily, started within 48 hours of onset, contributed 98% of the data. The risk of bias was low. The maximum follow-up was six months. With treatment, there was a significant decrease in death or dependency at the end of follow-up (odds ratio (OR) 0.95, 95% confidence interval (CI) 0.91 to 0.99). For every 1000 people treated with

  13. Natural product derived antiprotozoal agents: synthesis, biological evaluation, and structure-activity relationships of novel chromene and chromane derivatives.

    Science.gov (United States)

    Harel, Dipak; Schepmann, Dirk; Prinz, Helge; Brun, Reto; Schmidt, Thomas J; Wünsch, Bernhard

    2013-09-26

    Various natural products with the chromane and chromene scaffold exhibit high antiprotozoal activity. The natural product encecalin (7) served as key intermediate for the synthesis of different ethers 9, amides 11, and amines 12. The chromane analogues 14 and the phenols 15 were obtained by reductive amination of ketones 13 and 6, respectively. Angelate 3, ethers 9, and amides 11 did not show considerable antiprotozoal activity. However, the chromene and chromane derived amines 12, 14, and 15 revealed promising antiprotozoal activity and represent novel lead compounds. Whereas benzylamine 12a and α-methylbenzylamine 12g were active against P. falciparum with IC50 values in the range of chloroquine, the analogous phenols 15a and 15b were unexpectedly 10- to 25-fold more potent than chloroquine with selectivity indexes of 6760 and 1818, respectively. The phenylbutylamine 14d based on the chromane scaffold has promising activity against T. brucei rhodesiense and L. donovani.

  14. When a Single Antiplatelet Agent for Stroke Prevention Is Not Enough: Current Evidence and Future Applications of Dual Antiplatelet Therapy.

    Science.gov (United States)

    Yuan, Kristy; Kim, Anthony S

    2016-04-01

    For secondary stroke prevention, long-term dual antiplatelet therapy is not recommended due to increased bleeding risks. There is no specific evidence for using dual antiplatelet therapy for cervical artery dissection or for adding a second antiplatelet agent after a stroke while taking aspirin monotherapy. For patients with atrial fibrillation and stroke/TIA unable to tolerate warfarin, aspirin monotherapy is reasonable. Dual antiplatelet therapy carries a similar risk of major bleeding as warfarin that offsets reductions in stroke risk. Dual antiplatelet therapy is recommended for endovascular cerebrovascular stenting procedures, although the optimal duration of therapy is not well established. Short-term dual antiplatelet therapy when initiated acutely after minor stroke/TIA, particularly in Asian populations or for intracranial atherosclerosis, holds promise though studies to evaluate this approach more generally are ongoing. New antiplatelet agents and additional data on the pharmacogenetics of clopidogrel metabolism have the potential to help to individualize these recommendations moving forward.

  15. Antimalarial sesquiterpene lactones from oncosiphon piluliferum

    CSIR Research Space (South Africa)

    Pillay, P

    2006-02-01

    Full Text Available With the emergence and spread of drug- resistant parasites, there is a need for new chemically diverse, effective antimalarial drugs. A national multidisciplinary consortium was established to validate scientifically South African medicinal plants...

  16. Recent developments in the antiprotozoal and anticancer activities of the 2-alkynoic fatty acids

    Science.gov (United States)

    Carballeira, Néstor M.

    2013-01-01

    The 2-alkynoic fatty acids are an interesting group of synthetic compounds that display antimycobacterial, antifungal, anticancer, and pesticidal activities but their antiprotozoal activity has received little attention until recently. In this review we have summarized our present knowledge of the biomedical potential of the 2-hexadecynoic acid (2-HDA) and 2-octadecynoic acid (2-ODA) together with several mechanistic pieces of work attesting to the fact that these compounds, and their metabolites, are good fatty acid biosynthesis inhibitors. The antiprotozoal activity of 2-HDA and 2-ODA against Leishmania donovani and Plasmodium falciparum, parasites responsible for visceral leishmaniasis and malaria, respectively, is also reviewed. The evidence obtained so far supports the fact that these fatty acids are good inhibitors of the L. donovani DNA topoisomerase IB enzyme (LdTopIB) and the potency of LdTopIB inhibition is chain length dependent. We also demonstrate the generality of the antiprotozoal activity of 2-HDA and 2-ODA against P. falciparum, and review our present knowledge of their inhibition of key P. falciparum enzymes such as PfFabZ, PfFabG, and PfFabI together with some possible modes of inhibition. Recent research by our group has also demonstrated that 2-ODA displays antineoplastic activity, specifically against the neuroblastoma SH-SY5Y cell line via lactate dehydrogenase (LDH) release, which is a cell death mechanism principally associated to necrosis. This is the first comprehensive review of the medicinal chemistry of this interesting group of acetylenic fatty acids. PMID:23727443

  17. Antiprotozoal assessment and phenolic acid profiling of five Fumaria (fumitory) species

    Institute of Scientific and Technical Information of China (English)

    Ilkay Erdogan Orhan; Nilgun Ozturk; Bilge Sener

    2015-01-01

    Objective: To explore some Fumaria species which were recorded to be traditionally used against malaria and other protozoal diseases. Methods: Consequently, in the current study, antiprotozoal effect of the ethanol extracts obtained from five Fumaria species (Fumaria densiflora, Fumaria cilicica, Fumaria rostellata, Fumaria kralikii, and Fumaria parviflora) was investigated against the parasites; Plasmodium falciparum (malaria) and Trypanosoma bruceirhodesiense (human African trypanosomiasis) at 0.81 and 4.85 μg/mL concentrations. Results: Among them, Fumaria densiflora extract exerted the highest antiplasmodial (93.80%) and antitrypanasomal effect (55.40%), while the ethanol extracts of Fumaria kralikii (43.45%) and Fumaria rostellata (41.65%) showed moderate activity against Plasmodium falciparum. Besides, phenolic acid contents of the extracts were analyzed using high performance liquid chromatography (HPLC) and trans-cinnamic (4.32 mg/g) and caffeic (3.71 mg/g) acids were found to be the dominant phenolic acids in Fumaria densiflora. Conclusions: According to our results, Fumaria densiflora deserve further study for its promising antiprotozoal activity.

  18. Antiplatelet drug interactions with proton pump inhibitors

    Science.gov (United States)

    Scott, Stuart A; Obeng, Aniwaa Owusu; Hulot, Jean-Sébastien

    2014-01-01

    Introduction Non-aspirin antiplatelet agents (e.g., clopidogrel, prasugrel, ticagrelor) are commonly prescribed for the prevention of recurrent cardiovascular events among patients with acute coronary syndromes (ACS) and/or those undergoing percutaneous coronary intervention (PCI). In addition, combination therapy with proton pump inhibitors (PPIs) is often recommended to attenuate gastrointestinal bleeding risk, particularly during dual antiplatelet therapy (DAPT) with clopidogrel and aspirin. Importantly, a pharmacological interaction between clopidogrel and some PPIs has been proposed based on mutual CYP450-dependent metabolism, but available evidence is inconsistent. Areas covered This article provides an overview of the currently approved antiplatelet agents and PPIs, including their metabolic pathways. Additionally, the CYP450 isoenzyme at the center of the drug interaction, CYP2C19, is described in detail, and the available evidence on both the potential pharmacological interaction and influence on clinical outcomes are summarized and evaluated. Expert opinion Although concomitant DAPT and PPI use reduces clopidogrel active metabolite levels and ex vivo-measured platelet inhibition, the influence of the drug interaction on clinical outcomes has been conflicting and largely reported from non-randomized observational studies. Despite this inconsistency, a clinically important interaction cannot be definitively excluded, particularly among patient subgroups with higher overall cardiovascular risk and potentially among CYP2C19 loss-of-function allele carriers. PMID:24205916

  19. Antiplatelet effect of active components derived from Chinese herbal medicine.

    Science.gov (United States)

    Zhang, Ying; Ma, Xiao-Juan; Shi, Da-Zhuo

    2015-10-10

    Atherothrombosis is the major cause of acute coronary syndromes and cardiovascular deaths. Platelets participate in the processes of forming and extending atherosclerotic plaques. Therefore, antiplatelet therapy is a milestone in the primary and second prevention of atherothrombotic diseases. Along with the longterm use of antiplatelet agents, the safety and drug resistance has become a big concern in clinic and new drugs possessing higher effectiveness and fewer adverse effects are needed. Abundant recent data support that traditional Chinese herbs may be a good alternative and complementary choice of new antiplatelet drugs. This review highlights the progress of antiplatelet effect of active components derived from traditional Chinese herbs based on their chemical structures.

  20. Dual antiplatelet therapy use by Canadian cardiac surgeons.

    Science.gov (United States)

    Yanagawa, Bobby; Ruel, Marc; Bonneau, Christopher; Lee, Myunghyun M; Chung, Jennifer; Al Shouli, Sadek; Fagan, Andrew; Al Khalifa, Abdulwahab; White, Christopher W; Yamashita, Michael H; Currie, Maria E; Teoh, Hwee; Mewhort, Holly E M; Verma, Subodh

    2015-12-01

    Dual antiplatelet therapy is the cornerstone treatment for patients with acute coronary syndrome. Recent Canadian Guidelines recommend the use of dual antiplatelet therapy for 1 year after coronary artery bypass grafting in patients with acute coronary syndrome, but considerable variability remains. We performed a survey of 75 Canadian cardiac surgeons to assess the use of dual antiplatelet therapy. Whereas 58.6% of respondents indicated that the benefits of dual antiplatelet therapy were seen irrespective of how patients were managed after acute coronary syndrome, 36.2% believed that the benefits of dual antiplatelet therapy were limited to those treated medically or percutaneously. In regard to the timing of dual antiplatelet therapy administration, 57% of respondents indicated that dual antiplatelet therapy should be given upstream in the emergency department, whereas 36.2% responded that dual antiplatelet therapy should be given only once the coronary anatomy has been defined. The majority surveyed (81%) weighed bleeding risk as being more important than ischemic risk reduction. In stable patients after acute coronary syndrome, the majority of surgeons would wait approximately 4 days after the last dose of P2Y12 antagonist before coronary artery bypass grafting. Only 44.6% indicated that they routinely use dual antiplatelet therapy postrevascularization in the setting of acute coronary syndrome. Rather, most surgeons use dual antiplatelet therapy for select patients, such as those with a stented vessel without a bypass graft, endarterectomy, or off-pump coronary artery bypass grafting. Cardiac surgeons exhibit variation in their attitudes and practice patterns toward dual antiplatelet therapy after coronary artery bypass grafting, and in approximately half of cases, their practice does not adhere to current guideline recommendations. New trials focusing on coronary artery bypass grafting cases in their primary analysis and educational initiatives for surgeons

  1. Optimization of propafenone analogues as antimalarial leads.

    Science.gov (United States)

    Lowes, David J; Guiguemde, W Armand; Connelly, Michele C; Zhu, Fangyi; Sigal, Martina S; Clark, Julie A; Lemoff, Andrew S; Derisi, Joseph L; Wilson, Emily B; Guy, R Kiplin

    2011-11-10

    Propafenone, a class Ic antiarrythmic drug, inhibits growth of cultured Plasmodium falciparum. While the drug's potency is significant, further development of propafenone as an antimalarial would require divorcing the antimalarial and cardiac activities as well as improving the pharmacokinetic profile of the drug. A small array of propafenone analogues was designed and synthesized to address the cardiac ion channel and PK liabilities. Testing of this array revealed potent inhibitors of the 3D7 (drug sensitive) and K1 (drug resistant) strains of P. falciparum that possessed significantly reduced ion channel effects and improved metabolic stability. Propafenone analogues are unusual among antimalarial leads in that they are more potent against the multidrug resistant K1 strain of P. falciparum compared to the 3D7 strain.

  2. Antiprotozoal, Antibacterial and Antidiarrheal Properties from the Flowers of Chiranthodendron pentadactylon and Isolated Flavonoids

    Science.gov (United States)

    Calzada, Fernando; Juárez, Teresa; García-Hernández, Normand; Valdes, Miguel; Ávila, Oscar; Mulia, Lilian Yepez; Velázquez, Claudia

    2017-01-01

    Background: Chiranthodendron pentadactylon Larreat. (Sterculiaceae) is a Mexican plant used in traditional medicine for the treatment of heart disease symptoms and infectious diarrhea. Objective: To evaluate in vitro antiprotozoal and antibacterial activities and in vivo antidiarrheal activity from the flowers of C. pentadactylon using the extract, fractions, and major isolated flavonoids. Materials and methods: Bioassay-guided fractionation of the methanol extract of C. pentadactylon (MECP) led to the isolation of five flavonoids, tiliroside, astragalin, isoquercitrin, (+)-catechin, and (-)-epicatechin. Antimicrobial activities were tested on two protozoa (Entamoeba histolytica and Giardia lamblia) and nine bacterial enteropathogens (two Escherichia coli strains, two Shigella sonnei strains, two Shigella flexneri strains, two Salmonella sp. strains, and Vibrio cholerae) isolated from feces of children with acute diarrhea or dysentery and resistant to chloramphenicol. Also, antidiarrheal activity was tested on cholera toxin-induced diarrhea in male Balb-c mice. Results: Epicatechin was the most potent antiamoebic and antigiardial compound with IC50 values of 1.9 μg/mL for E. histolytica and 1.6 μg/mL for G. lamblia; tiliroside showed moderate antiprotozoal activity against both protozoan. In contrast, in the antibacterial activity, tiliroside was the most potent compound on all microorganisms with minimum inhibitory concentration values less than 0.7 mg/mL. In the case of cholera toxin-induced diarrhea, epicatechin was the most potent flavonoid with IC50 of 14.7 mg/kg. Conclusion: Epicatechin and tiliroside were the flavonoids responsible for antimicrobial andantidiarrheal activities of C. pentadactylon. Its antiprotozoal, antibacterial, and antidiarrheal properties are in good agreement with the traditional medicinal use of C. pentadactylon for the treatment of infectious diarrhea. SUMMARY Epicatechin was the most potent antiamoebic and antigiardial compound

  3. The quality of antimalarials available in Yemen.

    Science.gov (United States)

    Abdo-Rabbo, Ahmed; Bassili, Amal; Atta, Hoda

    2005-06-29

    Malaria has always been a major public health problem in Yemen. Several studies in developing countries have demonstrated ineffective and poor quality drugs including antimalarials. Therefore, quality assessment of antimalarial drugs is of crucial importance. This study aimed to assess the quality of antimalarials (chloroquine and sulfadoxine/pyrimethamine) available in Yemen and to determine whether the quality of these products was related to the level of the distribution chain at which the samples were collected or related to the manufacturers. Four samples from each antimalarial product were collected from each of the various levels of the distribution chain. One sample was kept with the research team. Two were tested at Sana'a and Aden Drug Quality Control Laboratories. The fourth was sent to the Centre for Quality Assurance of Medicines in Potchefstroom, South Africa, for analysis. Quality indicators measured were the content of the active ingredient and dissolution rate (for tablets only) in comparison to standard specifications for these products in the relevant pharmacopoeia. The results identified several problems of sub-standard products within the drug distribution chain. They included high and low failures in ingredient content for chloroquine tablets and chloroquine syrup. There was some dissolution failure for chloroquine tablets, and high sulfadoxine/pyrimethamine tablets dissolution failures. Failures with the dissolution of the pyrimethamine were found at most of the collection points. No clear relationship neither between the quality products and the level of the distribution chain, nor between locally manufactured and imported products was observed. There are sub-standard antimalarial products circulating within the drug distribution chains in the country, which will have serious implications on the reduced therapeutic effectiveness and on the development of drug resistance. This appears to be due to non-compliance with Good Manufacturing

  4. The quality of antimalarials available in Yemen

    Directory of Open Access Journals (Sweden)

    Atta Hoda

    2005-06-01

    Full Text Available Abstract Background Malaria has always been a major public health problem in Yemen. Several studies in developing countries have demonstrated ineffective and poor quality drugs including antimalarials. Therefore, quality assessment of antimalarial drugs is of crucial importance. This study aimed to assess the quality of antimalarials (chloroquine and sulfadoxine/pyrimethamine available in Yemen and to determine whether the quality of these products was related to the level of the distribution chain at which the samples were collected or related to the manufacturers. Methods Four samples from each antimalarial product were collected from each of the various levels of the distribution chain. One sample was kept with the research team. Two were tested at Sana'a and Aden Drug Quality Control Laboratories. The fourth was sent to the Centre for Quality Assurance of Medicines in Potchefstroom, South Africa, for analysis. Quality indicators measured were the content of the active ingredient and dissolution rate (for tablets only in comparison to standard specifications for these products in the relevant pharmacopoeia. Results The results identified several problems of sub-standard products within the drug distribution chain. They included high and low failures in ingredient content for chloroquine tablets and chloroquine syrup. There was some dissolution failure for chloroquine tablets, and high sulfadoxine/pyrimethamine tablets dissolution failures. Failures with the dissolution of the pyrimethamine were found at most of the collection points. No clear relationship neither between the quality products and the level of the distribution chain, nor between locally manufactured and imported products was observed. Conclusion There are sub-standard antimalarial products circulating within the drug distribution chains in the country, which will have serious implications on the reduced therapeutic effectiveness and on the development of drug resistance. This

  5. [Antiplatelet therapy: resistance to traditional antiaggregation drugs and role of new antiplatelet agents].

    Science.gov (United States)

    del Castillo-Carnevali, Hugo; Barrios Alonso, Vivencio; Zamorano Gómez, José Luis

    2014-09-09

    Platelet aggregation plays a key role in the development of major cardiovascular events (MACE) related to atherothrombosis. Since the appearance of coronary stenting, the importance of measuring and modulating platelet activity has considerably increased in the scientific literature during the last decade. Double antiplatelet therapy with aspirin and clopidogrel administrated to stent carriers has widely demonstrated its efficacy in the prevention of MACE compared with aspirin alone. These benefits are also present when a conservatory approach is chosen for acute coronary syndrome management. However, there are an important number of patients who develop MACE despite optimal dual antiplatelet therapy, most likely related to an incomplete platelet activity inhibition. Many studies suggest an important inter-individual variability in the response to the drugs, maybe related, at least in part, to the use of different assessment techniques of platelet aggregation. Other authors suggest an incomplete platelet inhibition as a possible explanation for the presence of MACE in patients under optimal antiplatelet therapy. Resistance to usual drugs has become a clinically relevant issue that requires an individual approach where new antiplatelet agents, such as prasugrel or ticagrelor, could play an important role as stated in current consensus documents. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  6. Antimalarial properties of South African medicinal plants

    CSIR Research Space (South Africa)

    Pillay, P

    2007-01-01

    Full Text Available of structure-activity derivatives around these simplified structures is currently under way. CONCLUSIONS The study identified a number of promising South African medicinal plants for further investigation as plant-based antimalarial agents. The overall... as potential sources of antimalarial lead compounds. REFERENCES Clarkson, C., Maharaj, V.J., Crouch, N.R., Grace, O.M., Pillay, P., Matsabisa, M.G., Bhagwandin, N., Smith, P.J., Folb, P.I., 2004. In vitro antiplasmodial activity of medicinal plants native...

  7. Long-term use of antiplatelet drugs by stroke patients

    DEFF Research Database (Denmark)

    Ostergaard, Kamilla; Hallas, Jesper; Bak, Søren

    2012-01-01

    in a cohort of stroke patients discharged from a Danish neurology department. The antiplatelet drugs comprised acetylsalicylic acid (ASA), clopidogrel and dipyridamole (if combined with ASA use). Non-persistence was defined as failure to present a prescription for antiplatelet drugs within 180 days after...

  8. In Vitro Evaluation of Antiprotozoal and Antiviral Activities of Extracts from Argentinean Mikania Species

    Directory of Open Access Journals (Sweden)

    Laura C. Laurella

    2012-01-01

    Full Text Available The aim of this study was to investigate the antiprotozoal and antiviral activities of four Argentinean Mikania species. The organic and aqueous extracts of Mikania micrantha, M. parodii, M. periplocifolia, and M. cordifolia were tested on Trypanosoma cruzi epimastigotes, Leishmania braziliensis promastigotes, and dengue virus type 2. The organic extract of M. micrantha was the most active against T. cruzi and L. braziliensis exhibiting a growth inhibition of 77.6±4.5% and 84.9±6.1%, respectively, at a concentration of 10 μg/ml. The bioguided fractionation of M. micrantha organic extract led to the identification of two active fractions. The chromatographic profile and infrared analysis of these fractions revealed the presence of sesquiterpene lactones. None of the tested extracts were active against dengue virus type 2.

  9. In vitro cytotoxic, antiprotozoal and antimicrobial activities of medicinal plants from Vanuatu.

    Science.gov (United States)

    Bradacs, Gesine; Maes, Louis; Heilmann, Jörg

    2010-06-01

    Sixty-three extracts obtained from 18 plants traditionally used in the South Pacific archipelago Vanuatu for the treatment of infectious diseases were screened for antimicrobial and antiprotozoal activities. In addition, the extracts were subjected to a detailed analysis on cytotoxic effects toward a panel of human cancer cell lines, designed as a smaller version of the NCI60 screen. Intriguingly, 15 plant extracts exhibited strong cytotoxic effects specific for only one cancer cell line. Extracts of the leaves of Acalypha grandis Benth. significantly affected Plasmodium falciparum without showing obvious effects against the other protozoa tested. The leaves of Gyrocarpus americanus Jacq. displayed significant activity against Trypanosoma b. brucei and the leaves of Tabernaemontana pandacaqui Lam. I as well as the stems of Macropiper latifolium (L.f.) against Trypanosoma cruzi. In contrast none of the extracts showed relevant antibacterial or antifungal activity.

  10. How I use laboratory monitoring of antiplatelet therapy.

    Science.gov (United States)

    Michelson, Alan D; Bhatt, Deepak L

    2017-08-10

    Antiplatelet therapy is of proven benefit in coronary artery disease and a number of other clinical settings. This article reviews platelet function, molecular targets of antiplatelet agents, and clinical indications for antiplatelet therapy before focusing on a frequent question to hematologists about the 2 most commonly used antiplatelet therapies: Could the patient be aspirin "resistant" or clopidogrel "resistant"? If so, should results of a platelet function test be used to guide the dose or type of antiplatelet therapy? Whether such guided therapy is of clinical benefit to patients has been a source of controversy. The present article reviews this subject in the context of 2 prototypical clinical cases. Available evidence does not support the use of laboratory tests to guide the dose of aspirin or clopidogrel in patients with so-called aspirin or clopidogrel "resistance." © 2017 by The American Society of Hematology.

  11. Patent Foramen Ovale Closure or Antiplatelet Therapy for Cryptogenic Stroke

    DEFF Research Database (Denmark)

    Søndergaard, Lars; Kasner, Scott E; Rhodes, John F

    2017-01-01

    Background The efficacy of closure of a patent foramen ovale (PFO) in the prevention of recurrent stroke after cryptogenic stroke is uncertain. We investigated the effect of PFO closure combined with antiplatelet therapy versus antiplatelet therapy alone on the risks of recurrent stroke and new...... brain infarctions. Methods In this multinational trial involving patients with a PFO who had had a cryptogenic stroke, we randomly assigned patients, in a 2:1 ratio, to undergo PFO closure plus antiplatelet therapy (PFO closure group) or to receive antiplatelet therapy alone (antiplatelet-only group......). Imaging of the brain was performed at the baseline screening and at 24 months. The coprimary end points were freedom from clinical evidence of ischemic stroke (reported here as the percentage of patients who had a recurrence of stroke) through at least 24 months after randomization and the 24-month...

  12. Counterfeit and substandard antimalarial drugs in Cambodia.

    Science.gov (United States)

    Lon, C T; Tsuyuoka, R; Phanouvong, S; Nivanna, N; Socheat, D; Sokhan, C; Blum, N; Christophel, E M; Smine, A

    2006-11-01

    Counterfeit and substandard antimalarial drugs can cause death and contribute to the growing malaria drug resistance problem, particularly in Southeast Asia. Since 2003 in Cambodia the quality of antimalarial drugs both in the public and private health sector is regularly monitored in sentinel sites. We surveyed 34% of all 498 known facilities and drug outlets in four provinces. We collected 451 drug samples; 79% of these were not registered at the Cambodia Department of Drugs and Food (DDF). Twenty-seven percent of the samples failed the thin layer chromatography and disintegration tests; all of them were unregistered products. Immediate action against counterfeit drugs was taken by the National Malaria Control Program (NMCP) and the DDF. They communicated with the Provincial Health Department about the presence of counterfeit antimalarial drugs through alert letters, a manual, annual malaria conferencing and other training occasions. Television campaigns to alert the population about counterfeit drugs were conducted. Moreover, the NMCP has been promoting the use of good quality antimalarial drugs of a blister co-packaged combination of artesunate and mefloquine in public and private sectors. Appropriate strategies need to be developed and implemented by relevant government agencies and stakeholders to strengthen drug quality assurance and control systems in the country.

  13. Assessment of the in Vitro Antiprotozoal and Cytotoxic Potential of 20 Selected Medicinal Plants from the Island of Soqotra

    OpenAIRE

    Louis Maes; Paul Cos; An Matheeussen; Nawal M. Al-Musayeib; Mothana, Ramzi A.

    2012-01-01

    Malaria, leishmaniasis and human African trypanosomiasis continue to be major public health problems in need of new and more effective drugs. The aim of this study was to evaluate in vitro antiprotozoal activity of twenty endemic medicinal plants collected from the island of Soqotra in the Indian Ocean. The plant materials were extracted with methanol and tested for antiplasmodial activity against erythrocytic schizonts of Plasmodium falciparum, for antileishmanial activity against intracellu...

  14. Expanding the Antimalarial Drug Arsenal—Now, But How?

    Directory of Open Access Journals (Sweden)

    Rajeev K. Mehlotra

    2011-04-01

    Full Text Available The number of available and effective antimalarial drugs is quickly dwindling. This is mainly because a number of drug resistance-associated mutations in malaria parasite genes, such as crt, mdr1, dhfr/dhps, and others, have led to widespread resistance to all known classes of antimalarial compounds. Unfortunately, malaria parasites have started to exhibit some level of resistance in Southeast Asia even to the most recently introduced class of drugs, artemisinins. While there is much need, the antimalarial drug development pipeline remains woefully thin, with little chemical diversity, and there is currently no alternative to the precious artemisinins. It is difficult to predict where the next generation of antimalarial drugs will come from; however, there are six major approaches: (i re-optimizing the use of existing antimalarials by either replacement/rotation or combination approach; (ii repurposing drugs that are currently used to treat other infections or diseases; (iii chemically modifying existing antimalarial compounds; (iv exploring natural sources; (v large-scale screening of diverse chemical libraries; and (vi through parasite genome-based (“targeted” discoveries. When any newly discovered effective antimalarial treatment is used by the populus, we must maintain constant vigilance for both parasite-specific and human-related factors that are likely to hamper its success. This article is neither comprehensive nor conclusive. Our purpose is to provide an overview of antimalarial drug resistance, associated parasite genetic factors (1. Introduction; 2. Emergence of artemisinin resistance in P. falciparum, and the antimalarial drug development pipeline (3. Overview of the global pipeline of antimalarial drugs, and highlight some examples of the aforementioned approaches to future antimalarial treatment. These approaches can be categorized into “short term” (4. Feasible options for now and “long term” (5. Next generation of

  15. [Cardiovascular diseases, antiplatelet agents, anticoagulants and hemorrhagic risk].

    Science.gov (United States)

    Eusébio, Jorge; Reny, Jean-Luc; Fontana, Pierr; Nendaz, Mathieu

    2010-10-20

    If the benefits of antiplatelet and anticoagulant therapies are well established, bleeding complications appear underestimated in trials in comparison to their real-life incidence. Also, a large number of patients receive various associations of antiplatelet or anticoagulant treatments, while the benefit of some associations is not firmly established and data about their safety are missing. Identifying patients at high risk of bleeding is essential to define appropriate strategies. In this article we discuss the risk-benefit of various antiplatelet and anticoagulant molecules taken individually or in combination. An overview of the main clinical scores available to stratify the risk of bleeding is presented.

  16. RESISTANCE TO ANTIPLATELET DRUGS IN PATIENTS WITH ISCHEMIC HEART DISEASE

    Directory of Open Access Journals (Sweden)

    D. H. Aynetdinova

    2007-01-01

    Full Text Available The clinical, cell and genetic factors are distinguished among reasons for resistance to antiplatelet drugs. There are many methods to detect sensitivity to antiplatelet drugs, but they all have disadvantages. Moreover, there is no unified approach for interpretation of received results, and no recommendations for their practical use. It is necessary to work out unified procedure to assess platelet function, to define indications for its usage and to work out unified criteria of resistance. Individualized approach and each patient’s peculiarities consideration are essential when prescribing antiplatelet therapy.

  17. [Clinical pharmacology of current antiplatelet drugs].

    Science.gov (United States)

    Trenk, D; Nührenberg, T; Stratz, C; Valina, C M; Hochholzer, W

    2014-11-01

    Dual antiplatelet therapy with low-dose acetylsalicylic acid (ASA) and an inhibitor of the P2Y12 adenosine diphosphate (ADP) receptor is the standard treatment for patients presenting with acute coronary syndrome (ACS) or undergoing elective coronary interventions according to the current guidelines published by the European Society of Cardiology (ESC). New generation P2Y12 inhibitors, such as prasugrel and ticagrelor exert stronger and more consistent inhibition of the P2Y12 receptor. In clinical studies enrolling patients with ACS these drugs decreased the incidence of ischemic events compared to the standard therapy with clopidogrel and ASA; however, this beneficial effect was associated with an increase in bleeding events. Alternative therapeutic approaches via addition of drugs with different modes of action showed an overall reduction of ischemic events but also failed to uncouple this beneficial effect from an increased bleeding risk.

  18. Xanthone as Antimalarial: QSAR Analysis, Synthesis, Molecular Docking and In-vitro Antimalarial Evaluation

    Directory of Open Access Journals (Sweden)

    Jufrizal Syahri

    2017-02-01

    Full Text Available The rational design of eighteen new antimalarial compounds from xanthone derivatives has been conducted based on Quantitative Structure-Activity Relationship(QSAR calculation using semi-empirical AM1 methods. The best equation model obtained from QSAR calculation was Log pIC50 = 2.997 - 29.256 (qO8 - 138.234 (qC9 - 6.882 (qC12 - 107.836 (qC14 + 48.764 (qO15. Among the designed compounds, 3,6-dihydroxy-9H-xanthen-9-one (26 and 3,4,6-trihydroxy-9H-xanthen-9-one (27 have been synthesized and investigated their in-vitro antimalarial activities against the chloroquine-sensitive 3D7 strain. An in-vitro antimalarial activity of compound 26 and 27 showed to be highly potential as antimalarial compounds with IC50 of 0.71 and 0.11 µM respectively. Molecular docking studies of compound 26 and 27 showed the formation of a binding interaction between the compounds with the amino acids Ala16, Ser108, Phe58, Asp54 and Leu46, which is the crucial amino acids for antimalarial activity based on the protein-ligand co-crystal structure of WR99210(1,3,5-triazine, a pre-clinical molecule as P. falciparum DHFR-TS inhibitor.

  19. In Silico Mining for Antimalarial Structure-Activity Knowledge and Discovery of Novel Antimalarial Curcuminoids

    Directory of Open Access Journals (Sweden)

    Birgit Viira

    2016-06-01

    Full Text Available Malaria is a parasitic tropical disease that kills around 600,000 patients every year. The emergence of resistant Plasmodium falciparum parasites to artemisinin-based combination therapies (ACTs represents a significant public health threat, indicating the urgent need for new effective compounds to reverse ACT resistance and cure the disease. For this, extensive curation and homogenization of experimental anti-Plasmodium screening data from both in-house and ChEMBL sources were conducted. As a result, a coherent strategy was established that allowed compiling coherent training sets that associate compound structures to the respective antimalarial activity measurements. Seventeen of these training sets led to the successful generation of classification models discriminating whether a compound has a significant probability to be active under the specific conditions of the antimalarial test associated with each set. These models were used in consensus prediction of the most likely active from a series of curcuminoids available in-house. Positive predictions together with a few predicted as inactive were then submitted to experimental in vitro antimalarial testing. A large majority from predicted compounds showed antimalarial activity, but not those predicted as inactive, thus experimentally validating the in silico screening approach. The herein proposed consensus machine learning approach showed its potential to reduce the cost and duration of antimalarial drug discovery.

  20. In Silico Mining for Antimalarial Structure-Activity Knowledge and Discovery of Novel Antimalarial Curcuminoids.

    Science.gov (United States)

    Viira, Birgit; Gendron, Thibault; Lanfranchi, Don Antoine; Cojean, Sandrine; Horvath, Dragos; Marcou, Gilles; Varnek, Alexandre; Maes, Louis; Maran, Uko; Loiseau, Philippe M; Davioud-Charvet, Elisabeth

    2016-06-29

    Malaria is a parasitic tropical disease that kills around 600,000 patients every year. The emergence of resistant Plasmodium falciparum parasites to artemisinin-based combination therapies (ACTs) represents a significant public health threat, indicating the urgent need for new effective compounds to reverse ACT resistance and cure the disease. For this, extensive curation and homogenization of experimental anti-Plasmodium screening data from both in-house and ChEMBL sources were conducted. As a result, a coherent strategy was established that allowed compiling coherent training sets that associate compound structures to the respective antimalarial activity measurements. Seventeen of these training sets led to the successful generation of classification models discriminating whether a compound has a significant probability to be active under the specific conditions of the antimalarial test associated with each set. These models were used in consensus prediction of the most likely active from a series of curcuminoids available in-house. Positive predictions together with a few predicted as inactive were then submitted to experimental in vitro antimalarial testing. A large majority from predicted compounds showed antimalarial activity, but not those predicted as inactive, thus experimentally validating the in silico screening approach. The herein proposed consensus machine learning approach showed its potential to reduce the cost and duration of antimalarial drug discovery.

  1. World Antimalarial Resistance Network (WARN II: In vitro antimalarial drug susceptibility

    Directory of Open Access Journals (Sweden)

    Ringwald Pascal

    2007-09-01

    Full Text Available Abstract Intrinsic resistance of Plasmodium falciparum is clearly a major determinant of the clinical failure of antimalarial drugs. However, complex interactions between the host, the parasite and the drug obscure the ability to define parasite drug resistance in vivo. The in vitro antimalarial drug susceptibility assay determines ex-vivo growth of parasite in the presence of serial drug concentrations and, thus, eliminates host effects, such as drug metabolism and immunity. Although the sensitivity of the parasite to various antimalarials provided by such a test provides an important indicator of intrinsic parasite susceptibility, there are fundamental methodological issues that undermine comparison of in vitro susceptibility both between laboratories and within a single laboratory over time. A network of laboratories is proposed that will agree on the basic parameters of the in vitro test and associated measures of quality control. The aim of the network would be to establish baseline values of sensitivity to commonly used antimalarial agents from key regions of the world, and create a global database, linked to clinical, molecular and pharmacology databases, to support active surveillance to monitor temporal trends in parasite susceptibility. Such a network would facilitate the rapid detection of strains with novel antimalarial resistance profiles and investigate suitable alternative treatments with retained efficacy.

  2. [Historical overview of antimalarials used in Venezuela].

    Science.gov (United States)

    Zerpa de Artiles, N

    1993-06-01

    A historical review of antimalarials used in Venezuela is presented from the time when the bark of quina was used until the massive distribution of quinine and metoquine by the Dirección de Malariología y Saneamiento Ambiental. The utility of chloroquine and primaquine against sensible parasite isolates and of sulfadoxine-pyrimethamine and quinine, currently used against P. falciparum resistant strains, is thoroughly discussed. The author suggests use of artemisimine and its derivatives as a very promising antimalarial drug. She also stresses the possibility of the application of new antimalaria vaccine against P. falciparum blood states, presently assayed in the country as an additional tool in malaria control programs.

  3. Antimalarial pharmacology and therapeutics of atovaquone.

    Science.gov (United States)

    Nixon, Gemma L; Moss, Darren M; Shone, Alison E; Lalloo, David G; Fisher, Nicholas; O'Neill, Paul M; Ward, Stephen A; Biagini, Giancarlo A

    2013-05-01

    Atovaquone is used as a fixed-dose combination with proguanil (Malarone) for treating children and adults with uncomplicated malaria or as chemoprophylaxis for preventing malaria in travellers. Indeed, in the USA, between 2009 and 2011, Malarone prescriptions accounted for 70% of all antimalarial pre-travel prescriptions. In 2013 the patent for Malarone will expire, potentially resulting in a wave of low-cost generics. Furthermore, the malaria scientific community has a number of antimalarial quinolones with a related pharmacophore to atovaquone at various stages of pre-clinical development. With this in mind, it is timely here to review the current knowledge of atovaquone, with the purpose of aiding the decision making of clinicians and drug developers involved in the future use of atovaquone generics or atovaquone derivatives.

  4. The role of antiplatelet therapy in primary prevention. A review

    DEFF Research Database (Denmark)

    Østergaard, Lauge Klement Moltke; Fosbøl, Emil L; Roe, Matthew T

    2017-01-01

    The efficacy of antiplatelet therapy for the secondary prevention of cardiovascular disease after an ischemic event is well established. However, the role for antiplatelet therapy for the primary prevention of cardiovascular disease is more complex because of the interplay of efficacy vs safety...... in individuals without established cardiovascular disease who have a relatively low, but linear trajectory of cardiovascular risk. Several large randomized trials have investigated the efficacy and safety of antiplatelet therapy (primarily aspirin) for patients without established cardiovascular disease....... The pharmacological profile of the most commonly used primary prevention antiplatelet agent, aspirin, has been delineated by randomized clinical trials and showcased in practice guidelines for reducing cardiovascular risk. For this indication, aspirin has been consistently shown to reduce the risk of non...

  5. Medicinal Herbals with Antiplatelet Properties Benefit in Coronary Atherothrombotic Diseases

    Directory of Open Access Journals (Sweden)

    Nurul Huda Mohd Nor

    2016-01-01

    Full Text Available Coronary atherothrombotic diseases such as coronary artery disease, peripheral vascular disease, cerebrovascular disease, and heart failure are the serious concerns of the thrombus formed in blood vessels. Anticoagulant and antiplatelet drugs are the cornerstones of the management of these diseases. To prevent the recurrence of these diseases, double antiplatelet drugs such as aspirin and clopidogrel has been the standard management in most hospitals. However, aspirin resistance and clopidogrel inefficient effects due to noncompliance with double drugs regimen can cause a sinister effect on patients. Medicinal plants serve as a greater resource for new medication and their potential currently became a topic of interest to the researchers all over the world. Traditionally, certain herbs have been used as a treatment for heart diseases but have been investigated for their antiplatelet properties. This current review explained few traditional antithrombotic herbals and their antiplatelet properties in vitro and in vivo and this is to be deeply discussed in further research.

  6. The role of antiplatelet therapy in primary prevention. A review

    DEFF Research Database (Denmark)

    Østergaard, Lauge Klement Moltke; Fosbøl, Emil L; Roe, Matthew T

    2017-01-01

    The efficacy of antiplatelet therapy for the secondary prevention of cardiovascular disease after an ischemic event is well established. However, the role for antiplatelet therapy for the primary prevention of cardiovascular disease is more complex because of the interplay of efficacy vs safety...... in individuals without established cardiovascular disease who have a relatively low, but linear trajectory of cardiovascular risk. Several large randomized trials have investigated the efficacy and safety of antiplatelet therapy (primarily aspirin) for patients without established cardiovascular disease....... The pharmacological profile of the most commonly used primary prevention antiplatelet agent, aspirin, has been delineated by randomized clinical trials and showcased in practice guidelines for reducing cardiovascular risk. For this indication, aspirin has been consistently shown to reduce the risk of non...

  7. ANTIPLATELET THERAPY OF ATRIAL FIBRILLATION: FOCUS ON THE ELDERLY

    Directory of Open Access Journals (Sweden)

    E. А. Ushkalova

    2017-01-01

    Full Text Available Current guidelines for the management of atrial fibrillation (AF recommend using anticoagulants as first-line drugs for stroke prevention, but in real medical practice antiplatelet drugs are often prescribed to elderly patients. Review of clinical and pharmacoepidemiological studies allows us to conclude that  risk associated with acetylsalicylic acid (ASA use in patients ≥75 years can overweigh its potential benefit. Other antiplatelet drugs are poorly studied in patients with AF. Dual antiplatelet therapy (ASA + clopidogrel can be prescribed to elderly patients with cardiovascular comorbidity who are deemed unsuitable candidates for anticoagulant therapy for reasons other  than  bleeding risk or those  who refuse to take oral anticoagulants. Combined therapy of antiplatelet drugs with warfarin or new oral anticoagulants results in no reduction in stroke rate compared with anticoagulant monotherapy but is associated with increased risk of bleeding and can’t be recommended.

  8. Antiplatelet therapy at the time of coronary artery bypass grafting

    DEFF Research Database (Denmark)

    Kremke, Michael; Tang, Mariann; Bak, Mikkel;

    2013-01-01

    OBJECTIVES: The purpose of this multicentre cohort study was to examine the relationship between antiplatelet therapy (APT) at the time of coronary artery bypass grafting (CABG) and postoperative bleeding complications, transfusion requirements and adverse cardiovascular events. METHODS: A matched...

  9. Antimalarial Activity of Methanolic Leaf Extract of Piper betle L.

    OpenAIRE

    Amran, Adel A.; Rohela Mahmud; Zurainee M. Nor; Al-Mekhlafi, Hesham M; Al-Adhroey, Abdulelah H

    2010-01-01

    International audience; The need for new compounds active against malaria parasites is made more urgent by the rapid spread of drug-resistance to available antimalarial drugs. The crude methanol extract of Piper betle leaves (50-400 mg/kg) was investigated for its antimalarial activity against Plasmodium berghei (NK65) during early and established infections. The phytochemical and antioxidant potentials of the crude extract were evaluated to elucidate the possibilities of its antimalarial eff...

  10. Antimalarial compounds from Kniphofia foliosa roots.

    Science.gov (United States)

    Wube, Abraham Abebe; Bucar, Franz; Asres, Kaleab; Gibbons, Simon; Rattray, Lauren; Croft, Simon L

    2005-06-01

    During the course of screening Ethiopian medicinal plants for their antimalarial properties, it was found that the dichloromethane extract of the roots of Kniphofia foliosa Hochst. (Asphodelaceae), which have long been used in the traditional medicine of Ethiopia for the treatment of abdominal cramps and wound healing, displayed strong in vitro antiplasmodial activity against the chloroquine-sensitive 3D7 strain of Plasmodium falciparum with an ED50 value of 3.8 microg/mL and weak cytotoxic activity against KB cells with an ED50 value of 35.2 microg/mL. Five compounds were isolated from the roots and evaluated for their in vitro antimalarial activity. Among the compounds tested, 10-(chrysophanol-7'-yl)-10-(xi)-hydroxychrysopanol-9-anthrone and chryslandicin, showed a high inhibition of the growth of the malaria parasite, P. falciparum with ED50 values of 0.260 and 0.537 microg/mL, respectively, while the naphthalene derivative, 2-acetyl-1-hydroxy-8-methoxy-3-methylnaphthalene, exhibited a less significant antimalarial activity with an ED50 value of 15.4 microg/mL. To compare the effect on the parasite with toxicity to mammalian cells, the cytotoxic activities of the isolated compounds against the KB cell line were evaluated and 10-(chrysophanol-7'-yl)-10-(xi)-hydroxychrysopanol-9-anthrone and chryslandicin displayed very low toxicity with ED50 values of 104 and 90 microg/mL, respectively. This is the first report of the inhibition of the growth of P. falciparum by anthraquinone-anthrone dimers and establishes them as a new class of potential antimalarial compounds with very little host cell toxicity.

  11. Antiplatelet Drugs: Mechanisms and Risks of Bleeding Following Cardiac Operations

    Science.gov (United States)

    Ferraris, Victor A.; Ferraris, Suellen P.; Saha, Sibu P.

    2011-01-01

    Preoperative antiplatelet drug use is common in patients undergoing coronary artery bypass grafting (CABG). The impact of these drugs on bleeding and blood transfusion varies. We hypothesize that review of available evidence regarding drug-related bleeding risk, underlying mechanisms of platelet dysfunction, and variations in patient response to antiplatelet drugs will aid surgeons as they assess preoperative risk and attempt to limit perioperative bleeding. The purpose of this review is to (1) examine the role that antiplatelet drugs play in excessive postoperative blood transfusion, (2) identify possible mechanisms to explain patient response to antiplatelet drugs, and (3) formulate a strategy to limit excessive blood product usage in these patients. We reviewed available published evidence regarding bleeding risk in patients taking preoperative antiplatelet drugs. In addition, we summarized our previous research into mechanisms of antiplatelet drug-related platelet dysfunction. Aspirin users have a slight but significant increase in blood product usage after CABG (0.5 U of nonautologous blood per treated patient). Platelet adenosine diphosphate (ADP) receptor inhibitors are more potent antiplatelet drugs than aspirin but have a half-life similar to aspirin, around 5 to 10 days. The American Heart Association/American College of Cardiology and the Society of Thoracic Surgeons guidelines recommend discontinuation, if possible, of ADP inhibitors 5 to 7 days before operation because of excessive bleeding risk, whereas aspirin should be continued during the entire perioperative period in most patients. Individual variability in response to aspirin and other antiplatelet drugs is common with both hyper- and hyporesponsiveness seen in 5 to 25% of patients. Use of preoperative antiplatelet drugs is a risk factor for increased perioperative bleeding and blood transfusion. Point-of-care tests can identify patients at high risk for perioperative bleeding and blood

  12. Medicinal Herbals with Antiplatelet Properties Benefit in Coronary Atherothrombotic Diseases

    OpenAIRE

    2016-01-01

    Coronary atherothrombotic diseases such as coronary artery disease, peripheral vascular disease, cerebrovascular disease, and heart failure are the serious concerns of the thrombus formed in blood vessels. Anticoagulant and antiplatelet drugs are the cornerstones of the management of these diseases. To prevent the recurrence of these diseases, double antiplatelet drugs such as aspirin and clopidogrel has been the standard management in most hospitals. However, aspirin resistance and clopidogr...

  13. Aspidosperma species as sources of antimalarials. Part III. A review of traditional use and antimalarial activity.

    Science.gov (United States)

    de Paula, Renata Cristina; Dolabela, Maria Fâni; de Oliveira, Alaíde Braga

    2014-03-01

    Several plant species belonging to the genus Aspidosperma are traditionally used in Brazil and other Meso- and South American countries for the treatment of malaria and fevers. These traditional uses were motivation for this review. A literature survey completed for this review has identified scientific bibliographical references to the use of 24 Aspidosperma species to treat malaria/fevers and to 19 species that have had their extracts and/or alkaloids evaluated, with good results, for in vitro and/or in vivo antimalarial activity. Indole alkaloids are typical constituents of Aspidosperma species. However, only 20 out of more than 200 known indole alkaloids isolated from this genus have been assayed for antimalarial activity. These data support the potential of Aspidosperma species as sources of antimalarials and the importance of research aimed at validating their use in the treatment of human malaria.

  14. Antimalarial chemotherapy with natural products and chemically defined molecules

    National Research Council Canada - National Science Library

    Carvalho, Luzia Helena; Krettli, Antoniana U

    1991-01-01

    ... (Acanhospermum australe, Esenbeckia febrifuga, Lisianthus specious and Tachia guianensis) were selected after screening 22 crude extracts from different medicinal and some of them showed antimalarial activity in vitro...

  15. Surgical tracheotomy performed with and without dual antiplatelet therapy.

    Science.gov (United States)

    Markota, Andrej; Sinkovič, Andreja; Čizmarević, Bogdan

    2015-01-01

    Some patients who need dual antiplatelet therapy sometimes require tracheotomy. Aim of this study was to compare the rate of complications during and after surgical tracheotomy between patients requiring dual antiplatelet therapy and those without dual antiplatelet therapy. We retrospectively included 79 patients (62% men, mean age 64 ± 14 years) in the period 2007-2011. The following complications were analyzed: need for surgical revision within 24 hours after tracheotomy, need for bronchoscopy within 24 hour after tracheotomy, need for blood transfusion within 24 hours after tracheotomy, death attributed to tracheotomy and any complication attributed to tracheotomy. We compared patients where tracheotomy was performed while receiving dual antiplatelet therapy (n=27, 34%) to patients where tracheotomy was performed without dual antiplatelet therapy (n=52, 66%). Nonsignificant differences between the two groups were observed general characteristics. There were no statistically significant differences in complications after tracheotomy (surgical revision after tracheotomy p=0.63, bronchoscopy after tracheotomy p=0.74, blood transfusion after tracheotomy p=0.59, death attributed to tracheotomy p=1.00 and any complication attributed to tracheotomy p=1.00). The study shows that tracheotomy is safe in cardiac patients on dual antiplatelet therapy.

  16. [Clinical impact of dual antiplatelet therapy on peptic ulcer disease].

    Science.gov (United States)

    Ahn, Dae Geon; Kim, Beom Jin; Kim, Jeong Wook; Kim, Jae Gyu

    2014-08-01

    Increased incidence of coronary artery disease has led to the increased use of dual antiplatelet therapy composed of aspirin and clopidogrel. We investigated the incidence of gastrointestinal complications in patients who received single or dual antiplatelet therapy and analyzed their clinical characteristics in order to predict the prognostic factors. Between January 2009 and December 2011, we retrospectively reviewed the medical records of patients who underwent coronary angiography at Chung-Ang University Hospital (Seoul, Korea). One hundred and ninety-four patients were classified into two groups: aspirin alone group and dual antiplatelet group. Clinical characteristics, past medical history, and presence of peptic ulcer were analyzed. During the follow-up period, 11 patients had duodenal ulcer; the event rate was 2.02% in the aspirin alone group and 9.47% in the dual antiplatelet group (hazard ratio [HR] 5.24, 95% CI 1.03-26.55, pantiplatelet groups had a higher incidence of duodenal ulcers without significant bleeding compared with the aspirin alone group. In patients who received PPI, the dual antiplatelet therapy group had a higher incidence of gastric ulcers without significant bleeding compared with the aspirin alone group. Therefore, physicians must pay attention to high risk groups who receive dual antiplatelet therapy and aggressive diagnostic endoscopy should also be considered.

  17. Perspective: Tyrosine phosphatases as novel targets for antiplatelet therapy.

    Science.gov (United States)

    Tautz, Lutz; Senis, Yotis A; Oury, Cécile; Rahmouni, Souad

    2015-06-15

    Arterial thrombosis is the primary cause of most cases of myocardial infarction and stroke, the leading causes of death in the developed world. Platelets, highly specialized cells of the circulatory system, are key contributors to thrombotic events. Antiplatelet drugs, which prevent platelets from aggregating, have been very effective in reducing the mortality and morbidity of these conditions. However, approved antiplatelet therapies have adverse side effects, most notably the increased risk of bleeding. Moreover, there remains a considerable incidence of arterial thrombosis in a subset of patients receiving currently available drugs. Thus, there is a pressing medical need for novel antiplatelet agents with a more favorable safety profile and less patient resistance. The discovery of novel antiplatelet targets is the matter of intense ongoing research. Recent findings demonstrate the potential of targeting key signaling molecules, including kinases and phosphatases, to prevent platelet activation and aggregation. Here, we offer perspectives to targeting members of the protein tyrosine phosphatase (PTP) superfamily, a major class of enzymes in signal transduction. We give an overview of previously identified PTPs in platelet signaling, and discuss their potential as antiplatelet drug targets. We also introduce VHR (DUSP3), a PTP that we recently identified as a major player in platelet biology and thrombosis. We review our data on genetic deletion as well as pharmacological inhibition of VHR, providing proof-of-principle for a novel and potentially safer VHR-based antiplatelet therapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Anticoagulation and antiplatelet therapy in awake transcervical injection laryngoplasty.

    Science.gov (United States)

    Dang, Jennifer H; Liou, Nelson Eddie; Ongkasuwan, Julina

    2017-08-01

    Vocal fold movement impairment (VFMI) due to neuronal injury occurs in 20% to 30% of surgeries in the region of the aortic arch. Early injection laryngoplasty can aid with postoperative pulmonary toilet in these high-risk cardiovascular patients. The purpose of this study is to determine whether continuing antiplatelet and anticoagulation therapy during awake transcervical injection laryngoplasty surgery is safe, and if there is any increase in bleeding complications in these patients. This is a retrospective review of patients undergoing awake injection laryngoplasty surgery for VFMI between 2013 and 2016 at a tertiary academic center specializing in aortic and mediastinal diseases. Records were reviewed for patients regarding baseline antiplatelet or anticoagulation therapy, and whether these medications were stopped or continued preoperatively. The primary outcome was bleeding complications. Of the 95 surgeries reviewed, 44 (46%) were performed for patients on antiplatelet therapy, and 71 (75%) for patients on anticoagulation therapy. None of the patients on antiplatelet therapy had their treatment discontinued. Of the patients on anticoagulation, 13 (16.4%) had their therapy held prior to surgery. There was no observed difference in bleeding complications between patients who were continued on antiplatelet or anticoagulation treatment versus those whose therapy was withheld. These results suggest that patients undergoing awake transcervical injection laryngoplasty for VFMI can be maintained on antiplatelet or anticoagulation therapy without increased risk of bleeding. Further larger studies are needed to confirm these findings. 4. Laryngoscope, 127:1850-1854, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  19. EDTA-dependent pseudothrombocytopenia. Association with antiplatelet and antiphospholipid antibodies.

    Science.gov (United States)

    Bizzaro, N; Brandalise, M

    1995-01-01

    In a study of 88 patients with EDTA-dependent pseudothrombocytopenia (PTCP), EDTA-dependent antiplatelet antibodies were seen in the sera of 72 (81.8%) patients (44 IgM, 25 IgG, and 3 IgA). The same sera also were tested for anticardiolipin antibodies (aCL), and 56 (63.6%) patients had sera that also were reactive for aCL (33 IgM, 21 IgG, and 2 IgA). The 16 patients who were negative for antiplatelet antibodies also were negative for aCL antibody. Overall concordance between antiplatelet and aCL antibodies was 82.9%; the correlation between antiplatelet and aCL antibody isotype distribution was 82.1%. Following cardiolipin absorption, most of the PTCP-sera were negative for antiplatelet activity, and no longer reproduced platelet clumping when incubated with normal blood. This finding showed that the antiplatelet antibodies cross-reacted with negatively charged phospholipids. However, after absorption on normal platelets, complete inhibition of aCL activity was observed in 34 (60.7%), and partial inhibition in 14 of the 56 patients who were aCL positive. These findings support the hypothesis that antibody subpopulations (naturally occurring autoantibodies) directed against negatively charged phospholipids can bind to antigens modified by EDTA on the platelet membrane, and may be responsible for PTCP genesis.

  20. Antiplatelet agents and proton pump inhibitors – personalizing treatment

    Directory of Open Access Journals (Sweden)

    Eugene Lin

    2010-06-01

    Full Text Available Eugene Lin, Rajiv Padmanabhan, Majaz MoonisDepartment of Neurology, University of Massachusetts Medical School and UMass Memorial Medical Center, Worcester, Massachusetts, USAIntroduction: Antiplatelet therapy remains one of the cornerstones in the management of noncardioembolic ischemic stroke. However, a significant percentage of patients have concomitant gastroesophageal reflux or peptic ulcer disease that requires acid-reducing medications, the most powerful and effective being the proton pump inhibitors (PPIs. Antiplatelet efficacy, at least in vivo, and particularly for clopidogrel, has been shown to be reduced with concomitant proton pump inhibitor use. Whether this is clinically relevant is not clear from the limited studies available.Methods: We conducted an extensive review of studies available on Medline related to pharmacodynamic interactions between the antiplatelet medications and proton pump inhibitors as well as clinical studies that addressed this potential interaction.Results: Based on the present pharmacodynamic and clinical studies we did not find a significant interaction that would reduce the efficacy of antiplatelet agents with concomitant user of proton pump inhibitors.Conclusions: Patients on antiplatelet agents after a transient ischemic attack or ischemic stroke can safely use aspirin, and extended release dipyridamole/aspirin with proton pump inhibitors. Patients on clopidogrel may use other acid-reducing drugs besides proton pump inhibitors. In rare cases where proton pump inhibitors and clopidogrel have to be used concurrently, careful close monitoring for recurrent vascular events is required.Keywords: proton pump inhibitors, antiplatelet medications, clopidogrel, ischemic stroke, cardiovascular events

  1. Solid phase synthesis and antiprotozoal evaluation of di- and trisubstituted 5'-carboxamidoadenosine analogues.

    Science.gov (United States)

    Rodenko, Boris; Detz, Remko J; Pinas, Victorine A; Lambertucci, Catia; Brun, Reto; Wanner, Martin J; Koomen, Gerrit-Jan

    2006-03-01

    The rapid increase of resistance to drugs commonly used in the treatment of tropical diseases such as malaria and African sleeping sickness calls for the prompt development of new safe and efficacious drugs. The pathogenic protozoan parasites lack the capability of synthesising purines de novo and they take up preformed purines from their host through various transmembrane transporters. Adenosine derivatives constitute a class of potential therapeutics due to their selective internalisation by these transporters. Automated solid-phase synthesis can speed up the process of lead finding and we pursued the solid-phase synthesis of di- and trisubstituted 5'-carboxamidoadenosine derivatives by using a safety-catch approach. While efforts with Kenner's sulfonamide linker remained fruitless, successful application of the hydrazide safety-catch linker allowed the construction of two representative combinatorial libraries. Their antiprotozoal evaluation identified two compounds with promising activity: N(6)-benzyl-5'-N-phenylcarboxamidoadenosine with an IC(50) value of 0.91 microM against Trypanosoma brucei rhodesiense and N(6)-diphenylethyl-5'-phenylcarboxamidoadenosine with an IC(50) value of 1.8 microM against chloroquine resistant Plasmodium falciparum.

  2. Antiprotozoal glutathione derivatives with flagellar membrane binding activity against T. brucei rhodesiense.

    Science.gov (United States)

    Daunes, Sylvie; Yardley, Vanessa; Croft, Simon L; D'Silva, Claudius

    2017-02-15

    A new series of N-substituted S-(2,4-dinitrophenyl)glutathione dibutyl diesters were synthesized to improve in vitro anti-protozoal activity against the pathogenic parasites Trypanosoma brucei rhodesiense, Trypanosoma cruzi and Leishmania donovani. The results obtained indicate that N-substituents enhance the inhibitory properties of glutathione diesters whilst showing reduced toxicity against KB cells as in the cases of compounds 5, 9, 10, 16, 18 and 19. We suggest that the interaction of N-substituted S-(2,4-dinitrophenyl) glutathione dibutyl diesters with T. b. brucei occurs mainly by weak hydrophobic interactions such as London and van der Waals forces. A QSAR study indicated that the inhibitory activity of the peptide is associated negatively with the average number of C atoms, NC and positively to SZX, the ZX shadow a geometric descriptor related to molecular size and orientation of the compound. HPLC-UV studies in conjunction with optical microscopy indicate that the observed selectivity of inhibition of these compounds against bloodstream form T. b. brucei parasites in comparison to L. donovani under the same conditions is due to intracellular uptake via endocytosis in the flagellar pocket. Copyright © 2016. Published by Elsevier Ltd.

  3. In vitro antiprotozoal activities and cytotoxicity of some selected Cameroonian medicinal plants.

    Science.gov (United States)

    Ndjakou Lenta, B; Vonthron-Sénécheau, C; Fongang Soh, R; Tantangmo, F; Ngouela, S; Kaiser, M; Tsamo, E; Anton, R; Weniger, B

    2007-04-20

    Eight extracts from seven selected Cameroonian medicinal plants, traditionally used to treat malaria and other protozoal diseases, were tested in vitro for their antiprotozoal activities against Plasmodium falciparum K1 chloroquine-resistant strain, Leishmania donovani, Trypanosoma cruzi and Trypanosoma brucei rhodesiense, protozoa responsible for malaria, visceral leishmaniasis, Chagas disease and African trypanosomiasis, respectively. The most active extract against Plasmodium falciparum K1 strain and Trypanosoma brucei rhodesiense was the methanolic extract of Albizia zygia (Fabaceae) stem bark with IC(50) values of 1.0 microg/ml and 0.2 microg/ml, respectively. Five extracts showed IC(50) values below 5mug/ml against Leishmania donovani, with the methanolic seed extract of Harungana madagascarensis showing the highest activity, but only the methanolic extract of Albizia zygia showed activity against Trypanosoma cruzi. Cytotoxicity and selectivity indexes were estimated for the most active extracts. The best ratio of cytotoxicity to antiplasmodial activity (SI(a)=14) was established for the methanolic leaf extract of Symphonia globulifera (Clusiaceae), while the methanolic stem bark extract of Albizia zygia showed the best ratio of cytotoxicity to antitrypanosomal activity (SI(b)=22.5).

  4. Antiprotozoal and Antimycobacterial Activities of Pure Compounds from Aristolochia elegans Rhizomes

    Directory of Open Access Journals (Sweden)

    Adelina Jiménez-Arellanes

    2012-01-01

    Full Text Available We analyzed the antimycobacterial activity of the hexane extract of rhizomes from Aristolochia elegans. Some compounds of this extract were purified and tested against a group of drug-resistant Mycobacterium tuberculosis strains. We also evaluated their antiprotozoal activities. The hexane extract was active against M. tuberculosis H37Rv at a MIC=100 μg mL−1; the pure compounds eupomatenoid-1, fargesin, and (8R,8′R,9R-cubebin were active against M. tuberculosis H37Rv (MIC = 50 μg mL−1, while fargesin presented activity against three monoresistant strains of M. tuberculosis H37Rv and a MDR clinical isolate of M. tuberculosis (MIC<50 μg mL-1. Both the extract and eupomatenoid-1 were very active against E. histolytica and G. lamblia (IC50<0.624 μg mL-1; in contrast, fargesin and (8R,8′R,9R-cubebin were moderately active (IC50<275 μg mL-1. In this context, two compounds responsible for the antimycobacterial presented by A. elegans are fargesin and cubebin, although others may exert this activity also. In addition to the antimycobacterial activity, the hexane extract has important activity against E. histolytica and G. lamblia, and eupomatenoid-1 is one of the compounds responsible for the antiparasite activity.

  5. Search for Antiprotozoal Activity in Herbal Medicinal Preparations; New Natural Leads against Neglected Tropical Diseases

    Directory of Open Access Journals (Sweden)

    Núria Llurba Montesino

    2015-08-01

    Full Text Available Sleeping sickness, Chagas disease, Leishmaniasis, and Malaria are infectious diseases caused by unicellular eukaryotic parasites (“protozoans”. The three first mentioned are classified as Neglected Tropical Diseases (NTDs by the World Health Organization and together threaten more than one billion lives worldwide. Due to the lack of research interest and the high increase of resistance against the existing treatments, the search for effective and safe new therapies is urgently required. In view of the large tradition of natural products as sources against infectious diseases [1,2], the aim of the present study is to investigate the potential of legally approved and marketed herbal medicinal products (HMPs as antiprotozoal agents. Fifty-eight extracts from 53 HMPs on the German market were tested by a Multiple-Target-Screening (MTS against parasites of the genera Leishmania, Trypanosoma, and Plasmodium. Sixteen HMPs showed in vitro activity against at least one of the pathogens (IC50 < 10 µg/mL. Six extracts from preparations of Salvia, Valeriana, Hypericum, Silybum, Arnica, and Curcuma exhibited high activity (IC50 < 2.5 µg/mL. They were analytically characterized by UHPLC/ESI-QqTOF-MSMS and the activity-guided fractionation of the extracts with the aim to isolate and identify the active compounds is in progress.

  6. Search for Antiprotozoal Activity in Herbal Medicinal Preparations; New Natural Leads against Neglected Tropical Diseases.

    Science.gov (United States)

    Llurba Montesino, Núria; Kaiser, Marcel; Brun, Reto; Schmidt, Thomas J

    2015-08-04

    Sleeping sickness, Chagas disease, Leishmaniasis, and Malaria are infectious diseases caused by unicellular eukaryotic parasites ("protozoans"). The three first mentioned are classified as Neglected Tropical Diseases (NTDs) by the World Health Organization and together threaten more than one billion lives worldwide. Due to the lack of research interest and the high increase of resistance against the existing treatments, the search for effective and safe new therapies is urgently required. In view of the large tradition of natural products as sources against infectious diseases [1,2], the aim of the present study is to investigate the potential of legally approved and marketed herbal medicinal products (HMPs) as antiprotozoal agents. Fifty-eight extracts from 53 HMPs on the German market were tested by a Multiple-Target-Screening (MTS) against parasites of the genera Leishmania, Trypanosoma, and Plasmodium. Sixteen HMPs showed in vitro activity against at least one of the pathogens (IC50 Arnica, and Curcuma exhibited high activity (IC50 < 2.5 µg/mL). They were analytically characterized by UHPLC/ESI-QqTOF-MSMS and the activity-guided fractionation of the extracts with the aim to isolate and identify the active compounds is in progress.

  7. Dual Antiplatelet Therapy (DAPT) versus No Antiplatelet Therapy and Incidence of Major Bleeding in Patients on Venoarterial Extracorporeal Membrane Oxygenation.

    Science.gov (United States)

    Staudacher, Dawid L; Biever, Paul M; Benk, Christoph; Ahrens, Ingo; Bode, Christoph; Wengenmayer, Tobias

    2016-01-01

    Bleeding is a frequent complication in patients on venoarterial extracorporeal membrane oxygenation (VA-ECMO). An indication for dual antiplatelet therapy due to coronary stent implantation is present in a considerable number of these patients. The objective of this retrospective study was to evaluate if dual antiplatelet therapy (DAPT) significantly increases the high intrinsic bleeding risk in patients on VA-ECMO. A total of 93 patients were treated with VA-ECMO between October 2010 and October 2013. Average time on VA-ECMO was 58.9 ± 1.7 hours. Dual antiplatelet therapy was given to 51.6% of all patients. Any bleeding was recorded in 60.2% of all patients. There was no difference in bleeding incidence in patients on DAPT when compared to those without any antiplatelet therapy including any bleeding (66.7% vs. 57.1%, p = 0.35), BARC3 bleeding (43.8% vs. 33.3%, p = 0.31) or pulmonary bleeding (16.7% vs. 19.0%, p = 0.77). This holds true after adjustment for confounders. Rate of transfusion of red blood cells were similar in patients with or without DAPT (35.4% vs. 28.6%, p = 0.488). Bleeding on VA-ECMO is frequent. This registry recorded no statistical difference in bleeding in patients on dual antiplatelet therapy when compared to no antiplatelet therapy. When indicated, DAPT should not be withheld from VA ECMO patients.

  8. Patent Foramen Ovale Closure or Antiplatelet Therapy for Cryptogenic Stroke.

    Science.gov (United States)

    Søndergaard, Lars; Kasner, Scott E; Rhodes, John F; Andersen, Grethe; Iversen, Helle K; Nielsen-Kudsk, Jens E; Settergren, Magnus; Sjöstrand, Christina; Roine, Risto O; Hildick-Smith, David; Spence, J David; Thomassen, Lars

    2017-09-14

    The efficacy of closure of a patent foramen ovale (PFO) in the prevention of recurrent stroke after cryptogenic stroke is uncertain. We investigated the effect of PFO closure combined with antiplatelet therapy versus antiplatelet therapy alone on the risks of recurrent stroke and new brain infarctions. In this multinational trial involving patients with a PFO who had had a cryptogenic stroke, we randomly assigned patients, in a 2:1 ratio, to undergo PFO closure plus antiplatelet therapy (PFO closure group) or to receive antiplatelet therapy alone (antiplatelet-only group). Imaging of the brain was performed at the baseline screening and at 24 months. The coprimary end points were freedom from clinical evidence of ischemic stroke (reported here as the percentage of patients who had a recurrence of stroke) through at least 24 months after randomization and the 24-month incidence of new brain infarction, which was a composite of clinical ischemic stroke or silent brain infarction detected on imaging. We enrolled 664 patients (mean age, 45.2 years), of whom 81% had moderate or large interatrial shunts. During a median follow-up of 3.2 years, clinical ischemic stroke occurred in 6 of 441 patients (1.4%) in the PFO closure group and in 12 of 223 patients (5.4%) in the antiplatelet-only group (hazard ratio, 0.23; 95% confidence interval [CI], 0.09 to 0.62; P=0.002). The incidence of new brain infarctions was significantly lower in the PFO closure group than in the antiplatelet-only group (22 patients [5.7%] vs. 20 patients [11.3%]; relative risk, 0.51; 95% CI, 0.29 to 0.91; P=0.04), but the incidence of silent brain infarction did not differ significantly between the study groups (P=0.97). Serious adverse events occurred in 23.1% of the patients in the PFO closure group and in 27.8% of the patients in the antiplatelet-only group (P=0.22). Serious device-related adverse events occurred in 6 patients (1.4%) in the PFO closure group, and atrial fibrillation occurred in 29

  9. Cilostazol may prevent cardioembolic stroke in patients undergoing antiplatelet therapy.

    Science.gov (United States)

    Horie, Nobutaka; Kaminogo, Makio; Izumo, Tsuyoshi; Hayashi, Kentaro; Tsujino, Akira; Nagata, Izumi

    2015-07-01

    Randomised trials have shown the efficacy of antiplatelet therapy with cilostazol to prevent secondary ischaemic stroke. Recently, cilostazol has been reported to prevent the development and/or recurrence of atrial fibrillation (AF), which can potentially prevent cardioembolic stroke in patients undergoing antiplatelet therapy. Herein, we examined the impact of prior antiplatelet therapy with cilostazol on the incidence of cardioembolic stroke, which had not been fully investigated. Using the multicenter retrospective study of stroke risk in antithrombotic therapy (RESTATE) database, we analysed consecutive patients with primary or secondary stroke under single antiplatelet therapy. We evaluated the characteristics of ischaemic stroke based on the type of antiplatelet agent used: aspirin, ticlopidine/clopidogrel or cilostazol. Of 1069 consecutive patients with primary or secondary stroke during antithrombotic therapy from January to December 2012, 615 patients received single antiplatelet therapy (293 and 322 cases of primary and secondary strokes, respectively). Interestingly, the percentage of cardioembolic infarction was significantly lower in patients taking cilostazol compared with other agents. Multivariate regression analysis found that age (OR: 1.03, 95% CI: 1.01-1.06, P = 0.0029), serum creatinine (OR: 1.17, 95% CI: 1.03-1.34, P = 0.0198), aspirin (OR: 1.75, 95% CI: 1.00-3.22, P = 0.0486), cilostazol (OR: 0.19, 95% CI: 0.03-0.73, P = 0.0125), and smoking (OR: 1.86, 95% CI: 1.16-2.94, P = 0.0102) were independently associated with cardioembolic stroke. Cilostazol may prevent cardioembolic stroke in patients undergoing antiplatelet therapy. This could be a novel strategy for cardioembolic stroke prevention potentially by affecting cardiac remodelling, in contrast to secondary anticoagulant therapy.

  10. Interactions of hemin, antimalarial drugs and hemin-antimalarial complexes with phospholipid monolayers

    NARCIS (Netherlands)

    Ginsburg, H.; Demel, R.A.

    1984-01-01

    Hemin, antimalarial drugs and complexes formed between them, have demonstrable effects on biological membranes. Using the phospholipid monolayer model, we show that hemin intercalates into the membrane and increases its surface pressure, depending on the lipid composition and the initial surface pre

  11. Antiprotozoal, antimycobacterial, and anti-inflammatory evaluation of Cnidoscolus chayamansa (Mc Vaugh) extract and the isolated compounds.

    Science.gov (United States)

    Pérez-González, Mariana Z; Gutiérrez-Rebolledo, Gabriel A; Yépez-Mulia, Lilián; Rojas-Tomé, Irma S; Luna-Herrera, Julieta; Jiménez-Arellanes, María A

    2017-05-01

    Cnidoscolus chayamansa is a medicinal and edible plant known as Chaya, is commonly used as an anti-inflammatory, antiprotozoal, antibacterial agent and as a remedy for respiratory illness, gastrointestinal disorders, and vaginal infections related with the inflammation process. In this paper, we describe the plant's phytochemical analysis and biological activities (antimycobacterial, antibacterial, antiprotozoal, and anti-inflammatory properties) of the CHCl3:MeOH (1:1) leaves extract and isolated compounds, as well as the acute and sub-acute toxic effects. Chemical identification of isolated compounds was performed by (1)H- and (13)C NMR spectra data. In vitro antibacterial and antimycobacterial activities were determined by disc diffusion and MABA assays, respectively; antiprotozoal test by means of the sub-culture test. Topical and systemic anti-inflammatory effects were tested by TPA and carrageenan assay on BALB/c mice. Moretenol, moretenyl acetate, kaempferol-3,7-dimethyl ether, and 5-hydroxy-7-3',4'-trimethoxyflavanone were the main compounds isolated. The CHCl3:MeOH extract showed antiprotozoal (IC50≤65.29μg/mL), antimycobacterial (MIC≤50μg/mL), and anti-inflammatory activities (ED50=1.66mg/ear and 467.73mg/kg), but was inactive against the bacterial strains tested. The LD50 for extract was >2g/kg. In the sub-acute toxicity test, the extract was administered at 1g/kg for 28days and did not cause lethality or any alteration in hematological and biochemical parameters; in addition, liver, kidney, and spleen histological analysis exhibited no structural changes. Moretenol and moretenyl acetate showed MIC=25μg/mL against Mycobacterium tuberculosis H37Rv and against four monoresistant strains of M. tuberculosis H37Rv. Both compounds exhibited moderate activity against Entamoeba histolytica and Giardia lamblia (IC50≤71.70μg/mL). Kaempferol-3,7-dimethyl ether and 5-hydroxy-7-3',4'-trimethoxy-flavanone were more active than the extract against E

  12. Antiprotozoal Constituents from Annona cherimola Miller, a Plant Used in Mexican Traditional Medicine for the Treatment of Diarrhea and Dysentery

    Science.gov (United States)

    Calzada, Fernando; Correa-Basurto, Jose; Barbosa, Elizabeth; Mendez-Luna, David; Yepez-Mulia, Lilian

    2017-01-01

    Background: Annona cherimola Miller (Annonaceae) is a medicinal plant frequently recommended in Mexican traditional medicine for the treatment of gastrointestinal disorders such as diarrhea and dysentery. Objective: This work was undertaken to obtain information that support the traditional use of A. cherimola, on pharmacological basis using in vitro and computational experiments. Material and Methods: Bioassay-guided fractionation of the ethanol extract of the leaves of A. cherimola afforded five phenolic compounds: caffeic acid, quercetin, kaempferol, nicotinflorin, and rutin. Results: The in vitro antiprotozoal assay showed that kaempferol was the most potent antiamoebic and antigiardial compound with IC50 values of 7.9 μg/mL for Entamoeba histolytica and 8.7 μg/mL for Giardia lamblia. Computational molecular docking study showed that kaempferol interacted in a region different than metronidazole in the enzyme pyruvate: ferredoxin oxidoreductase (PFOR). Conclusion: Considering that PFOR is a target of metronidazole; kaempferol may be a lead compound for the development of novel antiprotozoal agent. Also, these findings give support to the use of A. cherimola in the traditional medicine from México for the treatment of diarrhea and dysentery. SUMMARY Bioassay-guided fractionation of the ethanol extract of the leaves of Annona cherimola afforded five phenolic compounds: caffeic acid, quercetin, kaempferol, nicotinflorin and rutin. The in vitro antiprotozoal assay showed that kaempferol was the most potent antiamoebic and antigiardial compound with IC50 values of 7.9 μg/mL for Entamoeba histolytica and 8.7 μg/mL for Giardia lamblia. Computational molecular docking study showed that kaempferol interacted in a region different that metronidazole in the enzyme pyruvate: ferredoxin oxidoreductase. Abbreviations used: PFOR:Pyruvate:ferredoxin oxidoreductase, G: lamblia: Giardia lamblia, E: histolytica: Entamoeba histolytica PMID:28216899

  13. Recent progress in the development of anti-malarial quinolones.

    Science.gov (United States)

    Beteck, Richard M; Smit, Frans J; Haynes, Richard K; N'Da, David D

    2014-08-30

    Available anti-malarial tools have over the ten-year period prior to 2012 dramatically reduced the number of fatalities due to malaria from one million to less than six-hundred and thirty thousand. Although fewer people now die from malaria, emerging resistance to the first-line anti-malarial drugs, namely artemisinins in combination with quinolines and arylmethanols, necessitates the urgent development of new anti-malarial drugs to curb the disease. The quinolones are a promising class of compounds, with some demonstrating potent in vitro activity against the malaria parasite. This review summarizes the progress made in the development of potential anti-malarial quinolones since 2008. The efficacy of these compounds against both asexual blood stages and other stages of the malaria parasite, the nature of putative targets, and a comparison of these properties with anti-malarial drugs currently in clinical use, are discussed.

  14. Antimalarial properties of imipramine and amitriptyline

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, P.; Siegel, L.; Pinto, J.; Meshnick, S.

    1986-03-01

    This laboratory has previously demonstrated that imipramine (IM) and amitriptyline (AM), inhibit the conversion of riboflavin to its coenzymic derivatives. Several other laboratories have shown that dietary riboflavin deficiency is protective against malarial infection. In the present investigation, the authors determined whether IM and AM exert antimalarial effects similar to that of riboflavin deficiency, as they have hypothesized. In addition, they evaluated whether these drugs, like other antimalarial agents, increase the hemolytic response to ferriprotoporphyrin IX (FP). The growth of P. falciparum (FCR3) in the absence or presence of these drugs (80 ..mu..M) was measured by incubating parasitized erythrocytes for 48 h in RPMI 1640 medium. Parasitemia was determined by counting erythrocyte smears and monitoring (/sup 3/H)hypoxanthine uptake. With no drug, parasitemia was 20.3 +/- 5.3%, whereas in the presence of IM and AM, parasitemia was reduced to 7.3 +/- 0.8% and 13.6 +/- 2.8%, respectively. The uptake of (/sup 3/H)hypoxanthine was reduced to 47 +/- 3.6% and 54 +/- 2.9% of control by IM and AM, respectively. Assays of hemolysis were conducted by incubating 0.5% RBC suspension in NaCl-Tris buffer for 3 h at 37/sup 0/C with variable concentrations of drugs and/or FP (1-7 ..mu..M). Both drugs at 10 to 100 ..mu..M significantly enhanced hemolysis induced by FP. No hemolysis by these drugs was detected in the absence of FP. It is concluded that the tricyclic antidepressants, IM and AM, possess substantial antimalarial properties, thereby supporting the hypothesis that drugs which interfere with riboflavin metabolism should also provide protection against malaria.

  15. Anticancer properties of distinct antimalarial drug classes.

    Directory of Open Access Journals (Sweden)

    Rob Hooft van Huijsduijnen

    Full Text Available We have tested five distinct classes of established and experimental antimalarial drugs for their anticancer potential, using a panel of 91 human cancer lines. Three classes of drugs: artemisinins, synthetic peroxides and DHFR (dihydrofolate reductase inhibitors effected potent inhibition of proliferation with IC50s in the nM- low µM range, whereas a DHODH (dihydroorotate dehydrogenase and a putative kinase inhibitor displayed no activity. Furthermore, significant synergies were identified with erlotinib, imatinib, cisplatin, dasatinib and vincristine. Cluster analysis of the antimalarials based on their differential inhibition of the various cancer lines clearly segregated the synthetic peroxides OZ277 and OZ439 from the artemisinin cluster that included artesunate, dihydroartemisinin and artemisone, and from the DHFR inhibitors pyrimethamine and P218 (a parasite DHFR inhibitor, emphasizing their shared mode of action. In order to further understand the basis of the selectivity of these compounds against different cancers, microarray-based gene expression data for 85 of the used cell lines were generated. For each compound, distinct sets of genes were identified whose expression significantly correlated with compound sensitivity. Several of the antimalarials tested in this study have well-established and excellent safety profiles with a plasma exposure, when conservatively used in malaria, that is well above the IC50s that we identified in this study. Given their unique mode of action and potential for unique synergies with established anticancer drugs, our results provide a strong basis to further explore the potential application of these compounds in cancer in pre-clinical or and clinical settings.

  16. Antimalarial Activity of Ultra-Short Peptides

    Directory of Open Access Journals (Sweden)

    María Yolanda Rios

    2009-12-01

    Full Text Available Ultra-short peptides 1-9 were designed and synthesized with phenylalanine, ornithine and proline amino acid residues and their effect on antimalarial activity was analyzed. On the basis of the IC50 data for these compounds, the effects of nature, polarity, and amino acid sequence on Plasmodium berghei schizont cultures were analyzed too. Tetrapeptides Phe-Orn-Phe-Orn (4 and Lys-Phe-Phe-Orn (5 showed a very important activity with IC50 values of 3.31 and 2.57 μM, respectively. These two tetrapeptides are candidates for subsequent in vivo assays and SARS investigations.

  17. Monitoring the effectiveness of antiplatelet therapy: opportunities and limitations

    Science.gov (United States)

    Sambu, Nalyaka; Curzen, Nick

    2011-01-01

    Previous clinical studies have shown heterogeneity in individual patient responses to antiplatelet therapy and high residual platelet reactivity is associated with increased risk of adverse clinical events. Monitoring response to antiplatelet therapy and tailoring treatment accordingly is currently not recommended in routine clinical practice largely due to the lack of a standardized definition of antiplatelet therapy hyporesponse and the need for a widely accepted point-of-care platelet function test that can be reliably utilized in frontline clinical practice. Recent data have shown that titrating the dose of clopidogrel in patients undergoing percutaneous coronary intervention significantly reduces the incidence of major adverse cardiovascular events and large-scale clinical trials are currently underway to investigate whether individually tailored treatment based on results of platelet function testing leads to improved clinical outcome. Furthermore, genetic testing has demonstrated a link between CYP2C19 genetic polymorphisms, altered clopidogrel metabolite concentrations and adverse clinical events. Clinical studies are currently underway to investigate the potential clinical benefit associated with genotype-guided tailoring of antiplatelet therapy. With the advent of newer, more potent antiplatelet agents and their associated increased bleeding risks, it will become imperative in the future to select the most appropriate, safe and effective drug. PMID:21366666

  18. Personalized antiplatelet and anticoagulation therapy: applications and significance of pharmacogenomics

    Science.gov (United States)

    Beitelshees, Amber L; Voora, Deepak; Lewis, Joshua P

    2015-01-01

    In recent years, substantial effort has been made to better understand the influence of genetic factors on the efficacy and safety of numerous medications. These investigations suggest that the use of pharmacogenetic data to inform physician decision-making has great potential to enhance patient care by reducing on-treatment clinical events, adverse drug reactions, and health care-related costs. In fact, integration of such information into the clinical setting may be particularly applicable for antiplatelet and anticoagulation therapeutics, given the increasing body of evidence implicating genetic variation in variable drug response. In this review, we summarize currently available pharmacogenetic information for the most commonly used antiplatelet (ie, clopidogrel and aspirin) and anticoagulation (ie, warfarin) medications. Furthermore, we highlight the currently known role of genetic variability in response to next-generation antiplatelet (prasugrel and ticagrelor) and anticoagulant (dabigatran) agents. While compelling evidence suggests that genetic variants are important determinants of antiplatelet and anticoagulation therapy response, significant barriers to clinical implementation of pharmacogenetic testing exist and are described herein. In addition, we briefly discuss development of new diagnostic targets and therapeutic strategies as well as implications for enhanced patient care. In conclusion, pharmacogenetic testing can provide important information to assist clinicians with prescribing the most personalized and effective antiplatelet and anticoagulation therapy. However, several factors may limit its usefulness and should be considered. PMID:25897256

  19. The antiprotozoal drug pentamidine ameliorates experimentally induced acute colitis in mice

    Directory of Open Access Journals (Sweden)

    Esposito Giuseppe

    2012-12-01

    Full Text Available Abstract Background Intestinal inflammation is partly driven by enteroglial-derived S100B protein. The antiprotozoal drug pentamidine directly blocks S100B activity. We aimed to investigate the effect of pentamidine on intestinal inflammation using an animal model of dextran sodium sulphate (DSS-induced acute colitis. Methods Mice were divided into: control group, colitis group (4% DSS for four days and two pentamidine-treated colitis groups (0.8 mg/kg and 4 mg/kg. Anti-inflammatory effect of pentamidine was assessed in colonic tissue by evaluating the disease activity index and the severity of histological changes. Colonic tissue were also used to evaluate cyclooxigenase-2, inducible nitric oxide synthase, S100B, glial fibrillary acidic protein, phosphorylated-p38 MAPkinase, p50, p65 protein expression, malondyaldheyde production, mieloperoxidase activity, and macrophage infiltration. Nitric oxide, prostaglandin E2, interleukin-1 beta, tumor necrosis factor alpha, and S100B levels were detected in plasma samples. Parallel measurements were performed in vitro on dissected mucosa and longitudinal muscle myenteric plexus (LMMP preparations after challenge with LPS + DSS or exogenous S100B protein in the presence or absence of pentamidine. Results Pentamidine treatment significantly ameliorated the severity of acute colitis in mice, as showed by macroscopic evaluation and histological/biochemical assays in colonic tissues and in plasma. Pentamidine effect on inflammatory mediators was almost completely abrogated in dissected mucosa but not in LMMP. Conclusions Pentamidine exerts a marked anti-inflammatory effect in a mice model of acute colitis, likely targeting S100B activity. Pentamidine might be an innovative molecule to broaden pharmacological tools against colitis.

  20. Antiplatelet Therapy in Carotid Artery Stenting and Carotid Endarterectomy in the Asymptomatic Carotid Surgery Trial-2

    NARCIS (Netherlands)

    Huibers, A; Halliday, A; Bulbulia, R; Coppi, G; de Borst, G J

    OBJECTIVE: Strokes are infrequent but potentially serious complications following carotid intervention, but antiplatelet therapy can reduce these risks. There are currently no specific guidelines on dose or duration of peri-procedural antiplatelet treatment for patients undergoing carotid

  1. Comparison of on-treatment platelet reactivity between triple antiplatelet therapy with cilostazol and standard dual antiplatelet therapy in patients undergoing coronary interventions: a meta-analysis.

    Science.gov (United States)

    Panchal, Hemang B; Shah, Tejaskumar; Patel, Parthavkumar; Albalbissi, Kais; Molnar, Janos; Coffey, Brandon; Khosla, Sandeep; Ramu, Vijay

    2013-11-01

    The recent literature has shown that triple antiplatelet therapy with cilostazol in addition to the standard dual antiplatelet therapy with aspirin and clopidogrel may reduce platelet reactivity and improve clinical outcomes following percutaneous coronary intervention. The purpose of this meta-analysis is to compare the efficacy of triple antiplatelet therapy and dual antiplatelet therapy in regard to on-treatment platelet reactivity. Nine studies (n = 2179) comparing on-treatment platelet reactivity between dual antiplatelet therapy (n = 1193) and triple antiplatelet therapy (n = 986) in patients undergoing percutaneous coronary intervention were included. Primary end points were P2Y12 reaction unit (PRU) and platelet reactivity index (PRI). Secondary end points were platelet aggregation with adenosine diphosphate (ADP) 5 and 20 µmol/L and P2Y12% inhibition. Mean difference (MD) and 95% confidence intervals (CI) were computed and 2-sided α error antiplatelet therapy, triple antiplatelet therapy had significantly lower maximum platelet aggregation with ADP 5 µmol/L (MD: -14.4, CI: -21.6 to -7.2, P antiplatelet therapy significantly lowers platelet reactivity and may explain a decrease in thromboembolic events following coronary intervention; however, additional studies evaluating clinical outcomes will be helpful to determine the benefit of triple antiplatelet therapy.

  2. Nonhemostatic adverse effects of anticoagulants and antiplatelet agents.

    Science.gov (United States)

    Walenga, Jeanine M; Thethi, Indermohan; Lewis, Bruce E

    2012-11-01

    The topic of adverse effects of drugs is now receiving due attention in both the lay and medical communities. For drugs of the coagulation disorder class, such as anticoagulants and antiplatelet agents, the obvious adverse effects are bleeding from a dose too high and thrombosis from a dose too low. However, these drugs have other potential adverse effects that are not directly related to blood coagulation, yet cannot be dismissed due to their medical importance. There has been a recent advancement of several new drugs in this category and this number will soon grow as more drugs are reaching the end of their clinical trials. This article will discuss the nonhemostatic adverse effects of anticoagulants and antiplatelet drugs. As the adverse effects of bleeding and thrombosis will be excluded, this article will be in contrast to the typical discussions on the anticoagulant and antiplatelet drug classes.

  3. Strokes attributable to underuse of warfarin and antiplatelets

    DEFF Research Database (Denmark)

    Olsen, Tom Skyhøj; Rasmussen, Berit Hammershaimb; Kammersgaard, Lars Peter;

    2007-01-01

    atrial fibrillation, prior myocardial infarction, angina, or prior stroke transient ischemic attack (TIA). Sufficient information on cardiovascular risk factors before stroke was available in 404 patients. A total of 54 patients had atrial fibrillation known before the stroke. Of these, 16 had......Despite their proven efficacy in stroke prevention, warfarin and antiplatelets remain underused. We determined the frequency of ischemic strokes attributable to underuse of warfarin and antiplatelets for stroke prevention in a Danish community. We included all patients with ischemic stroke...... of these strokes could have been prevented. Our findings indicate that underuse of warfarin and antiplatelets is still of considerable magnitude and attributable to 4% to 5% (16 to 22 out of 404) of the ischemic strokes in a Danish urban community....

  4. The effects of post coronary stenting triple antiplatelet therapies on platelet functions

    Institute of Scientific and Technical Information of China (English)

    韩雅玲

    2006-01-01

    Objective To explore the effects of triple antiplatelet therapy on platelet aggregation and activation in patients who underwent coronary stenting. Methods 120 inhospital coronary heart disease patients with coronary stenting were randomized into two groups receiving either triple antiplatelet drugs of aspirin and clopidogrel combined with cilostazol or dual antiplatelet drugs of aspirin and clopidogrel. On the first day after stenting cilostazol

  5. [Antiplatelet agents and anticoagulants: management of the anticoagulated surgical patient].

    Science.gov (United States)

    Llau, Juan V; Ferrandis, Raquel; López Forte, Cristina

    2009-06-01

    Among the drugs most widely consumed by patients are both antiplatelet agents (aspirin, clopidogrel, ticlopidine) and anticoagulants (acenocoumarol, warfarin, low molecular weight heparin, fondaparinux). The use of these drugs in the perioperative period is an essential concern in patient care due to the need to balance the risk of bleeding against thrombotic risk (arterial or venous), which is increased in surgical patients. The present review highlights three main aspects. Firstly, withdrawal of antiplatelet agents is recommended between 1 week and 10 days before surgery to minimize perioperative bleeding. However, this practice has been questioned because patients without the required antiplatelet coverage may be at greater risk of developing cardiac, cerebral or peripheral vascular complications. Therefore, the recommendation of systematic antiplatelet withdrawal for a specific period should be rejected. Currently, risks should be evaluated on an individual basis to minimize the time during which the patient remains without adequate antiplatelet protection. Secondly, thromboprophylaxis is required in most surgical patients due to the high prevalence of venous thromboembolic disease. This implies the use of anticoagulants and the practice of regional anesthesia has been questioned in these patients. However, with the safety recommendations established by the various scientific societies, this practice has been demonstrated to be safe. Finally, "bridge therapy" in patients anticoagulated with acenocoumarol should be performed on an individual basis rather than systematically without taking into account the thrombotic risks of each patient. The perioperative period involves high arterial and venous thrombotic risk and the optimal use of antiplatelet agents and anticoagulants should be a priority to minimize this risk without increasing hemorrhagic risk. Multidisciplinary consensus is essential on this matter.

  6. Antiplatelet Aggregation Coumarins from the Leaves of Murraya omphalocarpa

    Directory of Open Access Journals (Sweden)

    Yang-Chang Wu

    2008-01-01

    Full Text Available Using a bioactivity-guided fractionation method, two coumarins: minumicrolineacetonide (1 and epimurpaniculol senecioate (2, were isolated from the leaves ofMurraya omphalocarpa Hayata (Rutaceae. Compound 1 had been previously synthesizedand was now isolated from natural sources for the first time, and compound 2, possessing anegative optical rotation value, is new. The structures and their stereochemistry were fullyelucidated on the basis of spectroscopic and X-ray crystallographic techniques. Bothcompounds 1 and 2 are active in the antiplatelet aggregation assay. Interestingly, thepossible acetonide artifact 1 displayed significant antiplatelet aggregation induced not onlyby AA and collagen but also by platelet activating factor (PAF.

  7. Antiplatelet agents and Anticoagulants: from pharmacology to clinical practice.

    Science.gov (United States)

    Tsoumani, Maria E; Tselepis, Alexandros D

    2017-01-24

    Thrombosis is the formation of potentially deadly blood clots in the artery (arterial thrombosis) or vein (venous thrombosis). Since thrombosis is one of the main causes of death worldwide, the development of antithrombotic agents is a global medical priority. They are subdivided into antiplatelet agents and anticoagulants. Antiplatelet agents inhibit clot formation by preventing platelet activation and aggregation, while anticoagulants primarily inhibit the coagulation cascade and fibrin formation. Therapeutics within each category differs with respect to the mechanism of action, time to onset, duration of effect and route of administration. In this review, we critically discuss their main pharmacodynamic and pharmacokinetic characteristics as well as recent advances in daily clinical practice.

  8. Synthesis of nitro(benzo)thiazole acetamides and in vitro antiprotozoal effect against amitochondriate parasites Giardia intestinalis and Trichomonas vaginalis.

    Science.gov (United States)

    Navarrete-Vázquez, Gabriel; Chávez-Silva, Fabiola; Colín-Lozano, Blanca; Estrada-Soto, Samuel; Hidalgo-Figueroa, Sergio; Guerrero-Álvarez, Jorge; Méndez, Sara T; Reyes-Vivas, Horacio; Oria-Hernández, Jesús; Canul-Canché, Jaqueline; Ortiz-Andrade, Rolffy; Moo-Puc, Rosa

    2015-05-01

    We synthesized four 5-nitrothiazole (1-4) and four 6-nitrobenzothiazole acetamides (5-8) using an easy two step synthetic route. All compounds were tested in vitro against amitochondriate parasites Giardia intestinalis and Trichomonas vaginalis, showing excellent antiprotozoal effects. IC₅₀'s of the most potent compounds range from nanomolar to low micromolar order, being more active than their drugs of choice. Compound 1 (IC₅₀=122 nM), was 44-times more active than Metronidazole, and 10-fold more effective than Nitazoxanide against G. intestinalis and showed good trichomonicidal activity (IC₅₀=2.24 μM). This compound did not display in vitro cytotoxicity against VERO cells. The in vitro inhibitory effect of compounds 1-8 and Nitazoxanide against G. intestinalis fructose-1,6-biphosphate aldolase (GiFBPA) was evaluated as potential drug target, showing a clear inhibitory effect over the enzyme activity. Molecular docking of compounds 1, 4 and Nitazoxanide into the ligand binding pocket of GiFBPA, revealed contacts with the active site residues of the enzyme. Ligand efficiency metrics of 1 revealed optimal combinations of physicochemical and antiprotozoal properties, better than Nitazoxanide.

  9. Investigation of Calcium Channel Blockers as Antiprotozoal Agents and Their Interference in the Metabolism of Leishmania (L. infantum

    Directory of Open Access Journals (Sweden)

    Juliana Quero Reimão

    2016-01-01

    Full Text Available Leishmaniasis and Chagas disease are neglected parasitic diseases endemic in developing countries; efforts to find new therapies remain a priority. Calcium channel blockers (CCBs are drugs in clinical use for hypertension and other heart pathologies. Based on previous reports about the antileishmanial activity of dihydropyridine-CCBs, this work aimed to investigate whether the in vitro anti-Leishmania infantum and anti-Trypanosoma cruzi activities of this therapeutic class would be shared by other non-dihydropyridine-CCBs. Except for amrinone, our results demonstrated antiprotozoal activity for fendiline, mibefradil, and lidoflazine, with IC50 values in a range between 2 and 16 μM and Selectivity Index between 4 and 10. Fendiline demonstrated depolarization of mitochondrial membrane potential, with increased reactive oxygen species production in amlodipine and fendiline treated Leishmania, but without plasma membrane disruption. Finally, in vitro combinations of amphotericin B, miltefosine, and pentamidine against L. infantum showed in isobolograms an additive interaction when these drugs were combined with fendiline, resulting in overall mean sum of fractional inhibitory concentrations between 0.99 and 1.10. These data demonstrated that non-dihydropyridine-CCBs present antiprotozoal activity and could be useful candidates for future in vivo efficacy studies against Leishmaniasis and Chagas’ disease.

  10. Hemozoin Formation as a Target for Antimalarial Drug Design

    Science.gov (United States)

    2005-02-01

    AD Award Number: DAMD17-03-1-0030 TITLE: Hemozoin Formation as a Target for Antimalarial Drug Design PRINCIPAL INVESTIGATOR: Michael K. Riscoe, Ph.D...Formation as a Target for Antimalarial Drug Design DAMD17-03-1-0030 6. A UTHOR(S) Michael K. Riscoe, Ph.D. 7. PERFORMING ORGANIZA TION NAME(S) AND ADDRESS...Report: by Principal Investigator - Michael K. Riscoe, Ph.D. DAMD1 7-03-1-0030: "Hemozoin Formation as a Target for Antimalarial Drug Design " INTRODUCTION

  11. Antiprotozoal Activity against Entamoeba histolytica of Plants Used in Northeast Mexican Traditional Medicine. Bioactive Compounds from Lippia graveolens and Ruta chalepensis

    Directory of Open Access Journals (Sweden)

    Ramiro Quintanilla-Licea

    2014-12-01

    Full Text Available Amoebiasis caused by Entamoeba histolytica is associated with high morbidity and mortality is becoming a major public health problem worldwide, especially in developing countries. Because of the side-effects and the resistance that pathogenic protozoa build against the standard antiparasitic drugs, e.g., metronidazole, much recent attention has been paid to plants used in traditional medicine around the world in order to find new antiprotozoal agents. We collected 32 plants used in Northeast Mexican traditional medicine and the methanolic extracts of these species were screened for antiprotozoal activity against E. histolytica trophozoites using in vitro tests. Only 18 extracts showed a significant inhibiting activity and among them six plant extracts showed more than 80% growth inhibition against E. histolytica at a concentration of 150 µg/mL and the IC50 values of these extracts were determined. Lippia graveolens Kunth and Ruta chalepensis Pers. showed the more significant antiprotozoal activity (91.54% and 90.50% growth inhibition at a concentration of 150 µg/mL with IC50 values of 59.14 and 60.07 µg/mL, respectively. Bioassay-guided fractionation of the methanolic extracts from these two plants afforded carvacrol (1 and chalepensin (2, respectively, as bioactive compounds with antiprotozoal activity.

  12. Antiprotozoal activity against Entamoeba histolytica of plants used in northeast Mexican traditional medicine. Bioactive compounds from Lippia graveolens and Ruta chalepensis.

    Science.gov (United States)

    Quintanilla-Licea, Ramiro; Mata-Cárdenas, Benito David; Vargas-Villarreal, Javier; Bazaldúa-Rodríguez, Aldo Fabio; Kavimngeles-Hernández, Isvar; Garza-González, Jesús Norberto; Hernández-García, Magda Elizabeth

    2014-12-15

    Amoebiasis caused by Entamoeba histolytica is associated with high morbidity and mortality is becoming a major public health problem worldwide, especially in developing countries. Because of the side-effects and the resistance that pathogenic protozoa build against the standard antiparasitic drugs, e.g., metronidazole, much recent attention has been paid to plants used in traditional medicine around the world in order to find new antiprotozoal agents. We collected 32 plants used in Northeast Mexican traditional medicine and the methanolic extracts of these species were screened for antiprotozoal activity against E. histolytica trophozoites using in vitro tests. Only 18 extracts showed a significant inhibiting activity and among them six plant extracts showed more than 80% growth inhibition against E. histolytica at a concentration of 150 µg/mL and the IC50 values of these extracts were determined. Lippia graveolens Kunth and Ruta chalepensis Pers. showed the more significant antiprotozoal activity (91.54% and 90.50% growth inhibition at a concentration of 150 µg/mL with IC50 values of 59.14 and 60.07 µg/mL, respectively). Bioassay-guided fractionation of the methanolic extracts from these two plants afforded carvacrol (1) and chalepensin (2), respectively, as bioactive compounds with antiprotozoal activity.

  13. A global subsidy for antimalarial drugs.

    Science.gov (United States)

    Gelband, Hellen; Seiter, Andreas

    2007-12-01

    In 2004, the Institute of Medicine concluded that a global high-level subsidy was the best way to make effective antimalarial drugs--currently, artemisinin-combination therapies (ACTs)--widely available at affordable prices and at the same time substantially delay the emergence and spread of artemisinin-resistant strains of falciparum malaria. The subsidy would be available to manufacturers of all ACTs meeting pre-specified efficacy, safety, and quality criteria. Buyers would pay very low prices, allowing drugs to flow through existing channels, with the aim of reaching consumers at a similar price to chloroquine, the most frequently used (although no longer effective) malaria drug. Unsubsidized artemisinin monotherapies would be more expensive than subsidized ACTs (co-formulations), thereby largely eliminating their use through market forces. Conditions favoring the emergence of artemisinin-resistant malaria would be greatly reduced. The global high-level subsidy is a powerful idea that is moving from economic concept to pragmatic reality.

  14. Improving the antiprotozoal effect of saponins in the rumen by combination with glycosidase inhibiting iminosugars or by modification of their chemical structure

    Science.gov (United States)

    de la Fuente, Gabriel; Nash, Robert J.; Braganca, Radek; Duval, Stephane; Bouillon, Marc E.; Lahmann, Martina; Newbold, C. Jamie

    2017-01-01

    The antiprotozoal effect of saponins is transitory, as when saponins are deglycosylated to sapogenins by rumen microorganisms they become inactive. We hypothesised that the combination of saponins with glycosidase-inhibiting iminosugars might potentially increase the effectiveness of saponins over time by preventing their deglycosylation in the rumen. Alternatively, modifying the structure of the saponins by substituting the sugar moiety with other small polar residues might maintain their activity as the sugar substitute would not be enzymatically cleaved. The aim of this in vitro study was to evaluate the acute antiprotozoal effect and the stability of this effect over a 24 h incubation period using ivy saponins, a stevia extract rich in iminosugars, ivy saponins with stevia extract, and a chemically modified ivy saponin, hederagenin bis-succinate (HBS). The effects on fermentation parameters and rumen bacterial communities were also studied. Ivy saponins with stevia and HBS had a greater antiprotozoal effect than ivy saponins, and this effect was maintained after 24 h of incubation (Pstevia extracts was more effective in shifting the fermentation pattern towards higher propionate (+39%) and lower butyrate (-32%) and lower ammonia concentration (-64%) than the extracts incubated separately. HBS caused a decrease in butyrate (-45%) and an increase in propionate (+43%) molar proportions. However, the decrease in ammonia concentration (-42%) observed in the presence of HBS was less than that caused by ivy saponins, either alone or with stevia. Whereas HBS and stevia impacted on bacterial population in terms of community structure, only HBS had an effect in terms of biodiversity (Pstevia and the modified saponin HBS had a strong antiprotozoal effect, although they differed in their effects on fermentation parameters and bacteria communities. Ivy saponins combined with an iminosugar-rich stevia extract and/or HBS should be evaluated to determine their antiprotozoal

  15. Apixaban with antiplatelet therapy after acute coronary syndrome

    NARCIS (Netherlands)

    Alexander, J.H.; Lopes, R.D.; James, S.; Kilaru, R.; He, Y.; Mohan, P.; Bhatt, D.L.; Goodman, S.; Verheugt, F.W.A.; Flather, M.; Huber, K.; Liaw, D.; Husted, S.E.; Lopez-Sendon, J.; Caterina, R. de; Jansky, P.; Darius, H.; Vinereanu, D.; Cornel, J.H.; Cools, F.; Atar, D.; Leiva-Pons, J.L.; Keltai, M.; Ogawa, H.; Pais, P.; Parkhomenko, A.; Ruzyllo, W.; Diaz, R.; White, H.; Ruda, M.; Geraldes, M.; Lawrence, J.; Harrington, R.A.; Wallentin, L.

    2011-01-01

    BACKGROUND: Apixaban, an oral, direct factor Xa inhibitor, may reduce the risk of recurrent ischemic events when added to antiplatelet therapy after an acute coronary syndrome. METHODS: We conducted a randomized, double-blind, placebo-controlled clinical trial comparing apixaban, at a dose of 5 mg t

  16. Anti-platelet agents in pediatric cardiac practice

    Directory of Open Access Journals (Sweden)

    Sweta Mohanty

    2013-01-01

    Full Text Available Pediatric patients with a variety of congenital and acquired cardiac conditions receive antithrombotic therapy. Many of the indications are empirical, and have either not been proven in controlled studies or are extrapolated from adult studies. This article reviews the current available literature regarding the use of anti-platelet drugs in the pediatric cardiac population.

  17. Antiplatelet and anticoagulant therapy in elective percutaneous coronary intervention.

    Science.gov (United States)

    ten Berg, Jurriën M; Plokker, HW Thijs; Verheugt, Freek WA

    2001-01-01

    Thrombosis plays a major role in acute vessel closure both after coronary balloon angioplasty and after stenting. This review will address the role of antiplatelet and anticoagulant therapy in preventing early thrombotic complications after percutaneous coronary intervention. The focus will be on agents that are routinely available and commonly used.

  18. Peripheral interventions and antiplatelet therapy: Role in current practice.

    Science.gov (United States)

    Singh, Pahul; Harper, Yenal; Oliphant, Carrie S; Morsy, Mohamed; Skelton, Michelle; Askari, Raza; Khouzam, Rami N

    2017-07-26

    Peripheral arterial disease (PAD) is a common disorder associated with a high risk of cardiovascular mortality and continues to be under-recognized. The major risk factors for PAD are similar to those for coronary and cerebrovascular disease. Management includes exercise program, pharmacologic therapy and revascularization including endovascular and surgical approach. The optimal revascularization strategy, endovascular or surgical intervention, is often debated due to the paucity of head to head randomized controlled studies. Despite significant advances in endovascular interventions resulting in increased utilization over surgical bypass, significant challenges still remain. Platelet activation and aggregation after percutaneous transluminal angioplasty of atherosclerotic arteries are important risk factors for re-occlusion/restenosis and life-threatening thrombosis following endovascular procedures. Antiplatelet agents are commonly prescribed to reduce the risk of myocardial infarction, stroke and death from cardiovascular causes in patients with PAD. Despite an abundance of data demonstrating efficacy of antiplatelet therapy in coronary artery disease and cerebrovascular disease, there is a paucity of clinical information, clinical guidelines and randomized controlled studies in the PAD population. Hence, data on antiplatelet therapy in coronary interventions is frequently extrapolated to peripheral interventions. The aim of this review article is to elucidate the current data on revascularization and the role and duration of antiplatelet and anticoagulant therapy in re-vascularized lower limb PAD patients.

  19. Antiplatelet and anticoagulant therapy in elective percutaneous coronary intervention

    Directory of Open Access Journals (Sweden)

    Verheugt Freek WA

    2001-05-01

    Full Text Available Abstract Thrombosis plays a major role in acute vessel closure both after coronary balloon angioplasty and after stenting. This review will address the role of antiplatelet and anticoagulant therapy in preventing early thrombotic complications after percutaneous coronary intervention. The focus will be on agents that are routinely available and commonly used.

  20. New oral anticoagulants and dual antiplatelet therapy: Focus on apixaban.

    Science.gov (United States)

    Pelliccia, Francesco; Rollini, Fabiana; Marazzi, Giuseppe; Greco, Cesare; Gaudio, Carlo; Angiolillo, Dominick J; Rosano, Giuseppe

    2016-12-15

    The combination of AF and coronary artery disease not only is a common clinical setting, it is also a complex setting to deal with anticoagulation and antiplatelet therapy, and it is associated with significantly higher mortality rates. Unfortunately, there are no sufficient data available to optimally guide clinical practice in such settings. This review focuses specifically on newer oral anticoagulants (NOACs) associated with dual antiplatelet therapy (DAPT) in patients with coronary artery disease undergoing percutaneous coronary intervention (PCI). There are no randomized studies comparing vitamin K antagonists and NOACs in patients with AF undergoing PCI either for acute coronary syndromes or for stable patients, i.e. those patients who have an indication to receive DAPT. Moreover, new antiplatelet agents such as ticagrelor and prasugrel have entered the market for acute coronary syndromes. So far, there are no large-scale randomized studies published evaluating these newer antiplatelet agents in patients with AF receiving either vitamin K antagonists or NOACs, adding to the uncertainty on how to use these antithrombotics in combination when both coronary artery disease (unstable or stable patients) and AF converge in a given patient. The lack of large outcome trials and the large number of possible combinations are reflected in the wide variety of practices in the real world. To date, given the lack of data, watchfulness when using NOACs as component of DAPT or triple oral antithrombotic therapy is warranted.

  1. Novel antiplatelet and anticoagulant agents in the cardiac care unit.

    Science.gov (United States)

    Garg, Vaani Panse; Halperin, Jonathan L

    2013-11-01

    This article reviews the pivotal studies of several novel antiplatelet (prasugrel and ticagrelor) and anticoagulant (dabigatran, rivaroxaban, and apixaban) agents. The clinical use of these drugs in cardiac intensive care is discussed, focusing on the management of acute coronary syndromes, ischemic stroke, atrial fibrillation, and venous thromboembolism.

  2. Apixaban with antiplatelet therapy after acute coronary syndrome

    NARCIS (Netherlands)

    Alexander, J.H.; Lopes, R.D.; James, S.; Kilaru, R.; He, Y.; Mohan, P.; Bhatt, D.L.; Goodman, S.; Verheugt, F.W.A.; Flather, M.; Huber, K.; Liaw, D.; Husted, S.E.; Lopez-Sendon, J.; Caterina, R. de; Jansky, P.; Darius, H.; Vinereanu, D.; Cornel, J.H.; Cools, F.; Atar, D.; Leiva-Pons, J.L.; Keltai, M.; Ogawa, H.; Pais, P.; Parkhomenko, A.; Ruzyllo, W.; Diaz, R.; White, H.; Ruda, M.; Geraldes, M.; Lawrence, J.; Harrington, R.A.; Wallentin, L.

    2011-01-01

    BACKGROUND: Apixaban, an oral, direct factor Xa inhibitor, may reduce the risk of recurrent ischemic events when added to antiplatelet therapy after an acute coronary syndrome. METHODS: We conducted a randomized, double-blind, placebo-controlled clinical trial comparing apixaban, at a dose of 5 mg

  3. Strokes attributable to underuse of warfarin and antiplatelets

    DEFF Research Database (Denmark)

    Olsen, Tom Skyhøj; Rasmussen, Berit Hammershaimb; Kammersgaard, Lars Peter

    2007-01-01

    in a Copenhagen community with 302,000 inhabitants admitted to the hospital between September 1999 and May 2000 (n = 426). Patients who did not receive warfarin or antiplatelet medication even though they were at known risk for cardiovascular disease before the incident stroke were identified; they had known...

  4. Drug Discovery and Development of Antimalarial Agents: Recent Advances.

    Science.gov (United States)

    Thota, Sreekanth; Yerra, Rajeshwar

    2016-01-01

    Malaria, a deadly infectious parasitic disease, is a major issue of public health in the world today and already produces serious economic constraints in the endemic countries. Most of the malarial infections and deaths are due to Plasmodium falciparum and Plasmodium vivax species. The recent emergence of resistance necessitates the search for new antimalarial drugs, which overcome the resistance and act through new mechanisms. Although much effort has been directed towards the discovery of novel antimalarial drugs. 4-anilino quinolone triazines as potent antimalarial agents, their in silico modelling and bioevaluation as Plasmodium falciparum transketolase and β-hematin inhibitors has been reported. This review is primarily focused on the drug discovery of the recent advances in the development of antimalarial agents and their mechanism of action.

  5. Bioguided investigation of the antimalarial activities of Trema orientalis

    African Journals Online (AJOL)

    Aghomotsegin

    2015-10-28

    Oct 28, 2015 ... of the emergence of resistance to nearly all antimalarial drugs (Kim and Schneider, 2013). Trema orientalis ... parasitic disease remains a public health concern which ... cause of under five mortality (20%) and constitutes 10%.

  6. USE (JF INJECTABLE ANTI-MALARIALS AMONG PATIENTS IN

    African Journals Online (AJOL)

    “Department of Pharmacy,. University ... Because of the high burden of Teaching Hospital, Children specialist malaria ... antimalarials and factors responsible for this awareness, preference and use of .... Programme for Research & Training in.

  7. Synthesis of triazol derivatives of lupeol with potential antimalarial activity

    OpenAIRE

    Tatiane Freitas Borgati; Guilherme Rocha Pereira; Geraldo Célio Brandão; Alaíde Braga Oliveira; José Dias Souza Filho

    2012-01-01

    The goal of this project is synthesize and characterization of derivatives of lupeol and evaluated antimalarial activity. Historically, plants are important source of antimalarial medicines, highlighting quinine (1) (Figure 1), an important      alkaloid from the Cinchona calisaya bark. This compound was an important model for cloroquine  synthesis, a drug that was widely used in malaria treatment. In addition, one of the principal medicines used today is artemisinine, isolated from the Chine...

  8. Antimalarial activity of Malaysian Plectranthus amboinicus against Plasmodium berghei

    OpenAIRE

    Norazsida Ramli; Pakeer Oothuman Syed Ahamed; Hassan Mohamed Elhady; Muhammad Taher

    2014-01-01

    Context: Malaria is a mosquito-borne disease caused by parasitic protozoa from the genus of Plasmodium. The protozoans have developed resistance against many of current drugs. It is urgent to find an alternative source of new antimalarial agent. In the effort to discover new antimalarial agents, this research has been conducted on Plectranthus amboinicus. Aims: This study was conducted to evaluate the toxicity and antiplasmodial properties of P. amboinicus. Materials and Methods: Acute oral t...

  9. Prevention of dipyrone (metamizole) induced inhibition of aspirin antiplatelet effects.

    Science.gov (United States)

    Polzin, Amin; Richter, Stefan; Schrör, Karsten; Rassaf, Tienush; Merx, Marc W; Kelm, Malte; Hohlfeld, Thomas; Zeus, Tobias

    2015-07-01

    We have recently shown that dipyrone (metamizole), a non-opioid analgesic, can nullify aspirin (acetylsalicylic acid; ASA) antiplatelet effects in patients with coronary artery disease (CAD). In this study, we analysed the aspirin and dipyrone drug-drug interaction in order to identify strategies to prevent the dipyrone induced inhibition of asprin antiplatelet effects. Platelet function was measured by arachidonic acid-induced light-transmission aggregometry, thromboxane (TX) B2- formation by immunoassay. Dipyrone metabolite plasma levels were determined by high-performance-liquid-chromatography (HPLC). In seven healthy individuals, in vitro ASA (30 µM/ 100 µM/ 300 µM/ 1,000 µM) and dipyrone (10 µM) coincubation revealed, that the aspirin and dipyrone interaction can be overcome by increasing doses of aspirin. In 36 aspirin and dipyrone comedicated CAD patients, addition of ASA (30 µM/ 100 µM) in vitro inhibited, but did not completely overcome the dipyrone induced reduction of aspirin antiplatelet effects. Notably, the inhibition of thromboxane formation in aspirin and dipyrone comedicated CAD patients coincided with dipyrone plasma levels. In a cross-over designed study in four healthy individuals, we were able to prove that inhibition of aspirin (100 mg/ day) effects by dipyrone (750 mg/ day) was reversible. Furthermore, aspirin (100 mg/ day) medication prior to dipyrone (750 mg/ day) intake prevented the inhibition of antiplatelet effects by dipyrone in 12 healthy individuals. In conclusion, aspirin medication prior to dipyrone intake preserves antiplatelet effects, circumventing the pharmacodynamic drug-drug interaction at the level of cyclooxygenase-1.

  10. Personalized antiplatelet and anticoagulation therapy: applications and significance of pharmacogenomics

    Directory of Open Access Journals (Sweden)

    Beitelshees AL

    2015-02-01

    Full Text Available Amber L Beitelshees,1,* Deepak Voora,2,* Joshua P Lewis,1,* 1Program for Personalized and Genomic Medicine and Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD, USA; 2Center for Applied Genomics & Precision Medicine, Department of Medicine, Duke School of Medicine, Durham, NC, USA*All authors contributed equally to this work Abstract: In recent years, substantial effort has been made to better understand the influence of genetic factors on the efficacy and safety of numerous medications. These investigations suggest that the use of pharmacogenetic data to inform physician decision-making has great potential to enhance patient care by reducing on-treatment clinical events, adverse drug reactions, and health care-related costs. In fact, integration of such information into the clinical setting may be particularly applicable for antiplatelet and anticoagulation therapeutics, given the increasing body of evidence implicating genetic variation in variable drug response. In this review, we summarize currently available pharmacogenetic information for the most commonly used antiplatelet (ie, clopidogrel and aspirin and anticoagulation (ie, warfarin medications. Furthermore, we highlight the currently known role of genetic variability in response to next-generation antiplatelet (prasugrel and ticagrelor and anticoagulant (dabigatran agents. While compelling evidence suggests that genetic variants are important determinants of antiplatelet and anticoagulation therapy response, significant barriers to clinical implementation of pharmacogenetic testing exist and are described herein. In addition, we briefly discuss development of new diagnostic targets and therapeutic strategies as well as implications for enhanced patient care. In conclusion, pharmacogenetic testing can provide important information to assist clinicians with prescribing the most personalized and effective antiplatelet and

  11. The underutilisation of dual antiplatelet therapy in acute coronary syndrome.

    Science.gov (United States)

    Anastasius, Malcolm; Lau, Jerrett K; Hyun, Karice; D'Souza, Mario; Patel, Anushka; Rankin, Jamie; Walters, Darren; Juergens, Craig; Aliprandi-Costa, Bernadette; Yan, Andrew T; Goodman, Shaun G; Chew, Derek; Brieger, David

    2017-08-01

    Despite guideline recommendation of dual antiplatelet therapy (DAPT) in treating ACS, DAPT is underutilized. Our objective was to determine independent predictors of DAPT non-prescription in ACS and describe pattern of DAPT prescription over time. Patients presenting to 41 Australian hospitals with an ACS diagnosis between 2009 and 2016 were stratified according to discharge prescription with DAPT and single antiplatelet therapy (SAPT) or no antiplatelet therapy. Multiple stepwise logistic regression, accounting for within hospital clustering, was used to determine the independent predictors of DAPT non-prescription, defined as discharge with SAPT alone or no antiplatelet agent. 8939 patients survived to discharge with an ACS diagnosis. Of these, 6294 (70.4%) patients were discharged on DAPT, 2154 (24.1%) on SAPT and 491 (5.5%) on no antiplatelet agent. Independent predictors of DAPT non-prescription in the overall cohort were: in-hospital CABG (OR 0.09, 95%CI 0.05-0.14), discharge with warfarin (0.10 (0.07-0.14)), in hospital major bleeding (0.48 (0.34-0.67), diagnosis of unstable angina (0.35, (0.27-0.45)), non-ST-elevation myocardial infarction (0.67 (0.57-0.78)) [both vs. ST-segment elevation myocardial infarction], in hospital atrial arrhythmia (0.72 (0.60-0.86)), history of hypertension (0.83 (0.73-0.94)) and GRACE high risk (0.83 (0.71-0.98)). There was an increase in prescription of DAPT and a shift towards ticagrelor over clopidogrel for ACS from 2013 to 2016 (pantiplatelet management. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  12. [Bridging: Perioperative management of chronic anticoagulation or antiplatelet therapy].

    Science.gov (United States)

    Nowak-Göttl, U; Langer, F; Limperger, V; Mesters, R; Trappe, R U

    2014-06-01

    Oral anticoagulants [Vitamin-K-Antagonists, Dabigatran, Rivaroxaban, Apixaban] or antiplatelet agents [Aspirin, Clopidogrel, Prasugrel, Ticagrelor] are effective in preventing thromboembolic diseases. In case of interventional of surgical procedures patients with indications for chronic anticoagulation [atrial fibrillation, valve prosthesis, venous thromboembolism] or use of antiplatelet agents [cerebrovascular events, cardiovascular events] will require interruption of antithrombotic/antiplatelet therapy with the need of replacement with a short-acting agent. Due to limited data available from randomized studies and meta-analyses the evidence level is low in the majority of recommendations. Therefore for each patient the bleeding and thrombosis risk depending on the individual patient constitution and the planned intervention must be weighted. In patients with an intermediate risk for thrombosis the bleeding risk of the scheduled intervention will influence the bridging recommendation: In patients with a low bleeding risk oral anticoagulation/antiplatelet therapy can be continued or reduced in intensity. In patients with an intermediate or high bleeding risk along with a low thrombosis risk a temporary interruption of the anticoagulation/antiplatelet therapy is feasible. In patients with a high thrombosis and bleeding risk anticoagulation should be bridged with unfractionated heparin [renal insufficiency] or low molecular weight heparin. In the latter risk situation, inhibition of platelet function can be achieved with short-lasting GPIIb-IIIa inhibitors [Eptifibatide, Tirofiban]. Prior to intervention patients treated with the new oral anticoagulants [Dabigatran; Rivaroxaban; Apixaban] are requested to temporary interrupt the anticoagulation depending on the individual drug half-life and their renal function. Bridging therapy with heparin prior to intervention is not necessary with the new oral anticoagulants.

  13. New approaches in antimalarial drug discovery and development: a review

    Directory of Open Access Journals (Sweden)

    Anna Caroline C Aguiar

    2012-11-01

    Full Text Available Malaria remains a major world health problem following the emergence and spread of Plasmodium falciparum that is resistant to the majority of antimalarial drugs. This problem has since been aggravated by a decreased sensitivity of Plasmodium vivax to chloroquine. This review discusses strategies for evaluating the antimalarial activity of new compounds in vitro and in animal models ranging from conventional tests to the latest high-throughput screening technologies. Antimalarial discovery approaches include the following: the discovery of antimalarials from natural sources, chemical modifications of existing antimalarials, the development of hybrid compounds, testing of commercially available drugs that have been approved for human use for other diseases and molecular modelling using virtual screening technology and docking. Using these approaches, thousands of new drugs with known molecular specificity and active against P. falciparum have been selected. The inhibition of haemozoin formation in vitro, an indirect test that does not require P. falciparum cultures, has been described and this test is believed to improve antimalarial drug discovery. Clinical trials conducted with new funds from international agencies and the participation of several industries committed to the eradication of malaria should accelerate the discovery of drugs that are as effective as artemisinin derivatives, thus providing new hope for the control of malaria.

  14. How do antimalarial drugs reach their intracellular targets?

    Directory of Open Access Journals (Sweden)

    Katherine eBasore

    2015-05-01

    Full Text Available Drugs represent the primary treatment available for human malaria, as caused by Plasmodium spp. Currently approved drugs and antimalarial drug leads generally work against parasite enzymes or activities within infected erythrocytes. To reach their specific targets, these chemicals must cross at least three membranes beginning with the host cell membrane. Uptake at each membrane may involve partitioning and diffusion through the lipid bilayer or facilitated transport through channels or carriers. Here, we review the features of available antimalarials and examine whether transporters may be required for their uptake. Our computational analysis suggests that most antimalarials have high intrinsic membrane permeability, obviating the need for uptake via transporters; a subset of compounds appear to require facilitated uptake. We also review parasite and host transporters that may contribute to drug uptake. Broad permeability channels at the erythrocyte and parasitophorous vacuolar membranes of infected cells relax permeability constraints on antimalarial drug design; however, this uptake mechanism is prone to acquired resistance as the parasite may alter channel activity to reduce drug uptake. A better understanding of how antimalarial drugs reach their intracellular targets is critical to prioritizing drug leads for antimalarial development and may reveal new targets for therapeutic intervention.

  15. Analytical sample preparation strategies for the determination of antimalarial drugs in human whole blood, plasma and urine

    DEFF Research Database (Denmark)

    Casas, Mònica Escolà; Hansen, Martin; Krogh, Kristine A

    2014-01-01

    Abstract Antimalarial drugs commonly referred to as antimalarials , include a variety of compounds with different physicochemical properties. There is a lack of information on antimalarial distribution in the body over time after administration, eg the drug ...

  16. Predicting antiprotozoal activity of benzyl phenyl ether diamine derivatives through QSAR multi-target and molecular topology.

    Science.gov (United States)

    Garcia-Domenech, Ramon; Zanni, Riccardo; Galvez-Llompart, Maria; Galvez, Jorge

    2015-05-01

    Multi-target QSAR is a novel approach that can predict simultaneously the activity of a given chemical compound on different pharmacological targets. In this work, we have used molecular topology and statistical tools such as multilinear regression analysis and artificial neural networks, to achieve a multi-target QSAR model capable to predict the antiprotozoal activity of a group of benzyl phenyl ether diamine derivatives. The activity was related to three parasites with a high prevalence rate in humans: Trypanosoma brucei rhodesiense, Plasmodium falciparum, and Leishmania donovani. The multi-target model showed a high regression coefficient (R(2) = 0.9644 and R(2) = 0.9235 for training and test sets, respectively) and a low standard error of estimate (SEE = 0.279). Model validation was performed with an external test (R(2) = 0.9001) and a randomization analysis. Finally, the model was applied to the search of potential new active compounds.

  17. Assessment of the in vitro antiprotozoal and cytotoxic potential of 20 selected medicinal plants from the island of Soqotra.

    Science.gov (United States)

    Mothana, Ramzi A; Al-Musayeib, Nawal M; Matheeussen, An; Cos, Paul; Maes, Louis

    2012-12-03

    Malaria, leishmaniasis and human African trypanosomiasis continue to be major public health problems in need of new and more effective drugs. The aim of this study was to evaluate in vitro antiprotozoal activity of twenty endemic medicinal plants collected from the island of Soqotra in the Indian Ocean. The plant materials were extracted with methanol and tested for antiplasmodial activity against erythrocytic schizonts of Plasmodium falciparum, for antileishmanial activity against intracellular amastigotes of Leishmania infantum and for antitrypanosomal activity against intracellular amastigotes of Trypanosoma cruzi and free trypomastigotes of T. brucei. To assess selectivity, cytotoxicity was determined against MRC-5 fibroblasts. Selective activity was obtained for Punica protopunica against Plasmodium (IC₅₀ 2.2 µg/mL) while Eureiandra balfourii and Hypoestes pubescens displayed activity against the three kinetoplastid parasites (IC₅₀ cinnabari and Euphorbia socotrana displayed non-specific inhibition of the parasites related to high cytotoxicity.

  18. In vitro antiprotozoal and cytotoxic activity of 33 ethonopharmacologically selected medicinal plants from Democratic Republic of Congo.

    Science.gov (United States)

    Musuyu Muganza, D; Fruth, B I; Nzunzu Lami, J; Mesia, G K; Kambu, O K; Tona, G L; Cimanga Kanyanga, R; Cos, P; Maes, L; Apers, S; Pieters, L

    2012-05-07

    The antiprotozoal and cytotoxic activity of the aqueous extracts from 33 medicinal plants, used by traditional healers for the treatment of various parasitic diseases and collected after an ethnopharmacological inventory conducted in the Bolongo area, Bandundu province in DR Congo, was evaluated. Decoctions were prepared, lyophilized and evaluated for in vitro antiprotozoal activity against Trypanosoma b. brucei, Trypanosoma cruzi, Leishmania infantum, and the chloroquine- and pyrimethamine-resistant K1 strain of Plasmodium falciparum. Cytotoxicity against MRC-5 cells was included to assess selectivity of activity. Most of the tested extracts exhibited pronounced (IC(50)≤5μg/ml) or good (5plant extracts inhibited Trypanosoma b. brucei, especially the extract from Isolona hexaloba stem bark (IC(50)=1.95μg/ml, SI=16.5); 8 plant extracts were active against Trypanosoma cruzi, the extracts from Enanatia chlorantha stem bark and Quassia africana root bark being the most active with IC(50) values of 1.87 and 1.88μg/ml, respectively (SI=3.0 and 3.3, respectively); 8 plant extracts showed activity against Leishmania infantum, with extracts from Napoleona vogelii stem bark and Quassia africana root bark as the most active with IC(50) values of 5.66 and 5.04μg/ml (SI=11.3 and 1.2). Finally, 9 plant extracts inhibited Plasmodium falciparum K1 with the extracts from Quassia africana (root bark and stem bark) being the most active ones with IC(50) values of 0.46 and 1.27μg/ml (SI=13.7 and 13.6). Extracts from Enantia chlorantha stem bark, Piptadeniastrum africanum stem bark and Quassia africana root bark were cytotoxic for MRC-5 cells (CC(50)plant species for the treatment of parasitic diseases. Copyright © 2012. Published by Elsevier Ireland Ltd.

  19. Antiplatelet Therapy and the Risk of Hepatocellular Carcinoma in Chronic Hepatitis B Patients on Antiviral Treatment.

    Science.gov (United States)

    Lee, Minjong; Chung, Goh Eun; Lee, Jeong-Hoon; Oh, Sohee; Nam, Joon Yeul; Chang, Young; Cho, Hyeki; Ahn, Hongkeun; Cho, Young Youn; Yoo, Jeong-Ju; Cho, Yuri; Lee, Dong Hyeon; Cho, Eun Ju; Yu, Su Jong; Lee, Dong Ho; Lee, Jeong Min; Kim, Yoon Jun; Yoon, Jung-Hwan

    2017-06-15

    Antiplatelet therapy has shown protective effects against hepatocellular carcinoma (HCC) in preclinical studies. However, it is unclear whether antiplatelet therapy lowers the risk of HCC in patients with chronic hepatitis B. A retrospective analysis was conducted of data from 1,674 chronic hepatitis B patients, enrolled between January 2002 and May 2015, whose serum hepatitis B virus DNA levels were suppressed by antivirals to antiplatelet treatment (aspirin, clopidogrel, or both; antiplatelet group) and patients who were not treated (non-antiplatelet group) using a time-varying Cox proportional hazards model for total population and propensity score-matching analysis. The antiplatelet group included 558 patients, and the non-antiplatelet group had 1,116 patients. During the study period, 63 patients (3.8%) developed HCC. In time-varying Cox proportional analyses, the antiplatelet group showed a significantly lower risk of HCC (hazard ratio [HR], 0.44; 95% confidence interval [CI], 0.23-0.85; P = 0.01), regardless of antiplatelet agent. In propensity score-matched pairs, antiplatelet therapy significantly reduced the risk of HCC (HR, 0.34; 95% CI, 0.15-0.77; P = 0.01). However, the overall risk of bleeding was higher in the antiplatelet group (HR, 3.28; 95% CI, 1.98-5.42; P Antiplatelet therapy reduces the risk of HCC in chronic hepatitis B patients whose hepatitis B virus is effectively suppressed. However, antiplatelet therapy containing clopidogrel may increase the risk of bleeding. (Hepatology 2017). © 2017 by the American Association for the Study of Liver Diseases.

  20. World Antimalarial Resistance Network (WARN IV: Clinical pharmacology

    Directory of Open Access Journals (Sweden)

    Gbotosho Grace O

    2007-09-01

    Full Text Available Abstract A World Antimalarial Resistance Network (WARN database has the potential to improve the treatment of malaria, through informing current drug selection and use and providing a prompt warning of when treatment policies need changing. This manuscript outlines the contribution and structure of the clinical pharmacology component of this database. The determinants of treatment response are multi-factorial, but clearly providing adequate blood concentrations is pivotal to curing malaria. The ability of available antimalarial pharmacokinetic data to inform optimal dosing is constrained by the small number of patients studied, with even fewer (if any studies conducted in the most vulnerable populations. There are even less data relating blood concentration data to the therapeutic response (pharmacodynamics. By pooling all available pharmacokinetic data, while paying careful attention to the analytical methodologies used, the limitations of small (and thus underpowered individual studies may be overcome and factors that contribute to inter-individual variability in pharmacokinetic parameters defined. Key variables for pharmacokinetic studies are defined in terms of patient (or study subject characteristics, the formulation and route of administration of the antimalarial studied, the sampling and assay methodology, and the approach taken to data analysis. Better defining these information needs and criteria of acceptability of pharmacokinetic-pharmacodynamic (PK-PD studies should contribute to improving the quantity, relevance and quality of these studies. A better understanding of the pharmacokinetic properties of antimalarials and a more clear definition of what constitutes "therapeutic drug levels" would allow more precise use of the term "antimalarial resistance", as it would indicate when treatment failure is not caused by intrinsic parasite resistance but is instead the result of inadequate drug levels. The clinical pharmacology component

  1. A database of antimalarial drug resistance

    Directory of Open Access Journals (Sweden)

    Ringwald Pascal

    2006-06-01

    Full Text Available Abstract A large investment is required to develop, license and deploy a new antimalarial drug. Too often, that investment has been rapidly devalued by the selection of parasite populations resistant to the drug action. To understand the mechanisms of selection, detailed information on the patterns of drug use in a variety of environments, and the geographic and temporal patterns of resistance is needed. Currently, there is no publically-accessible central database that contains information on the levels of resistance to antimalaria drugs. This paper outlines the resources that are available and the steps that might be taken to create a dynamic, open access database that would include current and historical data on clinical efficacy, in vitro responses and molecular markers related to drug resistance in Plasmodium falciparum and Plasmodium vivax. The goal is to include historical and current data on resistance to commonly used drugs, like chloroquine and sulfadoxine-pyrimethamine, and on the many combinations that are now being tested in different settings. The database will be accessible to all on the Web. The information in such a database will inform optimal utilization of current drugs and sustain the longest possible therapeutic life of newly introduced drugs and combinations. The database will protect the valuable investment represented by the development and deployment of novel therapies for malaria.

  2. New anticoagulant and antiplatelet agents: a primer for the gastroenterologist.

    Science.gov (United States)

    Baron, Todd H; Kamath, Patrick S; McBane, Robert D

    2014-02-01

    A large number of patients worldwide receive anticoagulant and antiplatelet agents, collectively known as antithrombotic agents. Several new anticoagulants and antiplatelet agents recently were approved for use. Gastroenterologists may be unfamiliar with the mechanism of action, indications for use, and pharmacokinetics of these newer drugs. In patients undergoing elective and urgent endoscopic procedures, clinicians must be familiar with these medications to optimize outcomes. When the decision is made to continue the newer antithrombotic agents for elective procedures, the clinician must understand the risk that these agents may impart on procedural-induced bleeding. Finally, it is important to understand how to manage these agents in the presence of acute gastrointestinal bleeding. In this article the use of newer antithrombotic agents is reviewed.

  3. Anti-platelet effects of yuzu extract and its component.

    Science.gov (United States)

    Yu, Hye Yon; Park, Se Won; Chung, Ill Min; Jung, Yi-Sook

    2011-12-01

    In this study, we investigated whether the methanolic extract of yuzu (yuzu ME) and its components hesperidin and naringin, have anti-platelet activities. Yuzu ME and hesperidin inhibited collagen-, arachidonic acid (AA)-, ADP- and thrombin-induced rat platelet aggregation in vitro and ex vivo. Naringin also inhibited platelet aggregation induced by collagen, AA, or thrombin, but not aggregation induced by ADP. The oral administration of yuzu ME or hesperidin prolonged mouse tail vein bleeding time in a dose-dependent manner in vivo. These results suggest that yuzu ME and hesperidin have anti-platelet activity, and that intake of yuzu, which includes various flavonoids such as hesperidin, may be beneficial for individuals at high risk of cardiovascular diseases.

  4. Effect of antimalarial drugs on stimulation and interleukin 2 production of human lymphocytes

    DEFF Research Database (Denmark)

    Bygbjerg, I C; Svenson, M; Theander, T G

    1987-01-01

    Effect of pyrimethamine, an antimalarial antifolate, and of mefloquine, chloroquine, and quinine, which belong to the quinoline group of antimalarials, on proliferation and interleukin 2 (IL-2) production of human lymphocytes was studied in vitro. Pyrimethamine at concentrations above therapeutic...

  5. Lumbar puncture in patients using anticoagulants and antiplatelet agents

    OpenAIRE

    Renan Domingues; Gustavo Bruniera; Fernando Brunale; Cristóvão Mangueira; Carlos Senne

    2016-01-01

    ABSTRACT The use of anticoagulants and antiplatelet agents has largely increased. Diagnostic lumbar puncture in patients taking these drugs represents a challenge considering the opposing risks of bleeding and thrombotic complications. To date there are no controlled trials, specific guidelines, nor clear recommendations in this area. In the present review we make some recommendations about lumbar puncture in patients using these drugs. Our recommendations take into consideration the pharmaco...

  6. Generation of Anti-platelet Autoantibody During Dengue Virus Infection

    Directory of Open Access Journals (Sweden)

    Huan-Yao Lei

    2008-01-01

    Full Text Available Dengue virus infection causes dengue fever, Dengue Hemorrhagic Fever (DHF and Dengue Shock Syndrome (DSS. Thrombocytopenia is common in dengue fever and is always found in DHF/DSS. The pathogenesis of thrombocytopenia is poorly understood. To further understand the relationship between anti-dengue virus antibody and anti-platelet antibody, we generated monoclonal anti-dengue virus antibodies from the dengue virus infected mice that developed transient thrombocytopenia post dengue infection. The analysis of a panel of monoclonal anti-NS-1 antibodies reveals three different patterns of platelet binding: strong, intermediate, or dull. Their isotypes are different, some are IgM while others are IgG1. Most of anti-platelet antibodies are cross-reactive with NS-1 of dengue virus and can be competitively inhibited by recombinant NS-1 protein, suggesting a molecular mimicry between dengue virus NS-1 protein and platelet. A clone, 13-F4-G5, preferentially bound activated platelets, can recognize two or three proteins around 150 kD on platelets. The binding to platelet would lyse the platelet in the presence of complement or enhance the ADP-induced platelet aggregation. Furthermore, some of these monoclonal antibodies would also react with the cellular antigens of BHK. Based on the data, we conclude that dengue virus infection induces auto anti-platelet antibodies which thereafter may involve in the manifestation of thrombocytopenia. A molecular mimicry between NS-1 and platelet is demonstrated.

  7. Dental management of patients receiving anticoagulation or antiplatelet treatment.

    Science.gov (United States)

    Pototski, Mariele; Amenábar, José M

    2007-12-01

    Antiplatelet and anticoagulant agents have been extensively researched and developed as potential therapies in the prevention and management of arterial and venous thrombosis. On the other hand, antiplatelet and anticoagulant drugs have also been associated with an increase in the bleeding time and risk of postoperative hemorrhage. Because of this, some dentists still recommend the patient to stop the therapy for at least 3 days before any oral surgical procedure. However, stopping the use of these drugs exposes the patient to vascular problems, with the potential for significant morbidity. This article reviews the main antiplatelet and anticoagulant drugs in use today and explains the dental management of patients on these drugs, when subjected to minor oral surgery procedures. It can be concluded that the optimal INR value for dental surgical procedures is 2.5 because it minimizes the risk of either hemorrhage or thromboembolism. Nevertheless, minor oral surgical procedures, such as biopsies, tooth extraction and periodontal surgery, can safely be done with an INR lower than 4.0.

  8. Platelet count in healthy subjects treated with antiplatelet drugs

    Directory of Open Access Journals (Sweden)

    Maczy González-Rincón

    2016-07-01

    Full Text Available Platelet count in peripheral blood of healthy subjects with antiplatelet drugs. 20 subjects were analized. They were distributed in two groups: subject A: 10 who received aspirin (100 mg and B:10 with Clopidogrel (75 mg for 7 days. In all subjects studied platelet count in peripheral blood and PRP. It found a platelet count before treatment with antiplatelet agents in peripheral blood of 258,6 ± 54,46 x 109 l and 7 days after 254 ± 41,86 x 109 l (aspirin and 285,4 ± 70, 196,5 ± 37,90 x 109 l (Clopidogrel respectively. In the PRP of subjects before receiving aspirin was 486,5 ± 129,54 x 109 l and after 449,2 ± 85,51 x 109 l; prior to Clopidogrel ingestion was 565,2 ± 150,41 and 592,9 ± 203,46 x 109 l after treatment. Significant differences were found only for the platelet count in the Clopidogrel Group (p < 0.05. A significant decrease in platelet count was observed in peripheral blood after administration of Clopidogrel, possibly as a result of its pharmacological mechanism. More studies are needed to assess a greater number of individuals and better measure the effect of antiplatelet agents.

  9. Synthesis of triazol derivatives of lupeol with potential antimalarial activity

    Directory of Open Access Journals (Sweden)

    Tatiane Freitas Borgati

    2012-06-01

    Full Text Available The goal of this project is synthesize and characterization of derivatives of lupeol and evaluated antimalarial activity. Historically, plants are important source of antimalarial medicines, highlighting quinine (1 (Figure 1, an important      alkaloid from the Cinchona calisaya bark. This compound was an important model for cloroquine  synthesis, a drug that was widely used in malaria treatment. In addition, one of the principal medicines used today is artemisinine, isolated from the Chinese plant Artemisia annua L (2 (Figure 1, and their semi synthetic derivatives (artesunate, artemeter, arteter. However, the malaria parasite has already shown resistance    to most of these current drugs and  the search for new candidates is essential. Lupeol (3 (Figura 1 is a compound that occurs in many plant species and discloses antimalarial, antiinflamatoryl and antitumoral activities. Considering its potential as a lead antimalarial molecule, we focused our work in the synthesis of new lupeol derivatives with increased antimalarial activity(scheme 1.

  10. Continued Antiplatelet Therapy and Risk of Bleeding in Gastrointestinal Procedures: A Systematic Review.

    Science.gov (United States)

    Fang, Xiao; Baillargeon, Jacques G; Jupiter, Daniel C

    2016-05-01

    Management of perioperative antiplatelet medications in gastrointestinal (GI) surgery is challenging. The risk of intraoperative and postoperative bleeding is associated with perioperative use of antiplatelet medication. However, cessation of these drugs may be unsafe for patients who are required to maintain antiplatelet use due to cardiovascular conditions. The objective of this systematic review was to compare the risk of intraoperative or postoperative bleeding among patients who had GI surgery while on continuous antiplatelet therapy (aspirin, clopidogrel, or dual therapy) with the risk among those not taking continuous antiplatelet medication. We reviewed articles published between January 2000 and July 2015 from the Medline Ovid and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. Studies involving any GI procedures were included if the articles met our inclusion criteria (listed in Methods). The following key words were used for the search: clopidogrel, Plavix, aspirin, antiplatelet, bleeding, hemorrhage, and digestive system surgical procedures. Quality of the studies was assessed, depending on their study design, using the Newcastle-Ottawa score or the Cochrane Collaboration's tool for assessing risk of bias. Twenty-two studies were eligible for inclusion in the systematic review. Five showed that the risk of intraoperative bleeding or postoperative bleeding among patients who had GI surgery while on continuous antiplatelet therapy was higher compared that for those not on continuous therapy. The remaining 17 studies reported that there was no statistically significant difference in the risks of bleeding between the continuous antiplatelet therapy group and the group without continuous antiplatelet therapy. The risk of bleeding associated with GI procedures in patients receiving antiplatelet therapy was not significantly higher than in patients with no antiplatelet or interrupted antiplatelet therapy. Copyright © 2016 American

  11. Research progress of new antiplatelet drugs in the prevention and treatment for ischemic stroke

    OpenAIRE

    Zhou, Yu-ying; Li, Pan

    2013-01-01

    Nowadays, antiplatelet drugs are still the routine medication in the acute phase and in secondary prevention of ischemic stroke. Although the clinical effect of classic antiplatelet drugs, such as aspirin and clopidogrel, has been recognized, some problems still exist, such as clopidogrel resistance and increased bleeding risk. Therefore, new antiplatelet drugs have been studied and are incorporated into the clinical use currently. Their different pharmacokinetic and pharmacodynamic propertie...

  12. Dual antiplatelet therapy after noncardioembolic ischemic stroke or transient ischemic attack: pros and cons.

    Science.gov (United States)

    Hong, Keun-Sik

    2014-07-01

    Dual antiplatelet therapy simultaneously blocks different platelet activation pathways and might thus be more potent at inhibiting platelet activation and more effective at reducing major ischemic vascular events compared to antiplatelet monotherapy. Aspirin plus clopidogrel dual therapy is now the standard therapy for patients with acute coronary syndrome and for those undergoing percutaneous coronary intervention. However, dual antiplatelet therapy carries an increased risk of bleeding. Patients with ischemic stroke or transient ischemic attack (TIA) are generally older and likely to have a fragile cerebrovascular bed, which further increases the risk of systemic major bleeding events and intracranial hemorrhage. Clinical trials and meta-analyses suggest that in comparison to antiplatelet monotherapy, dual antiplatelet therapy initiated early after noncardioembolic ischemic stroke or TIA further reduces the rate of recurrent stroke and major vascular events without significantly increasing the rate of major bleeding events. In contrast, studies of long-term therapy in patients with noncardioembolic ischemic stroke or TIA have yielded inconsistent data regarding the benefit of dual antiplatelet therapy over monotherapy. However, the harm associated with major bleeding events, including intracranial hemorrhage, which is generally more disabling and more fatal than ischemic stroke, is likely to increase with dual antiplatelet therapy. Physicians should carefully assess the benefits and risks of dual antiplatelet therapy versus antiplatelet monotherapy when managing patients with ischemic stroke or TIA.

  13. Safety of dental extractions during uninterrupted single or dual antiplatelet treatment.

    Science.gov (United States)

    Lillis, Theodoros; Ziakas, Antonios; Koskinas, Konstantinos; Tsirlis, Anastasios; Giannoglou, George

    2011-10-01

    Optimal dental management in patients on long-term antiplatelet treatment is not clearly defined. Antiplatelet discontinuation increases the risk of thrombotic complications, whereas uninterrupted antiplatelet therapy, which is the currently recommended approach, is assumed to increase the bleeding hazard after dental procedures. We sought to prospectively compare the risk of immediate and late postextraction bleeding in patients receiving uninterrupted single or dual antiplatelet therapy. We recruited 643 consecutive patients referred for dental extractions. In total 111 (17.3%) were on clinically indicated antiplatelet therapy: aspirin (n = 42), clopidogrel (n = 36), and aspirin and clopidogrel (n = 33). Controls (n = 532, 82.7%) were not on antiplatelet treatment. Immediate and late bleeding complications were recorded. Compared to controls the risk of prolonged immediate bleeding was higher in patients on dual antiplatelet therapy (relative risk [RR] 177.3, 95% confidence interval [CI] 43.5 to 722, p patients on aspirin alone (RR = 6.3, 95% CI 0.6 to 68.4, p = 0.2) or clopidogrel alone (RR = 7.4, 95% CI 0.7 to 79.5, p = 0.18); however, all immediate bleeding complications in all treatment groups were successfully managed with local hemostatic measures. No patient developed any late hemorrhage. In conclusion, dental extractions may be safely performed in patients receiving single or dual antiplatelet therapy when appropriate local hemostatic measures are taken, thus averting thrombotic risk of temporary antiplatelet discontinuation.

  14. Immunomodulating and Antiprotozoal Effects of Different Extracts of the Oyster Culinary-Medicinal Mushroom Pleurotus ostreatus (Higher Basidiomycetes) Against Coccidiosis in Broiler.

    Science.gov (United States)

    Ullah, Muhammad Irfan; Akhtar, Masood; Iqbal, Zafar; Shahid, Muhammad; Awais, Mian Muhammad

    2015-01-01

    The culinary-medicinal oyster mushroom Pleurotus ostreatus, procured from local sources, was processed for hot water and methanolic extraction. Extracts obtained were subjected to proximate analysis to determine the amount of crude protein, crude fiber, ash, ether, and nitrogen-free extracts. These extracts were evaluated for immunomodulating and antiprotozoal effects against coccidiosis in a broiler. Cellular immune investigation revealed significantly higher (P ostreatus extracts compared with controls. Humoral immune investigation revealed higher immunoglobulin (total Ig, IgG, and IgM) titers against sheep red blood cells in treated groups compared with controls. However, nonsignificant (P > 0.05) findings were observed in investigations of lymphoid organs. Antiprotozoal studies revealed a significantly higher (P ostreatus extracts when compared with controls. Moreover, lesion scoring and oocysts per gram of droppings observed in the control group were significantly higher (P ostreatus. Results concluded that hot water and methanolic extracts of P. ostreatus had strong immune-enhancing activities. Further, these extracts also had excellent antiprotozoal activities against coccidiosis in a broiler.

  15. Quinine conjugates and quinine analogues as potential antimalarial agents.

    Science.gov (United States)

    Jones, Rachel A; Panda, Siva S; Hall, C Dennis

    2015-06-01

    Malaria is a tropical disease, prevalent in Southeast Asia and Africa, resulting in over half a million deaths annually; efforts to develop new antimalarial agents are therefore particularly important. Quinine continues to play a role in the fight against malaria, but quinoline derivatives are more widely used. Drugs based on the quinoline scaffold include chloroquine and primaquine, which are able to act against the blood and liver stages of the parasite's life cycle. The purpose of this review is to discuss reported biologically active compounds based on either the quinine or quinoline scaffold that may have enhanced antimalarial activity. The review emphasises hybrid molecules, and covers advances made in the last five years. The review is divided into three sections: modifications to the quinine scaffold, modifications to aminoquinolines and finally metal-containing antimalarial compounds.

  16. Antimalarial activity of methanolic leaf extract of Piper betle L.

    Science.gov (United States)

    Al-Adhroey, Abdulelah H; Nor, Zurainee M; Al-Mekhlafi, Hesham M; Amran, Adel A; Mahmud, Rohela

    2010-12-28

    The need for new compounds active against malaria parasites is made more urgent by the rapid spread of drug-resistance to available antimalarial drugs. The crude methanol extract of Piper betle leaves (50-400 mg/kg) was investigated for its antimalarial activity against Plasmodium berghei (NK65) during early and established infections. The phytochemical and antioxidant potentials of the crude extract were evaluated to elucidate the possibilities of its antimalarial effects. The safety of the extract was also investigated in ICR mice of both sexes by the acute oral toxicity limit test. The leaf extract demonstrated significant (P Piper betle leaves is toxicologically safe by oral administration. The results suggest that the Malaysian folklorical medicinal application of the extract of Piper betle leaf has a pharmacological basis.

  17. Anti-malarial Drug Design by Targeting Apicoplasts: New Perspectives

    Directory of Open Access Journals (Sweden)

    Avinaba Mukherjee

    2016-03-01

    Full Text Available Objectives: Malaria has been a major global health problem in recent times with increasing mortality. Current treatment methods include parasiticidal drugs and vaccinations. However, resistance among malarial parasites to the existing drugs has emerged as a significant area of concern in anti-malarial drug design. Researchers are now desperately looking for new targets to develop anti-malarials drug which is more target specific. Malarial parasites harbor a plastid-like organelle known as the ‘apicoplast’, which is thought to provide an exciting new outlook for the development of drugs to be used against the parasite. This review elaborates on the current state of development of novel compounds targeted againstemerging malaria parasites. Methods: The apicoplast, originates by an endosymbiotic process, contains a range of metabolic pathways and housekeeping processes that differ from the host body and thereby presents ideal strategies for anti-malarial drug therapy. Drugs are designed by targeting the unique mechanism of the apicoplasts genetic machinery. Several anabolic and catabolic processes, like fatty acid, isopenetyl diphosphate and heme synthess in this organelle, have also been targeted by drugs. Results: Apicoplasts offer exciting opportunities for the development of malarial treatment specific drugs have been found to act by disrupting this organelle’s function, which wouldimpede the survival of the parasite. Conclusion: Recent advanced drugs, their modes of action, and their advantages in the treatment of malaria by using apicoplasts as a target are discussed in this review which thought to be very useful in desigining anti-malarial drugs. Targetting the genetic machinery of apicoplast shows a great advantange regarding anti-malarial drug design. Critical knowledge of these new drugs would give a healthier understanding for deciphering the mechanism of action of anti-malarial drugs when targeting apicoplasts to overcome drug

  18. Medical need, scientific opportunity and the drive for antimalarial drugs.

    Science.gov (United States)

    Ridley, Robert G

    2002-02-07

    Continued and sustainable improvements in antimalarial medicines through focused research and development are essential for the world's future ability to treat and control malaria. Unfortunately, malaria is a disease of poverty, and despite a wealth of scientific knowledge there is insufficient market incentive to generate the competitive, business-driven industrial antimalarial drug research and development that is normally needed to deliver new products. Mechanisms of partnering with industry have been established to overcome this obstacle and to open up and build on scientific opportunities for improved chemotherapy in the future.

  19. Glycosyl hydroperoxides: a new class of potential antimalarial agents.

    Science.gov (United States)

    Szechner, Barbara; Jaromin, Anna; Parapini, Silvia; Basilico, Nicoletta; Grzeszczyk, Barbara; Furman, Bartłomiej; Chmielewski, Marek

    2015-07-01

    Motivated by the antimalarial properties observed in organic peroxides, an extensive series of glycosyl hydroperoxides was prepared with the aim of identifying new bioactive molecules. Selected compounds were tested against a Plasmodium falciparum culture (chloroquine-susceptible strain D10 and chloroquine-resistant strain W2). Screening results indicated that the factors critical for antimalarial activity were the presence of a hydroperoxide moiety and solubility in water at pH 5.0. Moreover, the ability to inhibit β-hematin formation in vitro has been evaluated (BHIA Assay). Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Potent antimalarial 4-pyridones with improved physico-chemical properties.

    Science.gov (United States)

    Bueno, José M; Manzano, Pilar; García, María C; Chicharro, Jesús; Puente, Margarita; Lorenzo, Milagros; García, Adolfo; Ferrer, Santiago; Gómez, Rubén M; Fraile, María T; Lavandera, José L; Fiandor, José M; Vidal, Jaume; Herreros, Esperanza; Gargallo-Viola, Domingo

    2011-09-15

    Antimalarial 4-pyridones are a novel class of inhibitors of the plasmodial mitochondrial electron transport chain targeting Cytochrome bc1 (complex III). In general, the most potent 4-pyridones are lipophilic molecules with poor solubility in aqueous media and low oral bioavailability in pre-clinical species from the solid dosage form. The strategy of introducing polar hydroxymethyl groups has enabled us to maintain the high levels of antimalarial potency observed for other more lipophilic analogues whilst improving the solubility and the oral bioavailability in pre-clinical species. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. The peri-operative management of anti-platelet therapy in elective, non-cardiac surgery.

    Science.gov (United States)

    Alcock, Richard F; Naoum, Chris; Aliprandi-Costa, Bernadette; Hillis, Graham S; Brieger, David B

    2013-07-31

    Cardiovascular complications are important causes of morbidity and mortality in patients undergoing elective non-cardiac surgery, with adverse cardiac outcomes estimated to occur in approximately 4% of all patients. Anti-platelet therapy withdrawal may precede up to 10% of acute cardiovascular syndromes, with withdrawal in the peri-operative setting incompletely appraised. The aims of our study were to determine the proportion of patients undergoing elective non-cardiac surgery currently prescribed anti-platelet therapy, and identify current practice in peri-operative management. In addition, the relationship between management of anti-platelet therapy and peri-operative cardiac risk was assessed. We evaluated consecutive patients attending elective non-cardiac surgery at a major tertiary referral centre. Clinical and biochemical data were collected and analysed on patients currently prescribed anti-platelet therapy. Peri-operative management of anti-platelet therapy was compared with estimated peri-operative cardiac risk. Included were 2950 consecutive patients, with 516 (17%) prescribed anti-platelet therapy, primarily for ischaemic heart disease. Two hundred and eighty nine (56%) patients had all anti-platelet therapy ceased in the peri-operative period, including 49% of patients with ischaemic heart disease and 46% of patients with previous coronary stenting. Peri-operative cardiac risk score did not influence anti-platelet therapy management. Approximately 17% of patients undergoing elective non-cardiac surgery are prescribed anti-platelet therapy, the predominant indication being for ischaemic heart disease. Almost half of all patients with previous coronary stenting had no anti-platelet therapy during the peri-operative period. The decision to cease anti-platelet therapy, which occurred commonly, did not appear to be guided by peri-operative cardiac risk stratification. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  2. In vitro Potentiation of Antimalarial Activities by Daphnetin Derivatives Against Plasmodium falciparum

    Institute of Scientific and Technical Information of China (English)

    FANG HUANG; LIN-HUA TANG; LIN-QIAN YU; YI-CHANG NI; QIN-MEI WANG; FA-JUN NAN

    2006-01-01

    Objective To screen the antimalarial compounds of daphnetin derivatives against Plasmodium falciparum in vitro. Method Plasmodium faciparum (FCC1) was cultured in vitro by a modified method of Trager and Jensen. Antimalarial compounds were screened by microscopy-based assay and microfluorimetric method. Results DA79 and DA78 showed potent antimalarial activity against Plasmodium falciparum cultured in vitro. Conclusion Though the relationship between the structures of daphnetin derivatives and their antimalarial activities has not been clarified yet, this study may provide a new direction for discovery of more potential antimalarial compounds.

  3. ANMCO/SICI-GISE document on antiplatelet therapy in acute coronary syndromes

    NARCIS (Netherlands)

    L. de Luca (Leonardo); L. Bolognese (Leonardo); M. Valgimigli (Marco); R. Ceravolo (Roberto); G.B. Danzi; P.P. Piccaluga; S. Rakar (Serena); A. Cremonesi (Alberto); F.M. Bovenzi (Francesco Maria)

    2013-01-01

    textabstractAntiplatelet therapy is the cornerstone of the pharmacologic management of patients with acute coronary syndrome (ACS). Over the last years, several studies have evaluated old and new oral or intravenous antiplatelet agents in ACS patients. In particular, research was focused on assessin

  4. ANMCO/SICI-GISE document on antiplatelet therapy in acute coronary syndromes

    NARCIS (Netherlands)

    L. de Luca (Leonardo); L. Bolognese (Leonardo); M. Valgimigli (Marco); R. Ceravolo (Roberto); G.B. Danzi; P.P. Piccaluga; S. Rakar (Serena); A. Cremonesi (Alberto); F.M. Bovenzi (Francesco Maria)

    2013-01-01

    textabstractAntiplatelet therapy is the cornerstone of the pharmacologic management of patients with acute coronary syndrome (ACS). Over the last years, several studies have evaluated old and new oral or intravenous antiplatelet agents in ACS patients. In particular, research was focused on assessin

  5. Clinical outcome in patients with venous thromboembolism receiving concomitant anticoagulant and antiplatelet therapy.

    Science.gov (United States)

    Tzoran, Inna; Brenner, Benjamin; Sakharov, Gleb; Trujillo-Santos, Javier; Lorenzo, Alicia; Madridano, Olga; López-Sáez, Juan Bosco; Monreal, Manuel

    2014-11-01

    Patients with arterial disease receiving antiplatelet agents may develop venous thromboembolism (VTE) and need anticoagulant therapy, although concomitant use of these drugs may increase bleeding risk. We analyzed RIETE data and compared clinical outcomes depending on decision to discontinue or maintain antiplatelet therapy at VTE diagnosis. Consecutive patients with acute VTE were enrolled in RIETE. Only patients receiving antiplatelet therapy at baseline were included in this analysis. Primary outcomes were: rate of subsequent ischemic events, major bleeding or death during anticoagulation course. 1178 patients who received antiplatelet drugs at VTE diagnosis were included. Antiplatelet therapy was discontinued in 62% of patients. During anticoagulation course, patients also receiving antiplatelet therapy had higher rates of lower limb amputations (2.28 vs. 0.21 events per 100 patients-years; pantiplatelet therapy were found to have a significantly higher rate of limb amputations (odds ratio: 15.3; 95% CI: 1.02-229) and an increased number of composite outcomes including all-cause deaths, arterial and VTE events (odds ratio: 1.46; CI: 1.03-2.06), with no differences in major bleeding rate. Concomitant anticoagulant and antiplatelet therapy in patients with VTE and arterial disease is not associated with increased risk for bleeding, recurrent VTE or death. The worse outcome observed in patients who continued antiplatelet therapy requires further investigations. Copyright © 2014 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  6. Recurrent Cardiovascular Events Despite Antiplatelet Therapy in a Patient with Polycythemia Vera and Accelerated Platelet Turnover

    DEFF Research Database (Denmark)

    Pedersen, Oliver Heidmann; Larsen, Mads Lamm; Kristensen, Steen Dalby

    2017-01-01

    who suffered 6 episodes of cerebral infarctions and 1 myocardial infarction, despite treatment with clopidogrel. Following his last ischemic event, the antiplatelet therapy was intensified from initially clopidogrel monotherapy to dual antiplatelet therapy with aspirin 75 mg once daily and ticagrelor...

  7. Diabetes Mellitus and Cardiovascular Prevention: The Role and the Limitations of Currently Available Antiplatelet Drugs

    Directory of Open Access Journals (Sweden)

    A. Tufano

    2011-01-01

    This paper reviews the role of currently available antiplatelet drugs in primary and secondary prevention of vascular events in diabetic patients and the limitations of these drugs, and it discusses the role of novel and more potent antiplatelets and of new agents currently under clinical development.

  8. Single antiplatelet therapy for patients with previous gastrointestinal bleeds.

    Science.gov (United States)

    Gellatly, Rochelle M; Ackman, Margaret L

    2008-06-01

    To determine whether aspirin plus a proton pump inhibitor (PPI) is preferable, from a gastrointestinal bleed (GIB) risk perspective, to clopidogrel in patients who have experienced a GIB while on aspirin and who require single antiplatelet therapy for secondary prevention of cardiovascular disease. A literature search was conducted using EMBASE (1980-January 2008), PubMed (1966-January 2008), Google, and a manual search of the reference lists using the search terms gastrointestinal bleed, gastrointestinal hemorrhage, peptic ulcer hemorrhage, ASA, aspirin, Plavix, clopidogrel, and PPI. The search, limited to human and English studies, yielded 110 returns. Randomized trials that compared aspirin with clopidogrel, involved patients who had previously experienced a GIB, and provided detailed information on the type and dose of drugs used were included. Studies were required to provide information on the recurrence of GIB. Two randomized trials were reviewed to assess the safety of secondary prevention of cardiovascular disease with respect to previous GIB. These noninferiority trials compared aspirin plus a PPI with clopidogrel over 12 months following confirmed healing of an aspirin-induced ulcer. In both trials, the majority of the GIB recurrences were in the clopidogrel group (8.6% vs 0.7%; difference 7.9%; 95% CI 3.4 to 12.4; p = 0.001 and 13.6% vs 0%; difference 13.6%; 95% CI 6.3 to 20.9; p = 0.0019) and the difference in recurrence rates exceeded the a priori selected upper boundary. Findings reported in the limited literature available support that clopidogrel is not equivalent to the combination of aspirin plus a PPI in the patient population studied. Aspirin plus a PPI would be considered clinically superior and should be used in medically managed patients who require single antiplatelet therapy but have had a prior GIB while on aspirin. Further research regarding dual antiplatelet therapy and a PPI is required.

  9. Ticagrelor: A new antiplatelet drug for acute coronary syndromes

    Directory of Open Access Journals (Sweden)

    Tirtha V Patel

    2013-01-01

    Full Text Available Coronary heart disease and acute coronary syndrome (ACS are a significant cause of morbidity and mortality all over the world. Antiplatelet agents play an essential role in the treatment of acute coronary syndrome (ACS, usually with aspirin and a thienopyridine. Currently, clopidogrel, a second generation thienopyridine, is the main drug of choice, and the combination of aspirin and clopidogrel is administered orally for the treatment of ACS. Clopidogrel, the most commonly used thienopyridine, is limited by a high degree of interpatient variability and inconsistent inhibition of platelets. Ticagrelor, a new, oral, direct-acting P2Y12 receptor antagonist, produces a more profound and consistent antiplatelet effect than clopidogrel. The U.S. Food and Drug Administration approved Ticagrelor on July 20, 2011. Furthermore, ticagrelor has at least one active metabolite, which has pharmacokinetics that are very similar to the parent compound. Therefore, ticagrelor has a more rapid onset and more pronounced platelet inhibition than other antiplatelet agents. The safety and efficacy of ticagrelor compared with clopidogrel, in an ACS patient, has been recently evaluated by the PLATelet inhibition and patient Outcomes (PLATO trial. Clinical studies of patients with both ST-elevation and non-ST-elevation ACS have shown that ticagrelor, when compared with clopidogrel, reduces the rates of vascular death and myocardial infarction. The clinical data currently available indicate that ticagrelor is a promising option for the treatment of patients with ACS and may be of particular use in those at high risk for ischemic events or in those unresponsive to clopidogrel.

  10. Microfluidic Thrombosis under Multiple Shear Rates and Antiplatelet Therapy Doses

    Science.gov (United States)

    Ku, David N.; Forest, Craig R.

    2014-01-01

    The mainstay of treatment for thrombosis, the formation of occlusive platelet aggregates that often lead to heart attack and stroke, is antiplatelet therapy. Antiplatelet therapy dosing and resistance are poorly understood, leading to potential incorrect and ineffective dosing. Shear rate is also suspected to play a major role in thrombosis, but instrumentation to measure its influence has been limited by flow conditions, agonist use, and non-systematic and/or non-quantitative studies. In this work we measured occlusion times and thrombus detachment for a range of initial shear rates (500, 1500, 4000, and 10000 s−1) and therapy concentrations (0–2.4 µM for eptifibatide, 0–2 mM for acetyl-salicylic acid (ASA), 3.5–40 Units/L for heparin) using a microfluidic device. We also measured complete blood counts (CBC) and platelet activity using whole blood impedance aggregometry. Effects of shear rate and dose were analyzed using general linear models, logistic regressions, and Cox proportional hazards models. Shear rates have significant effects on thrombosis/dose-response curves for all tested therapies. ASA has little effect on high shear occlusion times, even at very high doses (up to 20 times the recommended dose). Under ASA therapy, thrombi formed at high shear rates were 4 times more prone to detachment compared to those formed under control conditions. Eptifibatide reduced occlusion when controlling for shear rate and its efficacy increased with dose concentration. In contrast, the hazard of occlusion from ASA was several orders of magnitude higher than that of eptifibatide. Our results show similar dose efficacy to our low shear measurements using whole blood aggregometry. This quantitative and statistically validated study of the effects of a wide range of shear rate and antiplatelet therapy doses on occlusive thrombosis contributes to more accurate understanding of thrombosis and to models for optimizing patient treatment. PMID:24404131

  11. Microfluidic thrombosis under multiple shear rates and antiplatelet therapy doses.

    Directory of Open Access Journals (Sweden)

    Melissa Li

    Full Text Available The mainstay of treatment for thrombosis, the formation of occlusive platelet aggregates that often lead to heart attack and stroke, is antiplatelet therapy. Antiplatelet therapy dosing and resistance are poorly understood, leading to potential incorrect and ineffective dosing. Shear rate is also suspected to play a major role in thrombosis, but instrumentation to measure its influence has been limited by flow conditions, agonist use, and non-systematic and/or non-quantitative studies. In this work we measured occlusion times and thrombus detachment for a range of initial shear rates (500, 1500, 4000, and 10000 s(-1 and therapy concentrations (0-2.4 µM for eptifibatide, 0-2 mM for acetyl-salicylic acid (ASA, 3.5-40 Units/L for heparin using a microfluidic device. We also measured complete blood counts (CBC and platelet activity using whole blood impedance aggregometry. Effects of shear rate and dose were analyzed using general linear models, logistic regressions, and Cox proportional hazards models. Shear rates have significant effects on thrombosis/dose-response curves for all tested therapies. ASA has little effect on high shear occlusion times, even at very high doses (up to 20 times the recommended dose. Under ASA therapy, thrombi formed at high shear rates were 4 times more prone to detachment compared to those formed under control conditions. Eptifibatide reduced occlusion when controlling for shear rate and its efficacy increased with dose concentration. In contrast, the hazard of occlusion from ASA was several orders of magnitude higher than that of eptifibatide. Our results show similar dose efficacy to our low shear measurements using whole blood aggregometry. This quantitative and statistically validated study of the effects of a wide range of shear rate and antiplatelet therapy doses on occlusive thrombosis contributes to more accurate understanding of thrombosis and to models for optimizing patient treatment.

  12. The evaluation method for antiplatelet effect of acetylsalicylic acid.

    Science.gov (United States)

    Yokoyama, Haruko; Mastumura, Takashi; Soeda, Shinji; Suzuki, Yuji; Watanabe, Masayuki; Kashiwakura, Emiko; Saso, Takayuki; Ikeda, Noriyuki; Tokuoka, Kentaro; Kitagawa, Yasuhisa; Yamada, Yasuhiko

    2014-12-01

    Reduced platelet aggregation by acetylsalicylic acid administration has been associated with adverse outcomes in patients with thrombotic diseases, thus it is important to determine aspirin resistance in those cases. The antiplatelet effect of acetylsalicylic acid is rarely measured, but it has many problems. The aim of this study was to find the evaluation method for antiplatelet effect after administration of acetylsalicylic acid. We developed a particle counting method based upon laser light scattering, and utilized the platelet aggregation agonists, collagen, at 0.25, 0.5 and 1.0 μg/mL, and adenosine diphosphate (ADP), at 0.5, 1.0 and 2.0 μM, to determine their effective concentrations. Seventeen healthy volunteers were administered acetylsalicylic acid at 162 mg/day, with platelet aggregation determined before and 20 min after administration. In all subjects, the rate of platelet aggregation induced by 1.0 μg/mL of collagen before taking acetylsalicylic acid was the highest value obtained, while 20 min after acetylsalicylic acid administration, aggregation induced by collagen at 1.0 μg/mL was significantly decreased as compared to before administration. As for the other concentrations of collagen and all those of ADP tested, platelet aggregation was either not significantly induced before taking acetylsalicylic acid or the rate of aggregation was not significantly decreased after taking acetylsalicylic acid. Our results indicate that collagen at 1.0 μg/mL is appropriate as a platelet aggregation agonist for evaluating the antiplatelet effect of acetylsalicylic acid. Thus, it is useful that the measurement is performed only once.

  13. Antimalarial Activity of Methanolic Leaf Extract of Piper betle L.

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    Adel A. Amran

    2010-12-01

    Full Text Available The need for new compounds active against malaria parasites is made more urgent by the rapid spread of drug-resistance to available antimalarial drugs. The crude methanol extract of Piper betle leaves (50–400 mg/kg was investigated for its antimalarial activity against Plasmodium berghei (NK65 during early and established infections. The phytochemical and antioxidant potentials of the crude extract were evaluated to elucidate the possibilities of its antimalarial effects. The safety of the extract was also investigated in ICR mice of both sexes by the acute oral toxicity limit test. The leaf extract demonstrated significant (P < 0.05 schizonticidal activity in all three antimalarial evaluation models. Phytochemical screening showed that the leaf extract contains some vital antiplasmodial chemical constituents. The extract also exhibited a potent ability to scavenge the free radicals. The results of acute toxicity showed that the methanol extract of Piper betle leaves is toxicologically safe by oral administration. The results suggest that the Malaysian folklorical medicinal application of the extract of Piper betle leaf has a pharmacological basis.

  14. Natural cocoa as diet-mediated antimalarial prophylaxis.

    Science.gov (United States)

    Addai, F K

    2010-05-01

    The Maya of Central America are credited with the first consumption of cocoa and maintaining its ancient Olmec name kakawa translated in English as "God Food", in recognition of its multiple health benefits. The legend of cocoa is receiving renewed attention in recent years, on account of epidemiological and scientific studies that support its cardiovascular health benefits. Increasing numbers of scientific reports corroborating cocoa's antiquated reputation as health food persuaded this author to promote regular consumption of cocoa in Ghana since 2004. Cocoa is readily available in Ghana; the country is the second largest producer accounting for 14% of the world's output. Numerous anecdotal reports of reduced episodic malaria in people who daily drink natural unsweetened cocoa beverage prompted a search for scientific mechanisms that possibly account for cocoa's antimalarial effects. This paper presents the outcome as a hypothesis. Internet search for literature on effects of cocoa's ingredients on malaria parasites and illness using a variety of search tools. Evidential literature suggests five mechanisms that possibly underpin cocoa's anecdotal antimalarial effects. (i) Increased availability of antioxidants in plasma, (ii) membrane effects in general and erythrocyte membrane in particular, (iii) increased plasma levels of nitric oxide, (iv) antimalarial activity of cocoa flavanoids and their derivatives, and (v) boosted immune system mediated by components of cocoa including cocoa butter, polyphenols, magnesium, and zinc. A hypothesis is formulated that cocoa offers a diet-mediated antimalarial prophylaxis; and an additional novel tool in the fight against the legendary scourge.

  15. The antimalarial drug quinine interferes with serotonin biosynthesis and action

    DEFF Research Database (Denmark)

    Islahudin, Farida; Tindall, Sarah M.; Mellor, Ian R.

    2014-01-01

    The major antimalarial drug quinine perturbs uptake of the essential amino acid tryptophan, and patients with low plasma tryptophan are predisposed to adverse quinine reactions; symptoms of which are similar to indications of tryptophan depletion. As tryptophan is a precursor of the neurotransmit...

  16. Antimalarial activity of HIV-1 protease inhibitor in chromone series.

    Science.gov (United States)

    Lerdsirisuk, Pradith; Maicheen, Chirattikan; Ungwitayatorn, Jiraporn

    2014-12-01

    Increasing parasite resistance to nearly all available antimalarial drugs becomes a serious problem to human health and necessitates the need to continue the search for new effective drugs. Recent studies have shown that clinically utilized HIV-1 protease (HIV-1 PR) inhibitors can inhibit the in vitro and in vivo growth of Plasmodium falciparum. In this study, a series of chromone derivatives possessing HIV-1 PR inhibitory activity has been tested for antimalarial activity against P. falciparum (K1 multi-drug resistant strain). Chromone 15, the potent HIV-1 PR inhibitor (IC50=0.65μM), was found to be the most potent antimalarial compound with IC50=0.95μM while primaquine and tafenoquine showed IC50=2.41 and 1.95μM, respectively. Molecular docking study of chromone compounds against plasmepsin II, an aspartic protease enzyme important in hemoglobin degradation, revealed that chromone 15 exhibited the higher binding affinity (binding energy=-13.24kcal/mol) than the known PM II inhibitors. Thus, HIV-1 PR inhibitor in chromone series has the potential to be a new class of antimalarial agent. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. QSAR models for anti-malarial activity of 4-aminoquinolines.

    Science.gov (United States)

    Masand, Vijay H; Toropov, Andrey A; Toropova, Alla P; Mahajan, Devidas T

    2014-03-01

    In the present study, predictive quantitative structure - activity relationship (QSAR) models for anti-malarial activity of 4-aminoquinolines have been developed. CORAL, which is freely available on internet (http://www.insilico.eu/coral), has been used as a tool of QSAR analysis to establish statistically robust QSAR model of anti-malarial activity of 4-aminoquinolines. Six random splits into the visible sub-system of the training and invisible subsystem of validation were examined. Statistical qualities for these splits vary, but in all these cases, statistical quality of prediction for anti-malarial activity was quite good. The optimal SMILES-based descriptor was used to derive the single descriptor based QSAR model for a data set of 112 aminoquinolones. All the splits had r(2)> 0.85 and r(2)> 0.78 for subtraining and validation sets, respectively. The three parametric multilinear regression (MLR) QSAR model has Q(2) = 0.83, R(2) = 0.84 and F = 190.39. The anti-malarial activity has strong correlation with presence/absence of nitrogen and oxygen at a topological distance of six.

  18. Assessment of the in Vitro Antiprotozoal and Cytotoxic Potential of 20 Selected Medicinal Plants from the Island of Soqotra

    Directory of Open Access Journals (Sweden)

    Louis Maes

    2012-12-01

    Full Text Available Malaria, leishmaniasis and human African trypanosomiasis continue to be major public health problems in need of new and more effective drugs. The aim of this study was to evaluate in vitro antiprotozoal activity of twenty endemic medicinal plants collected from the island of Soqotra in the Indian Ocean. The plant materials were extracted with methanol and tested for antiplasmodial activity against erythrocytic schizonts of Plasmodium falciparum, for antileishmanial activity against intracellular amastigotes of Leishmania infantum and for antitrypanosomal activity against intracellular amastigotes of Trypanosoma cruzi and free trypomastigotes of T. brucei. To assess selectivity, cytotoxicity was determined against MRC-5 fibroblasts. Selective activity was obtained for Punica protopunica against Plasmodium (IC50 2.2 µg/mL while Eureiandra balfourii and Hypoestes pubescens displayed activity against the three kinetoplastid parasites (IC50 < 10 µg/mL. Acridocarpus socotranus showed activity against T. brucei and T. cruzi (IC50 3.5 and 8.4 µg/mL. Ballochia atrovirgata, Dendrosicycos socotrana, Dracaena cinnabari and Euphorbia socotrana displayed non-specific inhibition of the parasites related to high cytotoxicity.

  19. Chemical constituents, antimicrobial and antimalarial activities of Zanthoxylum monophyllum.

    Science.gov (United States)

    Rodríguez-Guzmán, Raquel; Fulks, Laura C Johansmann; Radwan, Mohamed M; Burandt, Charles L; Ross, Samir A

    2011-09-01

    From the leaves and bark of Zanthoxylum monophyllum, a new lignan, 3-methoxy-3',4'-methylenedioxylignan-4,8,9,9'-tetraol (1), has been isolated along with 22 known compounds (2- 23), fifteen of them reported for the first time from Z. monophyllum. Their chemical structures were elucidated using detailed spectroscopic studies and chemical analysis. All compounds were evaluated for antimicrobial and antiprotozoal activities. Alkaloids BIS-[6-(5,6-dihydro-chelerythrinyl)] ether (2) and 6-ethoxy-chelerythrine (4) exhibited strong activity against Aspergillus fumigatus and methicillin-resistant Staphylococcus aureus (MRSA). Compound 4-methoxy-N-methyl-2-quinolone (9) exhibited significant activity against MRSA (IC50 value of 8.0 µM) while compound 5,8,4'-trihydroxy-3,7,3'-trimethoxyflavone (10) showed weak activity against Plasmodium falciparum. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Antiplatelet Therapy in Carotid Artery Stenting and Carotid Endarterectomy in the Asymptomatic Carotid Surgery Trial-2.

    Science.gov (United States)

    Huibers, A; Halliday, A; Bulbulia, R; Coppi, G; de Borst, G J

    2016-03-01

    Strokes are infrequent but potentially serious complications following carotid intervention, but antiplatelet therapy can reduce these risks. There are currently no specific guidelines on dose or duration of peri-procedural antiplatelet treatment for patients undergoing carotid intervention. Within the ongoing Asymptomatic Carotid Surgery Trial-2 (ACST-2), this study aimed at assessing the current use of antiplatelet therapy before, during, and after CEA and CAS in patients with asymptomatic carotid stenosis. Questionnaires were sent to ACST-2 collaborators seeking information about the use of antiplatelet therapy during the pre-, peri-, and post-operative periods in patients undergoing carotid intervention at 77 participating sites and also whether sites tested for antiplatelet therapy resistance. The response rate was 68/77 (88%). For CAS, 82% of sites used dual antiplatelet therapy (DAPT) pre-operatively and 86% post-operatively with a mean post-procedural duration of 3 months (range 1-12), while 9% continued DAPT life-long. For CEA only 31% used DAPT pre-operatively, 24% post-operatively with a mean post-procedural duration of 3 months (range 1-5), while 10% continued DAPT life-long. For those prescribing post-procedural mono antiplatelet (MAPT) therapy (76%), aspirin was more commonly prescribed (59%) than clopidogrel (6%) and 11% of centres did not show a preference for either aspirin or clopidogrel. Eleven centres (16%) tested for antiplatelet therapy resistance. There appears to be broad agreement on the use of antiplatelet therapy in ACST-2 patients undergoing carotid artery stenting and surgery. Although evidence to help guide the duration of peri-procedural antiplatelet therapy is limited, long-term treatment with DAPT appears similar between both treatment arms. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  1. Onset Time of Ischemic Events and Antiplatelet Therapy after Intracranial Stent-assisted Coil Embolization.

    Science.gov (United States)

    Matsumoto, Yoshihisa; Nakai, Kanji; Tsutsumi, Masanori; Iko, Minoru; Nii, Kouhei; Narita, Sumito; Eto, Ayumu; Mitsutake, Takahumi; Aikawa, Hiroshi; Kazekawa, Kiyoshi

    2014-04-01

    Stent-assisted coil embolization is effective for intracranial aneurysms, especially wide-necked aneurysms; however, the optimal antiplatelet regimens for ischemic events that develop after coil embolization have not yet been established. We aimed to determine the onset time of such postoperative ischemic events and the relationship between these events and antiplatelet therapy. We performed coil embolization using a vascular reconstruction stent for 43 cases of intracranial aneurysms and evaluated the incidence of postoperative ischemic events in these cases. Nine patients showed postoperative ischemic events during the follow-up period (13 ± 7 months). Two patients developed cerebral infarction within 24 hours. Five patients developed transient ischemic attack within 40 days while they were receiving dual antiplatelet therapy. In addition, 1 patient showed cerebral infarction 143 days postoperatively during single antiplatelet therapy, and a case of transient visual disturbance was reported 191 days postoperatively (49 days after antiplatelet therapy had been discontinued). We increased the number of antiplatelet agents in 4 of these patients. The other 5 patients were under strict observation with dual antiplatelet therapy. All these patients were shifted to single antiplatelet therapy 3-13 months postoperatively. No recurrence of ischemic events was noted. Postoperative ischemic events are most likely to occur within 40 days postoperatively. For patients with postoperative ischemic events, additional ischemic events can be prevented by increasing the number of antiplatelet agents; subsequently, they can be shifted to single antiplatelet therapy after the risk of recurrence has decreased. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  2. Efficacy and safety of single versus dual antiplatelet therapy for coiling of unruptured aneurysms.

    Science.gov (United States)

    Nishikawa, Yusuke; Satow, Tetsu; Takagi, Toshinori; Murao, Kenichi; Miyamoto, Susumu; Iihara, Koji

    2013-07-01

    Although the efficacy of antiplatelet therapy for coiling of unruptured cerebral aneurysms has been reported, regimens for this therapy are not yet well established. The aim of this retrospective study was to analyze correlations among the modes of antiplatelet use, aneurysmal configuration, coiling methods, and complications to elucidate the optimal antiplatelet therapy for coiling. The study population comprised 154 patients with unruptured aneurysms who underwent coiling with antiplatelet therapy at our institution between 2001 and 2009. The patients were categorized by mode of antiplatelet therapy (single [n = 64] or dual [n = 90]), neck size (wide [n = 80] or narrow [n = 74]), and technique used (simple [n = 42] or adjunctive [n = 112]). The incidences of hemorrhagic/ischemic complications and abnormalities on postprocedural diffusion-weighted magnetic resonance imaging (DWI) in each group were statistically assessed. Hemorrhagic complications occurred in 1 case (1.5%) with single antiplatelet therapy and in 2 cases (2.2%) with dual antiplatelet therapy. Symptomatic ischemic complications occurred in 5 cases (7.8%) with single therapy and in 4 cases (4.4%) with dual therapy. Abnormalities were detected by DWI in 27 cases (42%) with single therapy and in 31 cases (34%) with dual therapy. No significant difference was found between modes of antiplatelet therapy even when the technique used was taken into account. In cases of wide neck, however, there were significant differences in the rate of symptomatic ischemic complications (single, 21.7%; dual, 3.5%; P = .014) and DWI abnormalities (single, 37.8%; dual, 20.9%; P = .048). Our data suggest that dual antiplatelet therapy may better prevent ischemic complications from coiling for wide-necked aneurysms compared with single antiplatelet therapy. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  3. Physician Response to Implementation of Genotype-Tailored Antiplatelet Therapy

    Science.gov (United States)

    Peterson, Josh F.; Field, Julie R.; Unertl, Kim; Schildcrout, Jonathan S.; Johnson, Daniel C.; Shi, Yaping; Danciu, Ioana; Cleator, John H.; Pulley, Jill M.; McPherson, John A.; Denny, Josh C.; Laposata, Michael; Roden, Dan M.; Johnson, Kevin B.

    2016-01-01

    Physician responses to genomic information are vital to the success of precision medicine initiatives. We prospectively studied a pharmacogenomics implementation program for the propensity of clinicians to select antiplatelet therapy based on CYP2C19 loss-of-function (LOF) variants in stented patients. Among 2,676 patients, 514 (19.2%) were found to have a CYP2C19 variant affecting clopidogrel metabolism. For the majority (93.6%) of the cohort, cardiologists received active and direct notification of CYP2C19 status. Over 12 months, 57.6% of poor metabolizers and 33.2% of intermediate metabolizers received alternatives to clopidogrel. CYP2C19 variant status was the most influential factor impacting the prescribing decision [HR in poor metabolizers 8.1, 95% CI (5.4,12.2) and HR 5.0, 95% CI (4.0,6.3) in intermediate metabolizers], followed by patient age and type of stent implanted. We conclude that cardiologists tailored antiplatelet therapy for a minority of patients with a CYP2C19 variant and considered both genomic and non-genomic risks in their clinical decision-making. PMID:26693963

  4. Duration of dual antiplatelet therapy in acute coronary syndrome

    Science.gov (United States)

    Wilson, Simon John; Newby, David E; Dawson, Dana; Irving, John; Berry, Colin

    2017-01-01

    Despite a large volume of evidence supporting the use of dual antiplatelet therapy in patients with acute coronary syndrome, there remains major uncertainty regarding the optimal duration of therapy. Clinical trials have varied markedly in the duration of therapy, both across and within trials. Recent systematic reviews and meta-analyses suggest that shorter durations of dual antiplatelet therapy are superior because the avoidance of atherothrombotic events is counterbalanced by the greater risks of excess major bleeding with apparent increases in all-cause mortality with longer durations. These findings did not show significant heterogeneity according to whether patients had stable or unstable coronary heart disease. Moreover, the potential hazards and benefits may differ when applied to the general broad population of patients encountered in everyday clinical practice who have markedly higher bleeding and atherothrombotic event rates. Clinicians lack definitive information regarding the duration of therapy in patients with acute coronary syndrome and risk scores do not appear to be sufficiently robust to address these concerns. We believe that there is a pressing need to undertake a broad inclusive safety trial of shorter durations of therapy in real world populations of patients with acute coronary syndrome. The clinical evidence would further inform future research into strategies for personalised medicine. PMID:28249994

  5. Thrombocytopenia: diagnosis with flow cytometry and antiplatelet antibodies.

    Science.gov (United States)

    Guerra, João Carlos de Campos; Kanayama, Ruth Hissae; Nozawa, Sonia Tsukasa; Ioshida, Márcia Regina; Takiri, Irina Yoko; Lazaro, Robson José; Hamerschlak, Nelson; Rosenfeld, Luiz Gastão Mange; Guerra, Celso Carlos de Campos; Bacal, Nydia Strachman

    2011-06-01

    To identify antiplatelet antibodies by flow cytometry (direct method) in patients with thrombocytopenia. Between January 1997 and March 2004 a total of 15100 patients were referred to the Centro de Hematologia de São Paulo for hematological investigation of several diagnoses (anemia, leukopenia, thrombocytopenia, coagulation abnormalities, adenomegaly, leukemia and others). Of those, 1057 were referred because of thrombocytopenia and were divided into two groups: Group Idiopathic thrombocytopenic purpura, with no identifiable cause; and Group Other thrombocytopenia, which included low normal platelet counts cause to be established, hepatitis C and HIV infection, hypersplenism, EDTA-induced artifacts, laboratory error, and other causes. Flow cytometry immunophenotyping was done in 115 cases to identify platelet autoantibodies (direct method). Of the total number of patients, 1057 (7%) presented low platelet counts, 670 were females (63.4%) and age range of one to 75 years. Of the 115 cases (9.7%) submitted to immunophenotyping, the results were positive in 40% and the test was inconclusive in 5%. Idiopathic thrombocytopenic purpura was found in 52% of patients, more often in women. Hepatitis C virus infection was found in 7% and HIV infection in 1%. Low normal platelet counts were found in 17%, laboratory errors in 6%, and laboratory artifacts in 1% of cases. Platelet autoantibodies were found in 76.9% of all idiopathic thrombocytopenic purpura cases. It was negative in 83.3% of the low normal counts. antiplatelet autoantibodies when present help to diagnose idiopathic thrombocytopenic purpura. When absent, suggest other causes of thrombocytopenia.

  6. DENTAL MANAGEMENT AND BLEEDING COMPLICATIONS OF PATIENTS ON LONG-TERM ORAL ANTIPLATELET THERAPY. REVIEW OF EXISTING STUDIES AND GUIDELINES.

    Directory of Open Access Journals (Sweden)

    Atanaska Dinkova

    2013-06-01

    Full Text Available Antiplatelet drugs are currently widely used in primary and especially secondary prevention of cardiovascular events. Dental management of patients on antiplatelet therapy is still not clearly defined: the discontinuation of antiplatelet therapy increases the risk of thrombotic complications, whereas uninterrupted antiplatelet therapy is assumed to increase the bleeding complications after dental surgical procedures. The aim of this article is to review the main antiplatelet drugs used for long-term oral antiplatelet therapy, the laboratory methods for evaluating effectiveness of this therapy, to identify the studies and guidelines available for dental management of patients on antiplatelet drugs and to summarize their conclusions and recommendations.The methodology used through the research for the literature review includes the following sources: Medscape, Pubmed - Medline database, Science Direct, and EBSCO host, the data base of Medical University Plovdiv and specialised published books in general medicine and dentistry.

  7. Poor responsiveness to antiplatelet drugs in acute coronary syndromes: clinical relevance and management.

    Science.gov (United States)

    Reny, Jean-Luc; Bonvini, Robert F; Bonvini, John M; Roffi, Marco; Fontana, Pierre

    2012-02-01

    Cardiovascular diseases are the most common cause of mortality and morbidity in Western countries, accounting for more than 40% of total mortality. An optimal pharmacological management in these patients is of major importance and antiplatelet agents remain the cornerstone of acute coronary syndrome (ACS) therapy at hospital admission and during percutaneous coronary interventions (PCI). The recently described poor biological responses to aspirin and clopidogrel have been source of major concern, especially in era of drug eluting stent implantation. Indeed, insufficient platelet inhibition at the time of PCI has been consistently associated with an increased risk of complications and recurrence of ischemic events. Despite the lack of uniformly accepted definitions of aspirin and clopidogrel poor response, we sought to describe the current evidence and gaps in knowledge. While trials on the potential benefit of an increased antiplatelet maintenance dose after PCI have shown only marginal benefits, the strengthening of the initial antiplatelet regimens by additional loading doses of clopidogrel, by the administration of glycoprotein IIb/IIIa receptor inhibitors or phosphodiesterase inhibitors might further improve outcomes during ACS and PCI in patients with poor responsiveness to conventional dual antiplatelet therapy. Overall, tailoring the antiplatelet treatment on the basis of the individual biological response improves the short-term outcome after PCI. New and more potent antiplatelet drugs may overcome the clinical consequences of the poor response to antiplatelet agents. © 2010 Blackwell Publishing Ltd.

  8. Perioperative Outcomes Following Partial Nephrectomy Performed on Patients Remaining on Antiplatelet Therapy.

    Science.gov (United States)

    Ito, Timothy; Derweesh, Ithaar H; Ginzburg, Serge; Abbosh, Philip H; Raheem, Omer A; Mirheydar, Hossein; Hamilton, Zachary; Chen, David Y T; Smaldone, Marc C; Greenberg, Richard E; Viterbo, Rosalia; Kutikov, Alexander; Uzzo, Robert G

    2017-01-01

    We evaluated the risk of bleeding complications in patients undergoing partial nephrectomy in whom perioperative antiplatelet therapy was continued, as antiplatelet therapy is increasingly used and hemorrhage is a significant concern in partial nephrectomy. In this 2-center retrospective analysis 1,097 patients underwent partial nephrectomy between 2000 and 2014. The cohort was split into 3 groups of perioperative continuation of antiplatelet therapy (group 1-67), antiplatelet therapy stopped preoperatively (group 2-254) and no chronic antiplatelet therapy (group 3-776). Bleeding complications were defined as any transfusion, or any hospital readmission or secondary procedure performed for hemorrhage. Multivariable analysis was performed to elucidate independent risk factors for bleeding complications. Patients in group 1 were older (median age 66 years vs 64 and 57 years in groups 2/3, p antiplatelet therapy was an independent predictor of bleeding complications (OR 2.19, 95% CI 1.06-4.51, p=0.03). These findings appear attributable to intraoperative clopidogrel use. On multivariable analysis the use of aspirin alone was not associated with bleeding complications (OR 1.64, 95% CI 0.72-3.75, p=0.24). The risk of bleeding complications due to antiplatelet therapy use at partial nephrectomy may be due to clopidogrel. The need to continue perioperative aspirin alone does not appear to be a contraindication to the safe performance of partial nephrectomy. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  9. Personalized antiplatelet therapy with P2Y12 receptor inhibitors: benefits and pitfalls

    Science.gov (United States)

    Winter, Max-Paul; Koziński, Marek; Kubica, Jacek; Aradi, Daniel

    2015-01-01

    Antiplatelet therapy with P2Y12 receptor inhibitors has become the cornerstone of medical treatment in patients with acute coronary syndrome, after percutaneous coronary intervention and in secondary prevention of atherothrombotic events. Clopidogrel used to be the most broadly prescribed P2Y12 receptor inhibitor with undisputable benefits especially in combination with aspirin, but a considerable number of clopidogrel-treated patients experience adverse thrombotic events in whom insufficient P2Y12-inhibition and a consequential high on-treatment platelet reactivity is a common finding. This clinically relevant limitation of clopidogrel has driven the increased use of new antiplatelet agents. Prasugrel (a third generation thienopyridine) and ticagrelor (a cyclopentyl-triazolo-pyrimidine) feature more potent and predictable P2Y12-inhibition compared to clopidogrel, which translates into improved ischemic outcomes. However, excessive platelet inhibition and consequential low on-treatment platelet reactivity comes at the price of increased risk of major bleeding. The majority of randomized clinical trials failed to demonstrate improved clinical outcomes with platelet function testing and tailored antiplatelet therapy, but results of all recent trials of potent antiplatelets and prolonged antiplatelet durations point towards a need for individualized antiplatelet approach in order to decrease thrombotic events without increasing bleeding. This review focuses on potential strategies for personalizing antiplatelet treatment. PMID:26677375

  10. Causes, Timing, and Impact of Dual Antiplatelet Therapy Interruption for Surgery (from the Patterns of Non-adherence to Anti-platelet Regimens In Stented Patients Registry).

    Science.gov (United States)

    Schoos, Mikkel; Chandrasekhar, Jaya; Baber, Usman; Bhasin, Aarti; Sartori, Samantha; Aquino, Melissa; Vogel, Birgit; Farhan, Serdar; Sorrentino, Sabato; Kini, Annapoorna; Kruckoff, Mitchell; Moliterno, David; Henry, Timothy D; Weisz, Giora; Gibson, C Michael; Iakovou, Ioannis; Colombo, Antonio; Steg, P Gabriel; Witzenbichler, Bernhard; Chieffo, Alaide; Cohen, David; Stuckey, Thomas; Ariti, Cono; Dangas, George; Pocock, Stuart; Mehran, Roxana

    2017-09-15

    Temporary interruption of dual antiplatelet therapy (DAPT) is not infrequently required in patients undergoing percutaneous coronary intervention (PCI). We sought to describe the procedures and outcomes associated with DAPT interruption in patients treated with DAPT following successful PCI from the Patterns of non-adherence to anti-platelet regimens in stented patients registry (n = 5018). DAPT interruption was prespecified as physician recommended cessation for antiplatelet agent was interrupted in 57.2% cases and interruption was frequently recommended by noncardiologists (51.3%). Where type of surgery was reported, majority of DAPT interruptions occurred for minor surgery (68.4% vs 31.6%) and a similar cessation pattern of single versus dual antiplatelet cessation was observed regardless of minor or major surgery. Subsequent to DAPT interruption, 12 patients (2.4%) experienced 1 thrombotic event each, of which 5 (1.0%) occurred during the interruption period. All events occurred in patients who either stopped both agents (8 of 12) or clopidogrel-only (4 of 12), with no events occurring due to aspirin cessation alone. In conclusion, in the Patterns of Non-adherence to Anti-platelet Regiments in Stented Patients registry, 1 in 10 patients were recommended DAPT interruption for surgery within 2 years of PCI. Interruption was more common for a single agent rather than both antiplatelet agents regardless of severity of surgery, and was frequently recommended by noncardiologists. Only 1% of patients with DAPT interruption experienced a subsequent thrombotic event during the interruption period, which mainly occurred in patients stopping both antiplatelet agents. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Comparison between single antiplatelet therapy and combination of antiplatelet and anticoagulation therapy for secondary prevention in ischemic stroke patients with antiphospholipid syndrome

    Directory of Open Access Journals (Sweden)

    Hirohisa Okuma, Yasuhisa Kitagawa, Takashi Yasuda, Kentaro Tokuoka, Shigeharu Takagi

    2010-01-01

    Full Text Available Satisfactory results have not yet been obtained in therapy for secondary prevention in ischemic stroke patients with antiphospholipid syndrome (APS. We therefore compared single antiplatelet therapy and a combination of antiplatelet and anticoagulation therapy for secondary prevention in ischemic stroke patients with APS. The subjects were 20 ischemic stroke patients with antiphospholipid antibody, 13 with primary antiphospholipid syndrome and 7 with SLE-related antiphospholipid syndrome. Diagnosis of APS was based on the 2006 Sydney criteria. Eligible patients were randomly assigned to either single antiplatelet therapy (aspirin 100 mg or a combination of antiplatelet and anticoagulation therapy (target INR: 2.0-3.0; mean 2.4±0.3 for the secondary prevention of stroke according to a double-blind protocol. There was no significant difference between the two groups in age, gender, NIH Stroke Scale on admission, mRS at discharge, or rate of hypertension, diabetes mellitus, hyperlipidemia, or cardiac disease. We obtained Kaplan-Meier survival curves for each treatment. The primary outcome was the occurrence of stroke. The mean follow-up time was 3.9±2.0 years. The cumulative incidence of stroke in patients with single antiplatelet treatment was statistically significantly higher than that in patients receiving the combination of antiplatelet and anticoagulation therapy (log-rank test, p-value=0.026. The incidence of hemorrhagic complications was similar in the two groups. The recent APASS study did not show any difference in effectiveness for secondary prevention between single antiplatelet (aspirin and single anticoagulant (warfarin therapy. Our results indicate that combination therapy may be more effective in APS-related ischemic stroke.

  12. Encecalol angelate, an unstable chromene from Ageratum conyzoides L.: total synthesis and investigation of its antiprotozoal activity.

    Science.gov (United States)

    Harel, Dipak; Khalid, Sami A; Kaiser, Marcel; Brun, Reto; Wünsch, Bernhard; Schmidt, Thomas J

    2011-09-01

    In agreement with ethnomedicinal reports, the dichloromethane extract of Ageratum conyzoides L. (Asteraceae) was recently shown to be of considerable activity against Trypanosoma brucei rhodesiense, the etiologic agent of East African Human Trypanosomiasis (East African Sleeping Sickness). Isolated compounds, namely, methoxylated flavonoids as well as the chromene derivative encecalol methyl ether, were less active than the crude extract. The activity of the extract was found to decrease considerably while stored in solution. An unstable compound was detected in the fresh extract by HPLC, which was converted rapidly into the encecalol methyl ether while stored in methanolic solution. This compound, deemed to represent a constituent with antitrypanosomal activity, could not be isolated from the extract in intact form. To elucidate the structure of this unstable compound and to investigate its potential role in the antitrypanosomal activity of the total extract. UHPLC/ESI-qQTOF MSMS and NMR data of the degraded product indicated its chemical identity as encecalol angelate (1) which was therefore prepared by total synthesis via a linear six steps synthesis, starting from resorcinol and 2-methylbut-3-en-2-ol. Total synthesis, in an overall yield of 15%, led to pure 1, which was chromatographically and spectroscopically identical with the natural product. The compound degraded in methanol with a half-life of approximately 6h to yield encecalol methyl ether (2). The antiprotozoal activity of synthetic encecalol angelate against T. brucei rhodesiense as well as T. cruzi, Leishmania donovani and Plasmodium falciparum was investigated and found to be quite low. The synthetic approach applied here for the first time also provides access to the related bioactive chromenes encecalin (7) and encecalol (8) with improved yields compared with reported methods. Encecalol angelate, however, is most likely not responsible for the high antitrypanosomal activity of the freshly prepared

  13. Apixaban with antiplatelet therapy after acute coronary syndrome.

    Science.gov (United States)

    Alexander, John H; Lopes, Renato D; James, Stefan; Kilaru, Rakhi; He, Yaohua; Mohan, Puneet; Bhatt, Deepak L; Goodman, Shaun; Verheugt, Freek W; Flather, Marcus; Huber, Kurt; Liaw, Danny; Husted, Steen E; Lopez-Sendon, Jose; De Caterina, Raffaele; Jansky, Petr; Darius, Harald; Vinereanu, Dragos; Cornel, Jan H; Cools, Frank; Atar, Dan; Leiva-Pons, Jose Luis; Keltai, Matyas; Ogawa, Hisao; Pais, Prem; Parkhomenko, Alexander; Ruzyllo, Witold; Diaz, Rafael; White, Harvey; Ruda, Mikhail; Geraldes, Margarida; Lawrence, Jack; Harrington, Robert A; Wallentin, Lars

    2011-08-25

    Apixaban, an oral, direct factor Xa inhibitor, may reduce the risk of recurrent ischemic events when added to antiplatelet therapy after an acute coronary syndrome. We conducted a randomized, double-blind, placebo-controlled clinical trial comparing apixaban, at a dose of 5 mg twice daily, with placebo, in addition to standard antiplatelet therapy, in patients with a recent acute coronary syndrome and at least two additional risk factors for recurrent ischemic events. The trial was terminated prematurely after recruitment of 7392 patients because of an increase in major bleeding events with apixaban in the absence of a counterbalancing reduction in recurrent ischemic events. With a median follow-up of 241 days, the primary outcome of cardiovascular death, myocardial infarction, or ischemic stroke occurred in 279 of the 3705 patients (7.5%) assigned to apixaban (13.2 events per 100 patient-years) and in 293 of the 3687 patients (7.9%) assigned to placebo (14.0 events per 100 patient-years) (hazard ratio with apixaban, 0.95; 95% confidence interval [CI], 0.80 to 1.11; P=0.51). The primary safety outcome of major bleeding according to the Thrombolysis in Myocardial Infarction (TIMI) definition occurred in 46 of the 3673 patients (1.3%) who received at least one dose of apixaban (2.4 events per 100 patient-years) and in 18 of the 3642 patients (0.5%) who received at least one dose of placebo (0.9 events per 100 patient-years) (hazard ratio with apixaban, 2.59; 95% CI, 1.50 to 4.46; P=0.001). A greater number of intracranial and fatal bleeding events occurred with apixaban than with placebo. The addition of apixaban, at a dose of 5 mg twice daily, to antiplatelet therapy in high-risk patients after an acute coronary syndrome increased the number of major bleeding events without a significant reduction in recurrent ischemic events. (Funded by Bristol-Myers Squibb and Pfizer; APPRAISE-2 ClinicalTrials.gov number, NCT00831441.).

  14. Treatment and prevention of gastrointestinal bleeding in patients receiving antiplatelet therapy

    Science.gov (United States)

    Yasuda, Hiroshi; Matsuo, Yasumasa; Sato, Yoshinori; Ozawa, Sun-ichiro; Ishigooka, Shinya; Yamashita, Masaki; Yamamoto, Hiroyuki; Itoh, Fumio

    2015-01-01

    Antiplatelet therapy is the standard of care for the secondary prevention of acute coronary syndrome and ischemic stroke, especially after coronary intervention. However, this therapy is associated with bleeding complications such as gastrointestinal bleeding, which is one of the most common life-threatening complications. Early endoscopy is recommended for most patients with acute upper gastrointestinal bleeding. After successful endoscopic hemostasis, immediate resumption of antiplatelet therapy with proton-pump inhibitors (PPIs) is recommended to prevent further ischemic events. PPI prophylaxis during antiplatelet therapy reduces the risk of upper gastrointestinal bleeding. The potential negative metabolic interaction between PPIs and clopidogrel is still unclear. PMID:25685721

  15. Management of antiplatelet therapy during acute percutaneous coronary intervention: new strategies and therapeutics.

    Science.gov (United States)

    Tan, Jack W C; Guo, Kenneth W Q

    2010-03-01

    Aggressive intravenous and oral dual antiplatelet therapy has established primary percutaneous coronary intervention (PCI) as the standard of care for acute myocardial infarction. Clopidogrel is currently the thienopyridine of choice for dual antiplatelet therapy in patients treated with PCI. The dose regime and duration of therapy of clopidogrel has undergone multiple refinements. Recently, 2 novel third generation oral inhibitors of P2Y12 receptors, prasugrel and ticagrelor, have undergone clinical evaluation with promising results. This article is a non-exhaustive review of the literature, concentrating on the role of current and novel oral antiplatelet agents for acute myocardial infarction particularly highlighting the limitations and issues associated with clopidogrel use.

  16. Fake anti-malarials: start with the facts.

    Science.gov (United States)

    Kaur, Harparkash; Clarke, Siȃn; Lalani, Mirza; Phanouvong, Souly; Guérin, Philippe; McLoughlin, Andrew; Wilson, Benjamin K; Deats, Michael; Plançon, Aline; Hopkins, Heidi; Miranda, Debora; Schellenberg, David

    2016-02-13

    This meeting report presents the key findings and discussion points of a 1-day meeting entitled 'Fake anti-malarials: start with the facts' held on 28th May 2015, in Geneva, Switzerland, to disseminate the findings of the artemisinin combination therapy consortium's drug quality programme. The teams purchased over 10,000 samples, using representative sampling approaches, from six malaria endemic countries: Equatorial Guinea (Bioko Island), Cambodia, Ghana, Nigeria, Rwanda and Tanzania. Laboratory analyses of these samples showed that falsified anti-malarials (fact that the WHO has urged regulatory authorities in malaria-endemic countries to take measures to halt the production and marketing of these oral monotherapies since 2007. This report summarizes the presentations that reviewed the public health impact of falsified and substandard drugs, sampling strategies, techniques for drug quality analysis, approaches to strengthen health systems capacity for the surveillance of drug quality, and the ensuing discussion points from the dissemination meeting.

  17. Antimalarial Drugs as Immune Modulators: New Mechanisms for Old Drugs.

    Science.gov (United States)

    An, Jie; Minie, Mark; Sasaki, Tomikazu; Woodward, Joshua J; Elkon, Keith B

    2017-01-14

    The best known of the naturally occurring antimalarial compounds are quinine, extracted from cinchona bark, and artemisinin (qinghao), extracted from Artemisia annua in China. These and other derivatives are now chemically synthesized and remain the mainstay of therapy to treat malaria. The beneficial effects of several of the antimalarial drugs (AMDs) on clinical features of autoimmune disorders were discovered by chance during World War II. In this review, we discuss the chemistry of AMDs and their mechanisms of action, emphasizing how they may impact multiple pathways of innate immunity. These pathways include Toll-like receptors and the recently described cGAS-STING pathway. Finally, we discuss the current and future impact of AMDs on systemic lupus erythematosus, rheumatoid arthritis, and devastating monogenic disorders (interferonopathies) characterized by expression of type I interferon in the brain.

  18. Potential antimalarials from African natural products: A reviw.

    Science.gov (United States)

    Lawal, Bashir; Shittu, Oluwatosin Kudirat; Kabiru, Adamu Yusuf; Jigam, Ali Audu; Umar, Maimuna Bello; Berinyuy, Eustace Bonghan; Alozieuwa, Blessing Uchenna

    2015-01-01

    Malaria remains an overwhelming infectious disease with significant health challenges in African and other endemic countries globally. Resistance to antimalarial drugs has become one of the most momentous challenges to human health, and thus has necessitated the hunt for new and effective drugs. Consequently, few decades have witnessed a surfeit of research geared to validate the effectiveness of commonly used traditionally medicines against malaria fever. The present review work focuses on documenting natural products from African whose activity has been reported in vivo or in vitro against malaria parasite. Literature was collected using electronic search of published articles (Google Scholar, PubMed, Medline, Sciencedirect, and Science domain) that report on antiplasmodial activity of natural products from differernts Africa region. A total of 652 plant taxa from 146 families, 134 isolated antimalarial compounds from 39 plants species, 2 herbal formulations and 4 insect/products were found to be reported in literature from 1996 to 2015. Plants species from family Asteraceae (11.04%), Fababceae (8.128%), Euphorbiaceae (5.52%), Rubiaceas (5.52%), and Apocyanaceae (5.214%), have received more scientific validation than others. African natural products possess remarkable healing properties as revealed in the various citations as promising antimalarial agents. Some of these natural products from Africa demonstrate high, promising or low activities against Plasmodium parasite. This study also shows that natural products from Africa have a huge amount of novel antimalarial compounds that could serve as a leads for the development of new and effective antiplasmodial drugs. However, in a view of bridging the gap in knowledge, clinical validation of these natural products are of paramount importance.

  19. Rational Design of Proteasome Inhibitors as Antimalarial Drugs.

    Science.gov (United States)

    Le Chapelain, Camille; Groll, Michael

    2016-05-23

    One life, two strategies: Crucial structural differences between the human and the Plasmodium falciparum proteasomes were recently identified. A combination of cryo-EM and functional characterization enabled the design of a selective antimalarial proteasome inhibitor that shows low toxicity in the host. When used with artemisinin, this ligand offers a new approach for the efficient treatment of malaria at all stages of the parasite lifecycle.

  20. Antimalarial diterpene alkaloids from the seeds of Caesalpinia minax.

    Science.gov (United States)

    Ma, Guoxu; Sun, Zhaocui; Sun, Zhonghao; Yuan, Jingquan; Wei, Hua; Yang, Junshan; Wu, Haifeng; Xu, Xudong

    2014-06-01

    Two new diterpene alkaloids, caesalminines A (1) and B (2), possessing a tetracyclic cassane-type furanoditerpenoid skeleton with γ-lactam ring, were isolated from the seeds of Caesalpinia minax. Their structures were determined by different spectroscopic methods and ECD calculation. The plausible biosynthetic pathway of caesalminines A and B was proposed. The anti-malarial activity of compounds 1 and 2 is presented with IC50 values of 0.42 and 0.79 μM, respectively.

  1. Antimalarial Activity of Small-Molecule Benzothiazole Hydrazones

    Science.gov (United States)

    Sarkar, Souvik; Siddiqui, Asim A.; Saha, Shubhra J.; De, Rudranil; Mazumder, Somnath; Banerjee, Chinmoy; Iqbal, Mohd S.; Nag, Shiladitya; Adhikari, Susanta

    2016-01-01

    We synthesized a new series of conjugated hydrazones that were found to be active against malaria parasite in vitro, as well as in vivo in a murine model. These hydrazones concentration-dependently chelated free iron and offered antimalarial activity. Upon screening of the synthesized hydrazones, compound 5f was found to be the most active iron chelator, as well as antiplasmodial. Compound 5f also interacted with free heme (KD [equilibrium dissociation constant] = 1.17 ± 0.8 μM), an iron-containing tetrapyrrole released after hemoglobin digestion by the parasite, and inhibited heme polymerization by parasite lysate. Structure-activity relationship studies indicated that a nitrogen- and sulfur-substituted five-membered aromatic ring present within the benzothiazole hydrazones might be responsible for their antimalarial activity. The dose-dependent antimalarial and heme polymerization inhibitory activities of the lead compound 5f were further validated by following [3H]hypoxanthine incorporation and hemozoin formation in parasite, respectively. It is worth mentioning that compound 5f exhibited antiplasmodial activity in vitro against a chloroquine/pyrimethamine-resistant strain of Plasmodium falciparum (K1). We also evaluated in vivo antimalarial activity of compound 5f in a murine model where a lethal multiple-drug-resistant strain of Plasmodium yoelii was used to infect Swiss albino mice. Compound 5f significantly suppressed the growth of parasite, and the infected mice experienced longer life spans upon treatment with this compound. During in vitro and in vivo toxicity assays, compound 5f showed minimal alteration in biochemical and hematological parameters compared to control. In conclusion, we identified a new class of hydrazone with therapeutic potential against malaria. PMID:27139466

  2. Antimicrobial peptides: a new class of antimalarial drugs?

    Directory of Open Access Journals (Sweden)

    Nuno eVale

    2014-12-01

    Full Text Available A range of antimicrobial peptides (AMP exhibit activity on malaria parasites, Plasmodium spp, in their blood or mosquito stages, or both. These peptides include a diverse array of both natural and synthetic molecules varying greatly in size, charge, hydrophobicity and secondary structure features. Along with an overview of relevant literature reports regarding AMP that display antiplasmodial activity, this review makes a few considerations about those molecules as a potential new class of antimalarial drugs.

  3. Current status of antiplatelet treatment before and after ischemic stroke, and an analysis of factors associated with antiplatelet treatment, in the Qingdao area of China

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; WANG Ping; YU Tan-fang; ZHANG Min; DU Zheng-qiang; XING Cheng-ming

    2011-01-01

    Background Stroke is the most common neurological disease in China,and antiplatelet treatment is important for primary and secondary prevention.This study aimed to describe the current status of antiplatelet treatment before,immediately after,and 1 month after ischemic stroke in the Qingdao area of China,and to determine the factors and potential barriers influencing use.Methods A total of 1114 patients with acute ischemic stroke were enrolled from 11 hospitals in the Qingdao area.Patient demographic data,clinical data,and treatment before and after the stroke were recorded.Univariate analysis (two sample t-test or Mann-Whitney U test,and chi-square test) and multivariate Logistic regression analysis were used to determine the frequency of antiplatelet treatment,and factors associated with treatment,at three time points:before the stroke,in hospital after the stroke,and at 1-month follow-up.Results The frequency of antiplatelet treatment was 6.4% before the stroke,91.5% in hospital,and 77.2% at 1 month.Aspirin pretreatment was independently associated with higher education level,higher income level,history of hyperlipidemia,and history of cerebral vascular disease.Antiplatelet treatment in hospital was independently associated with treatment in an urban hospital,National Institutes of Health Stroke Scale at onset,and statin use in hospital.Antiplatelet treatment at 1-month follow-up was independently associated with higher income level,diagnosis of transient ischemic attack,antiplatelet treatment in hospital,large artery atherosclerosis according to the Trial of Org 10172 in Acute Stroke Treatment classification,and statin use at follow-up.Modified Rankin Scale >4 at 1-month follow-up and history of coronary heart disease were negatively associated with antiplatelet treatment at follow-up.Conclusions This study documents the current status of antiplatelet treatment in primary and early secondary prevention of ischemic stroke in China.Further education of

  4. Antiplatelet therapy: aspirin resistance and all that jazz!

    Science.gov (United States)

    Divani, Afshin A; Zantek, Nicole D; Borhani-Haghighi, Afshin; Rao, Gundu H R

    2013-01-01

    Platelets play a crucial role in the pathogenesis of atherosclerosis, thrombosis, and stroke. Aspirin used alone or in combination with other antiplatelet drugs has been shown to offer significant benefit to patients at high risk of vascular events. Resistance to the action of aspirin may decrease this benefit. Aspirin resistance has been defined by clinical and/or laboratory criteria; however, detection by laboratory methods prior to experiencing a clinical event will likely provide the greatest opportunity for intervention. Numerous laboratory methods with different cutoff points have been used to evaluate the resistance. Noncompliance with aspirin treatment has also confounded studies. A single assay is currently insufficient to establish resistance. Combinations of results to confirm compliance and platelet inhibition may identify "at-risk" individuals who truly have aspirin resistance. The most effective strategy for managing patients with aspirin resistance is unknown; however, studies are currently underway to address this issue.

  5. Lumbar puncture in patients using anticoagulants and antiplatelet agents.

    Science.gov (United States)

    Domingues, Renan; Bruniera, Gustavo; Brunale, Fernando; Mangueira, Cristóvão; Senne, Carlos

    2016-08-01

    The use of anticoagulants and antiplatelet agents has largely increased. Diagnostic lumbar puncture in patients taking these drugs represents a challenge considering the opposing risks of bleeding and thrombotic complications. To date there are no controlled trials, specific guidelines, nor clear recommendations in this area. In the present review we make some recommendations about lumbar puncture in patients using these drugs. Our recommendations take into consideration the pharmacology of these drugs, the thrombotic risk according to the underlying disease, and the urgency in cerebrospinal fluid analysis. Evaluating such information and a rigorous monitoring of neurological symptoms after lumbar puncture are crucial to minimize the risk of hemorrhage associated neurological deficits. An individualized patient decision-making and an effective communication between the assistant physician and the responsible for conducting the lumbar puncture are essential to minimize potential risks.

  6. Lumbar puncture in patients using anticoagulants and antiplatelet agents

    Directory of Open Access Journals (Sweden)

    Renan Domingues

    2016-08-01

    Full Text Available ABSTRACT The use of anticoagulants and antiplatelet agents has largely increased. Diagnostic lumbar puncture in patients taking these drugs represents a challenge considering the opposing risks of bleeding and thrombotic complications. To date there are no controlled trials, specific guidelines, nor clear recommendations in this area. In the present review we make some recommendations about lumbar puncture in patients using these drugs. Our recommendations take into consideration the pharmacology of these drugs, the thrombotic risk according to the underlying disease, and the urgency in cerebrospinal fluid analysis. Evaluating such information and a rigorous monitoring of neurological symptoms after lumbar puncture are crucial to minimize the risk of hemorrhage associated neurological deficits. An individualized patient decision-making and an effective communication between the assistant physician and the responsible for conducting the lumbar puncture are essential to minimize potential risks.

  7. Two new arylnaphthalide lignans and antiplatelet constituents from Justicia procumbens.

    Science.gov (United States)

    Weng, Jing-Ru; Ko, Horng-Huey; Yeh, Ting-Li; Lin, Hsien-Cheng; Lin, Chun-Nan

    2004-04-01

    Two new arylnaphthalide lignans, procumphthalide A (1) and 4-O-beta-D-glucopyranosyl-(1"'-->2")-beta-D-apiofuranosyldiphyllin, named procumbenoside B (2), along with cilinaphthalide B (3) and several other known compounds were isolated from the methanolic extracts of Justicia procumbens. By using NMR and other spectral methods, the structures of 1 and 2 were elucidated. Cilinaphthalide B (3), justicidin A (4), and taiwan E methyl ether (5) were shown to have an antiplatelet effect in human plateletrich plasma. In human citrated PRP, 5 showed a strong inhibitory effect on platelet aggregation induced by adrenaline in a concentration-dependent manner, with an IC(50) value of about 27.6 microM.

  8. DUAL ANTIPLATELET THERAPY IN THE REAL CLINICAL PRACTICE

    Directory of Open Access Journals (Sweden)

    G. N. Guseva

    2015-09-01

    Full Text Available Aim. To evaluate an adequacy of dual antiplatelet therapy (DAPT in patients with acute coronary syndrome (ACS with ST segment elevation and bare metal stent implantation after hospital discharge.Material and methods. 311 patients with ACS with ST segment elevation were included into the study. All of them underwent percutaneous coronary intervention with bare metal stent implantation. The information was obtained by the telephone survey.Results. 54.5% of patients received DAPT during 12 months. 43.8% of patients also received combination of clopidogrel and acetylsalicylic acid, but changed medicinal products of clopidogrel due to different reasons. 1.7% of patients received acetylsalicylic acid only.Conclusion. More than 50% of patients received recommended DAPT at that they preferred generic drugs of clopidogrel original one.

  9. Comparison of antiplatelet regimens in secondary stroke prevention

    DEFF Research Database (Denmark)

    Christiansen, Christine Benn; Pallisgaard, Jannik; Gerds, Thomas Alexander

    2015-01-01

    BACKGROUND: In patients with ischemic stroke of non-cardioembolic origin, acetylsalicylic acid, clopidogrel, or a combination of acetylsalicylic acid and dipyridamole are recommended for the prevention of a recurrent stroke. The purpose of this study was to examine the risk of bleeding or recurrent...... were calculated for each antiplatelet regimen. RESULTS: Among patients discharged after first-time ischemic stroke, 3043 patients were treated with acetylsalicylic acid, 12,295 with a combination of acetylsalicylic acid and dipyridamole, and 3885 with clopidogrel. Adjusted HRs for clopidogrel versus...... the combination of acetylsalicylic acid and dipyridamole were 1.02 (95% confidence interval [CI]: 0.89-1.17) for ischemic stroke and 1.06 (95% CI: 0.83-1.35) for bleeding. Adjusted HRs for acetylsalicylic acid versus the combination of acetylsalicylic acid and dipyridamole were 1.48 (95% CI: 1.31-1.67) for stroke...

  10. New antiplatelet and anticoagulant drugs. Considerations for dental patient management.

    Science.gov (United States)

    Cohen, Harold V; Quek, Samuel Y P; Subramanian, Gayathri; Abbas, Ali

    2013-01-01

    A recent occurrence in dental practice is the noting of new "blood thinners" when the clinician is reviewing a patient's medical history and medications. "Doc, I take Pradaxa or Effient or Xarelto" etc. After many years of the widespread use of aspirin and Coumadin there has appeared a new generation of medications focused on reducing thromboembolic events in patients at risk. This trend has been driven by a need for drugs providing better drug efficacy based on patient biologic processing of the medications and the frequency and cost factors associated with the monitoring the degree of anticoagulation. Guidelines for assessing bleeding risk and managing patients on these new medications in dental practice are not yet defined and are empirically based on medical practitioner experience. This paper will review these new medications and will discuss current considerations for dental patient care. (Note that not all new antiplatelet and anticoagulant medications will be reviewed in this paper.)

  11. Antimalarial Activity of Cocos nucifera Husk Fibre: Further Studies

    Directory of Open Access Journals (Sweden)

    J. O. Adebayo

    2013-01-01

    Full Text Available In this study, the antimalarial and toxicity potentials of husk fibre extracts of five Nigerian varieties of Cocos nucifera were evaluated in vitro. The only active extract fraction, West African Tall (WAT ethyl acetate extract fraction, was then evaluated for its phytochemical constituents, antimalarial and toxicity potentials at varying doses (31.25–500 mg/kg body weight using various organ function indices. The results revealed that WAT ethyl acetate extract fraction (WATEAEF contained alkaloids, tannins, and flavonoids and was active against Plasmodium falciparum W2 strain maintained in continuous culture, with a selectivity index of 30.3. The same extract fraction was active in vivo against Plasmodium berghei NK65, causing more than 50% reduction in parasitaemia on days 4 and 6 after inoculation at various doses administered. WATEAEF did not significantly alter (P>0.05 function indices of the liver and cardiovascular system at all doses administered but significantly increased (P<0.05 plasma creatinine concentration at 250 and 500 mg/Kg body weight compared to controls. The results of this study suggest that WATEAEF possesses antimalarial activity and may not adversely affect normal liver function nor predispose subjects to cardiovascular diseases but may impair normal kidney function at higher doses. Further studies are underway to isolate the active principles.

  12. Antimalarials and the fight against malaria in Brazil

    Directory of Open Access Journals (Sweden)

    Luiz MA Carmargo

    2009-04-01

    Full Text Available Luiz MA Carmargo1, Saulo de Oliveira2, Sergio Basano3, Célia RS Garcia21ICBV-USP, Monte Negro, Rondônia, Brasil; 2Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, SP, Brazil; 3CEMETRON, Porto Velho, Guaporé, BrazilAbstract: Malaria, known as the “fevers,” has been treated for over three thousand years in China with extracts of plants of the genus Artemisia (including Artemisia annua, A. opiacea, and A. lancea from which the active compound is artemisin, a sesquiterpene that is highly effective in the treatment of the disease, especially against young forms of the parasite. South American Indians in the seventeenth century already used an extract of the bark of chinchona tree, commonly named “Jesuits’ powder.” Its active compound was isolated in 1820 and its use spread all over the world being used as a prophylactic drug during the construction of the Madeira–Mamoré railroad in the beginning of the twentieth century. During the 1920s to the 1940s, new antimalarial drugs were synthesized to increase the arsenal against this parasite. However, the parasite has presented systematic resistence to conventional antimalarial drugs, driving researchers to find new strategies to treat the disease. In the present review we discuss how Brazil treats Plasmodium-infected patients.Keywords: Plasmodium falciparum, malaria, antimalarials, calcium

  13. Antimalarial effect of agmatine on Plasmodium berghei K173 strain

    Institute of Scientific and Technical Information of China (English)

    SURui-Bin; WEIXiao-Li; LIUYin; LIJin

    2003-01-01

    AIM: To study the antimalarial effect of agmatine (Agm) on chloroquine-susceptible Plasmodium berghei K173strain (S strain) and the P berghei K173 resistant strain (R strain). METHODS: The antimalarial effects of Agm onP berghei K173 S strain and R strain were evaluated by Peters 4-d suppression test in mice. RESULTS: Agm(12.5-200 mg/kg,ig,daily) decreased the parasitemia for both P berghei K173 S strain (IC50=139 mg/kg) and Rstrain (IC50=126mg/kg) in mice. Subcutaneous injection (sc) of Agm (5-40mg/kg,tid) showed relatively strongerantimalarial effect than intragastric gavage (IC50=30 mg/kg) in P berghei K 173 S strain. Spermidine antagonized theantimalarial effect of Agm for P berghei K173 S strain and R strain. Agm did not reverse the chloroquine resistanceof P berghei K173 S strain, dl-α-Difluoromethylornithine (DFMO, sc) decreased the parasitemia of P BergheiK173 S strain and this effect was antagonized by spermidine. CONCLUSION: Agm has an antimalarial effect andthe mechanism is related to its inhibition of polyamine synthesis.

  14. Anti-Malarial Plants of Jonai, India: an Ethnobotanical Approach

    Directory of Open Access Journals (Sweden)

    Tonlong WANGPAN

    2016-03-01

    Full Text Available North-East India represents a unique ecosystem with treasured medicinal plant wealth closely related with Folk medicines. A large number of plants having medicinal properties and their folk uses have remained confined to the natives of this region. The tribal community of Jonai, Assam was explored to expose the indigenous herbal remedy for malaria. Sixteen antimalarial plants belonging to 13 families were reported. The analysis revealed highest fidelity level (FL value for Ajuga integrifolia (100% followed by Ricinus communis (94%, Alstonia scholaris (88%, Oroxylum indicum (86% and Achyranthes aspera (82%. The percentage of respondent’s knowledge (PRK about anti-malarial plants showed Alstonia scholaris as the most commonly known antimalarial species (53% within this region. Preference ranking (PR unveiled eight species to be very effective against malarial parasite, which includes Allium sativum, Artemisia indica, Azadirachta indica, Carica papaya, Clerodendrum glandulosum, Ocimum tenuiflorum, Oroxylum indicum, Piper longum and Piper nigrum. All medicine preparations are made using water as the medium and are orally administered in the form of crude extract, powder, juice and decoction. Overall analysis suggested Ajuga integrifolia, Achyranthes aspera, Alstonia scholaris, Artemisia indica, Oroxylum indicum and Ricinus communis to be used for the development of novel, economical, effective and ecofriendly herbal formulations for healthcare management.

  15. In vitro susceptibility of Plasmodium vivax to antimalarials in Colombia.

    Science.gov (United States)

    Fernández, Diana; Segura, César; Arboleda, Margarita; Garavito, Giovanny; Blair, Silvia; Pabón, Adriana

    2014-11-01

    The in vitro susceptibilities of 30 isolates of Plasmodium vivax to a number of antimalarials (chloroquine [CQ], mefloquine, amodiaquine, quinine, and artesunate [AS]) were evaluated. The isolates came from the region of Urabá in Colombia, in which malaria is endemic, and were evaluated by the schizont maturation test. The 50% inhibitory concentration (IC50) was 0.6 nM (95% confidence interval [CI], 0.3 to 1.0 nM) for artesunate, 8.5 nM (95% CI, 5.6 to 13.0 nM) for amodiaquine, 23.3 nM (95% CI, 12.4 to 44.1 nM) for chloroquine, 55.6 nM (95% CI, 36.8 to 84.1 nM) for mefloquine, and 115.3 nM (95% CI, 57.7 to 230.5 nM) for quinine. The isolates were classified according to whether the initial parasites were mature or immature trophozoites (Tfz). It was found that the IC50s for chloroquine and artesunate were significantly different in the two aforementioned groups (P Colombia, P. vivax continues to be susceptible to antimalarials. This is the first report, to our knowledge, showing in vitro susceptibilities of P. vivax isolates to antimalarials in Colombia.

  16. Review of pyronaridine anti-malarial properties and product characteristics

    Directory of Open Access Journals (Sweden)

    Croft Simon L

    2012-08-01

    Full Text Available Abstract Pyronaridine was synthesized in 1970 at the Institute of Chinese Parasitic Disease and has been used in China for over 30 years for the treatment of malaria. Pyronaridine has high potency against Plasmodium falciparum, including chloroquine-resistant strains. Studies in various animal models have shown pyronaridine to be effective against strains resistant to other anti-malarials, including chloroquine. Resistance to pyronaridine appears to emerge slowly and is further retarded when pyronaridine is used in combination with other anti-malarials, in particular, artesunate. Pyronaridine toxicity is generally less than that of chloroquine, though evidence of embryotoxicity in rodents suggests use with caution in pregnancy. Clinical pharmacokinetic data for pyronaridine indicates an elimination T1/2 of 13.2 and 9.6 days, respectively, in adults and children with acute uncomplicated falciparum and vivax malaria in artemisinin-combination therapy. Clinical data for mono or combined pyronaridine therapy show excellent anti-malarial effects against P. falciparum and studies of combination therapy also show promise against Plasmodium vivax. Pyronaridine has been developed as a fixed dose combination therapy, in a 3:1 ratio, with artesunate for the treatment of acute uncomplicated P. falciparum malaria and blood stage P. vivax malaria with the name of Pyramax® and has received Positive Opinion by European Medicines Agency under the Article 58 procedure.

  17. Antimalarial activity of newly synthesized chalcone derivatives in vitro.

    Science.gov (United States)

    Yadav, Neesha; Dixit, Sandeep K; Bhattacharya, Amit; Mishra, Lokesh C; Sharma, Manish; Awasthi, Satish K; Bhasin, Virendra K

    2012-08-01

    Twenty-seven novel chalcone derivatives were synthesized using Claisen-Schmidt condensation and their antimalarial activity against asexual blood stages of Plasmodium falciparum was determined. Antiplasmodial IC(50) (half-maximal inhibitory concentration) activity of a compound against malaria parasites in vitro provides a good first screen for identifying the antimalarial potential of the compound. The most active compound was 1-(4-benzimidazol-1-yl-phenyl)-3-(2, 4-dimethoxy-phenyl)-propen-1-one with IC(50) of 1.1 μg/mL, while that of the natural phytochemical, licochalcone A is 1.43 μg/mL. The presence of methoxy groups at position 2 and 4 in chalcone derivatives appeared to be favorable for antimalarial activity as compared to other methoxy-substituted chalcones. Furthermore, 3, 4, 5-trimethoxy groups on chalcone derivative probably cause steric hindrance in binding to the active site of cysteine protease enzyme, explaining the relative lower inhibitory activity.

  18. Percutaneous coronary interventions and antiplatelet therapy in renal transplant recipients.

    Science.gov (United States)

    Summaria, Francesco; Giannico, Maria Benedetta; Talarico, Giovanni Paolo; Patrizi, Roberto

    2016-04-01

    Cardiovascular disease is the leading cause of mortality and morbidity following renal transplantation (RT), accounting for 40-50% of all deaths. After renal transplantation, an adverse cardiovascular event occurs in nearly 40% of patients; given the dialysis vintage and the average wait time, the likelihood of receiving coronary revascularization is very high. There is a significant gap in the literature in terms of the outcomes of prophylactic coronary revascularization in renal transplantation candidates. Current guidelines on myocardial revascularization stipulate that renal transplant patients with significant coronary artery disease (CAD) should not be excluded from the potential benefit of revascularization. Compared with percutaneous coronary intervention (PCI), however, coronary artery bypass grafting is associated with higher early and 30-day mortality. About one-third of renal transplant patients with CAD have to be treated invasively and so PCI is currently the most popular mode of revascularization in these fragile and compromised patients. A newer generation drug-eluting stent (DES) should be preferred over a bare metal stent (BMS) because of its lower risk of restenosis and improved safety concerns (stent thrombosis) compared with first generation DES and BMS. Among DES, despite no significant differences being reported in terms of efficacy, the newer everolimus and zotarolimus eluting stents should be preferred given the possibility of discontinuing, if necessary, dual antiplatelet therapy before 12 months. Since there is a lack of randomized controlled trials, the current guidelines are inadequate to provide a specifically tailored antiplatelet therapeutic approach for renal transplant patients. At present, clopidogrel is the most used agent, confirming its central role in the therapeutic management of renal transplant patients undergoing PCI. While progress in malignancy-related mortality seems a more distant target, a slow but steady reduction in

  19. Formulary and economic considerations in the selection of antiplatelet agents.

    Science.gov (United States)

    Crane, V S

    1998-10-01

    A pharmacoeconomic model for evaluating antiplatelet therapies is described. In order to conduct a pharmacoeconomic analysis, it is important to understand the course of the disease under study and the prevention and treatment options, identify the associated economic consequences, develop concomitant strategies, and target high-yield decisions. The steps of a pharmacoeconomics-based decision are defining the pharmacoeconomic problem, creating a cross-functional team, determining the study's perspective, determining the treatment alternatives and outcomes, selecting the appropriate pharmacoeconomic method, placing a monetary value on outcomes, identifying resources and data sources, establishing probabilities of outcomes, using decision analysis, undertaking a cost or sensitivity analysis, presenting the results, developing and implementing a policy or clinical intervention based on the results, educating health care professionals about the new policy or intervention, and documenting the quality of care and potential cost savings through follow-up. Clopidogrel is given as an example. The composite endpoint of myocardial infarction, stroke, or vascular death has been shown to be 8.7% lower with clopidogrel than with aspirin in patients with recent myocardial infarction, recent ischemic stroke, or symptomatic peripheral arterial disease. Clopidogrel costs more than aspirin but may be considered as first-line therapy for high-risk patients, patients who are allergic to aspirin, or patients who cannot tolerate the gastrointestinal effects of aspirin. Cost-effectiveness analyses can be used to support formulary decisions about which antiplatelet agent should be used; the use of a particular agent ultimately also depends on efficacy, safety, pharmacodynamics, patient-specific factors, and relative direct and indirect costs.

  20. Anti-malarial effect of semi-synthetic drug amitozyn.

    Science.gov (United States)

    Tcherniuk, Sergey O; Chesnokova, Olga; Oleinikov, Irina V; Potopalsky, Anatoly I; Oleinikov, Andrew V

    2015-10-29

    Malaria caused by Plasmodium falciparum is the most virulent form of malaria, leading to approximately a half million deaths per year. Chemotherapy continues to be a key approach in malaria prevention and treatment. Due to widespread parasite drug resistance, identification and development of new anti-malarial compounds remains an important task of malarial parasitology. The semi-synthetic drug amitozyn, obtained through alkylation of major celandine (Chelidonium majus) alkaloids with N,N'N'-triethylenethiophosphoramide (ThioTEPA), is a widely used Eastern European folk medicine for the treatment of various tumours. However, its anti-malarial effect has never been studied. The anti-malarial effects of amitozyn alone and in combination with chloroquine, pyrimethamine and artemisinin on the blood stages of P. falciparum were analysed. The cytostatic effects of amitozyn on parasites and various cancerous and non-cancerous human cells were compared and their toxic effects on unparasitized human red blood cells were analysed. Obtained results demonstrate that amitozyn effectively inhibits the growth of blood-stage parasites with IC50 9.6 ± 2, 11.3 ± 2.8 and 10.8 ± 1.8 μg/mL using CS2, 3G8 and NF54 parasite lines, respectively. The median IC50 for 14 tested human cell lines was 33-152 μg/mL. Treatment of uninfected red blood cells with a high dose of amitozyn (500 μg/mL) did not change cell morphology, demonstrating its non-toxicity for erythrocytes. The synergistic impact of the amitozyn/chloroquine combination was observed at growth inhibition levels of 10-80 %, while demonstrating a nearly additive effect at a growth inhibition level of 90 %. The combination of amitozyn with pyrimethamine has a synergistic effect at growth inhibition levels of 10-70 % and a nearly additive effect at a growth inhibition level of 90 %. The synergistic anti-malarial effect of the amitozyn/artemisinin combination was observed at growth inhibition levels of 10-40 % and a nearly

  1. Influence of genetic variants and drug interactions on the response to antiplatelet drugs

    NARCIS (Netherlands)

    Harmsze, A.M.

    2011-01-01

    Antiplatelet therapy plays an important role in the treatment of cardiovascular disease. The combination of acetylsalicylic acid and clopidogrel is routine care in patients with acute coronary syndromes (ACS) or undergoing percutaneous coronary interventions (PCI). Although the effectiveness of anti

  2. Antiplatelet and antithrombotic effect of Phyllostachys pubescens leaves and Mume Fructus combination

    Directory of Open Access Journals (Sweden)

    Wen Yi Jin

    2013-06-01

    Conclusion: These results suggest that combination preparations of PL and MF, especially their 2:1 combination, can increase antiplatelet and antithromboticeffects more than PL and MF alone, offering evidence for a potential novel combination antithrombotic therapy.

  3. Initiation and persistence with dual antiplatelet therapy after acute myocardial infarction

    DEFF Research Database (Denmark)

    Green, Anders; Pottegård, Anton; Broe, Anne;

    2016-01-01

    OBJECTIVES: The study investigated dual antiplatelet therapy (DAPT) patterns over time and patient characteristics associated with the various treatments in a myocardial infarction (MI) population. DESIGN: A registry-based observational cohort study was performed using antecedent data. SETTING...

  4. Thrombelastographic haemostatic status and antiplatelet therapy after coronary artery bypass surgery (TEG-CABG trial)

    DEFF Research Database (Denmark)

    Rafiq, Sulman; Johansson, Pär I; Zacho, Mette;

    2012-01-01

    ABSTRACT: BACKGROUND: Hypercoagulability, assessed by the thrombelastography (TEG) assay, has in several observational studies been associated with an increased risk of post-procedural thromboembolic complications. We hypothesize that intensified antiplatelet therapy with clopidogrel and aspirin,...

  5. Risk and benefit of dual antiplatelet treatment among nonrevascularized myocardial infarction patients in different age groups

    DEFF Research Database (Denmark)

    Juul, Nikolai; Gislason, Gunnar; Olesen, Jonas Bjerring;

    2017-01-01

    BACKGROUND: Dual anti-platelet treatment with clopidogrel and aspirin is indicated for most patients after myocardial infarction. We examined the risk/benefit relationship of dual anti-platelet treatment according to age in a nationwide cohort of 30,532 myocardial infarction patients without...... revascularization. METHODS: Patients admitted with first-time myocardial infarction in 2002-2010, not undergoing revascularization, were identified from nationwide Danish registers. Dual anti-platelet treatment use was assessed by claimed prescriptions. Stratified into age groups, risk of bleeding, all...... included (mean age 67.02 (±13.8) years and 64.7% males). Use of dual anti-platelet treatment decreased with age: 80% (79 years). We found a reduced risk of cardiovascular death, recurrent myocardial infarction and ischaemic stroke in users

  6. Cost-effectiveness analysis of personalized antiplatelet therapy in patients with acute coronary syndrome.

    Science.gov (United States)

    Jiang, Minghuan; You, Joyce Hs

    2016-05-01

    This study aimed to compare the clinical and economic outcomes of pharmacogenetic-guided (PG-guided) and platelet reactivity testing-guided antiplatelet therapy for patients with acute coronary syndrome undergoing percutaneous coronary intervention. A decision-analytic model was simulated including four antiplatelet strategies: universal clopidogrel 75 mg daily, universal alternative P2Y12 inhibitor (prasugrel or ticagrelor), PG-guided therapy, and platelet reactivity testing-guided therapy. PG-guided therapy was the preferred option with lowest cost (US$75,208) and highest quality-adjusted life years gained (7.6249 quality-adjusted life years). The base-case results were robust in sensitivity analysis. PG-guided antiplatelet therapy showed the highest probability to be preferred antiplatelet strategy for acute coronary syndrome patients with percutaneous coronary intervention.

  7. Antiplatelet therapy for stable coronary artery disease in atrial fibrillation patients taking an oral anticoagulant

    DEFF Research Database (Denmark)

    Lamberts, Morten; Gislason, Gunnar H.; Lip, Gregory Y. H.

    2014-01-01

    Background The optimal long-term antithrombotic treatment of patients with coexisting atrial fibrillation and stable coronary artery disease is unresolved, and commonly, a single antiplatelet agent is added to oral anticoagulation. We investigated the effectiveness and safety of adding antiplatelet...... or thromboembolism, whereas risk of bleeding is increased significantly. The common practice of adding antiplatelet therapy to oral VKA anticoagulation in patients with atrial fibrillation and stable coronary artery disease warrants reassessment........23-1.82]) or clopidogrel (hazard ratio, 1.84 [95% confidence interval, 1.11-3.06]) was added to VKA. Conclusions In atrial fibrillation patients with stable coronary artery disease, the addition of antiplatelet therapy to VKA therapy is not associated with a reduction in risk of recurrent coronary events...

  8. Do Aspirin and Other Antiplatelet Drugs Reduce the Mortality in Critically Ill Patients?

    Directory of Open Access Journals (Sweden)

    Wolfgang Lösche

    2012-01-01

    Full Text Available Platelet activation has been implicated in microvascular thrombosis and organ failure in critically ill patients. In the first part the present paper summarises important data on the role of platelets in systemic inflammation and sepsis as well as on the beneficial effects of antiplatelet drugs in animal models of sepsis. In the second part the data of retrospective and prospective observational clinical studies on the effect of aspirin and other antiplatelet drugs in critically ill patients are reviewed. All of these studies have shown that aspirin and other antiplatelet drugs may reduce organ failure and mortality in these patients, even in case of high bleeding risk. From the data reviewed here interventional prospective trials are needed to test whether aspirin and other antiplatelet drugs might offer a novel therapeutic option to prevent organ failure in critically ill patients.

  9. Antiplatelet Drugs for Secondary Prevention of Cardiovascular Diseases : Drug Utilization, Effectiveness, and Safety

    NARCIS (Netherlands)

    Noorsyahdy, A.Y.

    2017-01-01

    Antiplatelet drugs are recommended for secondary prevention of recurrent cardiovascular events in patients who experience diseases in which the pathophysiology is associated with platelet aggregation and atherosclerosis, including acute coronary syndrome, transient ischemic attack, ischemic stroke,

  10. Dual antiplatelet therapy with prasugrel or ticagrelor versus clopidogrel in interventional cardiology

    DEFF Research Database (Denmark)

    Clemmensen, Peter; Dridi, Nadia Paarup; Holmvang, Lene

    2013-01-01

    For several years, clopidogrel plus aspirin has been the dual antiplatelet therapy (DAPT) of choice for patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) with stent implantation. More recently, prasugrel and ticagrelor have demonstrated greater effica...

  11. Aspirin, Plavix, and Other Antiplatelet Medications: What the Oral and Maxillofacial Surgeon Needs to Know.

    Science.gov (United States)

    Ghantous, Andre E; Ferneini, Elie M

    2016-11-01

    Most patients with coronary artery disease and peripheral vascular disease are on long-term antiplatelet therapy and dual therapy. Achieving a balance between ischemic and bleeding risk remains an important factor in managing patients on antiplatelet therapy. For most outpatient surgical procedures, maintenance and continuation of this therapy are recommended. Consultation with the patient's cardiologist, physician, and/or vascular surgeon is always recommended before interrupting or withholding this treatment modality. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Efficacy of antiplatelet therapy in secondary prevention following lacunar stroke: pooled analysis of randomized trials.

    Science.gov (United States)

    Kwok, Chun Shing; Shoamanesh, Ashkan; Copley, Hannah Charlotte; Myint, Phyo Kyaw; Loke, Yoon K; Benavente, Oscar R

    2015-04-01

    Lacunar stroke accounts for ≈25% of ischemic stroke, but optimal antiplatelet regimen to prevent stroke recurrence remains unclear. We aimed to evaluate the efficacy of antiplatelet agents in secondary stroke prevention after a lacunar stroke. We searched MEDLINE, Embase, and the Cochrane library for randomized controlled trials that reported risk of recurrent stroke or death with antiplatelet therapy in patients with lacunar stroke. We used random effects meta-analysis and evaluated heterogeneity with I(2). We included 17 trials with 42,234 participants (mean age 64.4 years, 65% male) and follow up ranging from 4 weeks to 3.5 years. Compared with placebo, any single antiplatelet agent was associated with a significant reduction in recurrence of any stroke (risk ratio [RR] 0.77, 0.62-0.97, 2 studies) and ischemic stroke (RR 0.48, 0.30-0.78, 2 studies), but not for the composite outcome of any stroke, myocardial infarction, or death (RR 0.89, 0.75-1.05, 2 studies). When other antiplatelet agents (ticlodipine, cilostazol, and dipyridamole) were compared with aspirin, there was no consistent reduction in stroke recurrence (RR 0.91, 0.75-1.10, 3 studies). Dual antiplatelet therapy did not confer clear benefit over monotherapy (any stroke RR 0.83, 0.68-1.00, 3 studies; ischemic stroke RR 0.80, 0.62-1.02, 3 studies; composite outcome RR 0.90, 0.80-1.02, 3 studies). Our results suggest that any of the single antiplatelet agents compared with placebo in the included trials is adequate for secondary stroke prevention after lacunar stroke. Dual antiplatelet therapy should not be used for long-term stroke prevention in this stroke subtype. © 2015 American Heart Association, Inc.

  13. Systematic review of the clinical impact of dual antiplatelet therapy discontinuation after acute coronary syndromes.

    Science.gov (United States)

    Zeymer, Uwe; Becher, Anja; Jennings, Em; Johansson, Saga; Westergaard, Mogens

    2017-09-01

    The aim of this systematic literature review was to assess the consequences of dual antiplatelet therapy discontinuation on clinical outcomes after acute coronary syndromes. A systematic literature search was conducted in PubMed to identify studies reporting data on patients who discontinued dual antiplatelet therapy (planned or unplanned) following acute coronary syndromes and on the clinical impact of dual antiplatelet therapy discontinuation. To be included, more than 50% of the study population had to have had acute coronary syndrome as their index event or, if less than 50%, outcomes data must have been reported separately for the group with acute coronary syndromes. Thirty publications covering 29 studies were identified for inclusion. There was much heterogeneity across studies regarding the included patient populations, treatment durations and outcome definitions and ascertainments. Dual antiplatelet therapy discontinuation was most commonly based on physician decision. Twenty-six studies reported that clopidogrel was prescribed as part of dual antiplatelet therapy. Dual antiplatelet therapy duration was positively associated with a lower risk of all-cause mortality (seven/eight studies), cardiovascular mortality (two/two studies), non-fatal myocardial infarction (two/three studies) and stent thrombosis (five/five studies) in patients and/or patient subgroups in studies without randomised treatment designs, although such associations were not observed in the one study that randomly assigned patients to treatment (i.e. planned discontinuation). Results from our systematic literature review generally support the benefit of longer-term dual antiplatelet therapy after acute coronary syndromes; however, further research is needed to determine the optimal length of dual antiplatelet therapy in patients after acute coronary syndrome, ideally using prospective studies.

  14. Dental extraction without stopping single or dual antiplatelet therapy: results of a retrospective cohort study.

    Science.gov (United States)

    Lu, S-Y; Tsai, C-Y; Lin, L-H; Lu, S-N

    2016-10-01

    The aim of this study was to investigate the incidence of bleeding after dental extraction without stopping antiplatelet therapy. Postoperative bleeding was assessed in a total of 1271 patients who were divided into two groups: a study group comprising 183 patients on antiplatelet therapy (aspirin 125 patients/185 occasions; clopidogrel 42 patients/65 occasions; dual therapy 16 patients/24 occasions) who underwent 548 dental extractions on 274 occasions, and a control group comprising 1088 patients who were not receiving any antiplatelet or anticoagulant therapy and underwent 2487 dental extractions on 1472 occasions. The incidence of postoperative bleeding was higher in the study group (5/274, 1.8%) than in the control group (10/1472, 0.7%), and also in the dual antiplatelet subgroup (1/24, 4.2%) than in the single antiplatelet subgroups (clopidogrel: 2/65, 3.1%; aspirin: 2/185, 1.1%); however, these differences were not significant. Postoperative bleeding was managed successfully by repacking with Gelfoam impregnated with tranexamic acid powder in 12 patients and by resuturing in three of the control patients undergoing extraction of impacted teeth with flap elevation. These findings indicate that there is no need to interrupt antiplatelet drugs before dental extraction. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  15. Antiplatelet activity of white and pink Nelumbo nucifera Gaertn flowers

    Directory of Open Access Journals (Sweden)

    Brindha Durairaj

    2010-09-01

    Full Text Available Nelumbo nucifera Gaertn (Nelumbonaceae a plant used in Ayurvedic medicine (common name: lotus, is a perennial, large and rhizomatous aquatic herb most prevalent in South India. Preliminary phytochemical screening of both white and pink Nelumbo nucifera flowers revealed the presence of phytochemical constituents (flavonoids, alkaloids, phenols etc,. Hence, an attempt has been made to screen the effect of Nelumbo nucifera flowers (both types on platelet aggregation. The antiplatelet activity of hydroethanolic extract of both types of flowers was studied using platelet-rich plasma in different concentrations (100-500µg/ml. Both white and pink Nelumbo nucifera flower extracts showed dose-dependent effective antiplatelet activity with maximum activity at 500µg/ml concentration; prevention of platelet aggregation was 50% of that achieved with standard aspirin. Furthermore, the antiplatelet activity of white flowers was relatively high (pNelumbo nucifera Gaertn (Nelumbonaceae, planta utilizada na medicina Ayurvédica, é erva aquática rizomatosa grande, predominante no sul da Índia. A triagem fitoquímica preliminar das flores brancas e cor-de-rosa de Nelumbo nucifera revelou a presença de constituintes fitoquímicos (flavonoides, alcaloides, fenóis etc. Assim, tentou-se a triagem do efeito das flores de Nelumbo nucifera de ambos os tipos na agregação plaquetária. A atividade antiplaquetária dos extratos hidroetanólico de ambos os tipos de flores foi estudada, utilizando-se plasma rico em plaquetas em duas diferentes concentrações (100 - 500 µg/mL. Tanto os extratos das flores brancas quanto daquelas de cor-de-rosa mostraram atividade antiplaquetária dose-dependente, com o máximo na concentração de 500 µg/mL. A prevenção da agregação plaquetária foi 50% daquela alcançada com o padrão de ácido acetilsalicílico. Além disso, a atividade antiplaquetária das flores brancas foi, relativamente, alta (p<0,05; ANOVA

  16. Adaptation of targeted nanocarriers to changing requirements in antimalarial drug delivery

    OpenAIRE

    Marques, Joana; Valle-Delgado, Juan J.; Urbán, Patricia; Baró, Elisabet; Prohens, Rafel; Mayor, Alfredo; Cisteró, Pau; Delves, Michael; Robert E Sinden; Grandfils, Christian; de Paz, José L.; García-Salcedo, José A.; Fernández-Busquets, Xavier

    2016-01-01

    The adaptation of existing antimalarial nanocarriers to new Plasmodium stages, drugs, targeting molecules, or encapsulating structures is a strategy that can provide new nanotechnology-based, cost-efficient therapies against malaria. We have explored the modification of different liposome prototypes that had been developed in our group for the targeted delivery of antimalarial dru...

  17. Antimalarial drug discovery: screening of Brazilian medicinal plants and purified compounds.

    Science.gov (United States)

    Krettli, Antoniana Ursine

    2009-02-01

    Malaria is the most important parasitic disease and its control depends on specific chemotherapy, now complicated by Plasmodium falciparum that has become resistant to most commonly available antimalarials. Treatment of the disease requires quinine or drug combinations of artemisinin derivatives and other antimalarials. Further drug resistance is expected. New active compounds need to be discovered. To find new antimalarials from medicinal and randomly collected plants, crude extracts are screened against P. falciparum in cultures and in malaria animal models, following bioassays of purified fractions, and cytotoxicity tests. For antimalarial research, screening medicinal plants is more efficient than screening randomly chosen plants. Biomonitored fractionation allows selection of new active molecules identified as potential antimalarials in multidisciplinary projects in Brazil; no new molecule is available for human testing. The advantages of projects based on ethnopharmacology are discussed.

  18. Antimalarial activity of Malaysian Plectranthus amboinicus against Plasmodium berghei

    Directory of Open Access Journals (Sweden)

    Norazsida Ramli

    2014-01-01

    Full Text Available Context: Malaria is a mosquito-borne disease caused by parasitic protozoa from the genus of Plasmodium. The protozoans have developed resistance against many of current drugs. It is urgent to find an alternative source of new antimalarial agent. In the effort to discover new antimalarial agents, this research has been conducted on Plectranthus amboinicus. Aims: This study was conducted to evaluate the toxicity and antiplasmodial properties of P. amboinicus. Materials and Methods: Acute oral toxicity dose at 5000 mg/kg was conducted to evaluate the safety of this extract. Twenty mice were divided into control and experimental group. All the mice were observed for signs of toxicity, mortality, weight changes and histopathological changes. Antimalarial activity of different extract doses of 50, 200, 400 and 1000 mg/kg were tested in vivo against Plasmodium berghei infections in mice (five mice for each group during early, established and residual infections. Results: The acute oral toxicity test revealed that no mortality or evidence of adverse effects was seen in the treated mice. The extract significantly reduced the parasitemia by the 50 (P = 0.000, 200 (P = 0.000 and 400 mg/kg doses (P = 0.000 in the in vivo prophylactic assay. The percentage chemo-suppression was calculated as 83.33% for 50 mg/kg dose, 75.62% for 200 mg/kg dose and 90.74% for 400 mg/kg dose. Body weight of all treated groups; T1, T2, T3 and T4 also showed enhancement after 7 days posttreatment. Statistically no reduction of parasitemia calculated for curative and suppressive test. Conclusion: Thus, this extract may give a promising agent to be used as a prophylactic agent of P. berghei infection.

  19. Antimalarial Benzoxaboroles Target Plasmodium falciparum Leucyl-tRNA Synthetase.

    Science.gov (United States)

    Sonoiki, Ebere; Palencia, Andres; Guo, Denghui; Ahyong, Vida; Dong, Chen; Li, Xianfeng; Hernandez, Vincent S; Zhang, Yong-Kang; Choi, Wai; Gut, Jiri; Legac, Jennifer; Cooper, Roland; Alley, M R K; Freund, Yvonne R; DeRisi, Joseph; Cusack, Stephen; Rosenthal, Philip J

    2016-08-01

    There is a need for new antimalarials, ideally with novel mechanisms of action. Benzoxaboroles have been shown to be active against bacteria, fungi, and trypanosomes. Therefore, we investigated the antimalarial activity and mechanism of action of 3-aminomethyl benzoxaboroles against Plasmodium falciparum Two 3-aminomethyl compounds, AN6426 and AN8432, demonstrated good potency against cultured multidrug-resistant (W2 strain) P. falciparum (50% inhibitory concentration [IC50] of 310 nM and 490 nM, respectively) and efficacy against murine Plasmodium berghei infection when administered orally once daily for 4 days (90% effective dose [ED90], 7.4 and 16.2 mg/kg of body weight, respectively). To characterize mechanisms of action, we selected parasites with decreased drug sensitivity by culturing with stepwise increases in concentration of AN6426. Resistant clones were characterized by whole-genome sequencing. Three generations of resistant parasites had polymorphisms in the predicted editing domain of the gene encoding a P. falciparum leucyl-tRNA synthetase (LeuRS; PF3D7_0622800) and in another gene (PF3D7_1218100), which encodes a protein of unknown function. Solution of the structure of the P. falciparum LeuRS editing domain suggested key roles for mutated residues in LeuRS editing. Short incubations with AN6426 and AN8432, unlike artemisinin, caused dose-dependent inhibition of [(14)C]leucine incorporation by cultured wild-type, but not resistant, parasites. The growth of resistant, but not wild-type, parasites was impaired in the presence of the unnatural amino acid norvaline, consistent with a loss of LeuRS editing activity in resistant parasites. In summary, the benzoxaboroles AN6426 and AN8432 offer effective antimalarial activity and act, at least in part, against a novel target, the editing domain of P. falciparum LeuRS.

  20. Antimaláricos e Ototoxicidade Antimalarials and Ototoxicity

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    Marcelo Cardoso Figueiredo

    2004-06-01

    Full Text Available Os antimaláricos, como o difosfato de cloroquina, têm sido usados amplamente no tratamento não só da malária, mas também de doenças reumatológicas como a síndrome de Sjögren (SS, artrite reumatóide (AR e lúpus eritematoso sistêmico (LES. Essas drogas são usadas cronicamente e, em conseqüência do acúmulo nos melanócitos, podem causar hiperpigmentação cutânea, retinopatia e lesão no ouvido interno. Como o protocolo do uso de antimaláricos só envolve a avaliação oftalmológica e das enzimas hepáticas, esta revisão discute a necessidade de novos estudos da avaliação periódica da audição desses pacientes.Antimalarials such as chloroquine diphosphate have been widely used not only for the treatment of malaria, but also for several rheumatic diseases such as Sjögren's syndrome (SS, rheumatoid arthritis (RA and Systemic Lupus Erythematosus (SLE. These drugs are used on a long-term basis and, due to melanocytes' accumulation, can cause cutaneous hyperpigmentation, retinopathy and internal ear damage. As the antimalarials' user follow-up protocol recommends only periodic eye exams and liver function testing, we reviewed the literature questioning whether new studies on the periodic hearing evaluation are required for antimalarials' users.

  1. Substandard anti-malarial drugs in Burkina Faso

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    Sie Ali

    2008-05-01

    Full Text Available Abstract Background There is concern about an increasing infiltration of markets by substandard and fake medications against life-threatening diseases in developing countries. This is particularly worrying with regard to the increasing resistance development of Plasmodium falciparum against affordable anti-malarial medications, which has led to a change to more expensive drugs in most endemic countries. Methods A representative sample of modern anti-malarial medications from licensed (public and private pharmacies, community health workers and illicit (market and street vendors, shops sources has been collected in the Nouna Health District in north-western Burkina Faso in 2006. All drugs were tested for their quality with the standard procedures of the German Pharma Health Fund-Minilab. Detected low standard drugs were re-tested with European Pharmacopoeia 2.9.1 standards for disintegration and ultraviolet-visible spectroscopy at the laboratory of the Heidelberg University for confirmation. Results Overall, 86 anti-malarial drug samples were collected, of which 77 samples have been included in the final analysis. The sample consisted of 39/77 (50% chloroquine, 10/77 (13% pyrimethamine-sulphadoxine, 9/77 (12% quinine, 6/77 (8% amodiaquine, 9/77 (12% artesunate, and 4/77 (5% artemether-lumefantrine. 32/77 (42% drug samples were found to be of poor quality, of which 28 samples failed the visual inspection, nine samples had substandard concentrations of the active ingredient, four samples showed poor disintegration, and one sample contained non of the stated active ingredient. The licensed and the illicit market contributed 5/47 (10.6% and 27/30 (90.0% samples of substandard drugs respectively. Conclusion These findings provide further evidence for the wide-spread existence of substandard anti-malarial medications in Africa and call for strengthening of the regulatory and quality control capacity of affected countries, particularly in view of the

  2. Targeting Plasmodium falciparum Hsp90: Towards Reversing Antimalarial Resistance

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    Dea Shahinas

    2013-02-01

    Full Text Available Malaria continues to exact a great human toll in tropical settings. Antimalarial resistance is rife and the parasite inexorably develops mechanisms to outwit our best drugs, including the now first-line choice, artesunate. Novel strategies to circumvent resistance are needed. Here we detail drug development focusing on heat shock protein 90 and its central role as a chaperone. A growing body of evidence supports the role for Hsp90 inhibitors as adjunctive drugs able to restore susceptibility to traditionally efficacious compounds like chloroquine.

  3. Non-persistence with antiplatelet therapy in elderly patients after a transient ischemic attack.

    Science.gov (United States)

    Wawruch, Martin; Zatko, Dusan; Wimmer, Gejza; Luha, Jan; Wimmerova, Sona; Kukumberg, Peter; Murin, Jan; Hloska, Adam; Tesar, Tomas; Shah, Rashmi

    2017-03-11

    Antiplatelet therapy following a transient ischemic attack (TIA) constitutes an important secondary prevention measure. The study was aimed at evaluating the development of non-persistence with antiplatelet therapy in elderly patients after a TIA and identifying patient-related characteristics associated with the probability of non-persistence during the follow-up period. The study cohort (n = 854) was selected from the database of the largest health insurance provider of the Slovak Republic. It included patients aged ≥65 years, in whom antiplatelet medication was initiated following a TIA diagnosis during the period between 1 January 2010 and 31 December 2010. Each patient was followed for a period of 3 years from the date of the first antiplatelet medication prescription associated with TIA diagnosis. Patients in whom there was a treatment gap of at least 6 months without antiplatelet medication prescription were defined as "non-persistent". The factors predicting non-persistence were identified in the Cox proportional hazards model. At the end of the follow-up period, 345 (40.4%) patients were non-persistent with antiplatelet medication. Protective factors decreasing a patient´s likelihood of becoming non-persistent were age ≥75 years [hazard ratio (HR) = 0.75], polypharmacy (concurrent use of ≥6 drugs) (HR = 0.79), arterial hypertension (HR = 0.68), diabetes mellitus (HR = 0.74), hypercholesterolemia (HR = 0.75), and antiplatelet medication switching during the follow-up period (HR = 0.73). It is concluded that following a TIA, elderly patients aged <75 years or those with normal serum cholesterol levels, without certain comorbid conditions and polypharmacy may benefit from special counselling to encourage persistence with secondary preventive medication.

  4. Comparison of two antiplatelet therapy strategies in patients undergoing transcatheter aortic valve implantation.

    Science.gov (United States)

    Durand, Eric; Blanchard, Didier; Chassaing, Stephan; Gilard, Martine; Laskar, Marc; Borz, Bogdan; Lafont, Antoine; Barbey, Christophe; Godin, Matthieu; Tron, Christophe; Zegdi, Rachid; Chatel, Didier; Le Page, Olivier; Litzler, Pierre-Yves; Bessou, Jean-Paul; Danchin, Nicolas; Cribier, Alain; Eltchaninoff, Hélène

    2014-01-15

    Dual antiplatelet therapy is commonly used in patients undergoing transcatheter aortic valve implantation (TAVI), but the optimal antiplatelet regimen is uncertain and remains to be determined. The objective of this study was to compare 2 strategies of antiplatelet therapy in patients undergoing TAVI. A strategy using monoantiplatelet therapy (group A, n = 164) was prospectively compared with a strategy using dual antiplatelet therapy (group B, n = 128) in 292 consecutive patients undergoing TAVI. The primary end point was a combination of mortality, major stroke, life-threatening bleeding (LTB), myocardial infarction, and major vascular complications at 30 days. All adverse events were adjudicated according to the Valve Academic Research Consortium. The primary end point occurred in 22 patients (13.4%) in the group A and in 30 patients (23.4%) in the group B (hazard ratio 0.51, 95% confidence interval 0.28 to 0.94, p = 0.026). LTB (3.7% vs 12.5%, p = 0.005) and major bleedings (2.4% vs 13.3%, p antiplatelet therapy persisted after multivariate adjustment and propensity score analysis (hazard ratio 0.53, 95% confidence interval 0.28 to 0.95, p = 0.033). In conclusion, a strategy using mono versus dual antiplatelet therapy in patients undergoing TAVI reduces LTB and major bleedings without increasing the risk of stroke and myocardial infarction. The results of our study question the justification of dual antiplatelet therapy and require confirmation in a randomized trial. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Circulating primers enhance platelet function and induce resistance to antiplatelet therapy

    Science.gov (United States)

    Blair, T A; Moore, S F; Hers, I

    2015-01-01

    Background Aspirin and P2Y12 antagonists are antiplatelet compounds that are used clinically in patients with thrombosis. However, some patients are ‘resistant’ to antiplatelet therapy, which increases their risk of developing acute coronary syndromes. These patients often present with an underlying condition that is associated with altered levels of circulating platelet primers and platelet hyperactivity. Platelet primers cannot stimulate platelet activation, but, in combination with physiologic stimuli, significantly enhance platelet function. Objectives To explore the role of platelet primers in resistance to antiplatelet therapy, and to evaluate whether phosphoinositide 3-kinase (PI3K) contributes to this process. Methods and Results We used platelet aggregation, thromboxane A2 production and ex vivo thrombus formation as functional readouts of platelet activity. Platelets were treated with the potent P2Y12 inhibitor AR-C66096, aspirin, or a combination of both, in the presence or absence of the platelet primers insulin-like growth factor-1 (IGF-1) and thrombopoietin (TPO), or the Gz-coupled receptor ligand epinephrine. We found that platelet primers largely overcame the inhibitory effects of antiplatelet compounds on platelet functional responses. IGF-1-mediated and TPO-mediated, but not epinephrine-mediated, enhancements in the presence of antiplatelet drugs were blocked by the PI3K inhibitors wortmannin and LY294002. Conclusions These results demonstrate that platelet primers can contribute to antiplatelet resistance. Furthermore, our data demonstrate that there are PI3K-dependent and PI3K-independent mechanisms driving primer-mediated resistance to antiplatelet therapy. PMID:26039631

  6. Antiplatelet Agents Inhibit the Generation of Platelet-Derived Microparticles

    Science.gov (United States)

    Giacomazzi, Alice; Degan, Maurizio; Calabria, Stefano; Meneguzzi, Alessandra; Minuz, Pietro

    2016-01-01

    Platelet microparticles (PMPs) contribute to thrombogenesis but the effects of antiplatelet drugs on PMPs generation is undefined. The present study investigated the cellular events regulating PMPs shedding, testing in vitro platelet agonists and inhibitors. Platelet-rich plasma from healthy subjects was stimulated with arachidonic acid (AA), U46619, collagen type-I (10 and 1.5 μg/mL), epinephrine, ADP or TRAP-6 and pre-incubated with acetylsalicylic acid (ASA, 100 and 10 μmol/L), SQ-29,548, apyrase, PSB-0739, or eptifibatide. PMPs were detected by flow-cytometry using CD61 and annexin-V as fluorescent markers. Platelet agonists induced annexin V-positive PMPs shedding. The strongest response was to high concentration collagen. ADP-triggered PMPs shedding was dose-independent. ASA reduced PMPs induced by AA- (645, 347–2946 vs. 3061, 446–4901 PMPs/μL; median ad range, n = 9, P PMP shedding. The crucial role of the fibrinogen receptor and the collagen receptor in PMPs generation, independently of platelet aggregation, was identified. PMID:27695417

  7. Management of anticoagulants and antiplatelet agents during colonoscopy.

    Science.gov (United States)

    Feagins, Linda Anne

    2017-03-23

    Colonoscopy frequently is performed for patients who are taking aspirin, NSAIDs, antiplatelet agents and other anticoagulants. These colonoscopies often involve polypectomy, which can be complicated by bleeding. The risks of precipitating thromboembolic complications if anticoagulants are stopped must be weighed against the risk of postpolypectomy bleeding if these agents are continued. This article systematically reviews the management of anticoagulation during elective and emergency colonoscopy. For patients undergoing colonoscopic polypectomy, the overall of risk of postpolypectomy bleeding is less than 0.5%. Risk factors for postpolypectomy bleeding include large polyp size and anticoagulant use, especially warfarin and thienopyridines. For patients who do not stop aspirin or other NSAIDs prior to colonoscopy, the rate of postpolypectomy bleeding is not significantly different than that for patients who do not take those medications. For patients who continue thienopyridines and undergo polypectomy, the risk of delayed postpolypectomy bleeding is approximately 2.4%. Even for patients who interrupt warfarin, the risk of postpolypectomy bleeding is increased. The direct oral anticoagulants (direct thrombin inhibitors and factor Xa inhibitors) have a rapid onset and offset of action, and periprocedural bridging generally is not necessary. For the thienopyridines, warfarin and the direct oral anticoagulants, the decision to interrupt or continue these agents for endoscopy will involve considerable exercise of clinical judgment.

  8. Novel anticoagulants and antiplatelet agents; a guide for the urologist.

    Science.gov (United States)

    Ellis, Gidon; John Camm, Alan; Datta, Soumendra N

    2015-11-01

    Novel oral anti-coagulants (NOACs) are increasingly being used in clinical practice and are set to almost entirely replace the vitamin K antagonists, such as warfarin, in the near future. Similarly, new antiplatelet agents are now regularly used in place of older agents, such as aspirin and clopidogrel. In an ageing population, with an increasing burden of complex comorbidities, urologists will frequently encounter patients who will be using such agents. Some background knowledge, and an understanding, of these drugs and the issues that surround their usage, is essential. The present article will provide readers with an understanding of these new drugs, including their mechanisms of action, the up-to-date evidence justifying their recent introduction into clinical practice and the appropriate interval for stopping them before surgery. It will also consider the risks of perioperative bleeding for patients taking these drugs and the risks of venous thromboembolism in those in whom they are stopped. Strategies to manage anticoagulant-associated bleeding are discussed.

  9. Antimalarial potential of leaves of Chenopodium ambrosioides L.

    Science.gov (United States)

    Cysne, Dalila Nunes; Fortes, Thiare Silva; Reis, Aramys Silva; de Paulo Ribeiro, Bruno; Dos Santos Ferreira, Amália; do Amaral, Flavia Maria Mendonça; Guerra, Rosane Nassar Meireles; Marinho, Claudio Romero Farias; Nicolete, Roberto; Nascimento, Flávia Raquel Fernandes

    2016-11-01

    In an effort to identify novel therapeutic alternatives for the treatment of malaria, the present study evaluated the antimalarial effect of the crude hydroalcoholic extract (HCE) from the leaves of Chenopodium ambrosioides L. For this purpose, the molecular affinity between the total proteins from erythrocytes infected with Plasmodium falciparum and HCE or chloroquine was evaluated by surface plasmon resonance (SPR). Subsequently, the plasmodicidal potential of HCE was assessed in a P. falciparum culture. Using BALB/c mice infected with Plasmodium berghei intraperitoneally (ip.), we evaluated the effects of ip. treatment, for three consecutive days (day 7, 8, and 9 after infection), with chloroquine (45 mg/kg) or HCE (5 mg/kg), considering the survival index and the parasitaemia. The groups were compared to an untreated control group that receives only PBS at the same periods. The results indicated that HCE could bind to the total proteins of infected erythrocytes and could inhibit the parasite growth in vitro (IC50 = 25.4 g/mL). The in vivo therapeutic treatment with HCE increased the survival and decreased the parasitaemia in the infected animals. Therefore, the HCE treatment exhibited a significant antiplasmodial effect and may be considered as a potential candidate for the development of new antimalarial drugs.

  10. Antimalarial drugs disrupt ion homeostasis in malarial parasites

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    Marcos L Gazarini

    2007-06-01

    Full Text Available Plasmodium chabaudi malaria parasite organelles are major elements for ion homeostasis and cellular signaling and also target for antimalarial drugs. By using confocal imaging of intraerythrocytic parasites we demonstrated that the dye acridine orange (AO is accumulated into P. chabaudi subcellular compartments. The AO could be released from the parasite organelles by collapsing the pH gradient with the K+/H+ ionophore nigericin (20 µM, or by inhibiting the H+-pump with bafilomycin (4 µM. Similarly, in isolated parasites loaded with calcium indicator Fluo 3-AM, bafilomycin caused calcium mobilization of the acidic calcium pool that could also be release with nigericin. Interestingly after complete release of the acidic compartments, addition of thapsigargin at 10 µM was still effective in releasing parasite intracellular calcium stores in parasites at trophozoite stage. The addition of antimalarial drugs chloroquine and artemisinin resulted in AO release from acidic compartments and also affected maintenance of calcium in ER store by using different drug concentrations.

  11. Quantifying the pharmacology of antimalarial drug combination therapy

    Science.gov (United States)

    Hastings, Ian M.; Hodel, Eva Maria; Kay, Katherine

    2016-01-01

    Most current antimalarial drugs are combinations of an artemisinin plus a ‘partner’ drug from another class, and are known as artemisinin-based combination therapies (ACTs). They are the frontline drugs in treating human malaria infections. They also have a public-health role as an essential component of recent, comprehensive scale-ups of malaria interventions and containment efforts conceived as part of longer term malaria elimination efforts. Recent reports that resistance has arisen to artemisinins has caused considerable concern. We investigate the likely impact of artemisinin resistance by quantifying the contribution artemisinins make to the overall therapeutic capacity of ACTs. We achieve this using a simple, easily understood, algebraic approach and by more sophisticated pharmacokinetic/pharmacodynamic analyses of drug action; the two approaches gave consistent results. Surprisingly, the artemisinin component typically makes a negligible contribution (≪0.0001%) to the therapeutic capacity of the most widely used ACTs and only starts to make a significant contribution to therapeutic outcome once resistance has started to evolve to the partner drugs. The main threat to antimalarial drug effectiveness and control comes from resistance evolving to the partner drugs. We therefore argue that public health policies be re-focussed to maximise the likely long-term effectiveness of the partner drugs. PMID:27604175

  12. Maximizing antimalarial efficacy and the importance of dosing strategies.

    Science.gov (United States)

    Beeson, James G; Boeuf, Philippe; Fowkes, Freya J I

    2015-05-09

    Artemisinin-based combination therapies (ACTs) are the cornerstone for the treatment of malaria. However, confirmed resistance to artemisinins in South-East Asia, and reports of reduced efficacy of ACTs raise major concerns for malaria treatment and control. Without new drugs to replace artemisinins, it is essential to define dosing strategies that maximize therapeutic efficacy, limit the spread of resistance, and preserve the clinical value of ACTs. It is important to determine the extent to which reduced efficacy of ACTs reflects true resistance versus sub-optimal dosing, and quantify other factors that determine treatment failure. Pooled analyses of individual patient data from multiple clinical trials, by investigators in the Worldwide Antimalarial Resistance Network, have shown high overall efficacy for three widely used ACTs, artemether-lumefantrine, artesunate-amodiaquine, and dihydroartemisinin-piperaquine. Analyses also highlight that suboptimal dosing leads to increased risk of treatment failure, especially among children. In the most recent study, an analysis of clinical trials of artesunate-amodiaquine, widely used among children in Africa, revealed a superior efficacy for fixed-dose combination tablets compared to loose non-fixed dose combinations. This highlights the benefits of fixed-dose combinations as a practical strategy for ensuring optimal antimalarial dosing and maximizing efficacy. Please see related article: http://www.biomedcentral.com/1741-7015/13/66.

  13. Antimalarial drug resistance in Bangladesh, 1996-2012.

    Science.gov (United States)

    Haque, Ubydul; Glass, Gregory E; Haque, Waziul; Islam, Nazrul; Roy, Shyamal; Karim, Jahirul; Noedl, Harald

    2013-12-01

    Malaria remains an important health problem in Bangladesh, with approximately 14 million people at risk. Antimalarial drug resistance is a major obstacle to the control of malaria in endemic countries. In 2012, Bangladesh reported an estimated 29 522 malaria episodes, of which 94% were reported as being caused by Plasmodium falciparum. In this study, we reviewed and summarized antimalarial drug resistance data from Bangladesh published until June 2013. We searched published sources for data referring to any type of P. falciparum drug resistance (in vivo, in vitro, or molecular) and found 169 articles published in peer-reviewed journals. Of these, 143 articles were excluded because they did not meet our inclusion criteria. After detailed review of the remaining 26 articles, 14 were selected for evaluation. Published studies indicate that P. falciparum shows varying levels of resistance to chloroquine, mefloquine and sulfadoxine-pyrimethamine. Combination therapy of chloroquine and primaquine has proven ineffective and combinations of sulfadoxine-pyrimethamine with either quinine or chloroquine have also shown poor efficacy. Recent studies indicate that artemisinin derivatives, such as artesunate, remain highly efficacious in treating P. falciparum malaria. Available data suggest that artemisinins, quinine, doxycyline, mefloquine-artesunate and azithromycin-artesunate combination therapy remain efficacious in the treatment of P. falciparum malaria in Bangladesh.

  14. The role of antimalarial treatment in the elimination of malaria.

    Science.gov (United States)

    Gosling, R D; Okell, L; Mosha, J; Chandramohan, D

    2011-11-01

    With declining transmission of malaria in several regions of the world and renewed interest in the elimination of malaria, strategies for malaria control using antimalarial drugs are being revisited. Drug-based strategies to reduce transmission of malaria need to target the asymptomatic carriers of infection. Drugs that are effective against gametocytes are few in number, but it may be possible to reduce gametocyte production by killing the asexual stages, for which more drugs are available. Drugs for use in large-scale programmes must be safe and tolerable. Strategies include improving access to treatment for malaria with an efficacious drug, intermittent-treatment programmes, and mass drug administration, with and without screening for malaria. Recent proposals have targeted high-risk groups for interventions. None of the strategies has been rigorously tested with appropriate control groups for comparison. Because of the lack of field evidence, modelling has been used. Models have shown, first, that for long-lasting effects, drug administration programmes should be linked with vector control, and second, that if elimination is the aim, programmes are likely to be more successful when applied to smaller populations of a few thousand or less. In order to sustain the gains following the scaling up of vector control and use of artemisinin combination therapies (ACTs), strategies that use antimalarials effectively need to be devised and evidence generated for the most cost-efficient way forward.

  15. Proteomics analysis of antimalarial targets of Garcinia mangostana Linn.

    Institute of Scientific and Technical Information of China (English)

    Wanna Chaijaroenkul; Artitiya Thiengsusuk; Kanchana Rungsihirunrat; Stephen Andrew Ward; Kesara Na-Bangchang

    2014-01-01

    Objective: To investigate possible protein targets for antimalarial activity of Garcinia mangostana Linn. (G. mangostana) (pericarp) in 3D7 Plasmodium falciparum clone using 2-dimensional electrophoresis and liquid chromatography mass-spectrometry (LC/MS/MS). Methods: 3D7 Plasmodium falciparum was exposed to the crude ethanolic extract of G.mangostana Linn. (pericarp) at the concentrations of 12µg/mL (IC50 level: concentration that inhibits parasite growth by 50%) and 30 µg/mL (IC90 level: concentration that inhibits parasite growth by 90%) for 12 h. Parasite proteins were separated by 2-dimensional electrophoresis and identified by LC/MS/MS.Results:At the IC50 concentration, about 82% of the expressed parasite proteins were matched with the control (non-exposed), while at the IC90 concentration, only 15% matched proteins were found. The selected protein spots from parasite exposed to the plant extract at the concentration of 12 µg/mL were identified as enzymes that play role in glycolysis pathway, i.e., phosphoglycerate mutase putative, L-lactate dehydrogenase/glyceraldehyde-3-phosphate dehydrogenase, and fructose-bisphosphate aldolase/phosphoglycerate kinase. The proteosome was found in parasite exposed to 30 µg/mL of the extract.Conclusions:Results suggest that proteins involved in the glycolysis pathway may be the targets for antimalarial activity of G. mangostana Linn. (pericarp).

  16. Proteomics analysis of antimalarial targets of Garcinia mangostana Linn.

    Institute of Scientific and Technical Information of China (English)

    Wanna; Chaijaroenkul; Artitiya; Thiengsusuk; Kanchana; Rungsihirunrat; Stephen; Andrew; Ward; Kesara; Na-Bangchang

    2014-01-01

    Objective:To investigate possible protein targets for antimalarial activity of Garcina mangostana Linn.(G.mangostana)(pericarp)in 3D7 Plasmodium falciparum clone using 2-dimensional electrophoresis and liquid chromatography mass-spectrometry(LC/MS/MS).Methods:3D7 Plasmodium falciparum was exposed to the crude ethanolic extract of G.mangostana Linn.(pericarp)at the concentrations of 12μg/mL(1C50level:concentration that inhibits parasite growth by 50%)and 30μg/mL(1C90level:concentration that inhibits parasite growth by 90%)for 12 h.Parasite proteins were separated by 2-dimensional electrophoresis and identified by LC/MS/MS.Results:At the IC50concentration,about 82%of the expressed parasite proteins were matched with the control(non-exposed),while at the IC90concentration,only 15%matched proteins were found.The selected protein spots from parasite exposed to the plant extract at the concentration of 12μg/mL were identified as eneymes that play role in glycolysis pathway,i.e.,phosphoglyeerate mutase putative,L-lactate dehydrogenase/glyceraldehyde-3-phosphate dehydrogenase,and fruetose-bisphosphate aldolase/phosphoglyeerate kinase.The proteosome was found in parasite exposed to 30μg/mL of the extract.Conclusions:Results suggest that proteins involved in the glycolysis pathway may be the targets for antimalarial activity of G.mangostana Linn.(pericarp).

  17. Plants of the Annonaceae traditionally used as antimalarials: a review

    Directory of Open Access Journals (Sweden)

    Gina Frausin

    2014-01-01

    Full Text Available Species of the Annonaceae family are used all over the tropics in traditional medicine in tropical regions for the treatment of malaria and other illnesses. Phytochemical studies of this family have revealed chemical components which could offer new alternatives for the treatment and control of malaria. Searches in scientific reference sites (SciFinder Scholar, Scielo, PubMed, ScienceDirect and ISI Web of Science and a bibliographic literature search for species of Annonaceae used traditionally to treat malaria and fever were carried out. This family contains 2,100 species in 123 genera. We encountered 113 articles reporting medicinal use of one or more species of this family including 63 species in 27 genera with uses as antimalarials and febrifuges. Even though the same species of Annonaceae are used by diverse ethnic groups, different plant parts are often chosen for applications, and diverse methods of preparation and treatment are used. The ethanol extracts of Polyalthia debilis and Xylopia aromatica proved to be quite active against Plasmodium falciparum in vitro (median inhibition concentration, IC50 < 1.5 µg/mL. Intraperitoneal injection of Annickia chlorantha aqueous extracts (cited as Enantia chlorantha cleared chloroquine-resistant Plasmodium yoelii nigeriensis from the blood of mice in a dose-dependant manner. More phytochemical profiles of Annonaceous species are required; especially information on the more commonly distributed antimalarial compounds in this family.

  18. Extended duration dual antiplatelet therapy and mortality: a systematic review and meta-analysis.

    Science.gov (United States)

    Elmariah, Sammy; Mauri, Laura; Doros, Gheorghe; Galper, Benjamin Z; O'Neill, Kelly E; Steg, Philippe Gabriel; Kereiakes, Dean J; Yeh, Robert W

    2015-02-28

    Treatment with aspirin and a P2Y12 inhibitor is commonly used in patients with cardiovascular disorders. The overall effect of such treatment on all-cause mortality is unknown. In the Dual Antiplatelet Therapy (DAPT) Study, continuation of dual antiplatelet therapy beyond 12 months after coronary stenting was associated with an unexpected increase in non-cardiovascular death. In view of the potential public health importance of these findings, we aimed to assess the effect of extended duration dual antiplatelet therapy on mortality by doing a meta-analysis of all randomised, controlled trials of treatment duration in various cardiovascular disorders. We searched Medline, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) to identify randomised controlled trials assessing the effect of extended duration versus no or short duration dual antiplatelet therapy, published before Oct 1, 2014. We did a meta-analysis to pool results with a hierarchical Bayesian random-effects model. The primary outcomes were hazard ratios comparing rates of all-cause, cardiovascular, and non-cardiovascular death. Including the DAPT Study, we identified 14 eligible trials that randomly assigned 69,644 participants to different durations of dual antiplatelet therapy. Compared with aspirin alone or short duration dual antiplatelet therapy (≤6 months), continued treatment was not associated with a difference in all-cause mortality (hazard ratio [HR] 1·05, 95% credible interval [CrI] 0·96-1·19; p=0·33). Similarly, cardiovascular (1·01, 0·93-1·12; p=0·81) and non-cardiovascular mortality (1·04, 0·90-1·26; p=0·66) were no different with extended duration versus short duration dual antiplatelet therapy or aspirin alone. Extended duration dual antiplatelet therapy was not associated with a difference in the risk of all-cause, cardiovascular, or non-cardiovascular death compared with aspirin alone or short duration dual antiplatelet therapy. None. Copyright © 2015

  19. Pre-procedural dual antiplatelet therapy in patients undergoing transcatheter aortic valve implantation increases risk of bleeding.

    Science.gov (United States)

    Hioki, Hirofumi; Watanabe, Yusuke; Kozuma, Ken; Nara, Yugo; Kawashima, Hideyuki; Kataoka, Akihisa; Yamamoto, Masanori; Takagi, Kensuke; Araki, Motoharu; Tada, Norio; Shirai, Shinichi; Yamanaka, Futoshi; Hayashida, Kentaro

    2017-03-01

    To evaluate the clinical benefit of pre-procedural antiplatelet therapy in patients undergoing transfemoral (TF) transcatheter aortic valve implantation (TAVI). OCEAN (Optimized transCathEter vAlvular interveNtion)-TAVI is a prospective, multicentre, observational cohort registry, enrolling 749 patients who underwent TAVI from October 2013 to August 2015 in Japan. We identified 540 patients (median age 85 years, 68.1% female) undergoing TF-TAVI; of these, 80 had no pre-procedural antiplatelet therapy and 460 had antiplatelet therapy. The endpoints were any bleeding (life-threatening, major, and minor bleeding) and thrombotic events (stroke, myocardial infarction, and valve thrombosis) during hospitalisation. Patients with dual antiplatelet therapy (DAPT) had a significantly higher incidence of any bleeding than those with single antiplatelet therapy (SAPT) (36.5% vs 27.5%, p=0.049) and no antiplatelet therapy (36.5% vs 21.3%, p=0.010). Patients without pre-procedural antiplatelet therapy did not experience an increased risk of thrombotic events. In multivariable logistic regression analysis, DAPT before TF-TAVI significantly increased any bleeding compared with SAPT (OR 2.05, 95% CI 1.16 to 3.65) and no antiplatelet therapy (OR 2.30, 95% CI 1.08 to 4.90). The current study demonstrated that DAPT before TF-TAVI increased the risk of bleeding compared with single or no antiplatelet therapy. Lower intensity antiplatelet therapy was not associated with thrombotic events. In modern practice, it might be reasonable to perform TAVI using single or no pre-procedural antiplatelet therapy with an expectation of no increase of adverse events. UMIN-ID; 000020423; Results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. [Risk factors of upper gastrointestinal complications in outpatients on antiplatelet therapy: description and management].

    Science.gov (United States)

    Ducrocq, G; Bigard, M-A; Marouene, S; Delaage, P-H; Fabry, C; Barthelemy, P; Steg, P-G

    2012-08-01

    Patients on antiplatelet therapy have a gastrointestinal bleeding risk. It is increased by risk factors. The frequency of those risk factors, the prevalence of upper digestive symptoms and their management in patients on antiplatelet agents is unknown. We performed an observational multi-centred prospective survey among 560 French cardiologists with private practice. Each cardiologist completed a questionnaire for the first four patients treated with antiplatelet agents in primary or secondary prevention. Among the 2182 patients included, (age = 67 ± 11 years; 74% male), 83% had at least one gastrointestinal bleeding risk factor and 38.9% had a history of upper digestive tract symptom. A history of gastrointestinal bleeding was reported in 3.4% and a history of documented gastro-duodenal ulcer in 5.5%. A proton pump inhibitor was already prescribed in 39% of the patients. At the time of the consultation, upper digestive symptoms were described in 21% of the patients. In those patients with symptoms, 85% had no modification in antiplatelet therapy and 62.7% were prescribed gastro-protective drugs (proton pump inhibitors: 51.8%, H(2)-blockers 3.6% other anti-acid medication: 7.3%). Among patients on antiplatelet agents, the prevalence of upper digestive symptoms and risk factors for gastrointestinal bleeding is high. Preventative management needs to be clarified in this population. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  1. Anti-platelet Therapy Resistance – Concept, Mechanisms and Platelet Function Tests in Intensive Care Facilities

    Directory of Open Access Journals (Sweden)

    Mărginean Alina

    2016-01-01

    Full Text Available It is well known that critically ill patients require special attention and additional consideration during their treatment and management. The multiple systems and organ dysfunctions, typical of the critical patient, often results in different patterns of enteral absorption in these patients. Anti-platelet drugs are the cornerstone in treating patients with coronary and cerebrovascular disease. Dual anti-platelet therapy with aspirin and clopidogrel is the treatment of choice in patients undergoing elective percutaneous coronary interventions and is still widely used in patients with acute coronary syndromes. However, despite the use of dual anti-platelet therapy, some patients continue to experience cardiovascular ischemic events. Recurrence of ischemic events is partly attributed to the fact that some patients have poor inhibition of platelet reactivity despite treatment. These patients are considered low- or nonresponders to therapy. The underlying mechanisms leading to resistance are not yet fully elucidated and are probably multifactorial, cellular, genetic and clinical factors being implicated. Several methods have been developed to asses platelet function and can be used to identify patients with persistent platelet reactivity, which have an increased risk of thrombosis. In this paper, the concept of anti-platelet therapy resistance, the underlying mechanisms and the methods used to identify patients with low responsiveness to anti-platelet therapy will be highlighted with a focus on aspirin and clopidogrel therapy and addressing especially critically ill patients.

  2. Managing anticoagulation and antiplatelet medications in GI endoscopy: a survey comparing the East and the West.

    Science.gov (United States)

    Lee, Sun-Young; Tang, Shou-jiang; Rockey, Don C; Weinstein, Douglas; Lara, Luis; Sreenarasimhaiah, Jayaprakash; Choi, Kyoo Wan

    2008-06-01

    Anticoagulation and antiplatelet medications may potentiate GI bleeding, and their use may lead to an increased need for a GI endoscopy. We hypothesized that there might be different practice patterns among international endoscopists. To explore the differences in management practices for patients who receive anticoagulation and antiplatelet medications from Eastern and Western endoscopists. International survey study. Academic medical centers and private clinics. Members of the American Society for Gastrointestinal Endoscopy (ASGE) in Eastern (Korea, Japan, China, India, Thailand, Singapore, Malaysia, and Philippines) and Western (United States and Canada) countries were invited to complete a Web-site-based questionnaire. In addition, the questionnaire was sent to university hospitals in South Korea and academic institutions in the United States. A survey was administered that contained detailed questions about the use of an endoscopy in patients on anticoagulation and antiplatelet medications. Different opinions and clinical practice patterns regarding the use of anticoagulation and antiplatelet medications by Eastern and Western endoscopists. A total of 105 Eastern and 106 Western endoscopists completed the survey. Western endoscopists experienced more instances of procedure-related bleeding (P = .003) and thromboembolism after withdrawal of medications (P = .016). Eastern endoscopists restarted medications later (1-3 days) than Western endoscopists after a biopsy (same day) (P education are required in the area of GI endoscopy for patients on anticoagulation and antiplatelet medications, particularly given that individual patient characteristics may be associated with unique types of complications.

  3. The Safety and Efficacy of Triple Antiplatelet Therapy after Intracranial Stent-Assisted Coil Embolization.

    Science.gov (United States)

    Matsumoto, Yoshihisa; Iko, Minoru; Tsutsumi, Masanori; Mitsutake, Takahumi; Eto, Ayumu; Nii, Kouhei; Nakai, Kanji; Oishi, Hiromichi; Aikawa, Hiroshi; Kazekawa, Kiyoshi

    2015-07-01

    Stent-assisted coil embolization is effective for intracranial aneurysms, especially for wide-necked aneurysms; however, the optimal antiplatelet regimens for postoperative ischemic events have not yet been established. We aimed at determining the efficacy and safety of a triple antiplatelet therapy regimen after intracranial stent-assisted coil embolization. We retrospectively evaluated patients who underwent stent-assisted coil embolization for unruptured intracranial aneurysms or during the chronic phase of a ruptured intracranial aneurysm (≥ 4 weeks after subarachnoid hemorrhage onset). We recorded the incidence of ischemic and bleeding events 140 days postoperatively. We assessed 79 cases in patients who received either dual (n = 51) or triple (n = 28) antiplatelet therapy. The duration of triple antiplatelet therapy was 49 ± 29 days. Seven patients in the dual group experienced postoperative ischemic events. Compared to the dual group, the triple group had a similar incidence of postoperative bleeding events but a significantly lower incidence of postoperative ischemic events (P antiplatelet therapy had a significantly lower incidence of postoperative ischemic events and a similar incidence of postoperative bleeding events 140 days postoperatively. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  4. Does Antiplatelet Therapy during Bridging Thrombolysis Increase Rates of Intracerebral Hemorrhage in Stroke Patients?

    Science.gov (United States)

    Broeg-Morvay, Anne; Mordasini, Pasquale; Slezak, Agnieszka; Liesirova, Kai; Meisterernst, Julia; Schroth, Gerhard; Arnold, Marcel; Jung, Simon; Mattle, Heinrich P; Gralla, Jan; Fischer, Urs

    2017-01-01

    Symptomatic intracerebral hemorrhage (sICH) after bridging thrombolysis for acute ischemic stroke is a devastating complication. We aimed to assess whether the additional administration of aspirin during endovascular intervention increases bleeding rates. We retrospectively compared bleeding complications and outcome in stroke patients who received bridging thrombolysis with (tPA+ASA) and without (tPA-ASA) aspirin during endovascular intervention between November 2008 and March 2014. Furthermore, we analyzed bleeding complications and outcome in antiplatelet naïve patients with those with prior or acute antiplatelet therapy. Baseline characteristics, previous medication, and dosage of rtPA did not differ between 50 tPA+ASA (39 aspirin naïve, 11 preloaded) and 181 tPA-ASA patients (p>0.05). tPA+ASA patients had more often internal carotid artery (ICA) occlusion (p0.1). There were no differences in bleeding complications and mortality among 112 bridging patients with antiplatelet therapy (62 preloaded, 39 acute administration, 11 both) and 117 antiplatelet naïve patients. In a logistic regression analysis, aspirin administration during endovascular procedure was not a predictor of sICH. Antiplatelet therapy before or during bridging thrombolysis in patients with acute ischemic stroke did not increase the risk of bleeding complications and had no impact on outcome. This finding has to be confirmed in larger studies.

  5. Spontaneous Resolution of Non Traumatic Chronic Subdural Haematoma Despite Continued Antiplatelet Therapy: A Case Report.

    Science.gov (United States)

    Tiwari, Ajeet Ramamani; Maheshwari, Shradha; Balasubramaniam, Srikant; Devendra, Tyagi; Savant, Hemantkumar

    2015-06-01

    Spontaneous resolution of traumatic chronic subdural haematoma (CSDH) has been reported in literature. However, those with non traumatic CSDH are exceedingly rare and none reported with continued antiplatelet therapy where it itself is an aetiological agent for development of non traumatic CSDH. A 50-year-old male presented to us with a non haemorrhagic cerebellar infarct with a concomitant CSDH without history of any trauma. Patient's PT/INR, Bleeding time and Clotting time were normal. Patient was started on antiplatelet therapy (Tablet Aspirin 150 mg OD) for the acute infarct. MR Brain at 1 month showed an increased size of CSDH. However patient denied surgical evacuation hence we continued conservative line of management, however we continued anti-platelet therapy with close neurological and coagulation profile monitoring that remained within normal range throughout the period of observation. CT at 5(th) month showed complete resolution of CSDH. Patient was on antiplatelet drugs throughout the period of observation. Our case argues about the role of antiplatelet therapy in patients with CSDH with contrary lesions requiring anticoagulation.

  6. Use of antiplatelet agents and anticoagulants for cardiovascular disease: current standards and best practices.

    Science.gov (United States)

    Faxon, David P

    2005-01-01

    Thrombosis superimposed on arteriosclerosis is the principal cause of mortality and morbidity in patients with arteriosclerosis. The use of antiplatelet agents and anticoagulants in the treatment of arteriosclerosis is well established, based on many large randomized trials. Aspirin is indicated for primary prevention in patients at increased risk of developing symptomatic atherosclerotic vascular disease. For patients with known vascular disease, antiplatelet therapy with aspirin is a well-established treatment. For high-risk patients such as those with acute coronary syndromes (ACS; unstable angina, myocardial infarction), dual antiplatelet therapy with aspirin and clopidogrel is indicated, based on results of the Clopidogrel in Unstable Angina to Prevent Recurrent Events (CURE) trial. Platelet glycoprotein IIb/IIIa agents are powerful inhibitors of platelet function and are also effective in ACS, but the benefit is confined to high-risk patients. Anticoagulation with heparin or low-molecular-weight heparin (eg, enoxaparin) is also effective, with an approximately 50% reduction in cardiovascular events. These agents are also indicated for patients undergoing percutaneous coronary intervention. Prolonged dual antiplatelet therapy (at least 6 months) is recommended for patients receiving drug-eluting stents. The efficacy of antiplatelet therapy is thus well established in treating atherothrombosis, but aggressive therapy is associated with an increased bleeding risk. Newer agents may provide improved efficacy with a lower risk of bleeding.

  7. A review of traditional and novel oral anticoagulant and antiplatelet therapy for dermatologists and dermatologic surgeons.

    Science.gov (United States)

    Brown, Deanna G; Wilkerson, Eric C; Love, W Elliot

    2015-03-01

    Dermatologic surgeons will increasingly encounter patients on novel oral antiplatelet and anticoagulant medications. We conducted a complete overview of the pharmacokinetics, pharmacodynamics, and side effects of traditional and novel oral anticoagulant and antiplatelet therapies along with dietary supplements with anticoagulant or antiplatelet properties. A PubMed search was completed for "aspirin," "warfarin," "clopidogrel," "dabigatran," "rivaroxaban," "apixaban," "prasugrel," and "ticagrelor." Review articles and publications emphasizing perioperative management of oral anticoagulant or antiplatelet medications were selected. An additional PubMed search was completed for "hemorrhage," "bleeding," and "thrombosis" in conjunction with "dermatology," "dermatologic surgery," and "cutaneous surgery." Aspirin, clopidogrel, and warfarin have shortfalls in dosing, monitoring, and efficacy. Several trials show superior efficacy with dabigatran, rivaroxaban, and apixaban, with equal or reduced risk of bleeding compared with warfarin. Prasugrel and ticagrelor may be associated with an increased bleeding risk. Many over-the-counter medications also have anticoagulant properties with associated bleeding risks that cannot be overlooked. There are few publications evaluating the novel oral anticoagulants' effects on outpatient surgical procedures. Novel anticoagulant and antiplatelet drugs are revolutionizing therapy for cardiovascular diseases. As these medications become more prevalent, dermatologists and dermatologic surgeons must be mindful of the bleeding risk that will apply in our everyday practices. Copyright © 2014 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  8. The pharmacogenetic control of antiplatelet response: candidate genes and CYP2C19.

    Science.gov (United States)

    Yang, Yao; Lewis, Joshua P; Hulot, Jean-Sébastien; Scott, Stuart A

    2015-01-01

    Aspirin, clopidogrel, prasugrel and ticagrelor are antiplatelet agents for the prevention of ischemic events in patients with acute coronary syndromes (ACS), percutaneous coronary intervention (PCI) and other indications. Variability in response is observed to different degrees with these agents, which can translate to increased risks for adverse cardiovascular events. As such, potential pharmacogenetic determinants of antiplatelet pharmacokinetics, pharmacodynamics and clinical outcomes have been actively studied. This article provides an overview of the available antiplatelet pharmacogenetics literature. Evidence supporting the significance of candidate genes and their potential influence on antiplatelet response and clinical outcomes are summarized and evaluated. Additional focus is directed at CYP2C19 and clopidogrel response, including the availability of clinical testing and genotype-directed antiplatelet therapy. The reported aspirin response candidate genes have not been adequately replicated and few candidate genes have thus far been implicated in prasugrel or ticagrelor response. However, abundant data support the clinical validity of CYP2C19 and clopidogrel response variability among ACS/PCI patients. Although limited prospective trial data are available to support the utility of routine CYP2C19 testing, the increased risks for reduced clopidogrel efficacy among ACS/PCI patients that carry CYP2C19 loss-of-function alleles should be considered when genotype results are available.

  9. Antiplatelet Therapy Considerations in Ischemic Cardiogenic Shock: Implications of Metabolic Bioactivation.

    Science.gov (United States)

    Weeks, Phillip A; Sieg, Adam; Paruthi, Christina; Rajapreyar, Indranee

    2015-07-01

    Dual antiplatelet therapy with aspirin and a P2Y12 receptor antagonist remains a mainstay in the prevention of ischemic events following coronary stent placement. Significant controversy exists regarding the optimal management of high platelet reactivity despite antiplatelet therapy; however this finding has been consistently associated with poor clinical outcomes including greater risk of stent thrombosis and myocardial infarction. Variability in antiplatelet effects of clopidogrel and prasugrel has been linked to genetic polymorphisms and potential drug-drug interactions. Both of these factors have significant influence on the cytochrome P-450 enzyme system activity of the liver responsible for their biotransformation to the active form of both drugs. Very little has been publicized regarding differences in antiplatelet effects which may be associated with conditions in which the functional capacity of the liver may be temporarily compromised. Patients who present with cardiogenic shock due to acute coronary syndromes have evidence of multiorgan dysfunction including liver dysfunction that may affect the activity of these drugs. This review aims to explore existing evidence and propose additional considerations to the selection of antiplatelet therapy in patients with cardiogenic shock who receive catheter-based revascularization and stent placement.

  10. Analytical sample preparation strategies for the determination of antimalarial drugs in human whole blood, plasma and urine

    DEFF Research Database (Denmark)

    Casas, Monica Escolà; Hansen, Martin; Krogh, Kristine A;

    2014-01-01

    Antimalarial drugs commonly referred to as antimalarials, include a variety of compounds with different physicochemical properties. There is a lack of information on antimalarial distribution in the body over time after administration, e.g. the drug concentrations in whole blood, plasma, and urin...... summarized. Finally, the main problems that the researchers have dealt with are highlighted. This information will aid analytical chemists in the development of novel methods for determining existing antimalarials and upcoming new drugs.......Antimalarial drugs commonly referred to as antimalarials, include a variety of compounds with different physicochemical properties. There is a lack of information on antimalarial distribution in the body over time after administration, e.g. the drug concentrations in whole blood, plasma, and urine...

  11. In vitro antimalarial activity and cytotoxicity of some selected cuban medicinal plants.

    Science.gov (United States)

    Valdés, Aymé Fernández-Calienes; Martínez, Judith Mendiola; Lizama, Ramón Scull; Gaitén, Yamilet Gutiérrez; Rodríguez, Deyanira Acuña; Payrol, Juan Abreu

    2010-01-01

    Terrestrial plants have been demonstrated to be sources of antimalarial compounds. In Cuba, little is known about antimalarial potentials of plant species used as medicinals. For that reason, we evaluated the antimalarial activity of 14 plant species used in Cuba as antimalarial, antipyretic and/or antiparasitic. Hydroalcoholic extracts were prepared and tested in vitro for the antimalarial activity against Plasmodium falciparum Ghana strain and over human cell line MRC-5 to determine cytotoxicity. Parasite multiplication was determined microscopically by the direct count of Giemsa stained parasites. A colorimetric assay was used to quantify cytotoxicity. Nine extracts showed IC50 values lower than 100 µg/mL against P. falciparum, four extracts were classified as marginally active (SI 10. B. vulgaris showed the most potent and specific antiplasmodial action (IC50 = 4.7 µg/mL, SI = 28.9). Phytochemical characterization of active extracts confirmed the presence of triterpenoids in B. vulgaris and polar compounds with phenol free groups and fluorescent metabolites in both extracts as major phytocompounds, by thin layer chromatography. In conclusion, antimalarial use of B. vulgaris and P. hysterophorus was validated. B. vulgaris and P. granatum extracts were selected for follow-up because of their strong antimalarial activity.

  12. Role of sodium tungstate as a potential antiplatelet agent

    Directory of Open Access Journals (Sweden)

    Fernández-Ruiz R

    2015-05-01

    Full Text Available Rebeca Fernández-Ruiz,1,2 Marc Pino,3 Begoña Hurtado,4 Pablo García de Frutos,4 Carolina Caballo,3 Ginés Escolar,3 Ramón Gomis,1,2,5 Maribel Diaz-Ricart3 1Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomediques August Pi i Sunyer (IDIBAPS, Rosellón, Barcelona, 2Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Barcelona, 3Hemotherapy–Hemostasis, Hospital Clínic, Universidad de Barcelona, IDIBAPS, Villarroel, Barcelona, 4Institutode Investigaciones Biomédicas de Barcelona, Consejo Superior de Investigaciones Científicas, Institut d’Investigacions Biomediques August Pi i Sunyer, Rosellón, Barcelona, 5Hospital Clinic, Universitat de Barcelona, Villarroel, Barcelona, Spain Purpose: Platelet inhibition is a key strategy in the management of atherothrombosis. However, the large variability in response to current strategies leads to the search for alternative inhibitors. The antiplatelet effect of the inorganic salt sodium tungstate (Na2O4W, a protein tyrosine phosphatase 1B (PTP1B inhibitor, has been investigated in this study.Methods: Wild-type (WT and PTP1B knockout (PTP1B-/- mice were treated for 1 week with Na2O4W to study platelet function with the platelet function analyzer PFA-100, a cone-and-plate analyzer, a flat perfusion chamber, and thrombus formation in vivo. Human blood aliquots were incubated with Na2O4W for 1 hour to measure platelet function using the PFA-100 and the annular perfusion chamber. Aggregometry and thromboelastometry were also performed.Results: In WT mice, Na2O4W treatment prolonged closure times in the PFA-100 and decreased the surface covered (%SC by platelets on collagen. Thrombi formed in a thrombosis mice model were smaller in animals treated with Na2O4W (4.6±0.7 mg vs 8.9±0.7 mg; P<0.001. Results with Na2O4W were similar to those in untreated PTP1B-/- mice (5.0±0.3 mg. Treatment of the PTP1B-/- mice with Na2O4W modified only

  13. The impact of antiplatelet drugs on trauma outcomes.

    Science.gov (United States)

    Ferraris, Victor A; Bernard, Andrew C; Hyde, Brannon

    2012-08-01

    Antiplatelet drugs (APDs) are among the most commonly prescribed medications.We wondered whether patients with trauma receiving preinjury APD have worse outcomes. We interrogated our institutional database during a 5-year period to evaluate preoperative risks and trauma outcomes in patients taking APDs before traumatic injury. We used propensity balancing scores to adjust for preoperative risks in assessing outcomes in APD-treated patients. During a 5-year period, 1,327 (11.7%) of 11,374 adult patients with trauma took APDs before injury. The yearly use of APD in patients with trauma increased nearly threefold during the study period. Cardiac, pulmonary, and renal comorbidities were significantly more common in APD-treated patients. Multivariate regression indicated that preinjury APDs predicted significantly worse composite morbidity and mortality. After propensity adjustment for preinjury risk factors, APD-treated patients demonstrated significantly increased composite morbidity (39.0 vs. 24.6%, p = 0.037) and cardiac complications (23.0 vs. 17.3%, p = 0.017) compared with patients without APDs. The type and intensity of APD conferred an incremental risk, with patients taking dual APDs having a significantly worse multivariate risk of adverse outcomes compared with patients taking a single APD. APD-treated patients with trauma have significantly more comorbidities compared with those not taking APDs. After adjusting for preoperative risks, APD-treated patients have significantly worse trauma outcomes. Dual APD treatment confers an incremental risk of adverse outcomes compared with single APD preinjury treatment. The number of patients with trauma taking APDs increased during the 5-year study period, so we speculate that trauma management of patients taking APDs will occur more commonly in the future.

  14. [Hip fracture, antiplatelet drugs treatment and postoperative complications].

    Science.gov (United States)

    Reguant, F; Martínez, E; Gil, B; Prieto, J C; del Milagro Jiménez, L; Arnau, A; Bosch, J

    2013-11-01

    To assess the incidence of postoperative complications, blood transfusions and survival at one month, in the old patients operated for hip fracture undergoing chronic treatment with antiplatelet drugs. Two hundred twenty three patients operated for hip fracture were studied retrospectively, separated into 3 groups: patients who received acetylsalicylic acid (group I), patients who were given 100mg/day of acetylsalicylic acid or 300mg/day of triflusal (group II) and patients receiving>100mg/day of acetylsalicylic acid, or>300mg/day of triflusal or thienopyridines (group III). Surgery was delayed for 4 days in patients in group III. Demographic, biological, clinical and treatment characteristics, postoperative complications and survival at one month were recorded. Patients in group III were older and sustain worse general health status. Patients with a higher transfusion requirement were those of group II (73.8%) (P=0.192), who also showed a higher percentage of anaemia on admission. Severe cardiovascular complications were experienced by 5.4% of group III patients, 4.8% of group II patients and 2.1% of group I patients. Patients from group III presented a significant amount of respiratory complications (P=0.007). Our results suggest that delaying surgery for 4 days in patients treated with clopidogrel can be associated to an increase in postoperative respiratory complications and severe adverse cardiovascular events, without increasing the tranfusional index, hospital stay, mortality, and without complications related to neuraxial anaesthesia. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

  15. Detection of experimental pulmonary emboli using radiolabeled monoclonal antiplatelet antibody

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Tomiyoshi (Fukushima Medical Coll. (Japan))

    1988-12-01

    This study compared the ability of radiolabeled anti-platelet antibody (7E3) and Tc-99m macroaggregated albumin (MAA) to detect pulmonary emboli induced by thrombin and barium or by thrombogenic copper coils in mongrel dogs. In-111 diethylene triamine pentaacetic acid-7E3-F (ab'){sub 2} was incubated with platelet-rich plasma before i.v. administration to minimize unbound antibody. Serial planar images were obtained over a 4-5 hour, followed by single photon emission computed tomography (SPECT) images. Similarly, planar and SPECT images were obtained after i.v. injection of Tc-99m MAA. The animals were autopsied for the confirmation of embolus localization. A total of 34 emboli were recovered. When the In-111 or Tc-99m activity for the lung distal to an embolus was {le}10% of the normal lung one, an occlusive embolus was regarded as present. Eighteen emboli were considered occlusive and the 16 others non-occlusive. In-111 antibody imaging revealed: 14 emboli (41%)--6 occlusive and 8 non-occlusive emboli--by planar study and 22 emboli (65%)--13 occlusive and 9 non-occlusive-- by SPECT study. In detecting occlusive emboli, SPECT was significantly superior to planar imaging with In-111. Conventional lung perfusion imaging with Tc-99m MAA, whether by planar or SPECT study, revealed 18 emboli (53%), consisting of 11 occlusive and 7 non-occlusive emboli. It is concluded that SPECT with In-111 platelets is equivalent or sometimes superior to lung perfusion imaging with Tc-99m MAA, especially in detecting non-occlusive emboli.

  16. Is anti-platelet therapy interruption a real clinical issue? Its implications in dentistry and particularly in periodontics.

    Science.gov (United States)

    Kumar, A Jaya; Kumari, M Meena; Arora, Nupur; Haritha, A

    2009-09-01

    The use of anti-platelet therapy has reduced the mortality and morbidity of cardiovascular disease remarkably. A considerable number of patients presenting before a dentist or periodontist give a history of anti-platelet therapy. A clinical dilemma whether to discontinue the anti-platelet therapy or continue the same always confronts the practitioner. Diverse opinions exist regarding the management of such patients. While one group of researchers advise continuation of anti-platelet therapy rather than invite remote, but possible, thromboembolic events, another group encourages discontinuation for variable periods. This study aims at reviewing the current rationale of anti-platelet therapy and the various options available to a clinician, with regard to the management of a patient under anti-platelet therapy. Current recommendations and consensus favour no discontinuation of anti-platelet therapy. This recommendation, however, comes with a rider to use caution and consider other mitigating factors as well. With a large number of patients giving a history of anti-platelet therapy, the topic is of interest and helps a clinician to arrive at a decision.

  17. Ultra-Early Combination Antiplatelet Therapy with Cilostazol for the Prevention of Branch Atheromatous Disease: A Multicenter Prospective Study.

    Science.gov (United States)

    Kimura, Teruo; Tucker, Adam; Sugimura, Toshihide; Seki, Toshitaka; Fukuda, Shin; Takeuchi, Satoru; Miyata, Shiro; Fujita, Tsutomu; Hashizume, Akira; Izumi, Naoto; Kawasaki, Kazutsune; Katsuno, Makoto; Hashimoto, Masaaki; Sako, Kazuhiro

    2016-01-01

    The optimal use of antiplatelet therapy for intracranial branch atheromatous disease (BAD) is not known. We conducted a prospective multicenter, single-group trial of 144 consecutive patients diagnosed with probable BAD. All patients were treated within 12 h of symptom onset to prevent clinical progression using dual antiplatelet therapy with cilostazol plus one oral antiplatelet drug (aspirin or clopidogrel). Endpoints of progressive BAD in the dual therapy group at 2 weeks were compared with a matched historical control group of 142 patients treated with single oral antiplatelet therapy using either cilostazol, aspirin, or clopidogrel. Progressive motor paresis occurred in 14 patients (9.7%) in the aggressive antiplatelet group, compared with 48 (33.8%) in the matched single antiplatelet group. Multivariate logistic regression analysis revealed the following variables to be associated with a better prognosis for BAD: baseline modified Rankin Scale score, dual oral antiplatelet therapy with cilostazol, and dyslipidemia (odds ratios of 0.616, 0.445, and 0.297, respectively). Hypertension was associated with a worse prognosis for BAD (odds ratio of 1.955). Our trial showed that clinical progression of BAD was significantly reduced with the administration of ultra-early aggressive combination therapy using cilostazol compared to treatment with antiplatelet monotherapy. © 2016 The Author(s) Published by S. Karger AG, Basel.

  18. HMG-CoA reductase inhibitors, other lipid-lowering medication, antiplatelet therapy, and the risk of venous thrombosis

    NARCIS (Netherlands)

    Ramcharan, A.S.; van Stralen, K.J.; Snoep, J.D.; Mantel-Teeuwisse, A.K.; Doggen, Catharina Jacoba Maria

    2009-01-01

    Background: Statins [3-hydroxymethyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors] and antiplatelet therapy reduce the risk of atherosclerotic disease. Besides a reduction of lipid levels, statins might also have antithrombotic and anti-inflammatory properties, and anti-platelet

  19. HMG-CoA reductase inhibitors, other lipid-lowering medication, antiplatelet therapy, and the risk of venous thrombosis

    NARCIS (Netherlands)

    Ramcharan, A.S.; Stralen, van K.J.; Snoep, J.D.; Mantel-Teeuwisse, A.K.; Doggen, C.J.M.

    2009-01-01

    Background: Statins [3-hydroxymethyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors] and antiplatelet therapy reduce the risk of atherosclerotic disease. Besides a reduction of lipid levels, statins might also have antithrombotic and anti-inflammatory properties, and anti-platelet therap

  20. Is anti-platelet therapy interruption a real clinical issue? Its implications in dentistry and particularly in periodontics

    Directory of Open Access Journals (Sweden)

    Kumar A

    2009-01-01

    Full Text Available The use of anti-platelet therapy has reduced the mortality and morbidity of cardiovascular disease remarkably. A considerable number of patients presenting before a dentist or periodontist give a history of anti-platelet therapy. A clinical dilemma whether to discontinue the anti-platelet therapy or continue the same always confronts the practitioner. Diverse opinions exist regarding the management of such patients. While one group of researchers advise continuation of anti-platelet therapy rather than invite remote, but possible, thromboembolic events, another group encourages discontinuation for variable periods. This study aims at reviewing the current rationale of anti-platelet therapy and the various options available to a clinician, with regard to the management of a patient under anti-platelet therapy. Current recommendations and consensus favour no discontinuation of anti-platelet therapy. This recommendation, however, comes with a rider to use caution and consider other mitigating factors as well. With a large number of patients giving a history of anti-platelet therapy, the topic is of interest and helps a clinician to arrive at a decision.

  1. A review of the use of common antiplatelet agents in orthopaedic practice.

    LENUS (Irish Health Repository)

    Dineen, P F

    2010-09-01

    Antiplatelet agents are widely prescribed for the primary and secondary prevention of cardiovascular events. A common clinical problem facing orthopaedic and trauma surgeons is how to manage patients receiving these agents who require surgery, either electively or following trauma. The dilemma is to balance the risk of increased blood loss if the antiplatelet agents are continued peri-operatively against the risk of coronary artery\\/stent thrombosis and\\/or other vascular event if the drugs are stopped. The traditional approach of stopping these medications up to two weeks before surgery appears to pose significant danger to patients and may require review. This paper covers the important aspects regarding the two most commonly prescribed antiplatelet agents, aspirin and clopidogrel.

  2. Subdural haematoma complicating shunting for normal pressure hydrocephalus in the setting of concomitant antiplatelet medication

    DEFF Research Database (Denmark)

    Birkeland, Peter; Lauritsen, Jens; Poulsen, Frantz Rom

    2016-01-01

    OBJECTIVE: To report on the occurrence and management of subdural haematoma after shunt implantation for normal pressure hydrocephalus and to determine the risk of recurrence in the setting of antiplatelet medication. METHODS: From a consecutive series of 80 patients implanted with a cerebrospinal...... fluid shunt for normal pressure hydrocephalus, records from 11 patients taking antiplatelet drugs, who subsequently had surgery for subdural haematoma were extracted and retrospectively reviewed. RESULTS: Patients were followed up for a mean of 1819 days after shunt implantation. Subdural haematomas...... reoperations done before the subdural collection disappeared. Only one patient had a late recurrence almost 11 years after shunt implantation. CONCLUSIONS: Subdural haematoma in the setting of a ventriculoperitoneal implantation for normal pressure hydrocephalus and concomitant antiplatelet medication can...

  3. Review of atrial fibrillation outcome trials of oral anticoagulant and antiplatelet agents.

    Science.gov (United States)

    Bassand, Jean-Pierre

    2012-03-01

    Atrial fibrillation (AF) is strongly associated with cardioembolic stroke, and thromboprophylaxis is an established means of reducing stroke risk in patients with AF. Oral vitamin K antagonists such as warfarin have been the mainstay of therapy for stroke prevention in patients with AF. However, they are associated with a number of limitations, including excessive bleeding when not adequately controlled. Antiplatelet agents do not match vitamin K antagonists in terms of their preventive efficacy. Dual-antiplatelet therapy (clopidogrel and acetylsalicylic acid) or combined antiplatelet-vitamin K antagonist therapy in AF has also failed to provide convincing evidence of their additional benefit over vitamin K antagonists alone. Novel oral anticoagulants, including the direct thrombin inhibitor dabigatran and direct Factor Xa inhibitors such as rivaroxaban, apixaban, and edoxaban, have now been approved or are currently in late-stage clinical development in AF. These newer agents may provide a breakthrough in the optimal management of stroke risk.

  4. Current antiplatelet agents: place in therapy and role of genetic testing.

    Science.gov (United States)

    Yang, Eugene

    2015-04-01

    Antiplatelet therapies play a central role in reducing the risk of cardiovascular events such as myocardial infarction and stroke. While aspirin, a cyclo-oxygenase-1 inhibitor has been the cornerstone of antithrombotic treatment for several decades, P2Y12 receptor inhibitors cangrelor, clopidogrel, prasugrel, and ticagrelor and protease-activated receptor-1 antagonist vorapaxar, have emerged as additional therapies to reduce the risk of recurrent cardiovascular events in high-risk patients. Recent clinical trials evaluating the role of these agents and major society guideline updates for use of antiplatelet therapies for secondary prevention of cardiovascular events will be examined. The latest studies regarding the appropriate duration of dual antiplatelet therapy after percutaneous coronary intervention will be presented. The current state of genetic and platelet function testing will be reviewed.

  5. Antiplatelets versus anticoagulants for the treatment of cervical artery dissection: Bayesian meta-analysis.

    Directory of Open Access Journals (Sweden)

    Hakan Sarikaya

    Full Text Available OBJECTIVE: To compare the effects of antiplatelets and anticoagulants on stroke and death in patients with acute cervical artery dissection. DESIGN: Systematic review with Bayesian meta-analysis. DATA SOURCES: The reviewers searched MEDLINE and EMBASE from inception to November 2012, checked reference lists, and contacted authors. STUDY SELECTION: Studies were eligible if they were randomised, quasi-randomised or observational comparisons of antiplatelets and anticoagulants in patients with cervical artery dissection. DATA EXTRACTION: Data were extracted by one reviewer and checked by another. Bayesian techniques were used to appropriately account for studies with scarce event data and imbalances in the size of comparison groups. DATA SYNTHESIS: Thirty-seven studies (1991 patients were included. We found no randomised trial. The primary analysis revealed a large treatment effect in favour of antiplatelets for preventing the primary composite outcome of ischaemic stroke, intracranial haemorrhage or death within the first 3 months after treatment initiation (relative risk 0.32, 95% credibility interval 0.12 to 0.63, while the degree of between-study heterogeneity was moderate (τ(2 = 0.18. In an analysis restricted to studies of higher methodological quality, the possible advantage of antiplatelets over anticoagulants was less obvious than in the main analysis (relative risk 0.73, 95% credibility interval 0.17 to 2.30. CONCLUSION: In view of these results and the safety advantages, easier usage and lower cost of antiplatelets, we conclude that antiplatelets should be given precedence over anticoagulants as a first line treatment in patients with cervical artery dissection unless results of an adequately powered randomised trial suggest the opposite.

  6. [Safety of intravenous thrombolysis in cerebral microbleeds patients with prior antiplatelet therapy].

    Science.gov (United States)

    Yan, Shen-qiang; Mao, Ying-ying; Zhong, Gen-long; Zhang, Sheng; Lou, Min

    2015-11-01

    To evaluate the safety of intravenous thrombolysis (IVT) in cerebral microbleeds (CMBs) patients with prior antiplatelet therapy. Four hundred and forty nine patients with acute ischemic stroke aged (66.8 ± 12.9) years, including 298 males and 151 females, underwent susceptibility-weighted imaging (SWI) examination and MRI-guided IVT therapy between June 2009 and June 2015. The presence of CMBs, previous antiplatelet therapy, HT subtypes according to ECASS II criteria and functional outcome based on modified Rankin scale (mRS) at 3 months were analyzed in logistic regression model. Total 934 CMBs were detected in 172 (38.3%) patients, among whom 63 (14.0%) previously received antiplatelet therapy. All patients received intravenous recombinant tissue-plasminogen activator (rt-PA) for thrombolysis with the onset-to needle time of (229.0 ± 103.7) min. The pretreatment National Institutes of Health Stroke Scale (NIHSS) score was 10 (IQR 5-15). Logistic regression analysis indicated that prior antiplatelet use increased neither risk of parenchymal hematoma (PH) (OR=0.809,95% CI:0.201-3.262, P=0.766) nor adverse functional outcome (OR=1.517, 95% CI:0.504-4.568, P=0.459) in patients with CMBs; while in patients with multiple CMBs (≥ 3) prior antiplatelet use increased risk of hemorrhagic transformation (OR=9.737, 95% CI: 1.364-69.494, P=0.023), but not adverse functional outcome (OR=1.697, 95% CI:0.275-10.487, P=0.569). The study indicates that in patients with CMBs, thrombolytic therapy should not be excluded due to the prior use of antiplatelet; however, the larger prospective studies are needed in future for patients with multiple CMBs.

  7. Interruption to antiplatelet therapy early after acute ischaemic stroke: a nested case-control study.

    Science.gov (United States)

    Mazlan-Kepli, Wardati; Macisaac, Rachael L; Walters, Matthew; Bath, Philip Michael William; Dawson, Jesse

    2017-09-01

    Antiplatelet drugs are often discontinued early after ischaemic stroke, either because of poor compliance, complications or withdrawal of care. It is unclear whether this places patients at increased risk of recurrence. We explored the association between cardiovascular event rate and persistence with prescribed antiplatelet drugs. We used a matched case-control design using the Virtual International Stroke Trials Archive (VISTA). Cases were patients who had an acute coronary syndrome, recurrent stroke or transient ischaemic attack within 90 days post-stroke and were matched for age ± 10 years and sex with up to four controls. Antiplatelet use was categorized as persistent (used for >3 days and continued up to day 90), early cessation (used antiplatelet 3 days but stopped prior to day 90). These categories were compared in cases and controls using a conditional logistic regression model that adjusted for potential confounders. A total of 970 patients were included, of whom 194 were cases and 776 were matched controls. At 90 days, 10 cases (5.2%) and 58 controls (7.5%) stopped/interrupted their antiplatelet. The risk of cardiovascular event was not different in stopped/interrupted users (adjusted odds ratio 0.70, 95% confidence interval 0.33, 1.48; P = 0.352) and early cessations (adjusted odds ratio 1.04, 95% confidence interval 0.62, 1.74; P = 0.876) when compared to persistent users. We found no increased risk in patients who stopped and interrupted antiplatelets early after stroke but the study was limited by a small sample size and further research is needed. © 2017 The British Pharmacological Society.

  8. Impairment of aspirin antiplatelet effects by non-opioid analgesic medication

    Institute of Scientific and Technical Information of China (English)

    Amin; Polzin; Thomas; Hohlfeld; Malte; Kelm; Tobias; Zeus

    2015-01-01

    Aspirin is the mainstay in prophylaxis of cardiovascular diseases. Impaired aspirin antiplatelet effects are associated with enhanced incidence of cardiovascular events. Comedication with non-opioid analgesic drugs has been described to interfere with aspirin,resulting in impaired aspirin antiplatelet effects. Additionally,nonopioid analgesic medication has been shown to enhance the risk of cardiovascular events and death. Pain is very frequent and many patients rely on analgesic drugs to control pain. Therefore effective analgesic options without increased risk of cardiovascular events are desirable. This review focuses on commonly used nonopioid analgesics,interactions with aspirin medication and impact on cardiovascular risk.

  9. Efficacy of antiplatelet therapy for treating lacunar infarct: Meta-analysis

    Directory of Open Access Journals (Sweden)

    Da XU

    2017-03-01

    Full Text Available   Objective To evaluate the efficacy of antiplatelet agents in secondary prevention of patients with lacunar infarct (LACI. Methods Retrieve relevant randomized controlled trials (RCTs that reported antiplatelet therapy in patients with LACI from online databases (January 1, 1980-November 20, 2016 in PubMed, EMBASE/SCOPUS and Cochrane Online Library with key words: stroke, lacunar infarction, platelet aggregation inhibitors, antiplatelet, randomized controlled trial. Quality of studies was evaluated by using Jadad Scale and Cochrane Handbook for Systematic Reviews of Interventions. All data were pooled by RevMan 5.3 software for Meta-analysis. A network Meta-analysis was done by R software Gemtc and JAGS software. Results A total of 4068 articles were enrolled and 12 high - quality RCTs (Jadad ≥ 4 scores with 24 969 eligible participants were finally included after excluding duplicates and those not meeting the inclusion criteria. Meta-analysis showed single antiplatelet therapy was more effective than placebo in reducing ischemic stroke recurrence rate (RR = 0.480, 95%CI: 0.300-0.780; P = 0.003 and any stroke recurrence rate (RR = 0.780, 95%CI: 0.630-0.970; P = 0.030. The efficacy of single antiplatelet therapy was not significantly different from that of dual antiplatelet therapy (ischemic stroke recurrence rate: RR = 0.900, 95%CI: 0.760-1.050, P = 0.170; any stroke recurrence rate: RR = 0.910, 95%CI: 0.820-1.010, P = 0.070. Network Meta-analysis (four interventions including aspirin, placebo, cilostazol and ticlopidine showed that cilostazol was associated with a significant reduction in recurrence of any stroke compared with aspirin (OR = 0.341, 95% CrI: 0.011-0.673 and placebo (OR = 0.615, 95% CrI: 0.191-1.042. Conclusions Single antiplatelet therapy could significantly reduce the recurrence of any stroke, especially ischemic stroke in patients with LACI. There is no evidence showing that dual antiplatelet therapy is probably better

  10. The role of anticoagulants, antiplatelet agents, and their reversal strategies in the management of intracerebral hemorrhage.

    Science.gov (United States)

    James, Robert F; Palys, Viktoras; Lomboy, Jason R; Lamm, J Richard; Simon, Scott D

    2013-05-01

    New anticoagulant and antiplatelet medications have been approved and are prescribed with increased frequency. Intracranial hemorrhage is associated with the use of these medications. Therefore, neurosurgeons need to be aware of these new medications, how they are different from their predecessors, and the strategies for the urgent reversal of their effects. Utilization of intraluminal stents by endovascular neurosurgeons has resulted in the need to have a thorough understanding of antiplatelet agents. Increased use of dabigatran, rivaroxaban, and apixaban as oral anticoagulants for the treatment of atrial fibrillation and acute deep venous thrombosis has increased despite the lack of known antidotes to these medications.

  11. Does antiplatelet therapy increase the risk of hemoptysis during percutaneous transthoracic needle biopsy of a pulmonary lesion?

    Science.gov (United States)

    Song, Yong Sub; Park, Chang Min; Park, Kyung Woo; Kim, Kwang Gi; Lee, Hyun-Ju; Shim, Mi-Suk; Goo, Jin Mo

    2013-05-01

    The purpose of this article is to evaluate whether antiplatelet therapy increases the occurrence and severity of percutaneous transthoracic needle biopsy (PTNB)-related hemoptysis. Our institutional review board approved this retrospective study, with waiver of informed consent. From May 2007 to December 2009, 1251 patients undergoing 1346 PTNBs constituted our study population. Of these PTNBs, 163 were performed in patients who had suspended antiplatelet therapy for less than 10 days (mean discontinuation time, 2.56 ± 2.35 days), and these patients were classified as antiplatelet agent users: 143 patients with single aspirin (mean discontinuation time, 2.55 ± 2.35 days), 12 patients with single clopidogrel (mean discontinuation time, 2.33 ± 2.10 days), and eight patients with dual-antiplatelet therapy (i.e., aspirin plus clopidogrel; mean discontinuation time, 3.12 ± 2.90 days). The influence of antiplatelet therapy on the occurrence and severity of PTNB-related hemoptysis was retrospectively evaluated. Among 1346 PTNBs, there were 128 cases (9.5%) of hemoptysis, including 21 cases of severe hemoptysis (1.6%). Multivariate analysis revealed that dual-antiplatelet therapy (odds ratio [OR], 10.09), female sex (OR, 1.88), smaller lesions (OR, 0.88), deeply located lesions (OR, 1.17), and the use of cutting needles (OR, 3.22) were independent risk factors for overall hemoptysis. For severe hemoptysis, dual-antiplatelet therapy (OR, 13.02), ground-glass nodules (OR, 8.86), and deeply located lesions (OR, 1.24) were proven to be independent risk factors. Single-antiplatelet therapy suspended for less than 10 days was not a significant risk factor for either overall or severe hemoptysis. Single-antiplatelet therapy suspended for less than 10 days is not an independent risk factor for the occurrence of PTNB-related hemoptysis, whereas dual-antiplatelet therapy increases its risk.

  12. The antimalarial drug quinine interferes with serotonin biosynthesis and action.

    Science.gov (United States)

    Islahudin, Farida; Tindall, Sarah M; Mellor, Ian R; Swift, Karen; Christensen, Hans E M; Fone, Kevin C F; Pleass, Richard J; Ting, Kang-Nee; Avery, Simon V

    2014-01-01

    The major antimalarial drug quinine perturbs uptake of the essential amino acid tryptophan, and patients with low plasma tryptophan are predisposed to adverse quinine reactions; symptoms of which are similar to indications of tryptophan depletion. As tryptophan is a precursor of the neurotransmitter serotonin (5-HT), here we test the hypothesis that quinine disrupts serotonin function. Quinine inhibited serotonin-induced proliferation of yeast as well as human (SHSY5Y) cells. One possible cause of this effect is through inhibition of 5-HT receptor activation by quinine, as we observed here. Furthermore, cells exhibited marked decreases in serotonin production during incubation with quinine. By assaying activity and kinetics of the rate-limiting enzyme for serotonin biosynthesis, tryptophan hydroxylase (TPH2), we showed that quinine competitively inhibits TPH2 in the presence of the substrate tryptophan. The study shows that quinine disrupts both serotonin biosynthesis and function, giving important new insight to the action of quinine on mammalian cells.

  13. Characterization of counterfeit artesunate antimalarial tablets from southeast Asia.

    Science.gov (United States)

    Hall, Krystyn Alter; Newton, Paul N; Green, Michael D; De Veij, Marleen; Vandenabeele, Peter; Pizzanelli, David; Mayxay, Mayfong; Dondorp, Arjen; Fernandez, Facundo M

    2006-11-01

    In southeast Asia, the widespread high prevalence of counterfeits tablets of the vital antimalarial artesunate is of great public health concern. To assess the seriousness of this problem, we quantified the amount of active ingredient present in artesunate tablets by liquid chromatography coupled to mass spectrometry. This method, in conjunction with analysis of the packaging, classified tablets as genuine, substandard, or fake and validated results of the colorimetric Fast Red TR test. Eight (35%) of 23 fake artesunate samples contained the wrong active ingredients, which were identified as different erythromycins and paracetamol. Raman spectroscopy identified calcium carbonate as an excipient in 9 (39%) of 23 fake samples. Multivariate unsupervised pattern recognition results indicated two major clusters of artesunate counterfeits, those with counterfeit foil stickers and containing calcium carbonate, erythromycin, and paracetamol, and those with counterfeit holograms and containing starch but without evidence of erythromycin or paracetamol.

  14. Tetraoxane-pyrimidine nitrile hybrids as dual stage antimalarials.

    Science.gov (United States)

    Oliveira, Rudi; Guedes, Rita C; Meireles, Patrícia; Albuquerque, Inês S; Gonçalves, Lídia M; Pires, Elisabete; Bronze, Maria Rosário; Gut, Jiri; Rosenthal, Philip J; Prudêncio, Miguel; Moreira, Rui; O'Neill, Paul M; Lopes, Francisca

    2014-06-12

    The use of artemisinin or other endoperoxides in combination with other drugs is a strategy to prevent development of resistant strains of Plasmodium parasites. Our previous work demonstrated that hybrid compounds, comprising endoperoxides and vinyl sulfones, were capable of high activity profiles comparable to artemisinin and chloroquine while acting through two distinct mechanisms of action: oxidative stress and falcipain inhibition. In this study, we adapted this approach to a novel class of falcipain inhibitors: peptidomimetic pyrimidine nitriles. Pyrimidine tetraoxane hybrids displayed potent nanomolar activity against three strains of Plasmodium falciparum and falcipain-2, combined with low cytotoxicity. In vivo, a decrease in parasitemia and an increase in survival of mice infected with Plasmodium berghei was observed when compared to control. All tested compounds combined good blood stage activity with significant effects on liver stage parasitemia, a most welcome feature for any new class of antimalarial drug.

  15. Antimalarial activity of thiosemicarbazones and purine derived nitriles

    Science.gov (United States)

    Mallari, Jeremy P.; Guiguemde, Wendyam A.; Guy, R. Kiplin

    2009-01-01

    Malaria is a devastating illness caused by multiple species of the Plasmodium genus. The parasite’s food vacuole of falcipain proteases have been extensively studied as potential drug targets. Here we report the testing of two established cysteine protease inhibitor scaffolds against both chloroquine sensitive and chloroquine resistant parasites. A subset of purine derived nitriles killed the parasite with moderate potency, and these inhibitors do not seem to exert their antiproliferative effects as cysteine protease inhibitors. Compound potency was determined to be similar against both parasite strains, indicating a low probability of cross resistance with chloroquine. These compounds represent a novel antimalarial scaffold, and a potential starting point for the development new inhibitors. PMID:19447616

  16. New 1-Aryl-3-Substituted Propanol Derivatives as Antimalarial Agents

    Directory of Open Access Journals (Sweden)

    Antonio Monge

    2009-10-01

    Full Text Available This paper describes the synthesis and in vitro antimalarial activity against a P. falciparum 3D7 strain of some new 1-aryl-3-substituted propanol derivatives. Twelve of the tested compounds showed an IC50 lower than 1 μM. These compounds were also tested for cytotoxicity in murine J774 macrophages. The most active compounds were evaluated for in vivo activity against P. berghei in a 4-day suppressive test. Compound 12 inhibited more than 50% of parasite growth at a dose of 50 mg/kg/day. In addition, an FBIT test was performed to measure the ability to inhibit ferriprotoporphyrin biocrystallization. This data indicates that 1-aryl-3-substituted propanol derivatives hold promise as a new therapeutic option for the treatment of malaria.

  17. Syntheses and antimalarial activities of N-substituted 11-azaartemisinins.

    Science.gov (United States)

    Torok, D S; Ziffer, H; Meshnick, S R; Pan, X Q; Ager, A

    1995-12-22

    A two-step reaction sequence between artemisinin and methanolic ammonia followed by treatment with Amberlyst 15 yielded 11-azaartemisinin in 65% yield. Substituting a variety of primary alkyl- and heteroaromatic amines for ammonia in the reaction sequence yields N-substituted 11-azaartemisinins in similar or greater yield. When Amberlyst 15 is replaced by a mixture of sulfuric acid/silica gel, both 11-azaartemisinin and the expected metabolite, 10-azadesoxyartemisinin, are formed in 45% and 15% yields, respectively. In vitro and in vivo test data for a number of novel N-substituted 11-azaartemisinins, against drug-resistant strains of Plasmodium falciparum, show they possess antimalarial activities equal to or greater than that of artemisinin. The most active derivative, N-(2'-acetaldehydo)-11-azaartemisinin, 17, was 26 times more active in vitro and 4 times more active in vivo than artemisinin.

  18. Perspective for the reproduction of antimalarial drugs in Brazil

    Directory of Open Access Journals (Sweden)

    Benjamin Gilbert

    1992-01-01

    Full Text Available The appears to be no chemical manufacture of antimalarial drugs is Brazil. Technology at laboratory process level has been developed for chloroquine, mefloquine, pyrimethamine and cycloquanil, but not perfected nor scaled-up, largely for economic reasons and market uncertainty. Development of primaquine has been contracted but it will run into the same difficulty. Manufacturing capacity for sulfadoxine was registred in the SDI by Roche. A project to produce artemisinine and its derivates is under way at UNICAMP-CPQBA but is hampered by low content in the plant. Proguanil could be produced easily, but apparently no attempt has been made to do so. Quinine is imported on a large scale mostly for softdrink production. Since malarial treatment falls largely within responsability of the Government health authorities, manufacture of drugs in Brazil will depend on an assured medium-term purchase order made to a potential local manufacturer, since competition in the world market is scarcelyviable at the present moment.

  19. Triterpenes from Minquartia guianensis (Olacaceae) and in vitro antimalarial activity

    Energy Technology Data Exchange (ETDEWEB)

    Cursino, Lorena Mayara de Carvalho; Nunez, Cecilia Veronica [Instituto Nacional de Pesquisas da Amazonia (INPA), Manaus, AM (Brazil). Lab. de Bioprospeccao e Biotecnologia; Paula, Renata Cristina de; Nascimento, Maria Fernanda Alves do [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Fac. de Farmacia. Dept. de Produtos Farmaceuticos; Santos, Pierre Alexandre dos, E-mail: cecilia@inpa.gov.br [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Fac. de Ciencias Farmaceuticas

    2012-07-01

    Minquartia guianensis, popularly known as acariquara, was phytochemically investigated. The following triterpenes were isolated from the dichloromethane extract of leaves: lupen-3-one (1), taraxer-3-one (2) and oleanolic acid (3). The dichloromethane extract of branches yielded the triterpene 3{beta}-methoxy-lup-20(29)-ene (4). The chemical structures were characterized by NMR data. Plant extracts, substance 3, squalene (5) and taraxerol (6), (5 and 6 previously isolated), were evaluated by in vitro assay against chloroquine resistant Plasmodium falciparum. The dichloromethane extract of leaves and the three triterpenes assayed have shown partial activity. Thus, these results demonstrated that new potential antimalarial natural products can be found even in partially active extracts. (author)

  20. Screening Mangrove Endophytic Fungi for Antimalarial Natural Products

    Directory of Open Access Journals (Sweden)

    Laurent Calcul

    2013-12-01

    Full Text Available We conducted a screening campaign to investigate fungi as a source for new antimalarial compounds. A subset of our fungal collection comprising Chinese mangrove endophytes provided over 5000 lipophilic extracts. We developed an accelerated discovery program based on small-scale cultivation for crude extract screening and a high-throughput malaria assay. Criteria for hits were developed and high priority hits were subjected to scale-up cultivation. Extracts from large scale cultivation were fractionated and these fractions subjected to both in vitro malaria and cytotoxicity screening. Criteria for advancing fractions to purification were developed, including the introduction of a selectivity index and by dereplication of known metabolites. From the Chinese mangrove endophytes, four new compounds (14–16, 18 were isolated including a new dimeric tetrahydroxanthone, dicerandrol D (14, which was found to display the most favorable bioactivity profile.

  1. Discovery of Novel Liver-Stage Antimalarials through Quantum Similarity.

    Directory of Open Access Journals (Sweden)

    David J Sullivan

    Full Text Available Without quantum theory any understanding of molecular interactions is incomplete. In principal, chemistry, and even biology, can be fully derived from non-relativistic quantum mechanics. In practice, conventional quantum chemical calculations are computationally too intensive and time consuming to be useful for drug discovery on more than a limited basis. A previously described, original, quantum-based computational process for drug discovery and design bridges this gap between theory and practice, and allows the application of quantum methods to large-scale in silico identification of active compounds. Here, we show the results of this quantum-similarity approach applied to the discovery of novel liver-stage antimalarials. Testing of only five of the model-predicted compounds in vitro and in vivo hepatic stage drug inhibition assays with P. berghei identified four novel chemical structures representing three separate quantum classes of liver-stage antimalarials. All four compounds inhibited liver-stage Plasmodium as a single oral dose in the quantitative PCR mouse liver-stage sporozoites-challenge model. One of the newly identified compounds, cethromycin [ABT-773], a macrolide-quinoline hybrid, is a drug with an extensive (over 5,000 people safety profile warranting its exploitation as a new weapon for the current effort of malaria eradication. The results of our molecular modeling exceed current state-of-the-art computational methods. Drug discovery through quantum similarity is data-driven, agnostic to any particular target or disease process that can evaluate multiple phenotypic, target-specific, or co-crystal structural data. This allows the incorporation of additional pharmacological requirements, as well as rapid exploration of novel chemical spaces for therapeutic applications.

  2. Epidemiological models for the spread of anti-malarial resistance

    Directory of Open Access Journals (Sweden)

    Antia R

    2003-02-01

    Full Text Available Abstract Background The spread of drug resistance is making malaria control increasingly difficult. Mathematical models for the transmission dynamics of drug sensitive and resistant strains can be a useful tool to help to understand the factors that influence the spread of drug resistance, and they can therefore help in the design of rational strategies for the control of drug resistance. Methods We present an epidemiological framework to investigate the spread of anti-malarial resistance. Several mathematical models, based on the familiar Macdonald-Ross model of malaria transmission, enable us to examine the processes and parameters that are critical in determining the spread of resistance. Results In our simplest model, resistance does not spread if the fraction of infected individuals treated is less than a threshold value; if drug treatment exceeds this threshold, resistance will eventually become fixed in the population. The threshold value is determined only by the rates of infection and the infectious periods of resistant and sensitive parasites in untreated and treated hosts, whereas the intensity of transmission has no influence on the threshold value. In more complex models, where hosts can be infected by multiple parasite strains or where treatment varies spatially, resistance is generally not fixed, but rather some level of sensitivity is often maintained in the population. Conclusions The models developed in this paper are a first step in understanding the epidemiology of anti-malarial resistance and evaluating strategies to reduce the spread of resistance. However, specific recommendations for the management of resistance need to wait until we have more data on the critical parameters underlying the spread of resistance: drug use, spatial variability of treatment and parasite migration among areas, and perhaps most importantly, cost of resistance.

  3. Discovery of Novel Liver-Stage Antimalarials through Quantum Similarity.

    Science.gov (United States)

    Sullivan, David J; Liu, Yi; Mott, Bryan T; Kaludov, Nikola; Martinov, Martin N

    2015-01-01

    Without quantum theory any understanding of molecular interactions is incomplete. In principal, chemistry, and even biology, can be fully derived from non-relativistic quantum mechanics. In practice, conventional quantum chemical calculations are computationally too intensive and time consuming to be useful for drug discovery on more than a limited basis. A previously described, original, quantum-based computational process for drug discovery and design bridges this gap between theory and practice, and allows the application of quantum methods to large-scale in silico identification of active compounds. Here, we show the results of this quantum-similarity approach applied to the discovery of novel liver-stage antimalarials. Testing of only five of the model-predicted compounds in vitro and in vivo hepatic stage drug inhibition assays with P. berghei identified four novel chemical structures representing three separate quantum classes of liver-stage antimalarials. All four compounds inhibited liver-stage Plasmodium as a single oral dose in the quantitative PCR mouse liver-stage sporozoites-challenge model. One of the newly identified compounds, cethromycin [ABT-773], a macrolide-quinoline hybrid, is a drug with an extensive (over 5,000 people) safety profile warranting its exploitation as a new weapon for the current effort of malaria eradication. The results of our molecular modeling exceed current state-of-the-art computational methods. Drug discovery through quantum similarity is data-driven, agnostic to any particular target or disease process that can evaluate multiple phenotypic, target-specific, or co-crystal structural data. This allows the incorporation of additional pharmacological requirements, as well as rapid exploration of novel chemical spaces for therapeutic applications.

  4. Formulation of nanotized curcumin and demonstration of its antimalarial efficacy

    Directory of Open Access Journals (Sweden)

    Ghosh A

    2014-11-01

    Full Text Available Aparajita Ghosh,1 Tanushree Banerjee,2 Suman Bhandary,1 Avadhesha Surolia31Division of Molecular Medicine, Bose Institute, Centenary Campus, Kolkata, West Bengal, India; 2Department of Biotechnology, University of Pune, Pune, India; 3Molecular Biophysics Unit, Indian Institute of Science, Bangalore, IndiaAim: The present study was conducted to overcome the disadvantages associated with the poor water solubility and low bioavailability of curcumin by synthesizing nanotized curcumin and demonstrating its efficacy in treating malaria. Materials and methods: Nanotized curcumin was prepared by a modified emulsion-diffusion-evaporation method and was characterized by means of transmission electron microscopy, atomic force microscopy, dynamic light scattering, Zetasizer, Fourier transform infrared spectroscopy, and differential thermal analysis. The novelty of the prepared nanoformulation lies in the fact that it was devoid of any polymeric matrices used in conventional carriers. The antimalarial efficacy of the prepared nanotized curcumin was then checked both in vitro and in vivo. Results: The nanopreparation was found to be non-toxic and had a particle size distribution of 20–50 nm along with improved aqueous dispersibility and an entrapment efficiency of 45%. Nanotized curcumin (half maximal inhibitory concentration [IC50]: 0.5 µM was also found to be ten-fold more effective for growth inhibition of Plasmodium falciparum in vitro as compared to its native counterpart (IC50: 5 µM. Oral bioavailability of nanotized curcumin was found to be superior to that of its native counterpart. Moreover, when Plasmodium berghei-infected mice were orally treated with nanotized curcumin, it prolonged their survival by more than 2 months with complete clearance of parasites in comparison to the untreated animals, which survived for 8 days only. Conclusion: Nanotized curcumin holds a considerable promise in therapeutics as demonstrated here for treating malaria

  5. Antimalarial activity of nepodin isolated from Rumex crispus.

    Science.gov (United States)

    Lee, Keyong Ho; Rhee, Ki-Hyeong

    2013-04-01

    The purpose of this study is to define the antimalarial activity of Rumex crispus. To identify an active compound that is isolated from R. crispus, bioassay-based chromatographic fractionation and purification is carried out from 70 % ethanol extract of R. crispus; then, an active compound, nepodin, is identified by spectroscopic analysis. Anitmalarial activity is measured by PfNDH2 assay, cytotoxicity, and animal test. From NADH:quinone oxidoreductase enzyme (PfNDAH2) assay, nepodin exhibited significant IC50 values that were 0.74 ± 0.07 and 0.79 ± 0.06 μg/ml against P. falciparum chloroquine-sensitive (3D7) and P. falciparum chloroquine-resistant (S20), respectively. Nepodin showed a potential selective inhibition (SI index: ratio of 50 % cytotoxic concentration to 50 % effective anti-plasmodial concentration) of 161.6 and 151.4 against P. falciparum 3D7 and P. falciparum S20. In the animal test, all groups of nepodin treatment of 10, 50, and 250 mg/kg were active with a parasitemia suppression of 97.1 ± 3.3, 99.1 ± 3.7, and 99.1 ± 2.6 %, respectively. The survival time with nepodin treatment was increased by 14.6 ± 2.5, 16.2 ± 1.5, and 19.8 ± 1.7 days at each dose, respectively. This study newly identified the plant R. crispus containing nepodin, which is a potential antimalarial compound. It exhibited the inhibitory activity of PfNDH2 and prolonged the survival time on the group of nepodin treatment; moreover, it inhibited the parasitemia in the animal test.

  6. Distillation time as tool for improved antimalarial activity and differential oil composition of cumin seed oil

    Science.gov (United States)

    A steam distillation extraction kinetics experiment was conducted to estimate essential oil yield, composition, antimalarial, and antioxidant capacity of cumin (Cuminum cyminum L.) seed (fruits). Furthermore, regression models were developed to predict essential oil yield and composition for a given...

  7. Atovaquone and quinine anti-malarials inhibit ATP binding cassette transporter activity

    NARCIS (Netherlands)

    Rijpma, S.R.; Heuvel, J.J.; Velden, M. van der; Sauerwein, R.W.; Russel, F.G.; Koenderink, J.B.

    2014-01-01

    BACKGROUND: Therapeutic blood plasma concentrations of anti-malarial drugs are essential for successful treatment. Pharmacokinetics of pharmaceutical compounds are dependent of adsorption, distribution, metabolism, and excretion. ATP binding cassette (ABC) transport proteins are particularly involve

  8. Effects of anti-malarial alkaloids on the sperm properties and blood ...

    African Journals Online (AJOL)

    The effects of treatment with the anti-malarial alkaloids quinine and chloroquine ... properties and blood levels of selected reproductive hormones (testosterone, ... the short term use of these drugs to treat malaria may be associated with fertility ...

  9. Antiplatelet Agents Inhibit The Generation Of Platelet-Derived Microparticles

    Directory of Open Access Journals (Sweden)

    Alice Giacomazzi

    2016-09-01

    Full Text Available Platelet microparticles (PMPs contribute to thrombogenesis but the effects of antiplatelet drugs on PMPs generation is undefined. The present study investigated the cellular events regulating PMP shedding, testing in vitro platelet agonists and inhibitors. Platelet-rich plasma from healthy subjects was stimulated with arachidonic acid, U46619, collagen type-I (10 and 1.5 µg/mL, epinephrine, ADP or TRAP-6 and pre-incubated with acetylsalicylic acid (ASA, 100 and 10 µmol/L, SQ-29,548, apyrase, PSB-0739, or eptifibatide. PMPs were detected by flow-cytometry using CD61 and annexin-V as fluorescent markers. Platelet agonists induced annexin V-positive PMP shedding. The strongest response was to high concentration collagen. ADP-triggered PMP shedding was dose-independent. ASA reduced PMPs induced by arachidonic acid- (645, 347-2946 vs 3061, 446-4901 PMPs/µL; median ad range, n=9, P<0.001, collagen 10 µg/mL (5317, 2027-15935 vs 10252, 4187-46316 PMPs/µL; n=13, P<0.001, collagen 1.5 µg/mL (1078, 528-2820 vs 1465, 582-5948 PMPs/µL; n=21, P<0.001 and TRAP-6 (2008, 1621-2495 vs 2840, 2404-3031 PMPs/µL; n=3, P<0.01 but did not affect the response to epinephrine or ADP. The ADP scavenger apyrase reduced PMPs induced by U46619 (1256, 395-2908 vs 3045, 1119-5494 PMPs/µL, n=6, P<0.05, collagen 1.5 µg/mL (1006, 780-1309 vs 2422, 1839-3494 PMPs/µL, n=3, P<0.01 and TRAP-6 (904, 761-1224 vs 2840, 2404-3031 PMPs/µL, n=3, P<0.01. The TP receptor antagonist SQ-29,548 and the P2Y12 receptor antagonist PSB-0739 markedly inhibited PMPs induced by low doses of collagen. Except for high-dose collagen, eptifibatide abolished agonist-induced PMP release. Both TXA2 generation and ADP secretion are required as amplifiers of PMP shedding. The crucial role of the fibrinogen receptor and the collagen receptor in PMPs generation, independently of platelet aggregation, was identified.

  10. Extended Duration Dual Antiplatelet Therapy After Coronary Stenting Among Patients With Peripheral Arterial Disease: A Subanalysis of the Dual Antiplatelet Therapy Study.

    Science.gov (United States)

    Secemsky, Eric A; Yeh, Robert W; Kereiakes, Dean J; Cutlip, Donald E; Steg, P Gabriel; Massaro, Joseph M; Apruzzese, Patricia K; Mauri, Laura

    2017-05-08

    This study sought to determine whether patients with peripheral arterial disease (PAD) experience different reductions in ischemic event and increases in bleeding events with extended duration dual antiplatelet therapy versus those without PAD. Patients with PAD have increased ischemic and bleeding risks after coronary stenting. The DAPT (Dual Antiplatelet Therapy) study randomized 11,648 patients free from ischemic and bleeding events 12 months after coronary stenting to continued thienopyridine plus aspirin therapy for an additional 18 months versus aspirin therapy alone. The effects of continued thienopyridine on myocardial infarction (MI) or stent thrombosis, major adverse cardiovascular and cerebrovascular events (death, MI, or stroke) and bleeding (GUSTO [Global Utilization of t-PA and Streptokinase for Occluded Coronary Arteries] moderate or severe) were assessed among those with versus without PAD. Among 11,648 randomized patients, 649 (5.57%) had PAD. Between 12 and 30 months, randomized patients with PAD had higher rates of MI/stent thrombosis (6.03% vs. 2.92%; p antiplatelet therapy is associated with consistent ischemic benefit and bleeding harm among patients with and without PAD. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  11. Synthesis and antimalarial activity of ethylene glycol oligomeric ethers of artemisinin

    OpenAIRE

    Steyn, Minette; N’Da, David D.; Breytenbach, Jaco C; Smith, Peter J.; Meredith, Sandra; Breytenbach, Wilma J.

    2011-01-01

    Objectives The aim of this study was to synthesize a series of ethylene glycol ether derivatives of the antimalarial drug artemisinin, determine their values for selected physicochemical properties and evaluate their antimalarial activity in vitro against Plasmodium falciparum strains. Methods The ethers were synthesized in a one-step process by coupling ethylene glycol moieties of various chain lengths to carbon C-10 of artemisinin. The aqueous solubility and log D values w...

  12. Rational Design of Antimalarial Drugs Using Molecular Modeling and Statistical Analysis.

    Science.gov (United States)

    Santos, Cleydson Breno Rodrigues dos; Lobato, Cleison Carvalho; Braga, Francinaldo Sarges; Costa, Josivan da Silva; Favacho, Hugo Alexandre Silva; Carvalho, Jose Carlos Tavares; Macedo, Williams Jorge da Cruz; Brasil, Davi Do Socorro Barros; Silva, Carlos Henrique Tomich de Paula da; Silva Hage-Melim, Lorane Izabel da

    2015-01-01

    Artemisinin is an antimalarial compound isolated from Artemisia annua L. that is effective against Plasmodium falciparum. This paper proposes the development of new antimalarial derivatives of artemisinin from a SAR study and statistical analysis by multiple linear regression (MLR). The HF/6-31G** method was used to determine the molecular properties of artemisinin and 10 derivatives with antimalarial action. MEP maps and molecular docking were used to study the interface between ligand and receptor (heme). The Pearson correlation was used to choose the most important properties interrelated to the antimalarial activity: Hydration Energy (HE), Energy of the Complex (Ecplex), bond length (FeO1), and maximum index of R/Electronegativity of Sanderson (RTe+). After the Pearson correlation, 72 MLR models were built between antimalarial activity and molecular properties; the statistical quality of the models was evaluated by means of correlation coefficient (r), squared correlation coefficient (r(2)), explained variance (adjusted R(2)), standard error of estimate (SEE), and variance ratio (F), and only four models showed predictive ability. The selected models were used to predict the antimalarial activity of ten new artemisinin derivatives (test set) with unknown activity, and only eight of these compounds were predicted to be more potent than artemisinin, and were therefore subjected to theoretical studies of pharmacokinetic and toxicological properties. The test set showed satisfactory results for six new artemisinin compounds which is a promising factor for future synthesis and biological assays.

  13. The in vitro antimalarial interaction of 9-hydroxycalabaxanthone and α-mangostin with mefloquine/artesunate.

    Science.gov (United States)

    Chaijaroenkul, Wanna; Na-Bangchang, Kesara

    2014-03-01

    Multidrug resistance Plasmodium falciparum is the major health problem in Thailand. Discovery and development of new antimalarial drugs with novel modes of action is urgently required. The aim of the present study was to investigate the antimalarial interaction of 9-hydroxycalabaxanthone and α-mangostin with the standard antimalarial drugs mefloquine and artesunate in chloroquine sensitive (3D7) and chloroquine resistant (K1) P. falciparum clones in vitro. Median (range) IC50 (drug concentration which produces 50% parasite growth inhibition) values of the 9-hydroxycalabaxanthone, α-mangostin, artesunate and mefloquine for 3D7 vs K1 clones were 1.5 (0.9-2.1) vs 1.2 (1.1-1.6) μM, 17.9 (15.7.0-20.0) vs 9.7 (6.0-14.0) μM, 1.0 (0.4-3.0) vs 1.7 (1.0-2.5) nM, and 13.3 (11.1-13.3) vs 7.1 (6.7-12.2) nM, respectively. Analysis of isobologram and combination index (CI) of 9-hydroxycalabaxanthone with artesunate or mefloquine showed synergistic and indifference antimalarial interaction, respectively. α-mangostin-artesunate combination exhibited a slight antagonistic effect of antimalarial interaction, whereas α-mangostin and mefloquine combination showed indifference interaction in both clones. The combination of 9-hydroxycalabaxanthone with α-mangostin showed the synergistic antimalarial interaction in both clones.

  14. Study of the antimalarial properties of hydroxyethylamine derivatives using green fluorescent protein transformed Plasmodium berghei

    Directory of Open Access Journals (Sweden)

    Mariana Conceição Souza

    2015-06-01

    Full Text Available A rapid decrease in parasitaemia remains the major goal for new antimalarial drugs and thus, in vivo models must provide precise results concerning parasitaemia modulation. Hydroxyethylamine comprise an important group of alkanolamine compounds that exhibit pharmacological properties as proteases inhibitors that has already been proposed as a new class of antimalarial drugs. Herein, it was tested the antimalarial property of new nine different hydroxyethylamine derivatives using the green fluorescent protein (GFP-expressing Plasmodium berghei strain. By comparing flow cytometry and microscopic analysis to evaluate parasitaemia recrudescence, it was observed that flow cytometry was a more sensitive methodology. The nine hydroxyethylamine derivatives were obtained by inserting one of the following radical in the para position: H, 4Cl, 4-Br, 4-F, 4-CH3, 4-OCH3, 4-NO2, 4-NH2 and 3-Br. The antimalarial test showed that the compound that received the methyl group (4-CH3 inhibited 70% of parasite growth. Our results suggest that GFP-transfected P. berghei is a useful tool to study the recrudescence of novel antimalarial drugs through parasitaemia examination by flow cytometry. Furthermore, it was demonstrated that the insertion of a methyl group at the para position of the sulfonamide ring appears to be critical for the antimalarial activity of this class of compounds.

  15. Pattern of the Antimalarials Prescription during Pregnancy in Bangui, Central African Republic

    Directory of Open Access Journals (Sweden)

    Alexandre Manirakiza

    2011-01-01

    Full Text Available Introduction. The aim of this study was to identify the antimalarials prescribed during the pregnancy and to document their timing. Method. From June to September 2009, a survey was conducted on 565 women who gave birth in the Castors maternity in Bangui. The antenatal clinics cards were checked in order to record the types of antimalarials prescribed during pregnancy according to gestational age. Results. A proportion of 28.8% ANC cards contained at least one antimalarial prescription. The commonest categories of antimalarials prescribed were: quinine (56.7%, artemisinin-based combinations (26.8% and artemisinin monotherapy (14.4%. Among the prescriptions that occurred in the first trimester of pregnancy, artemisinin-based combinations and artemisinin monotherapies represented the proportions of (10.9% and (13.3%. respectively. Conclusion. This study showed a relatively high rate (>80% of the recommended antimalarials prescription regarding categories of indicated antimalarials from national guidelines. But, there is a concern about the prescription of the artemisinin derivatives in the first trimester of pregnancy, and the prescription of artemisinin monotherapy. Thus, the reinforcement of awareness activities of health care providers on the national malaria treatment during pregnancy is suggested.

  16. Does anti-malarial drug knowledge predict anti-malarial dispensing practice in drug outlets? A survey of medicine retailers in western Kenya

    Directory of Open Access Journals (Sweden)

    Rusk Andria

    2012-08-01

    Full Text Available Abstract Background Malaria is a major cause of morbidity and mortality in Kenya, where it is the fifth leading cause of death in both children and adults. Effectively managing malaria is dependent upon appropriate treatment. In Kenya, between 17 to 83 percent of febrile individuals first seek treatment for febrile illness over the counter from medicine retailers. Understanding medicine retailer knowledge and behaviour in treating suspected malaria and dispensing anti-malarials is crucial. Methods To investigate medicine retailer knowledge about anti-malarials and their dispensing practices, a survey was conducted of all retail drug outlets that sell anti-malarial medications and serve residents of the Webuye Health and Demographic Surveillance Site in the Bungoma East District of western Kenya. Results Most of the medicine retailers surveyed (65% were able to identify artemether-lumefantrine (AL as the Kenyan Ministry of Health recommended first-line anti-malarial therapy for uncomplicated malaria. Retailers who correctly identified this treatment were also more likely to recommend AL to adult and paediatric customers. However, the proportion of medicine retailers who recommend the correct treatment is disappointingly low. Only 48% would recommend AL to adults, and 37% would recommend it to children. It was discovered that customer demand has an influence on retailer behaviour. Retailer training and education were found to be correlated with anti-malarial drug knowledge, which in turn is correlated with dispensing practices. Medicine retailer behaviour, including patient referral practice and dispensing practices, are also correlated with knowledge of the first-line anti-malarial medication. The Kenya Ministry of Health guidelines were found to influence retailer drug stocking and dispensing behaviours. Conclusion Most medicine retailers could identify the recommended first-line treatment for uncomplicated malaria, but the percentage that could

  17. Practice points in gynecardiology: Abnormal uterine bleeding in premenopausal women taking oral anticoagulant or antiplatelet therapy

    NARCIS (Netherlands)

    Maas, A.H.E.M.; Euler, M.; Bongers, M.Y.; Rolden, H.J.A.; Grutters, J.P.C.; Ulrich, L.; Schenck-Gustafsson, K.

    2015-01-01

    A growing number of premenopausal women are currently using antithrombotic and/or (dual) antiplatelet therapy for various cardiovascular indications. These may induce or exacerbate abnormal uterine bleeding and more awareness and knowledge among prescribers is required. Heavy and irregular menstrual

  18. Discontinuation of antiplatelet treatment and risk of recurrent stroke and all-cause death

    DEFF Research Database (Denmark)

    Ostergaard, Kamilla; Pottegård, Anton; Hallas, Jesper

    2014-01-01

    drugs. Recent statin use was associated with markedly increased risk of death (2.1 (1.7-2.6)), and only marginally with recurrent stroke (1.2 (0.9-1.6)). CONCLUSIONS: Antiplatelet drug discontinuation may be associated with an increased recurrent stroke risk. Our results on death risk indicate that non...

  19. Steam-cooking rapidly destroys and reverses onion-induced antiplatelet activity

    Directory of Open Access Journals (Sweden)

    Hansen Emilie A

    2012-09-01

    Full Text Available Abstract Background Foods in the diet that can aid in the prevention of diseases are of major interest. Onions are key ingredients in many cuisines around the world and moreover, onion demand has trended higher over the past three decades. An important pharmacological aspect of onion is the ability to inhibit platelet aggregation. Raw onions inhibit platelet aggregation; however, when onions are boiled or heated, antiplatelet activity may be abolished. Methods Onion quarters were steamed for 0, 1, 3, 6, 10, and 15 min. The in vitro antiplatelet activity of a yellow hybrid storage onion was examined at these times on the blood of 12 human subjects using in vitro whole blood aggregometry. Results Contrary to findings reported for boiling, antiplatelet activity was destroyed between 3 and 6 min of steaming, and at 10 min of steaming, cooked onions stimulated platelet activity. Extracts from cooked onion had the potential to reverse the inhibitory effect on blood platelets by 25%. Responses were consistent across all donors. Total polyphenolic concentration and soluble solids were not affected by steaming time. Conclusions The potential value of cooked onion preparations may result in destruction or reversal of antiplatelet activity, without affecting the polyphenolic concentration.

  20. Dentists' approach to patients on anti-platelet agents and warfarin: a survey of practice.

    LENUS (Irish Health Repository)

    Murphy, James

    2010-04-23

    In everyday practice, dentists are confronted with the dilemma of patients on anti-platelet agents and warfarin who require invasive dental procedures and, more pertinently, dental extractions. There may be a divergence of opinion among dentists regarding how they manage these patients. AIMS: To assess general dental practitioners\\' approach to the management of patients taking anti-platelet agents and\\/or warfarin who are undergoing invasive dental procedures. METHODS AND DATA: A semi-structured questionnaire was designed to survey general dental practitioners in a large Irish urban area. RESULTS: A response rate of 89% was achieved in a study population of 54 general dental practitioners. A total of 25% of respondents who carry out extractions on warfarinised patients do not check the INR prior to invasive dental procedures. Some 90% of respondents stop anti-platelet agents prior to extractions. CONCLUSIONS: A significant proportion of respondents fail to check warfarinised patients\\' INR prior to invasive dental procedures. Furthermore, a trend of stopping anti-platelet agents was noted, which is in contrast with current recommendations in the dental literature. Certain practices in this small study population proved alarming and highlight the need for improved awareness of current guidelines. A further large-scale study may be justified, as variation in practice may have clinical and medico-legal repercussions.

  1. Effects of chronic kidney disease on platelet response to antiplatelet therapy in acute myocardial infarction patients

    Institute of Scientific and Technical Information of China (English)

    邓捷

    2012-01-01

    Objective To elucidate the effects of dual antiplatelet therapy on platelet response in acute myocardial infarction patients with chronic kidney disease. Methods From September 2011 to June 2012,a total of 195 acute myocardial infarction patients with drug eluting stent implanting were enrolled. Among them,133 cases had normal

  2. Correlation between antiplatelet resistance and recurrent cardiac ischemic events of patients with acute myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    李蕾

    2012-01-01

    Objective To evaluate the predictive value of anti-platelet resistance assessed by whole blood electronic impedance aggregometry(EIA) for the risk of recurrent cardiac ischemic events in patients with acute myocardial infarction(AMI) who underwent coronary stenting. Methods We enrolled

  3. Review of postoperative bleeding risk in dental patients on antiplatelet therapy

    NARCIS (Netherlands)

    Napenas, J.J.; Oost, F.C.D.; deGroot, A.; Loven, B.; Hong, C.H.L.; Brennan, M.T.; Lockhart, P.B.; van Diermen, D.E.

    2013-01-01

    Objective We conducted a review of the literature to assess risk for oral bleeding complications after dental procedures in patients on antiplatelet therapy. Study Design We conducted a search in Medline, Embase, and National Guideline Clearinghouse databases for studies involving patients on single

  4. Bilateral Ultrasound Guided Supraclavicular Block in a Patient on Antiplatelet Drugs

    Directory of Open Access Journals (Sweden)

    Lokesh Kumar KS

    2015-04-01

    Full Text Available A 63 year old male hypertensive and diabetic patient, with coronary artery and chronic obstructive pulmonary disease, presented with bilateral both bone forearm fracture. Open reduction and internal fixation was done successfully with bilateral ultrasound guided supraclavicular block. The problems associated with peripheral nerve block in an Ischemic Heart Disease (IHD patient on antiplatelet therapy are discussed.

  5. Review of postoperative bleeding risk in dental patients on antiplatelet therapy

    NARCIS (Netherlands)

    Napenas, J.J.; Oost, F.C.D.; deGroot, A.; Loven, B.; Hong, C.H.L.; Brennan, M.T.; Lockhart, P.B.; van Diermen, D.E.

    2013-01-01

    Objective We conducted a review of the literature to assess risk for oral bleeding complications after dental procedures in patients on antiplatelet therapy. Study Design We conducted a search in Medline, Embase, and National Guideline Clearinghouse databases for studies involving patients on single

  6. Spontaneous subdural hematoma and antiplatelet therapy: Does efficacy of Ticagrelor come with added risk?

    Science.gov (United States)

    Suryanarayana Sharma, Pattanagere Manjunatha; Tekkatte Jagannatha, Aniruddha; Javali, Mahendra; Hegde, Anupama Venkatasubba; Mahale, Rohan; Madhusudhan; Srinivasa, Rangasetty

    2015-12-01

    Antiplatelet therapy has established clinical benefit on cardiovascular outcome and has reduced the rates of re-infarction/in stent thrombosis following percutaneous coronary intervention in acute coronary syndromes. Major bleeding episodes can occur with antiplatelet therapy and intracranial hemorrhage (ICH) is one of the most feared complications resulting in significant morbidity and mortality. Identification of high risk groups and judicious use of antiplatelet therapy reduces the bleeding risk. Ticagrelor is a newer P2Y12 receptor antagonist with established clinical benefit. However, risks of having an ICH with these newer molecules cannot be ignored. Here, we report a case of spontaneous acute subdural hematoma developing in a patient on antiplatelet therapy with aspirin and ticagrelor. Early recognition, discontinuation of the medication and appropriate management resulted in resolution of hematoma and good clinical outcome. Authors have reviewed the antithrombotic drugs and their tendencies in causing intracranial bleeds from a neurophysicians perspective. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  7. Prior antiplatelet therapy and outcome following intracerebral hemorrhage: a systematic review

    DEFF Research Database (Denmark)

    Thompson, B B; Béjot, Y; Caso, V

    2010-01-01

    Antiplatelet therapy (APT) promotes bleeding; therefore, APT might worsen outcome in patients with intracerebral hemorrhage (ICH). We performed a systematic review and meta-analysis to address the hypothesis that pre-ICH APT use is associated with mortality and poor functional outcome following ICH....

  8. Anticoagulants versus antiplatelet drugs for cervical artery dissection: case for anticoagulants.

    Science.gov (United States)

    Norris, John W

    2013-02-01

    There are no reliable data from randomised trials to decide whether anticoagulants or antiplatelet agents are better to prevent further thromboembolic events after cervical arterial dissection. Most neurologists favour anticoagulants based on the underlying pathology and the likely course of acute post-dissection thromboembolism.

  9. Peri-operative management of anticoagulation and antiplatelet therapy in gastrointestinal surgery.

    Science.gov (United States)

    Degirmenci, S-E; Steib, A

    2014-04-01

    Peri-operative management of the risks of hemorrhage and thrombosis related to gastrointestinal surgery tailored to patient characteristics are part of daily multidisciplinary practice tasks. The goal of this update is to discuss current practices concerning antithrombosis prophylaxis and the management of recently developed anticoagulants and antiplatelet agents. The duration of prophylaxis is 1 month for oncological surgery. The recommended doses in bariatric surgery are twice daily injections of low-molecular weight heparin without exceeding a total dose of 10,000 IU/day. Dual antiplatelet therapy is necessary for 6 weeks after placement of bare-metal stents, from 6-12 months for drug-eluting stents, and 12 months after an acute coronary artery syndrome. Abrupt discontinuation of antiplatelet therapy exposes the patient to an increased risk of thrombosis. Data are insufficient to make specific recommendations for antiplatelet therapy in gastrointestinal surgery. For major digestive surgery, prescription of daily aspirin should be discussed case by case. If discontinuation of treatment is absolutely necessary, this should be as short as possible (aspirin: 3 days, ticagrelor and clopidogrel: 5 days, prasugrel: 7 days). The modalities for elective management of new oral anticoagulants are similar to those for classical vitamin K antagonists (VKA) therapy, except that any overlapping with heparin administration must be avoided. In the emergency setting, an algorithm can be proposed depending on the drug, the available coagulation tests and the interval before performing surgery.

  10. Control of anticoagulant and antiplatelet therapy. Managing patients with acute thrombotic disorders.

    OpenAIRE

    Anderson, D. R.; Fernandez, L. A.

    1993-01-01

    Indications for using standard anticoagulants, heparin and warfarin; the dosage and route of administration; the importance of monitoring therapy with reliable laboratory indices; and complications of therapy are discussed. Acetylsalicylic acid and ticlopidine can be used as antiplatelet agents. Because their effect on platelet function is not monitored clinically, their clinical indications are emphasized.

  11. Anti-platelet antibodies in a natural animal model of sulphonamide-associated thrombocytopaenia.

    Science.gov (United States)

    Lavergne, Sidonie N; Trepanier, Lauren A

    2007-12-01

    Delayed hypersensitivity (HS) reactions to sulphonamide antimicrobials occur in both humans and dogs with a similar clinical presentation, and may include thrombocytopaenia. Drug-dependent anti-platelet antibodies have been identified in humans with sulphonamide-associated thrombocytopaenia. Our purpose was to determine whether similar antibodies were present in dogs with sulphonamide-associated thrombocytopaenia. Flow cytometry was used to detect anti-platelet antibodies in sera from 32 dogs with sulphonamide HS, eight dogs that tolerated sulphonamide therapy without adverse reactions and nine healthy control dogs were used as controls. Anti-platelet antibodies were found more frequently, with significantly stronger fluorescence signals, in HS dogs (75%) compared to 'tolerant' dogs (38%), and in HS dogs with thrombocytopaenia (90%) compared to HS dogs with normal platelet counts (46%). Binding to platelets was enhanced in the presence of soluble sulphonamide in 42% of positive samples. Experiments with canine Glanzmann's platelets, and competition assays with fibrinogen fragments or anti-GP antibodies, did not support the hypothesis that these canine antibodies target the fibrinogen receptor. In conclusion, anti-platelet antibodies were identified in dogs with sulphonamide-associated thrombocytopaenia, which suggests a similar immunopathogenesis for this reaction in dogs as seen in humans. Further work in both species will determine whether these antibodies are pathogenic in vitro.

  12. Prior antiplatelet therapy and outcome following intracerebral hemorrhage: a systematic review

    DEFF Research Database (Denmark)

    Thompson, B B; Béjot, Y; Caso, V

    2010-01-01

    Antiplatelet therapy (APT) promotes bleeding; therefore, APT might worsen outcome in patients with intracerebral hemorrhage (ICH). We performed a systematic review and meta-analysis to address the hypothesis that pre-ICH APT use is associated with mortality and poor functional outcome following ICH....

  13. Enteric coating can lead to reduced antiplatelet effect of low-dose acetylsalicylic acid

    DEFF Research Database (Denmark)

    Fentz Haastrup, Peter; Grønlykke, Thor; Jarbøl, Dorte Ejg

    2015-01-01

    Low-dose acetylsalicylic acid (ASA) is widely used as antithrombotic prophylaxis. Enteric coated ASA has been developed in order to decrease the risk of gastrointestinal side effects. The consequences of enteric coating on pharmacokinetics and antiplatelet effect of ASA have not systematically been...

  14. Effects of a health promotion program on medication adherence to antiplatelet therapy among ischemic stroke patients in Hainan Province, China.

    Science.gov (United States)

    Su, Qingjie; Li, Chaoyun; Long, Faqing; Chen, Bin; Wan, Zhongqin; Wu, Yingman; Dai, Mingming; Wang, Desheng; Zhang, Yuhui; Wang, Bufei

    2017-06-01

    Survivors of ischemic stroke are still at a significant risk for recurrence. Antiplatelet agents are the treatment of first choice for long-term secondary prevention of vascular events. This study aims to assess a health promotion program on medication adherence to antiplatelet therapy among ischemic stroke patients in Hainan province, China. In five hospitals from the intervention group, four highly experienced physicians trained 62 neurologists, who in turn trained 613 stroke patients to improve their awareness and adherence to antiplatelet therapy. Physicians and patients of the control group received usual stroke management programs. After one-year follow-up, the proportion of patients who took the antiplatelet therapy increased significantly in the intervention group, reaching 73.2%, with a pre-post difference between two arms of 22.9% ( P antiplatelet therapy (24.4%, P antiplatelet drug use in stroke patients. In conclusion, the health promotion program, based on a train-the-trainer approach, showed positive effects on awareness of and adherence to antiplatelet therapy, which has the potential to be scaled up to other resource-limited areas.

  15. Underutilization of antiplatelet and statin therapy after postoperative myocardial infarction following vascular surgery.

    Science.gov (United States)

    Steely, Andrea M; Callas, Peter W; Hohl, Patrick K; Schneider, David J; De Martino, Randall R; Bertges, Daniel J

    2017-08-19

    The objective of this study was to investigate adherence to practice guidelines for antiplatelet and statin use after postoperative myocardial infarction (POMI) and its effect on late mortality following vascular surgery in a multicenter registry. Antiplatelet and statin use was examined in 1749 vascular surgery procedures with POMI within the Vascular Quality Initiative (VQI) from 2005 to 2015. Our primary aim was to assess cardiac medication (CM) use at discharge, defined as (1) single antiplatelet therapy (SAPT; aspirin or P2Y12 inhibitor) or dual antiplatelet therapy (DAPT; aspirin and P2Y12 inhibitor) and (2) statin therapy. Long-term mortality in patients with POMI was analyzed on the basis of discharge CM. A proportional hazards model was developed to control for factors associated with mortality. Regional differences in CM use at discharge after POMI were compared. Overall discharge CM use after POMI included aspirin (81%), P2Y12 inhibitor (38%), statin therapy (76%), and combined antiplatelet and statin (74%). At discharge, 26% of patients were not receiving combined antiplatelet and statin therapy. SAPT (50%) was more common than DAPT (35%; P therapy had improved survival (79%) compared with those receiving noncombination or no therapy (69%) with mean follow-up of 5.5 years and 4.9 years, respectively (log-rank, P = .001). After adjustment for covariates including preoperative medications, treatment with SAPT or DAPT plus statin at discharge was associated with lower late mortality compared with noncombination or no therapy (hazard ratio, 0.72; 95% confidence interval, 0.56-0.93; P = .01). Regional variation in CM at discharge following POMI was also observed with a range of 33% to 100% (P = .05). Within the VQI, regional and procedure-specific variation exists in CM regimen after POMI following vascular surgery. Absence of combined antiplatelet and statin therapy at discharge after POMI was associated with higher late mortality and represents an

  16. Systematic Review and Meta-analysis of Dual Versus Single Antiplatelet Therapy in Carotid Interventions.

    Science.gov (United States)

    Barkat, M; Hajibandeh, S; Hajibandeh, S; Torella, F; Antoniou, G A

    2017-01-01

    The importance of antiplatelet therapy for the management and prevention of ischaemic stroke cannot be overstated. Despite the established guidelines, there is no clear consensus on how to manage antiplatelet therapy during and after carotid interventions. The objective was to undertake a systematic literature review and perform a meta-analysis to assess the effects of dual antiplatelet therapy in carotid endarterectomy (CEA) and stenting (CAS). Electronic information sources (MEDLINE, EMBASE, CINAHL, CENTRAL) and bibliographic reference lists were searched to identify randomised controlled trials (RCTs) and observational studies reporting comparative outcomes of dual versus single antiplatelet therapy in CEA and CAS. Primary outcomes were mortality and stroke within 30 days of intervention. Secondary outcomes were transient ischaemic attack (TIA), major bleeding, groin or neck haematoma, and myocardial infarction (MI). Dichotomous outcome measures were reported using the risk difference (RD) and 95% confidence interval (CI). Combined overall treatment effects were calculated using fixed-effect or random-effects models. Three RCTs and seven observational studies were identified reporting a total of 36,881 CEAs and 150 CAS procedures. In CEA, there were no differences in stroke/TIA/death between single and dual antiplatelet therapy, but there was a significant risk of major bleeding (RD, 0.00; 95% CI, 0.00-0.01; p = .0003) and neck haematoma with dual therapy (RD, 0.04; 95% CI, 0.01-0.06; p = .001). In addition, the rate of MI was higher in the dual therapy group than the single therapy group (RD, 0.00; 95% CI, 0.00-0.01; p = .003). In CAS, there was no difference in major bleeding or haematoma formation, but a significant difference in TIA in favour of dual therapy was identified (RD -0.13, 95% CI, -0.22 to -0.05; p = .003). Dual antiplatelet therapy demonstrates advantages over single therapy only in CAS, as indicated by a reduced risk of TIA. Dual

  17. Predictive value of antiplatelet resistance on early stent thrombosis in patients with acute coronary syndrome

    Institute of Scientific and Technical Information of China (English)

    LI Lei; LI Hai-yan; QIAO Rui; YU Hai-yi; ZENG Hui; GAO Wei; ZHANG Jie

    2013-01-01

    Background Despite outstanding antiplatelet properties of aspirin and clopidogrel,some patients taking these drugs continue to suffer complications.Antiplatelet resistance appears to be a new prognostic factor in acute coronary syndrome patients for clinical events associated with stent thrombosis (ST).However,there is no optimal method to identify it and assess its correlation to clinical outcomes.This study sought to evaluate the predictive value of antiplatelet resistance assessed by whole blood impedance aggregometry for the risk of early ST in patients with acute coronary syndrome who underwent coronary stenting.Methods Platelet responses to aspirin and clopidogrel in 86 patients with acute coronary syndrome were measured by whole blood impedance aggregometry.Spontaneous platelet aggregation was defined as antiplatelet resistance identified by the increased electrical impedance.The clinical endpoint was early stent thrombosis during 30-day follow-up after coronary stenting.Results The prevalence of aspirin resistance,clopidogrel resistance and dual resistance of combined clopidogrel and aspirin resistance were 19.8%,12.8% and 5.8% respectively.Diabetes,female and higher platelet counts were more frequently detected in clopidogrel-resistant and dual-resistant patients.During 30-day follow-up,the patients with clopidogrel resistance and dual resistance had higher incidence of early stent thrombosis (18.2% vs.1.3%,40.0% vs.1.2%,P <0.05).Binary Logistic Regression analysis indicated that dual resistance remained an independent predicator for early stent thrombosis (odds ratio 34.064,95% CI 1.919-604.656,P=-0.016).Conclusions Antiplatelet resistance assessed by whole blood impedance aggregometry is paralleled to clinical events,and dual antiplatelet resistance is an independent predicator for early stent thrombosis in patients with acute coronary syndrome.As a physiological assessment of platelet reactivity,whole blood impedance aggregometry is a

  18. Analysis of risk factors for chronic subdural haematoma recurrence after burr hole surgery: optimal management of patients on antiplatelet therapy.

    Science.gov (United States)

    Okano, Atsushi; Oya, Soichi; Fujisawa, Naoaki; Tsuchiya, Tsukasa; Indo, Masahiro; Nakamura, Takumi; Chang, Han Soo; Matsui, Toru

    2014-04-01

    OBJECTIVE. Not much is known about surgical management of patients with chronic subdural haematoma (CSDH) treated with antiplatelet or anticoagulant therapy. The aims of this study were to review the surgical outcomes of patients with CSDH and assess the risks of antiplatelet in their surgical management. METHODS. We retrospectively analysed 448 consecutive patients with CSDH treated by one burr hole surgery at our institution. Among them, 58 patients had been on antiplatelet therapy. We discontinued the antiplatelet agents before surgery for all 58 patients. For 51 of these 58 patients (87.9%), early surgery was performed within 0-2 days from admission. We analysed the association between recurrence and patient characteristics, including history of antiplatelet or anticoagulant therapy; age (therapy; and previous medical history of head trauma, infarction, hypertension, diabetes mellitus, haemodialysis, seizure, cancer, or liver cirrhosis. RESULTS. Recurrence occurred in 40 patients (8.9%), which was one of the lowest rates in the literature. Univariate analysis showed that only the presence of bilateral haematomas was associated with increased recurrence rate while antiplatelet or anticoagulant therapy did not significantly increase recurrence risk. Also, the recurrence rate from early surgery (0-2 days from drug cessation) for patients on antiplatelet therapy was not significantly higher than that from elective surgery (5 days or more after drug cessation). However, multivariate analysis revealed that previous history of cerebral infarction was an independent risk factor for CSDH recurrence. CONCLUSIOns. Our overall data support the safety of early surgery for patients on the preoperative antiplatelet therapy without drug cessation or platelet infusion. Patients with a previous history of infarction may need to be closely followed regardless of antiplatelet or anticoagulant therapy.

  19. The Effect of Preoperative Antiplatelet Therapy on Hemorrhagic Complications after Decompressive Craniectomy in Patients with Traumatic Brain Injury.

    Science.gov (United States)

    Han, Hokyun; Koh, Eun Jung; Choi, Hyunho; Kim, Byong-Cheol; Yang, Seung Yeob; Cho, Keun-Tae

    2016-10-01

    Traditionally, it is generally recommended that antiplatelet agent should be discontinued before surgery. However, decompressive craniectomy (DC) in patients with traumatic brain injury (TBI) is performed emergently in most cases. Therefore, DC cannot be delayed to the time when the effect of antiplatelet agent on bleeding tendency dissipates. In this study, we evaluated the effect of preinjury antiplatelet therapy on hemorrhagic complications after emergent DC in patients with TBI. We retrospectively investigated patients with TBI who underwent emergent DC between 2006 and 2015. The patients were separated into two groups according to the use of preinjury antiplatelet agent: group 1 (patients taking antiplatelet agent) and group 2 (patients not taking antiplatelet agent). The rate of hemorrhagic complications (postoperative epidural or subdural hemorrhage, newly developed, or progression of preexisting contusion or intracerebral hemorrhage within the field of DC) and the rate of reoperation within 7 days after DC were compared between two groups. During the study period, DC was performed in 90 patients. Of them, 19 patients were taking antiplatelet agent before TBI. The rate of hemorrhagic complications was 52.6% (10/19) in group 1 and 46.5% (33/71) in group 2 (p=0.633). The rate of reoperation was 36.8% (7/19) in group 1 and 36.6% (26/71) in group 2 (p=0.986). No statistical difference was found between two groups. Preinjury antiplatelet therapy did not influence the rate of hemorrhagic complications and reoperation after DC. Emergent DC in patients with TBI should not be delayed because of preinjury antiplatelet therapy.

  20. Determinants of reduced antiplatelet effect of aspirin in patients with stable coronary artery disease.

    Directory of Open Access Journals (Sweden)

    Sanne Bøjet Larsen

    Full Text Available Aspirin is a cornerstone in management of coronary artery disease (CAD. However, considerable variability in the antiplatelet effect of aspirin has been reported.To investigate independent determinants of reduced antiplatelet effect of aspirin in stable CAD patients.We performed a cross-sectional study including 900 stable, high-risk CAD patients. Among these, 795 (88% had prior myocardial infarction, 250 (28% had type 2 diabetes, and 170 (19% had both. All patients received 75 mg aspirin daily as mono antiplatelet therapy. The antiplatelet effect of aspirin was assessed by measurement of platelet aggregation employing 1 multiple electrode aggregometry (MEA, Multiplate Analyzer in whole blood anticoagulated with citrate or hirudin using arachidonic acid (AA or collagen as agonists, and 2 VerifyNow Aspirin Assay. Compliance was assessed by measurement of serum thromboxane B2.Platelet count, prior myocardial infarction, type 2 diabetes and body mass index were independent determinants of increased AA-induced MEA platelet aggregation in citrate and hirudin anticoagulated blood (p-values ≤ 0.045. Similar results were found with VerifyNow. Prior coronary artery bypass grafting, age, smoking (MEA, AA/citrate and female gender (MEA, AA/hirudin were also independent determinants of increased platelet aggregation (p-values ≤ 0.038. Compliance was confirmed by low serum thromboxane B2 levels in all patients (median [25%;75%]: 0.97 [0.52;1.97], range 0.02-26.44 ng/ml.Platelet count, prior myocardial infarction, type 2 diabetes and body mass index were independent determinants of increased platelet aggregation, indicating that these characteristics may be key factors in reduced antiplatelet effect of aspirin in stable CAD patients.

  1. Treatment of Severe Aortic Bleeding Using Hemopatch in Swine on Dual Antiplatelet Therapy.

    Science.gov (United States)

    Baumgartner, Bernhard; Draxler, Wolfgang; Lewis, Kevin M

    2016-12-01

    The perioperative management of patients on antithrombotic therapy is currently an unresolved problem as these therapies pose a considerable risk for perioperative hemorrhagic complications. The presented studies investigated the efficacy of a new collagen technology to achieve hemostasis. A polyethylene glycol-coated collagen pad (PCC) was compared to a marketed fibrinogen-thrombin coated collagen pad (FTC) for the treatment of an aortotomy incision in heparinized swine on dual antiplatelet therapy. Twenty-eight 3-mm aortotomy incisions were created in nine heparinized pigs without antiplatelet therapy and treated with PCC. Sixty-eight aortotomy incisions were created in ten heparinized pigs that received clopidogrel (10-11 mg/kg) and acetylsalicylic acid (8-11 mg/kg) orally for 5 days, and treated with either PCC or FTC (N = 34/group). Dual antiplatelet therapy resulted in significantly reduced platelet function. Aortotomy incisions resulted in life-threatening bleeding of 35-292 ml/min. In animals without antiplatelet treatment, PCC provided 96% immediate hemostatic success. In animals with antiplatelet treatment, FTC provided 18% immediate hemostatic success increasing to 74% after 10 min. Strikingly, PCC provided 94% immediate success increasing to 100% after 10 min. Controlling for differences in pretreatment bleeding rates, statistical model-estimated time to hemostasis was 12 times shorter in PCC-treated lesions (p < .02). The combination of a procoagulant collagen pad with a synthetic sealing component provides excellent hemostatic properties under a worst-case scenario. PCC rapidly and firmly adheres to tissue, thereby controlling severe arterial bleeding, even when platelet function is significantly reduced. Treatment with PCC provided superior time to hemostasis compared to FTC.

  2. Oral antiplatelet therapy for atherothrombotic disease: overview of current and emerging treatment options

    Directory of Open Access Journals (Sweden)

    Fintel DJ

    2012-02-01

    Full Text Available Dan J FintelBluhm Cardiovascular Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL, USAAbstract: Clinical presentations of atherothrombotic vascular disease, such as acute coronary syndromes, ischemic stroke or transient ischemic attack, and symptomatic peripheral arterial disease, are major causes of morbidity and mortality worldwide. Platelet activation and aggregation play a seminal role in the arterial thrombus formation that precipitates acute manifestations of atherothrombotic disease. As a result, antiplatelet therapy has become the cornerstone of therapy for the prevention and treatment of atherothrombotic disease. Dual antiplatelet therapy with aspirin and a P2Y12 adenosine diphosphate (ADP receptor inhibitor, such as clopidogrel or prasugrel, is the current standard-of-care antiplatelet therapy in patients with acute coronary syndromes managed with an early invasive strategy. However, these agents are associated with several important clinical limitations, including significant residual risk for ischemic events, bleeding risk, and variability in the degree of platelet inhibition. The residual risk can be attributed to the fact that aspirin and P2Y12 inhibitors block only the thromboxane A2 and ADP platelet activation pathways but do not affect the other pathways that lead to thrombosis, such as the protease-activated receptor-1 pathway stimulated by thrombin, the most potent platelet agonist. Bleeding risk associated with aspirin and P2Y12 inhibitors can be explained by their inhibitory effects on the thromboxane A2 and ADP pathways, which are critical for protective hemostasis. Interpatient variability in the degree of platelet inhibition in response to antiplatelet therapy may have a genetic component and contribute to poor clinical outcomes. These considerations underscore the clinical need for therapies with a novel mechanism of action that may reduce ischemic events without increasing the bleeding risk

  3. In silico and in vivo anti-malarial studies of 18β glycyrrhetinic acid from Glycyrrhiza glabra.

    Science.gov (United States)

    Kalani, Komal; Agarwal, Jyoti; Alam, Sarfaraz; Khan, Feroz; Pal, Anirban; Srivastava, Santosh Kumar

    2013-01-01

    Malaria is one of the most prevailing fatal diseases causing between 1.2 and 2.7 million deaths all over the world each year. Further, development of resistance against the frontline anti-malarial drugs has created an alarming situation, which requires intensive drug discovery to develop new, more effective, affordable and accessible anti-malarial agents possessing novel modes of action. Over the past few years triterpenoids from higher plants have shown a wide range of anti-malarial activities. As a part of our drug discovery program for anti-malarial agents from Indian medicinal plants, roots of Glycyrrhizaglabra were chemically investigated, which resulted in the isolation and characterization of 18β-glycyrrhetinic acid (GA) as a major constituent. The in vitro studies against P. falciparum showed significant (IC50 1.69 µg/ml) anti-malarial potential for GA. Similarly, the molecular docking studies showed adequate docking (LibDock) score of 71.18 for GA and 131.15 for standard anti-malarial drug chloroquine. Further, in silico pharmacokinetic and drug-likeness studies showed that GA possesses drug-like properties. Finally, in vivo evaluation showed a dose dependent anti-malarial activity ranging from 68-100% at doses of 62.5-250 mg/kg on day 8. To the best of our knowledge this is the first ever report on the anti-malarial potential of GA. Further work on optimization of the anti-malarial lead is under progress.

  4. Chemical profiling of deoxyhypusine hydroxylase inhibitors for antimalarial therapy.

    Science.gov (United States)

    von Koschitzky, Imke; Kaiser, Annette

    2013-11-01

    A first approach to discover new antimalarials has been recently performed in a combined approach with data from GlaxoSmithKline Tres Cantos Antimalarial Set, Novartis-GNF Malaria Box Data set and St. Jude Children's Research Hospital. These data are assembled in the Malaria Box. In a first phenotypic forward chemical genetic approach, 400 chemicals were employed to eradicate the parasite in the erythrocytic stages. The advantage of phenotypic screens for the identification of novel chemotypes is that no a priori assumptions are made concerning a fixed target and that active compounds inherently have cellular bioavailability. In a first screen 40 mostly heterocyclic, highly active compounds (in nmol range of growth inhibition) were identified with EC50 values ≤2 μM against chloroquine-resistant Plasmodium falciparum strains and a therapeutic window ≥10 against two mammalian cell lines. 78 % of the compounds had no violations with the Lipinski Rule of 5 and only 1 % of the compounds showed cytotoxicity when applied at concentrations of 10 μM. This pre-selective step of parasitic eradication will be used further for a test of the Malaria Box with a potential in iron chelating capacity to inhibit deoxyhypusine hydroxylase (DOHH) from P. falciparum and vivax. DOHH, a metalloprotein which consists of ferrous iron and catalyzes the second step of the posttranslational modification at a specific lysine in eukaryotic initiation factor 5A (EIF-5A) to hypusine. Hypusine is a novel, non-proteinogenic amino acid, which is essential in eukaryotes and for parasitic proliferation. DOHH seems to be a "druggable" target, since it has only 26 % amino acid identity to its human orthologue. For a High-throughput Screening (HTS) of DOOH inhibitors, rapid and robust analytical tools are a prerequisite. A proteomic platform for the detection of hypusine metabolites is currently established. Ultra performance Liquid Chromatography enables the detection of hypusine metabolites with

  5. Cheminformatic Analysis of Antimalarial Chemical Space Illuminates Therapeutic Mechanisms and Offers Strategies for Therapy Development.

    Science.gov (United States)

    Varela, Julia Nogueira; Lammoglia Cobo, María Fernanda; Pawar, Sandip V; Yadav, Vikramaditya G

    2017-09-25

    The clear and present danger of malaria, which has been amplified in recent years by climate change, and the progressive thinning of our drug arsenal over the past two decades raise uncomfortable questions about the current state and future of antimalarial drug development. Besides suffering from many of the same technical challenges that affect drug development in other disease areas, the quest for new antimalarial therapies is also hindered by the complex, dynamic life cycle of the malaria parasite, P. falciparum, in its mosquito and human hosts, and its role thereof in the elicitation of drug resistance. New strategies are needed in order to ensure economical and expeditious development of new, more efficacious treatments. In the present study, we employ open-source cheminformatics tools to analyze the chemical space traversed by approved antimalarial drugs and promising candidates at various stages of development to uncover insights that could shape future endeavors in the field. Our scaffold-centric analysis reveals that the antimalarial chemical space is disjointed and segregated into a few dominant structural groups. In fact, the structures of antimalarial drugs and drug candidates are distributed according to Pareto's principle. This structural convergence can potentially be exploited for future drug discovery by incorporating it into bioinformatics workflows that are typically employed for solving problems in structural biology. Significantly, we demonstrate how molecular scaffold hunting can be applied to unearth putative mechanisms of action of drugs whose activities remain a mystery, and how scaffold-centric analysis of drug space can also provide a recipe for combination therapies that minimize the likelihood of emergence of drug resistance, as well as identify areas on which to focus efforts. Finally, we also observe that over half of the molecules in the antimalarial space bear no resemblance to other molecules in the collection, which suggests that

  6. Compound antimalarial ethosomal cataplasm: preparation, evaluation, and mechanism of penetration enhancement.

    Science.gov (United States)

    Shen, Shuo; Liu, Shu-Zhi; Zhang, Yu-Shi; Du, Mao-Bo; Liang, Ai-Hua; Song, Li-Hua; Ye, Zu-Guang

    2015-01-01

    Malaria is still a serious public health problem in some parts of the world. The problems of recurrence and drug resistance are increasingly more serious. Thus, it is necessary to develop a novel antimalarial agent. The objectives of this study were to construct a novel compound antimalarial transdermal nanosystem-ethosomal cataplasm, to investigate its characteristics and efficiency, and to systematically explore the penetration-enhancing mechanisms of ethosomal cataplasm. Artesunate-loaded ethosomes and febrifugine-loaded ethosomes were prepared, and their characteristics were evaluated. Drug-loaded ethosomes were incorporated in the matrix of cataplasm to form the compound antimalarial ethosomal cataplasm. With the help of ethosomal technology, the accumulated permeation quantity of artesunate significantly increased at 8 hours after administration, which was 1.57 times as much as that of conventional cataplasm. Soon after administration, the ethosomal cataplasm could make a large quantity of antimalarial drug quickly penetrate through skin, then the remaining drug in the ethosomal cataplasm could be steadily released. These characteristics of ethosomal cataplasm are favorable for antimalarial drugs to kill Plasmodium spp. quickly and prevent the resurgence of Plasmodium spp. As expected, the ethosomal cataplasm showed good antimalarial efficiency in this experiment. The negative conversion rates were 100% and the recurrence rates were 0% at all dosages. The mechanism of penetration enhancement of the ethosomal cataplasm was systematically explored using an optics microscope, polarization microscope, and transmission electron microscopy. The microstructure, ultrastructure, and birefringent structure in skin were observed. Data obtained in this study showed that the application of ethosomal technology to antimalarial cataplasm could improve the transdermal delivery of drug, enhance the efficacy, and facilitate practical application in clinic.

  7. Antiprotozoal Activity of Buxus sempervirens and Activity-Guided Isolation of O-tigloylcyclovirobuxeine-B as the Main Constituent Active against Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    Julia B. Althaus

    2014-05-01

    Full Text Available Buxus sempervirens L. (European Box, Buxaceae has been used in ethnomedicine to treat malaria. In the course of our screening of plant extracts for antiprotozoal activity, a CH2Cl2 extract from leaves of B. sempervirens showed selective in vitro activity against Plasmodium falciparum (IC50 = 2.79 vs. 20.2 µg/mL for cytotoxicity against L6 rat cells. Separation of the extract by acid/base extraction into a basic and a neutral non-polar fraction led to a much more active and even more selective fraction with alkaloids while the fraction of non-polar neutral constituents was markedly less active than the crude extract. Thus, the activity of the crude extract could clearly be attributed to alkaloid constituents. Identification of the main triterpene-alkaloids and characterization of the complex pattern of this alkaloid fraction was performed by UHPLC/+ESI-QTOF-MS analyses. ESI-MS/MS target-guided larger scale preparative separation of the alkaloid fraction was performed by ‘spiral coil-countercurrent chromatography’. From the most active subfraction, the cycloartane alkaloid O-tigloylcyclovirobuxeine-B was isolated and evaluated for antiplasmodial activity which yielded an IC50 of 0.455 µg/mL (cytotoxicity against L6 rat cells: IC50 = 9.38 µg/mL. O-tigloylcyclovirobuxeine-B is thus most significantly responsible for the high potency of the crude extract.

  8. In Vivo Antiprotozoal Activity of the Chloroform Extract from Carica papaya Seeds against Amastigote Stage of Trypanosoma cruzi during Indeterminate and Chronic Phase of Infection

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    Matilde Jimenez-Coello

    2014-01-01

    Full Text Available In order to evaluate the antiprotozoal activity of the chloroform extract of Carica papaya seeds during the subacute and chronic phase of infection of Trypanosoma cruzi, doses of 50 and 75 mg/kg were evaluated during the subacute phase, including a mixture of their main components (oleic, palmitic, and stearic acids. Subsequently, doses of 50 and 75 mg/kg in mice during the chronic phase of infection (100 dpi were also evaluated. It was found that chloroform extract was able to reduce the amastigote nests numbers during the subacute phase in 55.5 and 69.7% (P > 0.05 as well as in 56.45% in animals treated with the mixture of fatty acids. Moreover, the experimental groups treated with 50 and 75 mg/kg during the chronic phase of the infection showed a significant reduction of 46.8 and 53.13% respectively (P < 0.05. It is recommended to carry out more studies to determine if higher doses of chloroformic extract or its administration in combination with other antichagasic drugs allows a better response over the intracellular stage of T. cruzi in infected animal models and determine if the chloroform extract of C. papaya could be considered as an alternative for treatment during the indeterminate and chronic phase of the infection.

  9. Anti-protozoal and anti-bacterial antibiotics that inhibit protein synthesis kill cancer subtypes enriched for stem cell-like properties

    Science.gov (United States)

    Cuyàs, Elisabet; Martin-Castillo, Begoña; Corominas-Faja, Bruna; Massaguer, Anna; Bosch-Barrera, Joaquim; Menendez, Javier A

    2015-01-01

    Key players in translational regulation such as ribosomes might represent powerful, but hitherto largely unexplored, targets to eliminate drug-refractory cancer stem cells (CSCs). A recent study by the Lisanti group has documented how puromycin, an old antibiotic derived from Streptomyces alboniger that inhibits ribosomal protein translation, can efficiently suppress CSC states in tumorspheres and monolayer cultures. We have used a closely related approach based on Biolog Phenotype Microarrays (PM), which contain tens of lyophilized antimicrobial drugs, to assess the chemosensitivity profiles of breast cancer cell lines enriched for stem cell-like properties. Antibiotics directly targeting active sites of the ribosome including emetine, puromycin and cycloheximide, inhibitors of ribosome biogenesis such as dactinomycin, ribotoxic stress agents such as daunorubicin, and indirect inhibitors of protein synthesis such as acriflavine, had the largest cytotoxic impact against claudin-low and basal-like breast cancer cells. Thus, biologically aggressive, treatment-resistant breast cancer subtypes enriched for stem cell-like properties exhibit exacerbated chemosensitivities to anti-protozoal and anti-bacterial antibiotics targeting protein synthesis. These results suggest that old/existing microbicides might be repurposed not only as new cancer therapeutics, but also might provide the tools and molecular understanding needed to develop second-generation inhibitors of ribosomal translation to eradicate CSC traits in tumor tissues. PMID:25970790

  10. Anti-protozoal and anti-bacterial antibiotics that inhibit protein synthesis kill cancer subtypes enriched for stem cell-like properties.

    Science.gov (United States)

    Cuyàs, Elisabet; Martin-Castillo, Begoña; Corominas-Faja, Bruna; Massaguer, Anna; Bosch-Barrera, Joaquim; Menendez, Javier A

    2015-01-01

    Key players in translational regulation such as ribosomes might represent powerful, but hitherto largely unexplored, targets to eliminate drug-refractory cancer stem cells (CSCs). A recent study by the Lisanti group has documented how puromycin, an old antibiotic derived from Streptomyces alboniger that inhibits ribosomal protein translation, can efficiently suppress CSC states in tumorspheres and monolayer cultures. We have used a closely related approach based on Biolog Phenotype Microarrays (PM), which contain tens of lyophilized antimicrobial drugs, to assess the chemosensitivity profiles of breast cancer cell lines enriched for stem cell-like properties. Antibiotics directly targeting active sites of the ribosome including emetine, puromycin and cycloheximide, inhibitors of ribosome biogenesis such as dactinomycin, ribotoxic stress agents such as daunorubicin, and indirect inhibitors of protein synthesis such as acriflavine, had the largest cytotoxic impact against claudin-low and basal-like breast cancer cells. Thus, biologically aggressive, treatment-resistant breast cancer subtypes enriched for stem cell-like properties exhibit exacerbated chemosensitivities to anti-protozoal and anti-bacterial antibiotics targeting protein synthesis. These results suggest that old/existing microbicides might be repurposed not only as new cancer therapeutics, but also might provide the tools and molecular understanding needed to develop second-generation inhibitors of ribosomal translation to eradicate CSC traits in tumor tissues.

  11. Stimulation of Suicidal Erythrocyte Death by the Antimalarial Drug Mefloquine

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    Rosi Bissinger

    2015-07-01

    Full Text Available Background: The antimalarial drug mefloquine has previously been shown to stimulate apoptosis of nucleated cells. Similar to apoptosis, erythrocytes may enter suicidal death or eryptosis, which is characterized by cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane with phosphatidylserine translocation to the erythrocyte surface. Stimulators of eryptosis include oxidative stress, increase of cytosolic Ca2+-activity ([Ca2+]i, and ceramide. Methods: Phosphatidylserine abundance at the cell surface was estimated from annexin V binding, cell volume from forward scatter, reactive oxidant species (ROS from 2′,7′-dichlorodihydrofluorescein diacetate (DCFDA fluorescence, [Ca2+]i from Fluo3-fluorescence, and ceramide abundance from specific antibody binding. Results: A 48 h treatment of human erythrocytes with mefloquine significantly increased the percentage of annexin-V-binding cells (≥5 µg/ml, significantly decreased forward scatter (≥5 µg/ml, significantly increased ROS abundance (5 µg/ml, significantly increased [Ca2+]i (7.5 µg/ml and significantly increased ceramide abundance (10 µg/ml. The up-regulation of annexin-V-binding following mefloquine treatment was significantly blunted but not abolished by removal of extracellular Ca2+. Even in the absence of extracellular Ca2+, mefloquine significantly increased annexin-V-binding. Conclusions: Mefloquine treatment leads to erythrocyte shrinkage and erythrocyte membrane scrambling, effects at least partially due to induction of oxidative stress, increase of [Ca2+]i and up-regulation of ceramide abundance.

  12. Perspective for the production of antimalarial drugs in Brazil.

    Science.gov (United States)

    Gilbert, B

    1992-01-01

    There appears to be no chemical manufacture of antimalarial drugs in Brazil. Technology at the laboratory process level has been developed for chloroquine, mefloquine, pyrimethamine and cycloguanil, but not perfected nor scaled-up, largely for economic reasons and market uncertainty. Development of primaquine has been contracted but it will run into the same difficulty. Manufacturing capacity for sulfadoxine was registered in the SDI by Roche. A project to produce artemisinine and its derivatives is under way at UNICAMP-CPQBA but is hampered by low content in the plant. Proguanil could be produced easily, but apparently no attempt has been made to do so. Quinine is imported on a large scale mostly for soft-drink production. Since malarial treatment falls largely within the responsibility of the Government health authorities, manufacture of drugs in Brazil will depend on an assured medium-term purchase order made to a potential local manufacturer, since competition in the world market is scarcely viable at the present moment.

  13. Antimalarial action of nitrobenzylthioinosine in combination with purine nucleoside antimetabolites.

    Science.gov (United States)

    Gero, A M; Scott, H V; O'Sullivan, W J; Christopherson, R I

    1989-04-01

    The infection of human erythrocytes by two strains of the human malarial parasite, Plasmodium falciparum (FCQ-27 or the multi-drug-resistant strain K-1), markedly changed the transport characteristics of the nucleosides, adenosine and tubercidin, compared to uninfected erythrocytes. A component of the transport of these nucleosides was insensitive to the classical mammalian nucleoside transport inhibitor nitrobenzylthioinosine (NBMPR). In vitro studies with tubercidin demonstrated ID50 values of 0.43 and 0.51 microM for FCQ-27 and K-1, respectively. In addition, the nucleoside transport inhibitors NBMPR, nitrobenzylthioguanosine (NBTGR), dilazep and dipyridamole also independently exhibited antimalarial activity in vitro. The combination of tubercidin and NBMPR or NBTGR in vitro demonstrated synergistic activity, whilst tubercidin together with dilazep or dipyridamole showed subadditive activity. Analysis by HPLC indicated that NBMPR could permeate the infected cell membrane and provided evidence for the catabolism of NBMPR in vitro, with subsequent alteration of the purine pool in the infected erythrocyte. These observations further indicated the possibility of the utilization of cytotoxic nucleosides against P. falciparum infection in conjunction with a nucleoside transport inhibitor to protect the host tissue.

  14. Targeting Plasmodium Metabolism to Improve Antimalarial Drug Design.

    Science.gov (United States)

    Avitia-Domínguez, Claudia; Sierra-Campos, Erick; Betancourt-Conde, Irene; Aguirre-Raudry, Miriam; Vázquez-Raygoza, Alejandra; Luevano-De la Cruz, Artemisa; Favela-Candia, Alejandro; Sarabia-Sanchez, Marie; Ríos-Soto, Lluvia; Méndez-Hernández, Edna; Cisneros-Martínez, Jorge; Palacio-Gastélum, Marcelo Gómez; Valdez-Solana, Mónica; Hernández-Rivera, Jessica; De Lira-Sánchez, Jaime; Campos-Almazán, Mara; Téllez-Valencia, Alfredo

    2016-01-01

    Malaria is one of the main infectious diseases in tropical developing countries and represents high morbidity and mortality rates nowadays. The principal etiological agent P. falciparum is transmitted through the bite of the female Anopheles mosquito. The issue has escalated due to the emergence of resistant strains to most of the antimalarials used for the treatment including Chloroquine, Sulfadoxine-Pyrimethamine, and recently Artemisinin derivatives, which has led to diminished effectiveness and by consequence increased the severity of epidemic outbreaks. Due to the lack of effective compounds to treat these drug-resistant strains, the discovery or development of novel anti-malaria drugs is important. In this context, one strategy has been to find inhibitors of enzymes, which play an important role for parasite survival. Today, promising results have been obtained in this regard, involving the entire P. falciparum metabolism. These inhibitors could serve as leads in the search of a new chemotherapy against malaria. This review focuses on the achievements in recent years with regard to inhibition of enzymes used as targets for drug design against malaria.

  15. Relationship between Platelet PPARs, cAMP Levels, and P-Selectin Expression: Antiplatelet Activity of Natural Products

    Science.gov (United States)

    Fuentes, Eduardo; Palomo, Iván

    2013-01-01

    Platelets are no longer considered simply as cells participating in thrombosis. In atherosclerosis, platelets are regulators of multiple processes, with the recruitment of inflammatory cells towards the lesion sites, inflammatory mediators release, and regulation of endothelial function. The antiplatelet therapy has been used for a long time in an effort to prevent and treat cardiovascular diseases. However, limited efficacy in some patients, drug resistance, and side effects are limitations of current antiplatelet therapy. In this context, a large number of natural products (polyphenols, terpenoids, alkaloids, and fatty acids) have been reported with antiplatelet activity. In this sense, the present paper describes mechanisms of antiplatelet action of natural products on platelet P-selectin expression through cAMP levels and its role as peroxisome proliferator-activated receptors agonists. PMID:24324520

  16. Antiplatelet agents and/or anticoagulants are not associated with worse outcome following nonvariceal upper gastrointestinal bleeding

    National Research Council Canada - National Science Library

    Teles Sampaio, Elvira; Maia, Luís; Salgueiro, Paulo; Marcos-Pinto, Ricardo; Dinis-Ribeiro, Mário; Pedroto, Isabel

    2016-01-01

    Background: Nonvariceal upper gastrointestinal bleeding emerges as a major complication of using antiplatelet agents and/or anticoagulants and represents a clinical challenge in patients undergoing these therapies. Aim...

  17. Relationship between Platelet PPARs, cAMP Levels, and P-Selectin Expression: Antiplatelet Activity of Natural Products

    Directory of Open Access Journals (Sweden)

    Eduardo Fuentes

    2013-01-01

    Full Text Available Platelets are no longer considered simply as cells participating in thrombosis. In atherosclerosis, platelets are regulators of multiple processes, with the recruitment of inflammatory cells towards the lesion sites, inflammatory mediators release, and regulation of endothelial function. The antiplatelet therapy has been used for a long time in an effort to prevent and treat cardiovascular diseases. However, limited efficacy in some patients, drug resistance, and side effects are limitations of current antiplatelet therapy. In this context, a large number of natural products (polyphenols, terpenoids, alkaloids, and fatty acids have been reported with antiplatelet activity. In this sense, the present paper describes mechanisms of antiplatelet action of natural products on platelet P-selectin expression through cAMP levels and its role as peroxisome proliferator-activated receptors agonists.

  18. Evaluation of bleeding following dental extraction in patients on long-term antiplatelet therapy: A clinical trial

    Directory of Open Access Journals (Sweden)

    K George Varghese

    2015-01-01

    Conclusion: Hence, we recommend routine single tooth extractions in patients on long-term antiplatelet medication, without interruption or alteration of their medication. Such patients do not have an increased risk of prolonged or excessive postoperative bleeding.

  19. The relationship between cerebrovascular complications and previously established use of antiplatelet therapy in left-sided infective endocarditis

    DEFF Research Database (Denmark)

    Snygg-Martin, Ulrika; Rasmussen, Rasmus Vedby; Hassager, Christian;

    2011-01-01

    Cerebrovascular complications (CVC) in infective endocarditis (IE) are common. The only established treatments to reduce the incidence of CVC in IE are antibiotics and in selected cases early cardiac surgery. Potential effects of previously established antiplatelet therapy are under debate....

  20. Do anticoagulants or antiplatelet drugs have a role in treating heart failure in the absence of atrial fibrillation?

    Science.gov (United States)

    Gouda, P; Ezekowitz, J A

    2013-10-01

    Patients with atrial fibrillation (AF) and heart failure (HF) are at risk for stroke, and progress in anticoagulation has led to new options for these patients. Patients in sinus rhythm may benefit from antiplatelet agents or anticoagulants, but much work remains to establish efficacy and safety. Additional progress is needed, including better tools for risk stratification and clarity regarding the need for antiplatelet agents in combination with anticoagulants for those with other vascular diseases.

  1. Median Lethal Dose, Antimalarial Activity, Phytochemical Screening and Radical Scavenging of Methanolic Languas galanga Rhizome Extract

    Directory of Open Access Journals (Sweden)

    Abdulelah H. Al-Adhroey

    2010-11-01

    Full Text Available The methanolic extract of Languas galanga rhizomes was investigated for antimalarial activity against Plasmodium berghei (NK65 infections in mice. The median lethal dose was determined to ascertain the safety of the extract in ICR mice of both sexes. The antimalarial activities during early and established infections, as well as the prophylactic activity were evaluated. Phytochemical screening and radical scavenging activity of the extract were also investigated to elucidate the possible mechanism of the antimalarial properties. The acute oral toxicity (LD50 of Languas galanga extract in mice was established to be 4,998 mg/kg. The extract of Languas galanga rhizomes demonstrated significant antiplasmodial activity in all the three models of the antimalarial evaluations. Phytochemical screening revealed the presence of some vital antiplasmodial constituents such as terpenoids and flavonoids. The extract also exhibited a moderate capacity to scavenge the free radicals. The rhizome extract of Languas galanga thus possesses antimalarial activity, which explains the rational usage of this plant in traditional Malaysian medicine.

  2. Median lethal dose, antimalarial activity, phytochemical screening and radical scavenging of methanolic Languas galanga rhizome extract.

    Science.gov (United States)

    Al-Adhroey, Abdulelah H; Nor, Zurainee M; Al-Mekhlafi, Hesham M; Mahmud, Rohela

    2010-11-16

    The methanolic extract of Languas galanga rhizomes was investigated for antimalarial activity against Plasmodium berghei (NK65) infections in mice. The median lethal dose was determined to ascertain the safety of the extract in ICR mice of both sexes. The antimalarial activities during early and established infections, as well as the prophylactic activity were evaluated. Phytochemical screening and radical scavenging activity of the extract were also investigated to elucidate the possible mechanism of the antimalarial properties. The acute oral toxicity (LD₅₀) of Languas galanga extract in mice was established to be 4.998 mg/kg. The extract of Languas galanga rhizomes demonstrated significant antiplasmodial activity in all the three models of the antimalarial evaluations. Phytochemical screening revealed the presence of some vital antiplasmodial constituents such as terpenoids and flavonoids. The extract also exhibited a moderate capacity to scavenge the free radicals. The rhizome extract of Languas galanga thus possesses antimalarial activity, which explains the rational usage of this plant in traditional Malaysian medicine.

  3. Residual antimalarial concentrations before treatment in patients with malaria from Cambodia: indication of drug pressure.

    Science.gov (United States)

    Hodel, Eva Maria; Genton, Blaise; Zanolari, Boris; Mercier, Thomas; Duong, Socheat; Beck, Hans-Peter; Olliaro, Piero; Decosterd, Laurent Arthur; Ariey, Frédéric

    2010-10-01

    The Thai-Cambodian border has been known as the origin of antimalarial drug resistance for the past 30 years. There is a highly diverse market for antimalarials in this area, and improved knowledge of drug pressure would be useful to target interventions aimed at reducing inappropriate drug use. Baseline samples from 125 patients with falciparum malaria recruited for 2 in vivo studies (in Preah Vihear and Pursat provinces) were analyzed for the presence of 14 antimalarials in a single run, by means of a liquid chromatography-tandem mass spectrometry assay. Half of the patients had residual drug concentrations above the lower limit of calibration for at least 1 antimalarial at admission. Among the drugs detected were the currently used first-line drugs mefloquine (25% and 35% of patients) and piperaquine (15% of patients); the first-line drug against vivax malaria, chloroquine (25% and 41% of patients); and the former first-line drug, quinine (5% and 34% patients). The findings demonstrate that there is high drug pressure and that many people still seek treatment in the private and informal sector, where appropriate treatment is not guaranteed. Promotion of comprehensive behavioral change, communication, community-based mobilization, and advocacy are vital to contain the emergence and spread of parasite resistance against new antimalarials.

  4. close: Closure of patent foramen ovale, oral anticoagulants or antiplatelet therapy to prevent stroke recurrence: Study design.

    Science.gov (United States)

    Mas, Jean-Louis; Derumeaux, Geneviève; Amarenco, Pierre; Arquizan, Caroline; Aubry, Pierre; Barthelet, Martine; Bertrand, Bernard; Brochet, Eric; Cabanes, Laure; Donal, Erwan; Dubois-Randé, Jean-Luc; Durand-Zaleski, Isabelle; Ernande, Laura; Finet, Gérard; Fraisse, Alain; Giroud, Maurice; Guérin, Patrice; Habib, Gilbert; Juliard, Jean-Michel; Leys, Didier; Lièvre, Michel; Lusson, Jean-René; Marcon, François; Michel, Patrick; Moulin, Thierry; Mounier-Vehier, François; Pierard, Luc; Piot, Christophe; Rey, Christian; Rodier, Gilles; Roudaut, Raymond; Schleich, Jean-Marc; Teiger, Emmanuel; Turc, Guillaume; Vuillier, Fabrice; Weimar, Christian; Woimant, France; Chatellier, Gilles

    2016-08-01

    Currently available data do not provide definitive evidence on the comparative benefits of closure of patent foramen ovale, oral anticoagulants and antiplatelet therapy in patients with patent foramen ovale-associated cryptogenic stroke To assess whether transcatheter patent foramen ovale closure plus antiplatelet therapy is superior to antiplatelet therapy alone and whether oral anticoagulant therapy is superior to antiplatelet therapy, for secondary stroke prevention in patients aged 16 to 60 years with a large patent foramen ovale or a patent foramen ovale associated with an atrial septal aneurysm, and an otherwise unexplained ischaemic stroke or retinal ischaemia. Six hundred and sixty-four patients were included in the study. CLOSE is an academic-driven, multicentre, randomized, open-label, three-group, superiority trial with blinded adjudication of outcome events. The trial has been registered with Clinical Trials Register (Clinicaltrials.gov, NCT00562289). Patient recruitment started in December 2007. Patient follow-up will continue until December 2016. Expected mean follow-up = 5.6 years. The primary efficacy outcome is the occurrence of fatal or nonfatal stroke. Safety outcomes include fatal, life-threatening or major procedure- or device-related complications and fatal, life-threatening or major haemorrhagic complications. CLOSE is the first specifically designed trial to assess the superiority of patent foramen ovale closure over antiplatelet therapy alone and the superiority of oral anticoagulants over antiplatelet therapy to prevent stroke recurrence in patients with patent foramen ovale-associated cryptogenic stroke. © 2016 World Stroke Organization.

  5. Appropriateness of antiplatelet therapy for primary and secondary cardio- and cerebrovascular prevention in acutely hospitalized older people.

    Science.gov (United States)

    Ardoino, Ilaria; Rossio, Raffaella; Di Blanca, Donnatella; Nobili, Alessandro; Pasina, Luca; Mannucci, Pier Mannuccio; Peyvandi, Flora; Franchi, Carlotta

    2017-07-19

    Antiplatelet therapy is recommended for the secondary prevention of cardio- and cerebrovascular disease, but for primary prevention it is advised only in patients at very high risk. With this background, this study aims to assess the appropriateness of antiplatelet therapy in acutely hospitalized older people according to their risk profile. Data were obtained from the REPOSI register held in Italian and Spanish internal medicine and geriatric wards in 2012 and 2014. Hospitalized patients aged ≥65 assessable at discharge were selected. Appropriateness of the antiplatelet therapy was evaluated according to their primary or secondary cardiovascular prevention profiles. Of 2535 enrolled patients, 2199 were assessable at discharge. Overall 959 (43.6%, 95% CI 41.5-45.7) were prescribed an antiplatelet drug, aspirin being the most frequently chosen. Among patients prescribed for primary prevention, just over half were inappropriately prescribed (52.1%), being mainly overprescribed (155/209 patients, 74.2%). On the other hand, there was also a high rate of inappropriate underprescription in the context of secondary prevention (222/726 patients, 30.6%, 95% CI 27.3-34.0%). This study carried out in acutely hospitalized older people shows a high degree of inappropriate prescription among patients prescribed with antiplatelets for primary prevention, mainly due to overprescription. Further, a large proportion of patients who had had overt cardio- or cerebrovascular disease were underprescribed, in spite of the established benefits of antiplatelet drugs in the context of secondary prevention. © 2017 The British Pharmacological Society.

  6. Benefits and Risks of Extended Duration Dual Antiplatelet Therapy After PCI in Patients With and Without Acute Myocardial Infarction.

    Science.gov (United States)

    Yeh, Robert W; Kereiakes, Dean J; Steg, Philippe Gabriel; Windecker, Stephan; Rinaldi, Michael J; Gershlick, Anthony H; Cutlip, Donald E; Cohen, David J; Tanguay, Jean-Francois; Jacobs, Alice; Wiviott, Stephen D; Massaro, Joseph M; Iancu, Adrian C; Mauri, Laura

    2015-05-26

    The benefits and risks of prolonged dual antiplatelet therapy may be different for patients with acute myocardial infarction (MI) compared with more stable presentations. This study sought to assess the benefits and risks of 30 versus 12 months of dual antiplatelet therapy among patients undergoing coronary stent implantation with and without MI. The Dual Antiplatelet Therapy Study, a randomized double-blind, placebo-controlled trial, compared 30 versus 12 months of dual antiplatelet therapy after coronary stenting. The effect of continued thienopyridine on ischemic and bleeding events among patients initially presenting with versus without MI was assessed. The coprimary endpoints were definite or probable stent thrombosis and major adverse cardiovascular and cerebrovascular events (MACCE). The primary safety endpoint was GUSTO (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Arteries) moderate or severe bleeding. Of 11,648 randomized patients (9,961 treated with drug-eluting stents, 1,687 with bare-metal stents), 30.7% presented with MI. Between 12 and 30 months, continued thienopyridine reduced stent thrombosis compared with placebo in patients with and without MI at presentation (MI group, 0.5% vs. 1.9%, p therapy, 30 months of dual antiplatelet therapy reduced the risk of stent thrombosis and MI in patients with and without MI, and increased bleeding. (The Dual Antiplatelet Therapy Study [The DAPT Study]; NCT00977938). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  7. Monitoring the efficacy of antimalarial medicines in India via sentinel sites: Outcomes and risk factors for treatment failure

    Directory of Open Access Journals (Sweden)

    Neelima Mishra

    2016-01-01

    Interpretation & conclusion: Till 2012, India′s national antimalarial drug resistance monitoring system proved highly efficacious and safe towards first-line antimalarials used in the country, except in Northeastern region where a decline in efficacy of AS+SP has been observed. This led to change in first-line treatment for P. falciparum to artemether-lumefantrine in Northeastern region.

  8. Cost-effectiveness of pre-referral antimalarial, antibacterial, and combined rectal formulations for severe febrile illness.

    OpenAIRE

    Buchanan, J.; Mihaylova, B.; Gray, A; White, N

    2010-01-01

    BACKGROUND: Malaria and bacterial infections account for most infectious disease deaths in developing countries. Prompt treatment saves lives, but rapid deterioration often prevents the use of oral therapies; delays in reaching health facilities providing parenteral interventions are common. Rapidly and reliably absorbed antimalarial/antibacterial rectal formulations used in the community could prevent deaths and disabilities. Rectal antimalarial treatments are currently available; rectal ant...

  9. Practice points in gynecardiology: Abnormal uterine bleeding in premenopausal women taking oral anticoagulant or antiplatelet therapy.

    Science.gov (United States)

    Maas, Angela H E M; Euler, Mia von; Bongers, Marlies Y; Rolden, Herbert J A; Grutters, Janneke P C; Ulrich, Lian; Schenck-Gustafsson, Karin

    2015-12-01

    A growing number of premenopausal women are currently using antithrombotic and/or (dual) antiplatelet therapy for various cardiovascular indications. These may induce or exacerbate abnormal uterine bleeding and more awareness and knowledge among prescribers is required. Heavy and irregular menstrual bleeding is common in women in their forties and may have a variety of underlying causes that require different treatment options. Thus using anticoagulants in premenopausal women demands specific expertise and close collaboration between cardiovascular physicians and gynecologists. In this article we summarize the scope of the problem and provide practical recommendations for the care for young women taking anticoagulants and/or (dual) antiplatelet therapy. We also recommend that more safety data on uterine bleeding with novel anticoagulants in premenopausal women should be obtained.

  10. Studies on the antiplatelet and antithrombotic profile of anti-inflammatory coumarin derivatives.

    Science.gov (United States)

    Kontogiorgis, Christos; Nicolotti, Orazio; Mangiatordi, Giuseppe Felice; Tognolini, Massimiliano; Karalaki, Foteini; Giorgio, Carmine; Patsilinakos, Alexandros; Carotti, Angelo; Hadjipavlou-Litina, Dimitra; Barocelli, Elisabetta

    2015-12-01

    The interest towards coumarin-based structures stems from their polypharmacological profile. Herein, we present a series of Mannich bases and 7-azomethine-linked coumarin derivatives exhibiting antiplatelet and antithrombotic activities, in addition to the already known anti-inflammatory and antioxidant activities. Among others, compounds 15 and 16 were found to be the most potent and selective inhibitors of platelet aggregation whereas compound 3 also proved to be the most potent in the clot retraction assay. Structure-activity relationship studies were conducted to elucidate the molecular determinants responsible for the herein observed activities. The chance of inhibiting cyclooxygenase-1 was also investigated for evaluating the platelet aggregation induced by arachidonic acid. Taken together, these results suggest that the investigation of other targets connected to the antiplatelet activity, such as phosphodiesterase-3 (PDE3), could be a viable strategy to shed light on the polypharmacological profile of coumarin-based compounds. Docking simulations towards PDE3 were also carried out.

  11. Detection of antiplatelet antibody in serum and on megakaryocytes of dogs with autoimmune thrombocytopenia.

    Science.gov (United States)

    Joshi, B C; Jain, N C

    1976-06-01

    Blood and bone marrow samples from 13 thrombocytopenic dogs were examined to determine whether immunologic thrombocytopenia existed. Antiplatelet antibody was detected in serum of 8 of the dogs by platelet factor 3 test or its modification. Moderate to strong immunofluorescence of megakaryocytes was noticed in bone marrow smears stained with rabbit anticanine globulin conjugated with fluorescin isothiocyanate. Negative results were obtained with serum and bone marrow samples collected from 6 of the dogs during therapy for autoimmune thrombocytopenia. Clinical and laboratory findings varied in individual patients with circulating antiplatelet antibodies. Thrombocytopenia was present in all the dogs, with platelet counts ranging from less than 3,000 to 20,000/mu1 of blood. Signs of bleeding in tissues and body cavities were present in all dogs, but anemia was evidenced in only 3 dogs. Differential leukocyte counts were variable. Morphologic abnormalities such as vacuolation and reduced or absence of granulation of the cytoplasm and nuclear fragmentation were seen in some megakaryocytes.

  12. 24-hour antiplatelet effect of aspirin in patients with previous definite stent thrombosis

    DEFF Research Database (Denmark)

    Würtz, Morten; Hvas, Anne-Mette; Jensen, Lisette O

    2014-01-01

    OBJECTIVE: Once-daily aspirin is standard treatment, but recent studies point towards increased platelet function at the end of the dosing interval. Stent thrombosis (ST) has been linked with reduced antiplatelet effect of aspirin, so we investigated if platelet inhibition by aspirin declines...... with 100 patients with stable coronary artery disease and 50 healthy volunteers. All participants were on aspirin 75 mg/day mono antiplatelet therapy. Platelet aggregation was measured 1 and 24 h after aspirin intake using platelet aggregometry (Multiplate® Analyzer). Cyclooxygenase-1 activity, platelet...... activation, immature platelets, and thrombopoietin were measured. RESULTS: Platelet aggregation increased by 109±150 (arachidonic acid) and 47±155 (collagen) aggregation units per minute from 1 to 24 h after aspirin intake (p-values

  13. Antiplatelet therapy in the era of percutaneous coronary intervention with drug-eluting balloons.

    Science.gov (United States)

    Bonaventura, Klaus; Sonntag, Steffen; Kleber, Franz X

    2011-05-01

    The high rate of restenosis associated with percutaneous coronary intervention (PCI) procedures can be reduced with the implantation of metallic stents into the stenotic vessels. The knowledge that neointimal formation can result in restenosis after stent implantation led to the development of drug-eluting stents (DES) which require long lasting antiplatelet therapy to avoid thrombotic complications. In the last years, the drug-eluting balloon (DEB) technology has emerged as an alternative option for the treatment of coronary and peripheral arteries. Clinical studies demonstrated the safety and effectiveness of DEB in various clinical scenarios and support the use of paclitaxel-eluting balloons for the treatment of in-stent restenosis, of small coronary arteries and bifurcations lesions. The protocols of DEB studies suggest that the dual antiplatelet therapy with aspirin and clopidogrel of four weeks after DEB is safe and effective.

  14. Antiplatelets and antithrombotics in patients with liver insufficiency. From pathophysiology to clinical practice.

    Science.gov (United States)

    Deutsch, Melanie; Koskinas, John

    2016-12-05

    The liver represents the site of synthesis of most procoagulant and anticoagulant factors, fibrinolytic proteins and thrombopoetin while being also involved in the clearance of hemostatic and fibrinolyic proteins. Therefore in patients with liver insufficiency a great variety of disturbances can be documented resulting however in a new "rebalanced" hemostatic system with a labile equilibrium between thromboses or bleeding. Interestingly patients with liver insufficiency may present with arterial or venous thrombotic episodes requiring antiplatelet and/or antithrombotic therapy despite low platelet count or prolonged INR. The aim of this review is to point on the current knowledge regarding hemostasis in patients with liver insufficiency underlining practical recommendations of the use of antiplatelet and anticoagulant drugs in this setting.

  15. Sequential measurement of anti-platelet antibodies in a patient who developed EDTA-dependent pseudothrombocytopenia.

    Science.gov (United States)

    Edelman, B; Kickler, T

    1993-01-01

    Ethylenediaminetetraacetic acid (EDTA)-dependent pseudothrombocytopenia is the occurrence of a falsely low platelet count caused by antibodies that agglutinate platelets in the presence of EDTA. If unrecognized, it may result in the erroneous diagnosis of thrombocytopenia and possible inappropriate therapy. It has been noted that this phenomenon tends to appear in hospitalized patients after an initially normal platelet count, but sequential measurements of anti-platelet antibody have not been reported. The case of a patient who developed EDTA-dependent pseudothrombocytopenia approximately 1 week after being hospitalized for severe trauma is described. Anti-platelet antibodies were not detected on admission by a radiolabeled antiglobulin technique but were shown to increase in titer concurrent with the appearance of EDTA-dependent pseudothrombocytopenia.

  16. Construction and Characterization of Novel Staphylokinase Variants with Antiplatelet Aggregation Activity and Reduced Immunogenecity

    Institute of Scientific and Technical Information of China (English)

    Hua-Bo SU; Yu-Gao ZHANG; Jin-Tian HE; Wei MO; Yan-Ling ZHANG; Xian-Mei TAO; Hou-Yan SONG

    2004-01-01

    To develop target thrombolytic agents with fibrinolytic activity, antiplatelet aggregation activity and reduced immunogenicity, two staphylokinase variants containing Arg-Gly-Asp (RGD) motif were constructed. Gene expression was induced in E. coli JF1125 and the variants, designated DGR and RL1, were purified with gel filtration and ion-exchange chromatography and the purity was over 95%. The fibrinolytic activity and kinetic constants of the two variants were comparable to those of recombinant wild-type staphylokinase. Both the variants can inhibit the platelet aggregation at a final concentration of 2 μM. Thetiters of antibodies against variants were much lower than those against recombinant staphylokinase in guineapigs, which indicated that the immunogenicity of the variants was greatly reduced. These results confirm thatit is possible to design and produce a bifunctional protein that possesses fibrinolytic and antiplatelet aggregation activities.

  17. Pyrazolinone analgesics prevent the antiplatelet effect of aspirin and preserve human platelet thromboxane synthesis.

    Science.gov (United States)

    Hohlfeld, T; Zimmermann, N; Weber, A-A; Jessen, G; Weber, H; Schrör, K; Höltje, H-D; Ebel, R

    2008-01-01

    Anti-inflammatory analgesics, including ibuprofen and naproxen, are known to interfere with the antiplatelet effect of aspirin, presumably as a result of a drug-drug interaction at the level of platelet cyclooxygenase-1 (COX-1). We studied whether dipyrone, which has recently been reported to inhibit COX isoforms by a mechanism different from conventional non-steroidal anti-inflammatory drugs (NSAIDs), also interferes with the antiplatelet effect of aspirin. Arachidonic acid- and collagen-induced aggregation, as well as thromboxane formation, were measured in human platelet-rich plasma. Platelet P-selectin expression was determined by flow cytometry and cell-free COX enzyme activity was quantified by luminol-enhanced luminescence of human platelet microsomes. In addition, computerized docking was performed based on the crystal structure of COX-1. 4-Methylaminoantipyrine (MAA), the active metabolite of dipyrone, largely attenuated or even completely abolished the inhibition of arachidonic acid-induced platelet aggregation, thromboxane formation and P-selectin expression by aspirin. Similar results were obtained for other pyrazolinones, as well as for the conventional NSAIDs ibuprofen and naproxen. Moreover, MAA attenuated the effect of aspirin on COX activity of platelet microsomes, suggesting a competition with aspirin at the COX-1 enzyme. This was confirmed by docking studies, which revealed that MAA forms a strong hydrogen bond with serine 530 within the COX-1, thereby preventing enzyme acetylation by aspirin. This study demonstrates for the first time that dipyrone and other pyrazolinones have a high potential to attenuate or prevent the antiplatelet effect of aspirin. This should be considered if pyrazolinone analgesics are administered to patients with cardiovascular disease requiring antiplatelet aspirin therapy.

  18. POSSIBILITIES OF CLINICAL LABORATORY EVALUATION OF ANTIPLATELET THERAPY EFFECTIVENESS IN PATIENTS WITH ISCHEMIC HEART DISEASE

    Directory of Open Access Journals (Sweden)

    O. V. Sirotkina

    2013-01-01

    Full Text Available Aim. To evaluate the functional activity of platelets by the optical standard aggregatometry and induced flow cytofluorometry during antiplatelet therapy with clopidogrel and acetylsalicylic acid (ASA.Material and methods. The evaluation of platelet function in 30 patients with ischemic heart disease treated with dual antiplatelet therapy (ASA and clopidogrel was performed by two methods: the standard photometric method with the assessment of degree of light transmission at the maximum point and by the original method of induced flow cytofluorometry with the platelet activity evaluation by changing of glycoprotein (GP IIb/IIIa receptor level and the expression of P-selectin before and after ADP induction.Results. Increase in platelet functional activity was detected in patients with ASA monotherapy at initial evaluation by both induced flow cytofluorometry and standard photometric method. After one month dual antiplatelet therapy platelet function significantly decreased according to standard photometric method (from 61.4Ѓ}3.6 to 45.9Ѓ}3.7; p<0.05; the induction of 2.5 mM ADP, as well as according to flow cytofluorometry with changing of GP IIb/IIIa receptor level (from 12.2Ѓ}0.8% to 5.2Ѓ}0.8%; p<0.05 and the expression of P-selectin (from 70.5Ѓ}5.9% to 57.4Ѓ}5.9%; p<0.05.Conclusion. The combined use of laboratory methods to assess platelet function (traditional and high-tech provides cardiologist with additional tool for assessing the effectiveness of antiplatelet therapy in patients with ischemic heart disease.

  19. POSSIBILITIES OF CLINICAL LABORATORY EVALUATION OF ANTIPLATELET THERAPY EFFECTIVENESS IN PATIENTS WITH ISCHEMIC HEART DISEASE

    Directory of Open Access Journals (Sweden)

    O. V. Sirotkina

    2015-09-01

    Full Text Available Aim. To evaluate the functional activity of platelets by the optical standard aggregatometry and induced flow cytofluorometry during antiplatelet therapy with clopidogrel and acetylsalicylic acid (ASA.Material and methods. The evaluation of platelet function in 30 patients with ischemic heart disease treated with dual antiplatelet therapy (ASA and clopidogrel was performed by two methods: the standard photometric method with the assessment of degree of light transmission at the maximum point and by the original method of induced flow cytofluorometry with the platelet activity evaluation by changing of glycoprotein (GP IIb/IIIa receptor level and the expression of P-selectin before and after ADP induction.Results. Increase in platelet functional activity was detected in patients with ASA monotherapy at initial evaluation by both induced flow cytofluorometry and standard photometric method. After one month dual antiplatelet therapy platelet function significantly decreased according to standard photometric method (from 61.4Ѓ}3.6 to 45.9Ѓ}3.7; p<0.05; the induction of 2.5 mM ADP, as well as according to flow cytofluorometry with changing of GP IIb/IIIa receptor level (from 12.2Ѓ}0.8% to 5.2Ѓ}0.8%; p<0.05 and the expression of P-selectin (from 70.5Ѓ}5.9% to 57.4Ѓ}5.9%; p<0.05.Conclusion. The combined use of laboratory methods to assess platelet function (traditional and high-tech provides cardiologist with additional tool for assessing the effectiveness of antiplatelet therapy in patients with ischemic heart disease.

  20. Impact of Optimal Medical Therapy in the Dual Antiplatelet Therapy Study.

    Science.gov (United States)

    Resor, Charles D; Nathan, Ashwin; Kereiakes, Dean J; Yeh, Robert W; Massaro, Joseph M; Cutlip, Donald E; Gabriel Steg, P; Hsieh, Wen-Hua; Mauri, Laura

    2016-10-04

    Continued dual antiplatelet therapy and optimal medical therapy (OMT) improve outcomes in selected patient populations with established coronary heart disease, but whether OMT modifies the treatment effect of dual antiplatelet therapy is unknown. The DAPT (Dual Antiplatelet Therapy) Study, a double-blind trial, randomly assigned 11 648 patients who had undergone coronary stenting and completed 1 year of dual antiplatelet therapy without major bleeding or ischemic events to an additional 18 months of continued thienopyridine or placebo. OMT was defined as a combination of statin, β-blocker, and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use in patients with an American College of Cardiology/American Heart Association class I indication for each medication. Per protocol, all patients were treated with 75 to 325 mg aspirin daily. End points included myocardial infarction, major adverse cardiovascular and cerebrovascular events, and Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Arteries moderate or severe bleeding events. Of 11 643 randomly assigned patients with complete medication data, 63% were on OMT. Between 12 and 30 months, continued thienopyridine reduced myocardial infarction in comparison with placebo in both groups (on OMT 2.1% versus 3.3%, hazard ratio [HR], 0.64; 95% confidence interval [CI], 0.48-0.86; P=0.003; off OMT 2.2% versus 5.2%, HR, 0.41; CI, 0.29-0.58; Ptherapy reduced the rate of myocardial infarction regardless of OMT status and had consistent effects on reduction in major adverse cardiovascular and cerebrovascular events and increased bleeding. URL: http://clinicaltrials.gov. Unique identifier: NCT00977938. © 2016 American Heart Association, Inc.

  1. Oral antiplatelet therapy for atherothrombotic disease: overview of current and emerging treatment options

    Science.gov (United States)

    Fintel, Dan J

    2012-01-01

    Clinical presentations of atherothrombotic vascular disease, such as acute coronary syndromes, ischemic stroke or transient ischemic attack, and symptomatic peripheral arterial disease, are major causes of morbidity and mortality worldwide. Platelet activation and aggregation play a seminal role in the arterial thrombus formation that precipitates acute manifestations of atherothrombotic disease. As a result, antiplatelet therapy has become the cornerstone of therapy for the prevention and treatment of atherothrombotic disease. Dual antiplatelet therapy with aspirin and a P2Y12 adenosine diphosphate (ADP) receptor inhibitor, such as clopidogrel or prasugrel, is the current standard-of-care antiplatelet therapy in patients with acute coronary syndromes managed with an early invasive strategy. However, these agents are associated with several important clinical limitations, including significant residual risk for ischemic events, bleeding risk, and variability in the degree of platelet inhibition. The residual risk can be attributed to the fact that aspirin and P2Y12 inhibitors block only the thromboxane A2 and ADP platelet activation pathways but do not affect the other pathways that lead to thrombosis, such as the protease-activated receptor-1 pathway stimulated by thrombin, the most potent platelet agonist. Bleeding risk associated with aspirin and P2Y12 inhibitors can be explained by their inhibitory effects on the thromboxane A2 and ADP pathways, which are critical for protective hemostasis. Interpatient variability in the degree of platelet inhibition in response to antiplatelet therapy may have a genetic component and contribute to poor clinical outcomes. These considerations underscore the clinical need for therapies with a novel mechanism of action that may reduce ischemic events without increasing the bleeding risk. PMID:22393298

  2. Advances in Induced Pluripotent Stem Cells, Genomics, Biomarkers, and Antiplatelet Therapy

    Science.gov (United States)

    Barbato, Emanuele; Lara-Pezzi, Enrique; Stolen, Craig; Taylor, Angela; Barton, Paul J.; Bartunek, Jozef; Iaizzo, Paul; Judge, Daniel P.; Kirshenbaum, Lorrie; Blaxall, Burns C.; Terzic, Andre; Hall, Jennifer L.

    2014-01-01

    The Journal provides the clinician and scientist with the latest advances in discovery research, emerging technologies, pre-clinical research design and testing, and clinical trials. We highlight advances in areas of induced pluripotent stem cells, genomics, biomarkers, multi-modality imaging and antiplatelet biology and therapy. The top publications are critically discussed and presented along with anatomical reviews and FDA insight to provide context. PMID:24659088

  3. Dental management of patients receiving anticoagulant and/or antiplatelet treatment

    OpenAIRE

    Mingarro de León, Ana; Chaveli López, Begonya; Gavaldá Esteve, Carmen

    2014-01-01

    Introduction: Adequate hemostasis is crucial for the success of invasive dental treatment, since bleeding problems can give rise to complications associated with important morbidity-mortality. The dental treatment of patients who tend to an increased risk of bleeding due to the use of anticoagulant and/or antiplatelet drugs raises a challenge in the daily practice of dental professionals. Adequate knowledge of the mechanisms underlying hemostasis, and the optimized management of such patients...

  4. Management of Antiplatelet Agents and Anticoagulants in Patients with Gastrointestinal Bleeding.

    Science.gov (United States)

    Abraham, Neena S

    2015-07-01

    Antithrombotic drugs (anticoagulants, aspirin, and other antiplatelet agents) are used to treat cardiovascular disease and to prevent secondary thromboembolic events. These drugs are independently associated with an increased risk of gastrointestinal bleeding (GIB), and, when prescribed in combination, further increase the risk of adverse bleeding events. Clinical evidence to inform the choice of endoscopic hemostatic procedure, safe temporary drug cessation, and use of reversal agents is reviewed to optimize management following clinically significant GIB.

  5. Antiplatelet/anticoagulant agents and chronic subdural hematoma in the elderly.

    Directory of Open Access Journals (Sweden)

    Pasquale De Bonis

    Full Text Available BACKGROUND AND PURPOSE: In the last decade there has been an increasing use of antiplatelet/anticoagulant agents in the elderly. The aim of the study was to evaluate the association between exposure to anticoagulant/antiplatelet therapy and chronic subdural haematoma-CSDH. METHODS: Single institution case-control study involving 138786 patients older than 60 years who visited our academic tertiary care Emergency Department from January 1st 2001 to December 31st 2010. 345 patients with CSDH (cases were identified by review of ICD-9 codes 432.1 and 852.2x. Case and controls were matched with a 1:3 ratio for gender, age (± 5 years, year of admission and recent trauma. A conditional logistic model was built. A stratified analysis was performed with respect to the presence (842 patients or absence (536 patients of recent trauma. RESULTS: There were 345 cases and 1035 controls. Both anticoagulant and antiplatelet agents were associated with an increased risk of CSDH with an OR of 2.46 (CI 95% 1.66-3.64 and 1.42 (CI 95% 1.07-1.89, respectively. OR was 2.70 (CI 95% 1.75-4.15, 1.90 (CI 95% 1.13-3.20, and 1.37(CI 95% 0.99-1.90 for patients receiving oral anticoagulants, ADP-antagonists, or Cox-inhibitors, respectively. History of recent trauma was an effect modifier of the association between anticoagulants and CSDH, with an OR 1.71 (CI 95% 0.99-2.96 for patients with history of trauma and 4.30 (CI 95% 2.23-8.32 for patients without history of trauma. CONCLUSIONS: Anticoagulant and antiplatelet therapy have a significant association with an increased risk of CSDH. This association, for patients under anticoagulant therapy, appears even stronger in those patients who develop a CSDH in the absence of a recent trauma.

  6. [Perioperative Management of Lung Cancer Patients with atrial fibrillation being treated by antiplatelet or anticoagulant therapy].

    Science.gov (United States)

    Ishikawa, Shinya; Kasai, Yoshitaka; Matsuura, Natsumi; Tarumi, Shintaro; Nakano, Jun; Okuda, Masaya; Goto, Masashi; Ryu, Dagu; Go, Tetsuhiko; Yokomise, Hiroyasu

    2015-04-01

    In an aging society, the high incidence of surgery for the patients with ischemic heart disease(IHD)or atrial fibrillation(Af) under antiplatelet or anticoagulant therapy is a great problem. Interruption of antiplatelet or anticoagulant oral agents in the perioperative period may increase the risk of coronary or cerebral events. We retrospectively reviewed the surgical outcomes for lung cancer patients with IHD or Af. We reviewed 135 patients with lung cancer(41~88 years;97 men) who had preoperative oral administration of antiplatelet or anticoagulant drugs for IHD or Af between 2005 and 2012 at 2 centers, and analyzed retrospectively the perioperative medications and complications. IHD, Af and vasospastic angina(VSA) were complicated in 94, 33 and 8 patients, respectively. Drugeluted and bare-metal stents had been placed in 18 and 19 patients. Oral agents were aspirin in 68 patients, ticlopidine in 10 patients, clopidogrel in 15 patients and warfarin in 25 patients. These agents were stopped 2 to 60 days before surgery. Perioperative heparinization was performed in 22 patients. Oral agents were restarted after confirmation of hemostasis and no need for further invasive treatment. The surgical procedures were lobectomy in 88 patients, segmentectomy in 19 and partial resection in 25. There were no hemorrhagic or thromboembolic complications in a perioperative period except 1 case of pulmonary hemorrhage and 1 case of cerebral infarction. No perioperative hospital death was documented. Short-term interruption of antiplatelet or anticoagulant drugs before lung cancer surgery and heparinization was acceptable from the view of perioperative outcomes.

  7. ANALYZES OF ANTIPLATELETS AND ANTICOAGULANTS UTILIZATION IN PATIENTS TREATED IN CARDIOVASCULAR REHABILITATION CENTER FROM CROATIA

    Directory of Open Access Journals (Sweden)

    Boban Marko

    2016-07-01

    Full Text Available Purpose: Discordance with the guidelines and underutilization of pharmacotherapy for secondary prevention frequently exists in clinical practice. Aim of our study was to assess the prescription routine and drug utilization patterns for antiplatelets and peroral anticoagulants in tertiary medical center specialized for cardiovascular rehabilitation. Methods: study included 96 consecutive patients scheduled for cardiovascular rehabilitation in period 1-6 months after the acute treatment for ischemic 87(80.2% and valvular heart disease 18(19.8%. Patients were divided according to etiology of heart disease and type of acute cardiovascular treatments (conservative, percutaneous coronary interventions (PCI and surgery. Results: Dual antiplatelet therapy was the most commonly applied regimen in 84(87.5% of conservatively treated myocardial infarctions, 47(61.9% of percutaneous coronary interventions (PCI and 13(58.9% of surgically treated group (p>0.05. Among studied group of patients significant differences in utilization were found for warfarin, or combinations of antiplatelets with warfarin(p0.05. All four of patients that received triple therapy (4.17% were from surgical group. Underutilization of antiplatelets in ischemic heart disease was at 11(14.3% what was congruent with the developed industrial nations. Conclusions: Acute cardiovascular treatment type, but not heart disease etiology, had significant influence on subsequent prescription routine. Decreased use of pharmacological agents for secondary prevention in surgical patients was revealed. Drug utilization analyzes can offer improvement in optimizing medical treatments, quality of care and decrease unnecessary polypragmasia, as well as improve economical efficiency of medical management.

  8. Anti-platelet aggregation triterpene saponins from the galls of Sapindus mukorossi.

    Science.gov (United States)

    Huang, Hui-Chi; Tsai, Wei-Jern; Liaw, Chia-Ching; Wu, Shih-Hsiung; Wu, Yang-Chang; Kuo, Yao-Haur

    2007-09-01

    Bioassay-directed fractionation of an ethanolic extract of the galls of Sapindus mukorossi has resulted in the isolation of two new tirucallane-type triterpenoid saponins, sapinmusaponins Q (1) and R (2), along with three known oleanane-type triterpenoid saponins (3-5). Their structures were elucidated on the basis of spectroscopic analysis and chemical hydrolysis. Biological evaluation showed that both sapinmusaponins Q and R demonstrated more potent anti-platelet aggregation activity than aspirin.

  9. Neuroprotective effect of butylphthalide combined with aspirin and clopidogrel antiplatelet therapy on progressive cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    Xing-Bing He

    2016-01-01

    Objective:To analyze the neuroprotective effect of butylphthalide combined with aspirin and clopidogrel antiplatelet therapy on progressive cerebral infarction.Methods:A total of 86 patients with progressive cerebral infarction were randomly divided into observation group and control group (n=43), control group received aspirin and clopidogrel antiplatelet therapy, observation group received butylphthalide combined with aspirin and clopidogrel antiplatelet therapy, and then the differences in platelet function, blood coagulation function, middle cerebral artery blood flow state and nerve function index levels were compared between two groups after treatment.Results: After 1 course of treatment, the relative content of P-selectin and GPIIb/IIIa on platelet surface as well as TXB2, vWF and D-D content in plasma of observation group were significantly lower than those of control group, while 6-Keto-PGF1 content in plasma was significantly higher than that of control group); thrombelastogram indexes R and K value were higher than those of control group while MA, Angle and CI value were lower than those of control group; middle cerebral artery PSV, EDV, Vm and PI were higher than those of control group while RI value was lower than that of control group; nerve function indexes BDNF and H2S content in plasma were higher than those of control group while NSE, MBP, S100B and MMP-9 content were lower than those of control group (P<0.05). Conclusions:Butylphthalide combined with aspirin and clopidogrel antiplatelet therapy can effectively optimize the platelet and blood coagulation function in patients with progressive cerebral infarction, promote the middle cerebral artery blood flow recovery and exert positive neuroprotective effect.

  10. Influence of smoking on disease severity and antimalarial therapy in cutaneous lupus erythematosus

    DEFF Research Database (Denmark)

    Kuhn, A; Sigges, J; Biazar, C

    2014-01-01

    BACKGROUND: In recent years it has been controversially discussed in the literature if smoking is associated with the activity of cutaneous lupus erythematosus (CLE) and the efficacy of antimalarial agents. OBJECTIVES: To investigate the influence of smoking on disease severity and antimalarial...... treatment in patients with CLE using the Core Set Questionnaire of the European Society of Cutaneous Lupus Erythematosus (EUSCLE). METHODS: A total of 1002 patients (768 female, 234 male) with different CLE subtypes were included in this cross-sectional study, which was performed in 14 different countries....... Smoking behaviour was assessed by the EUSCLE Core Set Questionnaire in 838 patients and statistically analysed using an SPSS database. The results were correlated with the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) and the efficacy of antimalarial treatment. RESULTS: A high...

  11. Lack of doxycycline antimalarial prophylaxis impact on Staphylococcus aureus tetracycline resistance.

    Science.gov (United States)

    Mende, Katrin; Beckius, Miriam L; Zera, Wendy C; Yu, Xin; Li, Ping; Tribble, David R; Murray, Clinton K

    2016-10-01

    There is concern that susceptibility of Staphylococcus aureus to tetracyclines may decrease due to use of antimalarial prophylaxis (doxycycline). We examined characteristics related to tetracycline resistance, including doxycycline exposure, in S. aureus isolates collected via admission surveillance swabs and inpatient clinical cultures from United States military personnel injured during deployment (June 2009-January 2012). Tetracycline class resistance was determined using antimicrobial susceptibility testing. The first S. aureus isolate from 168 patients were analyzed, of which 38 (23%) isolates were resistant to tetracyclines (class). Tetracycline-resistant isolates had a higher proportion of resistance to clindamycin (P=0.019) compared to susceptible isolates. There was no significant difference in tetracycline resistance between isolates collected from patients with and without antimalarial prophylaxis; however, significantly more isolates had tet(M) resistance genes in the doxycycline exposure group (P=0.031). Despite 55% of the patients receiving doxycycline as antimalarial prophylaxis, there was no association with resistance to tetracyclines.

  12. Blood schizontocidal activity of methylene blue in combination with antimalarials against Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    Garavito G.

    2007-06-01

    Full Text Available Methylene blue (MB is the oldest synthetic antimalarial. It is not used anymore as antimalarial but should be reconsidered. For this purpose we have measured its impact on both chloroquine sensitive and resistant Plasmodium strains. We showed that around 5 nM of MB were able to inhibit 50% of the parasite growth in vitro and that late rings and early trophozoites were the most sensitive stages; while early rings, late trophozoites and schizonts were less sensitive. Drug interaction study following fractional inhibitory concentrations (FIC method showed antagonism with amodiaquine, atovaquone, doxycycline, pyrimethamine; additivity with artemether, chloroquine, mefloquine, primaquine and synergy with quinine. These results confirmed the interest of MB that could be integrated in a new low cost antimalarial combination therapy.

  13. Small molecule screen for candidate antimalarials targeting Plasmodium Kinesin-5.

    Science.gov (United States)

    Liu, Liqiong; Richard, Jessica; Kim, Sunyoung; Wojcik, Edward J

    2014-06-06

    Plasmodium falciparum and vivax are responsible for the majority of malaria infections worldwide, resulting in over a million deaths annually. Malaria parasites now show measured resistance to all currently utilized drugs. Novel antimalarial drugs are urgently needed. The Plasmodium Kinesin-5 mechanoenzyme is a suitable "next generation" target. Discovered via small molecule screen experiments, the human Kinesin-5 has multiple allosteric sites that are "druggable." One site in particular, unique in its sequence divergence across all homologs in the superfamily and even within the same family, exhibits exquisite drug specificity. We propose that Plasmodium Kinesin-5 shares this allosteric site and likewise can be targeted to uncover inhibitors with high specificity. To test this idea, we performed a screen for inhibitors selective for Plasmodium Kinesin-5 ATPase activity in parallel with human Kinesin-5. Our screen of nearly 2000 compounds successfully identified compounds that selectively inhibit both P. vivax and falciparum Kinesin-5 motor domains but, as anticipated, do not impact human Kinesin-5 activity. Of note is a candidate drug that did not biochemically compete with the ATP substrate for the conserved active site or disrupt the microtubule-binding site. Together, our experiments identified MMV666693 as a selective allosteric inhibitor of Plasmodium Kinesin-5; this is the first identified protein target for the Medicines of Malaria Venture validated collection of parasite proliferation inhibitors. This work demonstrates that chemical screens against human kinesins are adaptable to homologs in disease organisms and, as such, extendable to strategies to combat infectious disease. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  14. Small Molecule Screen for Candidate Antimalarials Targeting Plasmodium Kinesin-5*

    Science.gov (United States)

    Liu, Liqiong; Richard, Jessica; Kim, Sunyoung; Wojcik, Edward J.

    2014-01-01

    Plasmodium falciparum and vivax are responsible for the majority of malaria infections worldwide, resulting in over a million deaths annually. Malaria parasites now show measured resistance to all currently utilized drugs. Novel antimalarial drugs are urgently needed. The Plasmodium Kinesin-5 mechanoenzyme is a suitable “next generation” target. Discovered via small molecule screen experiments, the human Kinesin-5 has multiple allosteric sites that are “druggable.” One site in particular, unique in its sequence divergence across all homologs in the superfamily and even within the same family, exhibits exquisite drug specificity. We propose that Plasmodium Kinesin-5 shares this allosteric site and likewise can be targeted to uncover inhibitors with high specificity. To test this idea, we performed a screen for inhibitors selective for Plasmodium Kinesin-5 ATPase activity in parallel with human Kinesin-5. Our screen of nearly 2000 compounds successfully identified compounds that selectively inhibit both P. vivax and falciparum Kinesin-5 motor domains but, as anticipated, do not impact human Kinesin-5 activity. Of note is a candidate drug that did not biochemically compete with the ATP substrate for the conserved active site or disrupt the microtubule-binding site. Together, our experiments identified MMV666693 as a selective allosteric inhibitor of Plasmodium Kinesin-5; this is the first identified protein target for the Medicines of Malaria Venture validated collection of parasite proliferation inhibitors. This work demonstrates that chemical screens against human kinesins are adaptable to homologs in disease organisms and, as such, extendable to strategies to combat infectious disease. PMID:24737313

  15. Antiplatelet antibody may cause delayed transfusion-related acute lung injury

    Directory of Open Access Journals (Sweden)

    Torii Y

    2011-09-01

    Full Text Available Yoshitaro Torii1, Toshiki Shimizu1, Takashi Yokoi1, Hiroyuki Sugimoto1, Yuichi Katashiba1, Ryotaro Ozasa1, Shinya Fujita1, Yasushi Adachi2, Masahiko Maki3, Shosaku Nomura11The First Department of Internal Medicine, Kansai Medical University, Osaka, 2Department of Clinical Pathology, Toyooka Hospital, Hyogo, 3First Department of Pathology, Kansai Medical University, Osaka, JapanAbstract: A 61-year-old woman with lung cancer developed delayed transfusion-related acute lung injury (TRALI syndrome after transfusion of plasma- and leukoreduced red blood cells (RBCs for gastrointestinal bleeding due to intestinal metastasis. Acute lung injury (ALI recurred 31 days after the first ALI episode. Both ALI episodes occurred 48 hours after transfusion. Laboratory examinations revealed the presence of various antileukocyte antibodies including antiplatelet antibody in the recipient's serum but not in the donors' serum. The authors speculate that antiplatelet antibodies can have an inhibitory effect in the recipient, which can modulate the bona fide procedure of ALI and lead to a delay in the onset of ALI. This case illustrates the crucial role of a recipient's platelets in the development of TRALI.Keywords: delayed TRALI syndrome, recurrence, anti-platelet antibody

  16. The net clinical benefit of personalized antiplatelet therapy in patients undergoing percutaneous coronary intervention.

    Science.gov (United States)

    Siller-Matula, Jolanta M; Gruber, Carina; Francesconi, Marcel; Dechant, Cornelia; Jilma, Bernd; Delle-Karth, Georg; Grohs, Katharina; Podczeck-Schweighofer, Andrea; Christ, Günter

    2015-01-01

    This was a prospective study comparing two groups: personalized and non-personalized treatment with P2Y12 receptor blockers during a 12-month follow-up. We aimed to investigate whether personalized antiplatelet treatment in patients with high on-treatment platelet reactivity (HTPR) improves clinical outcome. Platelet reactivity was assessed by adenosine diphosphate induced aggregation using a multiple electrode aggregometry (MEA) in 798 patients with coronary artery disease undergoing percutaneous coronary intervention (PCI). Patients with HTPR received up to four repeated loading doses of clopidogrel or prasugrel in the personalized treatment group (n=403), whereas no change in the treatment strategy was undertaken in patients with HTPR in the non-personalized treatment group (n=395). There were fewer major adverse cardiac events (MACE) in the personalized treatment group than in the non-personalized treatment group (7.4% compared with 15.3% respectively; Ppersonalized treatment group as compared with the non-personalized treatment group [hazard ratio (HR)=0.49; 95% confidence interval (CI): 0.31-0.77; Ppersonalized antiplatelet treatment over the non-personalized treatment (ischemic and bleedings events: 8.2% versus 18.7% respectively; HR=0.46; 95%CI: 0.29-0.70; Ppersonalized antiplatelet treatment might improve patients' outcome without increasing bleeding complications compared with the non-personalized treatment during a 12-month follow-up.

  17. Effect of Tomato Industrial Processing on Phenolic Profile and Antiplatelet Activity

    Directory of Open Access Journals (Sweden)

    Iván Palomo

    2013-09-01

    Full Text Available Background: Regular consumption of fruits and vegetables (e.g., tomatoes has been shown to be beneficial in terms of reducing the incidence of cardiovascular diseases. The industrial processing of tomatoes into tomato-based products includes several thermal treatments. Very little is known on the effect of tomato industrial processing on antiaggregatory activity and phenolic profile. Methods: It was assessed the effect of tomato and by-products extracts on platelet aggregation induced by ADP, collagen, TRAP-6 and arachidonic acid. These in vitro antithrombotic properties were further supported in an in vivo model of thrombosis. A set of antiplatelet compounds has been selected for HPLC analysis in the different extracts. Results: Some natural compounds such as chlorogenic, caffeic, ferulic and p-coumaric acids were identified by HPLC in tomatoes and its products may inhibit platelet activation. Red tomatoes, tomato products (sauce, ketchup and juice and by-products extracts inhibited platelet aggregation induced adenosine 5'-diphosphate, collagen, thrombin receptor activator peptide-6 and arachidonic acid, but to a different extent. Also, pomace extract presents antithrombotic activity. Conclusions: Processed tomatoes may have a higher content of health-benefiting compounds than fresh ones. Pomace even presents the best antiplatelet activity. Finally, tomato products may be used as a functional ingredient adding antiplatelet activities to processed foods.

  18. Pharmacophore Identification and QSAR Studies on Substituted Benzoxazinone as Antiplatelet Agents: kNN-MFA Approach.

    Science.gov (United States)

    Choudhari, Prafulla B; Bhatia, Manish S; Jadhav, Swapnil D

    2012-01-01

    The three-dimensional quantitative structure-activity relationship (3D-QSAR) and pharmacophore identification studies on 28 substituted benzoxazinone derivatives as antiplatelet agents have been carried out. Multiple linear regression (MLR) method was applied for QSAR model development considering training and test set approaches with various feature selection methods. Stepwise (SW), simulated annealing (SA) and genetic algorithm (GA) were applied to derive QSAR models which were further validated for statistical significance and predictive ability by internal and external validation. The results of pharmacophore identification studies showed that hydrogen bond accepters, aromatic and hydrophobic, are the important features for antiplatelet activity. The selected best 3D kNN-MFA model A has a training set of 23 molecules and test set of 5 molecules with validation (q(2)) and cross validation (pred_r(2)) values 0.9739 and 0.8217, respectively. Additionally, the selected best 3D QSAR (MLR) model B has a training set of 23 molecules and test set of 5 molecules with validation (r(2)) and cross validation (pred_r(2)) values of 0.9435 and 0.7663, respectively, and four descriptors at the grid points S_123, E_407, E_311 and H_605. The information rendered by 3D-QSAR models may lead to a better understanding and designing of novel potent antiplatelet molecules.

  19. National survey on thromboprophylaxis and anticoagulant or antiplatelet management in neurosurgical and neurocritical patients.

    Science.gov (United States)

    Vázquez-Alonso, E; Fábregas, N; Rama-Maceiras, P; Ingelmo Ingelmo, I; Valero Castell, R; Valencia Sola, L; Iturri Clavero, F

    2015-12-01

    To determine the protocols used by Spanish anaesthesiologists for thromboprophylaxis and anticoagulant or antiplatelet drugs management in neurosurgical or neurocritical care patients. An online survey with 22 questions, with one or multiple options, launched by the Neuroscience Subcommittee of the Spanish Anaesthesia Society and available between June and October 2012. Of the 73 hospitals included in the National Hospitals Catalogue, a valid response to the online questionnaire was received by 41 anaesthesiologists from 37 sites (response rate 50.7%). Only one response per site was used. A specific protocol was available in 27% of these centres. Mechanical thromboprophylaxis is used, intraoperatively or postoperatively, in 80%, and pharmacological treatment is used by 75% of respondents. Enoxaparin was the most frequent heparin used in craniotomy patients (78%). Craniotomies were performed maintaining acetylsalicylic acid treatment in patients with coronary stents and double anti-platelet treatment in a half of the centres. Mechanical thromboprophylaxis is used more frequently than the pharmacological approach in neurosurgical or neurocritical populations in Spanish hospitals. Management of patients under previous anticoagulant treatment was highly heterogeneous among hospitals included in this survey. Previous antiplatelet treatment is modified depending on primary or secondary prescription. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Impact of reticulated platelets on antiplatelet response to thienopyridines is independent of platelet turnover.

    Science.gov (United States)

    Stratz, Christian; Nührenberg, Thomas; Amann, Michael; Cederqvist, Marco; Kleiner, Pascal; Valina, Christian M; Trenk, Dietmar; Neumann, Franz-Josef; Hochholzer, Willibald

    2016-10-28

    Reticulated platelets are associated with impaired antiplatelet response to thienopyridines. It is uncertain whether this interaction is caused by a decreased drug exposure due to high platelet turnover reflected by elevated levels of reticulated platelets or by intrinsic properties of reticulated platelets. This study sought to investigate if the impact of reticulated platelets on early antiplatelet response to thienopyridines is mainly caused by platelet turnover as previously suggested. Elective patients undergoing coronary intervention were randomised to loading with clopidogrel 600 mg or prasugrel 60 mg (n=200). Adenosine diphosphate (ADP)-induced platelet reactivity was determined by impedance aggregometry before, at 30, 60, 90, and 120 minutes and at day 1 after loading. Immature platelet count was assessed as marker of reticulated platelets by flow cytometry. Platelet reactivity increased with rising levels of immature platelet count in both groups. This effect was more distinctive in patients on clopidogrel as compared to patients on prasugrel. Overall, immature platelet count correlated well with on-treatment platelet reactivity at all time-points (p < 0.001). These correlations did not change over time in the entire cohort as well as in patients treated with clopidogrel or prasugrel indicating an effect independent of platelet turnover (comparison of correlations 120 minutes/day 1: p = 0.64). In conclusion, the association of immature platelet count with impaired antiplatelet response to thienopyridines is similar early and late after loading. This finding suggests as main underlying mechanism another effect of reticulated platelets on thienopyridines than platelet turnover.

  1. Oral antiplatelet therapy in diabetes mellitus and the role of prasugrel: an overview

    Science.gov (United States)

    Hillegass, William B; Brott, Brigitta C; Dobbs, James C; Papapietro, Silvio E; Misra, Vijay K; Zoghbi, Gilbert J

    2011-01-01

    Diabetics have a prothrombotic state that includes increased platelet reactivity. This contributes to the less favorable clinical outcomes observed in diabetics experiencing acute coronary syndromes as well as stable coronary artery disease. Many diabetics are relatively resistant to or have insufficient response to several antithrombotic agents. In the setting of percutaneous coronary intervention, hyporesponsiveness to clopidogrel is particularly common among diabetics. Several strategies have been examined to further enhance the benefits of oral antiplatelet therapy in diabetics. These include increasing the dose of clopidogrel, triple antiplatelet therapy with cilostazol, and new agents such as prasugrel. The large TRITON TIMI 38 randomized trial compared clopidogrel to prasugrel in the setting of percutaneous coronary intervention for acute coronary syndromes. The diabetic subgroup (n = 3146) experienced considerable incremental benefit with a 4.8% reduction in cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke at 15-month follow-up with prasugrel treatment. Among diabetics on insulin this combined endpoint was reduced by 7.9% at 15 months. Major bleeding was not increased in the diabetic subgroup. This confirms the general hypothesis that more potent oral antiplatelet therapy can partially overcome the prothrombotic milieu and safely improve important clinical outcomes in diabetics. PMID:21822392

  2. An examination of the bleeding complications associated with herbal supplements, antiplatelet and anticoagulant medications.

    Science.gov (United States)

    Spolarich, A E; Andrews, L

    2007-01-01

    Dental professionals routinely treat patients taking prescription, nonprescription, and herbal medications that are known or have the potential to alter bleeding. Prescription anticoagulant and antiplatelet medications, as well as over-the-counter drugs such as aspirin, are typically taken to reduce the risk of thromboembolic events, including stroke. Herbal supplements are widely used for a variety of indications, and both patients and health care practitioners are often unaware of the anticoagulant and antiplatelet effects that occur as either predictable pharmacologic effects or adverse side effects of herbal medicines. In addition, patient use of these herbal supplements is usually undisclosed to health care providers. The purpose of this literature review is to examine the mechanisms of action of drugs and herbs that alter bleeding, and to educate dental professionals as to the proper care and management of patients using these medications. Decision-making strategies, including interpretation of laboratory tests, and when to discontinue the use of these medications are discussed. Patients undergoing routine dental and dental hygiene procedures do not need to discontinue the use of anticoagulant and antiplatelet medications. However, alterations in drug use may be required for those patients undergoing invasive surgical procedures. It is recommended that herbal supplements must be discontinued 2 weeks prior to receiving invasive surgical procedures. Dental practitioners must learn to weigh the risks of discontinuing drug therapy against the potential risks to patients, and implement risk reduction strategies to minimize adverse bleeding complications associated with dental treatment.

  3. Antimalarial plants used by indigenous people of the Upper Rio Negro in Amazonas, Brazil.

    Science.gov (United States)

    Kffuri, Carolina Weber; Lopes, Moisés Ahkʉtó; Ming, Lin Chau; Odonne, Guillaume; Kinupp, Valdely Ferreira

    2016-02-03

    This is the first intercultural report of antimalarial plants in this region. The aim of this study was to document the medicinal plants used against malaria by indigenous people in the Upper Rio Negro region and to review the literature on antimalarial activity and traditional use of the cited species. Participant observation, semi-structured interviews, and ethnobotanical walks were conducted with 89 informants in five indigenous communities between April 2010 and November 2013 to obtain information on the use of medicinal plants against malaria. We reviewed academic databases for papers published in scientific journals up to January 2014 in order to find works on ethnopharmacology, ethnobotany, and antimalarial activity of the species cited. Forty-six plant species belonging to 24 families are mentioned. Fabaceae (17.4%), Arecaceae (13.0%) and Euphorbiaceae (6.5%) account together for 36.9% of these species. Only seven plant species showed a relatively high consensus. Among the plant parts, barks (34.0%) and roots (28.0%) were the most widely used. Of the 46 species cited, 18 (39.1%) have already been studied for their antimalarial properties according to the literature, and 26 species (56.5%) have no laboratory essays on antimalarial activity. Local traditional knowledge of the use of antimalarials is still widespread in indigenous communities of the Upper Rio Negro, where 46 plants species used against malaria were recorded. Our studies highlight promising new plants for future studies: Glycidendron amazonicum, Heteropsis tenuispadix, Monopteryx uaucu, Phenakospermum guianensis, Pouteria ucuqui, Sagotia brachysepala and notably Aspidosperma schultesii, Ampelozizyphus amazonicus, Euterpe catinga, E. precatoria, Physalis angulata, Cocos nucifera and Swartzia argentea with high-use consensus. Experimental validation of these remedies may help in developing new drugs for malaria. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Brands, costs and registration status of antimalarial drugs in the Kenyan retail sector

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    Snow Robert W

    2005-07-01

    Full Text Available Abstract Background Although an important source of treatment for fevers, little is known about the structure of the retail sector in Africa with regard to antimalarial drugs. This study aimed to assess the range, costs, sources and registration of antimalarial drugs in the Kenyan retail sector. Methods In 2002, antimalarial drug registration and trade prices were established by triangulating national registration lists, government gazettes and trade price indices. Data on registration status and trade prices were compared with similar data generated through a retail audit undertaken among 880 randomly sampled retailers in four districts of Kenya. Results Two hundred and eighteen antimalarial drugs were in circulation in Kenya in 2002. These included 65 "sulfur"-pyrimethamine (sulfadoxine-pyrimethamine and sulfalene-pyrimethamine (SP, the first-line recommended drug in 2002 and 33 amodiaquine (AQ, the second-line recommended drug preparations. Only half of SP and AQ products were registered with the Pharmacy and Poisons Board. Of SP and AQ brands at district level, 40% and 44% were officially within legal registration requirements. 29% of retailers at district level stocked SP and 95% stocked AQ. The retail price of adult doses of SP and AQ were on average 0.38 and 0.76 US dollars, 100% and 347% higher than trade prices from manufacturers and importers. Artemether-lumefantrine, the newly announced first-line recommended antimalarial drug in 2004, was found in less than 1% of all retail outlets at a median cost of 7.6 US dollars. Conclusion There is a need to ensure that all antimalarial drugs are registered with the Pharmacy and Poisons Board to facilitate a more stringent post-marketing surveillance system to ensure drugs are safe and of good quality post-registration.

  5. A new in vivo screening paradigm to accelerate antimalarial drug discovery.

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    María Belén Jiménez-Díaz

    Full Text Available The emergence of resistance to available antimalarials requires the urgent development of new medicines. The recent disclosure of several thousand compounds active in vitro against the erythrocyte stage of Plasmodium falciparum has been a major breakthrough, though converting these hits into new medicines challenges current strategies. A new in vivo screening concept was evaluated as a strategy to increase the speed and efficiency of drug discovery projects in malaria. The new in vivo screening concept was developed based on human disease parameters, i.e. parasitemia in the peripheral blood of patients on hospital admission and parasite reduction ratio (PRR, which were allometrically down-scaled into P. berghei-infected mice. Mice with an initial parasitemia (P0 of 1.5% were treated orally for two consecutive days and parasitemia measured 24 h after the second dose. The assay was optimized for detection of compounds able to stop parasite replication (PRR = 1 or induce parasite clearance (PRR >1 with statistical power >99% using only two mice per experimental group. In the P. berghei in vivo screening assay, the PRR of a set of eleven antimalarials with different mechanisms of action correlated with human-equivalent data. Subsequently, 590 compounds from the Tres Cantos Antimalarial Set with activity in vitro against P. falciparum were tested at 50 mg/kg (orally in an assay format that allowed the evaluation of hundreds of compounds per month. The rate of compounds with detectable efficacy was 11.2% and about one third of active compounds showed in vivo efficacy comparable with the most potent antimalarials used clinically. High-throughput, high-content in vivo screening could rapidly select new compounds, dramatically speeding up the discovery of new antimalarial medicines. A global multilateral collaborative project aimed at screening the significant chemical diversity within the antimalarial in vitro hits described in the literature is a

  6. In vitro and in vivo assessment of the anti-malarial activity of Caesalpinia pluviosa

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    Eberlin Marcos N

    2011-05-01

    Full Text Available Abstract Background To overcome the problem of increasing drug resistance, traditional medicines are an important source for potential new anti-malarials. Caesalpinia pluviosa, commonly named "sibipiruna", originates from Brazil and possess multiple therapeutic properties, including anti-malarial activity. Methods Crude extract (CE was obtained from stem bark by purification using different solvents, resulting in seven fractions. An MTT assay was performed to evaluate cytotoxicity in MCF-7 cells. The CE and its fractions were tested in vitro against chloroquine-sensitive (3D7 and -resistant (S20 strains of Plasmodium falciparum and in vivo in Plasmodium chabaudi-infected mice. In vitro interaction with artesunate and the active C. pluviosa fractions was assessed, and mass spectrometry analyses were conducted. Results At non-toxic concentrations, the 100% ethanolic (F4 and 50% methanolic (F5 fractions possessed significant anti-malarial activity against both 3D7 and S20 strains. Drug interaction assays with artesunate showed a synergistic interaction with the F4. Four days of treatment with this fraction significantly inhibited parasitaemia in mice in a dose-dependent manner. Mass spectrometry analyses revealed the presence of an ion corresponding to m/z 303.0450, suggesting the presence of quercetin. However, a second set of analyses, with a quercetin standard, showed distinct ions of m/z 137 and 153. Conclusions The findings show that the F4 fraction of C. pluviosa exhibits anti-malarial activity in vitro at non-toxic concentrations, which was potentiated in the presence of artesunate. Moreover, this anti-malarial activity was also sustained in vivo after treatment of infected mice. Finally, mass spectrometry analyses suggest that a new compound, most likely an isomer of quercetin, is responsible for the anti-malarial activity of the F4.

  7. Monitoring antimalarial safety and tolerability in clinical trials: A case study from Uganda

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    Mpimbaza Arthur

    2008-06-01

    Full Text Available Abstract Background New antimalarial regimens, including artemisinin-based combination therapies (ACTs, have been adopted widely as first-line treatment for uncomplicated malaria. Although these drugs appear to be safe and well-tolerated, experience with their use in Africa is limited and continued assessment of safety is a priority. However, no standardized guidelines for evaluating drug safety and tolerability in malaria studies exist. A system for monitoring adverse events in antimalarial trials conducted in Uganda was developed. Here the reporting system is described, and difficulties faced in analysing and interpreting the safety results are illustrated, using data from the trials. Case description Between 2002 and 2007, eleven randomized, controlled clinical trials were conducted to compare the efficacy, safety, and tolerability of different antimalarial regimens for treatment of uncomplicated malaria in Uganda. The approach to adverse event monitoring was similar in all studies. A total of 5,614 treatments were evaluated in 4,876 patients. Differences in baseline characteristics and patterns of adverse event reporting were noted between the sites, which limited the ability to pool and analyse data. Clinical failure following antimalarial treatment confounded associations between treatment and adverse events that were also common symptoms of malaria, particularly in areas of lower transmission intensity. Discussion and evaluation Despite prospectively evaluating for adverse events, limitations in the monitoring system were identified. New standardized guidelines for monitoring safety and tolerability in antimalarial trials are needed, which should address how to detect events of greatest importance, including serious events, those with a causal relationship to the treatment, those which impact on adherence, and events not previously reported. Conclusion Although the World Health Organization has supported the development of

  8. The ACTwatch project: methods to describe anti-malarial markets in seven countries

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    Chapman Steven

    2011-10-01

    Full Text Available Abstract Background Policy makers, governments and donors are faced with an information gap when considering ways to improve access to artemisinin-based combination therapy (ACT and malaria diagnostics including rapid diagnostic tests (RDTs. To help address some of these gaps, a five-year multi-country research project called ACTwatch was launched. The project is designed to provide a comprehensive picture of the anti-malarial market to inform national and international anti-malarial drug policy decision-making. Methods The project is being conducted in seven malaria-endemic countries: Benin, Cambodia, the Democratic Republic of Congo, Madagascar, Nigeria, Uganda and Zambia from 2008 to 2012. ACTwatch measures which anti-malarials are available, where they are available and at what price and who they are used by. These indicators are measured over time and across countries through three study components: outlet surveys, supply chain studies and household surveys. Nationally representative outlet surveys examine the market share of different anti-malarials passing through public facilities and private retail outlets. Supply chain research provides a picture of the supply chain serving drug outlets, and measures mark-ups at each supply chain level. On the demand side, nationally representative household surveys capture treatment seeking patterns and use of anti-malarial drugs, as well as respondent knowledge of anti-malarials. Discussion The research project provides findings on both the demand and supply side determinants of anti-malarial access. There are four key features of ACTwatch. First is the overlap of the three study components where nationally representative data are collected over similar periods, using a common sampling approach. A second feature is the number and diversity of countries that are studied which allows for cross-country comparisons. Another distinguishing feature is its ability to measure trends over time. Finally, the

  9. Diversity-oriented synthesis-facilitated medicinal chemistry: toward the development of novel antimalarial agents.

    Science.gov (United States)

    Comer, Eamon; Beaudoin, Jennifer A; Kato, Nobutaka; Fitzgerald, Mark E; Heidebrecht, Richard W; Lee, Maurice duPont; Masi, Daniela; Mercier, Marion; Mulrooney, Carol; Muncipinto, Giovanni; Rowley, Ann; Crespo-Llado, Keila; Serrano, Adelfa E; Lukens, Amanda K; Wiegand, Roger C; Wirth, Dyann F; Palmer, Michelle A; Foley, Michael A; Munoz, Benito; Scherer, Christina A; Duvall, Jeremy R; Schreiber, Stuart L

    2014-10-23

    Here, we describe medicinal chemistry that was accelerated by a diversity-oriented synthesis (DOS) pathway, and in vivo studies of our previously reported macrocyclic antimalarial agent that derived from the synthetic pathway. Structure-activity relationships that focused on both appendage and skeletal features yielded a nanomolar inhibitor of P. falciparum asexual blood-stage growth with improved solubility and microsomal stability and reduced hERG binding. The build/couple/pair (B/C/P) synthetic strategy, used in the preparation of the original screening library, facilitated medicinal chemistry optimization of the antimalarial lead.

  10. Retinal toxicity induced by antimalarial drugs: literature review and case report.

    Science.gov (United States)

    Garza-Leon, Manuel; Flores-Alvarado, Diana Elsa; Muñoz-Bravo, Juan Manuel

    2016-06-17

    Antimalarial drugs are widely used in several countries for control of rheumatologic diseases such as systemic lupus erythematosus and rheumatoid arthritis. They are still used in Mexico because of their low cost and few secondary effects, most of which are mild and reversible. Even so, at an ophthalmological level, they could produce irreversible visual damage, which is why it is important to have ophthalmological evaluation and proper follow up. We present a clinical case as an example of characteristic ophthalmological findings as well as risk factors for retinal toxicity. We then discuss guidelines for diagnosis and follow up of patients who use antimalarial drugs for the treatment of rheumatologic illnesses.

  11. A reaction-diffusion system modeling the spread of resistance to an antimalarial drug.

    Science.gov (United States)

    Bacaer, Nicolas; Sokhna, Cheikh

    2005-04-01

    A mathematical model representing the difusion of resistance to an antimalarial drug is developed. Resistance can spread only when the basic reproduction number of the resistant parasites is bigger than the basic reproduction number of the sensitive parasites (which depends on the fraction of infected people treated with the antimalarial drug). Based on a linearization study and on numerical simulations, an expression for the speed at which resistance spreads is conjectured. It depends on the ratio of the two basic reproduction numbers, on a coefficient representing the difusion of mosquitoes, on the death rate of mosquitoes infected by resistant parasites, and on the recovery rate of nonimmune humans infected by resistant parasites.

  12. Access to artesunate-amodiaquine, quinine and other anti-malarials: policy and markets in Burundi

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    Dismas Baza

    2011-02-01

    Full Text Available Abstract Background Malaria is the leading cause of morbidity and mortality in post-conflict Burundi. To counter the increasing challenge of anti-malarial drug resistance and improve highly effective treatment Burundi adopted artesunate-amodiaquine (AS-AQ as first-line treatment for uncomplicated Plasmodium falciparum malaria and oral quinine as second-line treatment in its national treatment policy in 2003. Uptake of this policy in the public, private and non-governmental (NGO retail market sectors of Burundi is relatively unknown. This study was conducted to evaluate access to national policy recommended anti-malarials. Methods Adapting a standardized methodology developed by Health Action International/World Health Organization (HAI/WHO, a cross-sectional survey of 70 (24 public, 36 private, and 10 NGO medicine outlets was conducted in three regions of Burundi, representing different levels of transmission of malaria. The availability on day of the survey, the median prices, and affordability (in terms of number of days' wages to purchase treatment of AS-AQ, quinine and other anti-malarials were calculated. Results Anti-malarials were stocked in all outlets surveyed. AS-AQ was available in 87.5%, 33.3%, and 90% of public, private, and NGO retail outlets, respectively. Quinine was the most common anti-malarial found in all outlet types. Non-policy recommended anti-malarials were mainly found in the private outlets (38.9% compared to public (4.2% and NGO (0% outlets. The median price of a course of AS-AQ was US$0.16 (200 Burundi Francs, FBu for the public and NGO markets, and 3.5-fold higher in the private sector (US$0.56 or 700 FBu. Quinine tablets were similarly priced in the public (US$1.53 or 1,892.50 FBu, private and NGO sectors (both US$1.61 or 2,000 FBu. Non-policy anti-malarials were priced 50-fold higher than the price of AS-AQ in the public sector. A course of AS-AQ was affordable at 0.4 of a day's wage in the public and NGO sectors

  13. Antimalarial activity of Sida acuta Burm. f. (Malvaceae) and Pterocarpus erinaceus Poir. (Fabaceae).

    Science.gov (United States)

    Karou, Damintoti; Dicko, Mamoudou H; Sanon, Souleymane; Simpore, Jacques; Traore, Alfred S

    2003-12-01

    Among strategies to combat malaria, the search for new antimalarial drugs appears to be a priority. Sheering for new antimalarial activities, four plants of the traditional medicine of Burkina Faso: Combretum micranthum, Khaya senegalensis, Pterocarpus erinaceus and Sida acuta, were tested in vitro on fresh clinical isolates of Plasmodium falciparum. The screening showed that Sida acuta has a significant activity (IC50 Pterocarpus erinaceus has a moderate activity (5 microg/ml < IC50 < 50 microg/ml). Further chemical screening showed that the activity of the most active plant, Sida acuta, was related to its alkaloid contents.

  14. Anti-platelet drugs in patients with femoral neck fractures undergoing cemented hip hemiarthroplasty surgery. A study of complications and mortality.

    Science.gov (United States)

    Agudo Quiles, M; Sanz-Reig, J; Alcalá-Santaella Oria de Rueca, R

    2015-01-01

    To assess complications and factors predicting one-year mortality in patients on antiplatelet agents presenting with femoral neck fractures undergoing hip hemiarthroplasty surgery. A review was made on 50 patients on preoperative antiplatelet agents and 83 patients without preoperative antiplatelet agents. Patients in both groups were treated with cemented hip hemiarthroplasty. A statistical comparison was performed using epidemiological data, comorbidities, mental state, complications and mortality. There was no lost to follow-up. The one-year mortality was 20.3%. In patients without preoperative antiplatelet agents it was 14.4% and in patients with preoperative antiplatelet agents was 30%. Age, ASA grade, number of comorbidities and antiplatelet agent therapy were predictors of one-year mortality. The one-year mortality of patients on clopidogrel was 46.1%, versus 24.3% in patients on acetylsalicylic acid. Patients with preoperative antiplatelet therapy were older and had greater number of comorbidities, ASA grade, delayed surgery, and a longer length of stay than patients without antiplatelet therapy. The one-year mortality was higher in patients with preoperative antiplatelet therapy. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

  15. Antiplatelet therapy as a modulator of stroke aetiology: a meta-analysis

    Science.gov (United States)

    Rajkumar, Christopher A; Floyd, Christopher N; Ferro, Albert

    2015-01-01

    Aims Antiplatelet therapy reduces the incidence of ischaemic stroke. Platelet-mediated thrombosis contributes variably to the major subtypes of stroke as defined by the TOAST criteria: large artery atherosclerosis (LAA), cardioembolic (CE) and small vessel occlusion (SVO). The effect of antiplatelet therapy on the incidence of each subtype is unknown and is the subject of this meta-analysis. Methods Electronic databases were searched for articles comparing the effect of antiplatelet therapy on the incidence of stroke according to aetiological subtype. Studies containing subjects prescribed anticoagulant therapy or solely investigating subjects with atrial fibrillation were excluded. Pooled odds ratios (ORs) were calculated using a fixed effects model. Results Nine studies were included (n = 5739). In patients who had an ischaemic stroke, pre-event antiplatelet therapy was associated with significantly decreased incidence of LAA (OR 0.88, 95% CI 0.79, 0.99; P = 0.026), increased incidence of CE (OR 1.23, 95% CI 1.08, 1.41; P = 0.002) and no effect on SVO (OR 0.99, 95% CI 0.88, 1.11; P = 0.806). Concordant non-significant trends were observed in primary prevention populations (n = 751): LAA (OR 0.81, 95% CI 0.57, 1.15; P = 0.240), CE (OR 1.29, 95% CI 0.89, 1.87; P = 0.179) and SVO (OR 0.99, 95% CI 0.73, 1.36; P = 0.970). Subgroup analysis of aspirin monotherapy (n = 3786) demonstrated a significant reduction in LAA (OR 0.87, 95% CI 0.76, 1.00; P = 0.046), but non-significant effects on the incidence of CE (OR 1.17, 95% CI 0.99, 1.39; P = 0.068) and SVO (OR 1.04, 95% CI 0.91, 1.20; P = 0.570). Probability of publication bias was low (P > 0.05). Conclusions Antiplatelet therapy preferentially reduces the incidence of LAA stroke compared with CE and SVO subtypes. PMID:25784356

  16. Antiplatelet therapy as a modulator of stroke aetiology: a meta-analysis.

    Science.gov (United States)

    Rajkumar, Christopher A; Floyd, Christopher N; Ferro, Albert

    2015-09-01

    Antiplatelet therapy reduces the incidence of ischaemic stroke. Platelet-mediated thrombosis contributes variably to the major subtypes of stroke as defined by the TOAST criteria: large artery atherosclerosis (LAA), cardioembolic (CE) and small vessel occlusion (SVO). The effect of antiplatelet therapy on the incidence of each subtype is unknown and is the subject of this meta-analysis. Electronic databases were searched for articles comparing the effect of antiplatelet therapy on the incidence of stroke according to aetiological subtype. Studies containing subjects prescribed anticoagulant therapy or solely investigating subjects with atrial fibrillation were excluded. Pooled odds ratios (ORs) were calculated using a fixed effects model. Nine studies were included (n = 5739). In patients who had an ischaemic stroke, pre-event antiplatelet therapy was associated with significantly decreased incidence of LAA (OR 0.88, 95% CI 0.79, 0.99; P = 0.026), increased incidence of CE (OR 1.23, 95% CI 1.08, 1.41; P = 0.002) and no effect on SVO (OR 0.99, 95% CI 0.88, 1.11; P = 0.806). Concordant non-significant trends were observed in primary prevention populations (n = 751): LAA (OR 0.81, 95% CI 0.57, 1.15; P = 0.240), CE (OR 1.29, 95% CI 0.89, 1.87; P = 0.179) and SVO (OR 0.99, 95% CI 0.73, 1.36; P = 0.970). Subgroup analysis of aspirin monotherapy (n = 3786) demonstrated a significant reduction in LAA (OR 0.87, 95% CI 0.76, 1.00; P = 0.046), but non-significant effects on the incidence of CE (OR 1.17, 95% CI 0.99, 1.39; P = 0.068) and SVO (OR 1.04, 95% CI 0.91, 1.20; P = 0.570). Probability of publication bias was low (P > 0.05). Antiplatelet therapy preferentially reduces the incidence of LAA stroke compared with CE and SVO subtypes. © 2015 The British Pharmacological Society.

  17. Effects of antiplatelet therapy on platelet extracellular vesicle release and procoagulant activity in health and in cardiovascular disease.

    Science.gov (United States)

    Connor, David E; Ly, Ken; Aslam, Anoosha; Boland, John; Low, Joyce; Jarvis, Susan; Muller, David W; Joseph, Joanne E

    2016-12-01

    Dual antiplatelet therapy with aspirin and clopidogrel is commonly used to prevent recurrent ischemic events in patients with cardiovascular disease. Whilst their effects on platelet reactivity are well documented, it is unclear, however, whether antiplatelet therapy inhibits platelet extracellular vesicle (EV) release. The aim of this study was to investigate the effects of antiplatelet therapy on platelet EV formation and procoagulant activity. Blood samples from 10 healthy controls not receiving antiplatelet therapy were incubated in vitro with aspirin or a P2Y12 inhibitor (MeSAMP). Blood samples from 50 patients receiving long-term dual antiplatelet therapy and undergoing coronary angiography were also studied. Platelet reactivity was assessed by Multiplate™ impedance aggregometry. Platelet EV formation and procoagulant activity of pretreated and untreated blood samples in response to arachidonic acid (AA), adenosine diphosphate (ADP), ADP+PGE1, and thrombin receptor-activating peptide (TRAP) stimulation were assessed by flow cytometry and Procoag-PL assays, respectively. Incubation of normal platelets with aspirin significantly inhibited AA-induced platelet reactivity, EV formation, and procoagulant activity, whilst MeSAMP significantly inhibited platelet reactivity and EV formation in response to AA, ADP, and TRAP, but had minimal effect on procoagulant activity. Most patients receiving dual antiplatelet therapy showed an appropriate reduction in platelet reactivity in response to their treatment; however there was not complete inhibition of increased platelet and EV procoagulant activity in response to ADP, AA, or TRAP. In addition, we could not find any correlation between platelet reactivity and procoagulant activity in patients receiving dual antiplatelet therapy.

  18. Multicenter Retrospective Study of the Risk Factors of Hemorrhage After Tooth Extraction in Patients Receiving Antiplatelet Therapy.

    Science.gov (United States)

    Yanamoto, Souichi; Hasegawa, Takumi; Rokutanda, Satoshi; Komori, Sayaka; Tachibana, Akira; Kojima, Yuka; Koyama, Yoshito; Shibuya, Yasuyuki; Kurita, Hiroshi; Komori, Takahide; Umeda, Masahiro

    2017-07-01

    To identify the risk factors affecting hemorrhage after tooth extraction in patients receiving antiplatelet therapy, this study investigated the relation between various factors and hemorrhage events after tooth extraction. The records of 264 patients receiving antiplatelet therapy who underwent tooth extraction were retrospectively reviewed from 6 institutions belonging to the Japanese Study Group of Cooperative Dentistry with Medicine. Demographic information, hemorrhage events after tooth extraction, the presence or absence of comorbidities, antiplatelet agent, the use of preoperative antibiotics or nonsteroidal anti-inflammatory drugs, number of teeth extracted, serum creatinine level, estimated glomerular filtration rate, and alanine transaminase level were assessed. Risk factors for hemorrhage after tooth extraction were evaluated by univariate and multivariate analyses. The study population of 264 patients consisted of 153 men and 111 women with a mean age of 73.6 years (range, 24 to 96 yr). Six hundred ninety-four teeth were extracted (mean, 2.6 ± 2.3 teeth per patient). In patients receiving antiplatelet therapy, the frequency of hemorrhage after tooth extraction, including mild and self-controlled hemorrhages, was 17.4%. Univariate analysis showed that serum creatinine level and dual antiplatelet therapy were correlated with hemorrhage after tooth extraction (P = .001 and P = .049, respectively). Only serum creatinine was identified as an independent risk factor for hemorrhage after tooth extraction in patients receiving antiplatelet therapy (P = .037). The risk of hemorrhage after tooth extraction is increased in patients receiving dual antiplatelet therapy with or without chronic kidney disease. Local hemostatic treatments, such as at least suturing, are recommended. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  19. Embryotoxicity and toxicokinetics of the antimalarial artesunate in rats.

    Science.gov (United States)

    Chung, Moon-Koo; Yu, Wook-Joon; Lee, Jin-Soo; Lee, Jong-Hwa

    2013-03-01

    This study was conducted to investigate the potential embryo-fetal toxicity and toxicokinetics of the antimalarial agent artesunate (ARTS) in Sprague-Dawley rats. Pregnant rats were administered ARTS daily from gestational day 6~15 via oral gavage, at test doses of 0, 2, 4, or 8 mg/kg (22 females per group). The fetuses were examined for external, visceral, and skeletal abnormalities on gestational day 20. With regard to the dams, there were no deaths, treatment-related clinical signs, changes in body weight, or food intake in any of the treatment groups. There were no treatment-related gross findings at necropsy in any treatment group. In the 8 mg/kg group, there was a decrease in gravid uterine weight and in the weight of female fetuses. There was also an increase in fetal deaths (primarily late resorptions) and an increase in post-implantation losses (37%) at 8 mg/kg. An increase in the incidence of visceral and skeletal variations at 4 and 8 mg/kg was observed. These defects included minor changes in the appearance of the kidney and thymus, as well as absent ribs or thoracic vertebrae. Toxicokinetics were assessed in a parallel study, using 4 mated females per group. Using liquid chromatography-mass spectrometry (LC-MS) analysis, the concentration of ARTS and its metabolite dihydroartemisinin (DHA) were quantified in plasma from rats on gestational days 5, 6, 10, and 15. Amniotic fluid was assayed for ARTS and DHA on gestational day 15. There was evidence of rapid conversion of ARTS to the metabolite DHA in maternal plasma, since ARTS could not be consistently detected in plasma at the three doses tested. ARTS and DHA were not detected in amniotic fluid at gestational day 15, indicating limited placental transfer of the two agents. The embryofetal no-observable-adverse-effect level (NOAEL) of the test item was considered to be 8 mg/kg/day for dams, and 2 mg/kg/day for embryo-fetal development.

  20. Antiplatelet therapy before or after 16 weeks' gestation for preventing preeclampsia: an individual participant data meta-analysis.

    Science.gov (United States)

    Meher, Shireen; Duley, Lelia; Hunter, Kylie; Askie, Lisa

    2017-02-01

    The optimum time for commencing antiplatelet therapy for the prevention of preeclampsia and its complications is unclear. Aggregate data meta-analyses suggest that aspirin is more effective if given prior to 16 weeks' gestation, but data are limited because of an inability to place women in the correct gestational age subgroup from relevant trials. The objective of the study was to use the large existing individual participant data set from the Perinatal Antiplatelet Review of International Studies Collaboration to assess whether the treatment effects of antiplatelet agents on preeclampsia and its complications vary based on whether treatment is started before or after 16 weeks' gestation. A meta-analysis of individual participant data including 32,217 women and 32,819 babies recruited to 31 randomized trials comparing low-dose aspirin or other antiplatelet agents with placebo or no treatment for the prevention of preeclampsia has been published previously. Using this existing data set, we performed a prespecified subgroup analysis based on gestation at randomization to antiplatelet agents before 16 weeks, compared with at or after 16 weeks, for 4 of the main outcomes prespecified in the Perinatal Antiplatelet Review of International Studies protocol: preeclampsia, death of baby, preterm birth before 34 weeks, and small-for-gestational-age baby. Individual participant data for the subgroups were combined in a meta-analysis using RevMan software. Heterogeneity was assessed with the I(2) statistic. The χ(2) test for interaction was used to assess statistically significant (P antiplatelet therapy for women randomized before 16 weeks' gestation compared with those randomized at or after 16 weeks for any of the 4 prespecified outcomes: preeclampsia, relative risk, 0.90, (95% confidence interval, 0.79-1.03; 17 trials, 9241 women) for antiplatelet agents on preeclampsia and its complications is consistent, regardless of whether treatment is started before or after 16

  1. Tritium labelling and characterization of the antimalarial drug (+/-)-chloroquine by several methods

    Energy Technology Data Exchange (ETDEWEB)

    Egan, J.A.Judith A.; Laseter, Anne G.; Filer, C.N.Crist N. E-mail: crist.filer@perkinelmer.com

    2002-09-01

    To study its mechanism of antimalarial action, a tritium labelled analogue of (+/-)-chloroquine was required at high specific activity. Two synthetic methods were successfully employed. [3-{sup 3}H] (+/-)-Chloroquine 2 was prepared by the catalytic tritium dehalogenation of an iodo precursor and [N-ethyl-{sup 3}H] (+/-)-chloroquine 4 was synthesized by the alkylation of (+/-)-desethylchloroquine with [{sup 3}H] ethyl iodide.

  2. Potentiation of antimalarial activity of arteether in combination with Vetiver root extract.

    Science.gov (United States)

    Dhawan, Sangeeta; Gunjan, Sarika; Pal, Anirban; Tripathi, Renu

    2016-05-01

    In malaria, development of resistance towards artemisinin derivatives has urged the need for new drugs or new drug combinations to tackle the drug resistant malaria. We studied the fresh root extract of Vetiver zizanioides (Linn.) Nash (VET) with a CDRI-CIMAP antimalarial α/β arteether (ART) together for their antimalarial potential. Our results showed additive to synergistic antimalarial activity of VET and ART with sum fractional inhibitory concentrations Σ FICs 1.02 ± 0.24 and 1.12 ± 0.32 for chloroquine sensitive (CQS) and chloroquine resistant (CQR) strain of Plasmodium falciparum (William H. Welch), respectively. Further, these combinations were explored against multidrug resistant rodent malaria parasite i.e. P. yoelii nigeriensis. Analysis of in vivo interaction of ART and VET showed that 10 mg/kg x 5 days of ART with 1000 mg/kg of VET x 5 days cured 100% mice infected with MDR parasite, while the same dose of ART could produce only up to 30% cure and VET fraction was not curative at all. Synergism/additiveness, found between VET and ART is reported for the first time. The curative dose of ART in the combination was reduced to its one fourth, and thus limits the side effects, if any. Although antimalarial potential of ART was enhanced by VET, action mechanism of later needs to be elucidated in detail.

  3. Antimalarial qinghaosu/artemisinin: The therapy worthy of a Nobel Prize

    Directory of Open Access Journals (Sweden)

    Jerapan Krungkrai

    2016-05-01

    Full Text Available Malaria is a major cause of human morbidity and mortality in the tropical endemic countries worldwide. This is largely due to the emergence and spread of resistance to most antimalarial drugs currently available. Based on the World Health Organization recommendation, artemisinin-based combination therapies are now used as first-line treatment for Plasmodium falciparum malaria. Artemisinin or qinghaosu (Chinese name and its derivatives are highly potent, rapidly acting antimalarial drugs. Artemisinin was discovered in 1971 by a Chinese medical scientist Youyou Tu, who was awarded the Nobel Prize in 2015 on her discovering the antimalarial properties of qinghaosu from the traditional Chinese qinghao plant. Nevertheless, artemisinin resistance in falciparum malaria patients has first emerged on the Thai-Cambodian border in 2009, which is now prevalent across mainland Southeast Asia from Vietnam to Myanmar. Here, we reviewed malaria disease severity, history of artemisinin discovery, chemical structure, mechanism of drug action, artemisinin-based combination therapies, emergence and spread of drug resistance, including the recent findings on mechanism of resistance in the falciparum malaria parasite. This poses a serious threat to global malaria control and prompts renewed efforts for the urgent development of new antimalarial drugs.

  4. Oxidative pentose phosphate pathway inhibition is a key determinant of antimalarial induced cancer cell death.

    Science.gov (United States)

    Salas, E; Roy, S; Marsh, T; Rubin, B; Debnath, J

    2016-06-01

    Despite immense interest in using antimalarials as autophagy inhibitors to treat cancer, it remains unclear whether these agents act predominantly via autophagy inhibition or whether other pathways direct their anti-cancer properties. By comparing the treatment effects of the antimalarials chloroquine (CQ) and quinacrine (Q) on KRAS mutant lung cancer cells, we demonstrate that inhibition of the oxidative arm of the pentose phosphate pathway (oxPPP) is required for antimalarial induced apoptosis. Despite inhibiting autophagy, neither CQ treatment nor RNAi against autophagy regulators (ATGs) promote cell death. In contrast, Q triggers high levels of apoptosis, both in vitro and in vivo, and this phenotype requires both autophagy inhibition and p53-dependent inhibition of the oxPPP. Simultaneous genetic targeting of the oxPPP and autophagy is sufficient to trigger apoptosis in lung cancer cells, including cells lacking p53. Thus, in addition to reduced autophagy, oxPPP inhibition serves as an important determinant of antimalarial cytotoxicity in cancer cells.

  5. Antimalarial qinghaosu/artemisinin: The therapy worthy of a Nobel Prize

    Institute of Scientific and Technical Information of China (English)

    Jerapan Krungkrai; Sudaratana Rochanakij Krungkrai

    2016-01-01

    Malaria is a major cause of human morbidity and mortality in the tropical endemic countries worldwide. This is largely due to the emergence and spread of resistance to most antimalarial drugs currently available. Based on the World Health Organization recommendation, artemisinin-based combination therapies are now used as first-line treatment for Plasmodium falciparum malaria. Artemisinin or qinghaosu(Chinese name) and its derivatives are highly potent, rapidly acting antimalarial drugs. Artemisinin was discovered in 1971 by a Chinese medical scientist Youyou Tu, who was awarded the Nobel Prize in 2015 on her discovering the antimalarial properties of qinghaosu from the traditional Chinese qinghao plant. Nevertheless, artemisinin resistance in falciparum malaria patients has first emerged on the Thai-Cambodian border in 2009, which is now prevalent across mainland Southeast Asia from Vietnam to Myanmar. Here, we reviewed malaria disease severity, history of artemisinin discovery, chemical structure, mechanism of drug action, artemisinin-based combination therapies, emergence and spread of drug resistance, including the recent findings on mechanism of resistance in the falciparum malaria parasite. This poses a serious threat to global malaria control and prompts renewed efforts for the urgent development of new antimalarial drugs.

  6. Antimalarial qinghaosu/artemisinin:The therapy worthy of a Nobel Prize

    Institute of Scientific and Technical Information of China (English)

    Jerapan Krungkrai

    2016-01-01

    Malaria is a major cause of human morbidity and mortality in the tropical endemic countries worldwide. This is largely due to the emergence and spread of resistance to most antimalarial drugs currently available. Based on the World Health Organization recommendation, artemisinin-based combination therapies are now used as first-line treatment for Plasmodium falciparum malaria. Artemisinin or qinghaosu (Chinese name) and its derivatives are highly potent, rapidly acting antimalarial drugs. Artemisinin was discovered in 1971 by a Chinese medical scientist Youyou Tu, who was awarded the Nobel Prize in 2015 on her discovering the antimalarial properties of qinghaosu from the traditional Chinese qinghao plant. Nevertheless, artemisinin resistance in falciparum malaria patients has first emerged on the Thai-Cambodian border in 2009, which is now prevalent across mainland Southeast Asia from Vietnam to Myanmar. Here, we reviewed malaria disease severity, history of artemisinin discovery, chemical structure, mechanism of drug action, artemisinin-based combination therapies, emergence and spread of drug resistance, including the recent findings on mechanism of resistance in the falciparum malaria parasite. This poses a serious threat to global malaria control and prompts renewed efforts for the urgent development of new antimalarial drugs.

  7. A SAR and QSAR Study of New Artemisinin Compounds with Antimalarial Activity

    Directory of Open Access Journals (Sweden)

    Cleydson Breno R. Santos

    2013-12-01

    Full Text Available The Hartree-Fock method and the 6-31G** basis set were employed to calculate the molecular properties of artemisinin and 20 derivatives with antimalarial activity. Maps of molecular electrostatic potential (MEPs and molecular docking were used to investigate the interaction between ligands and the receptor (heme. Principal component analysis and hierarchical cluster analysis were employed to select the most important descriptors related to activity. The correlation between biological activity and molecular properties was obtained using the partial least squares and principal component regression methods. The regression PLS and PCR models built in this study were also used to predict the antimalarial activity of 30 new artemisinin compounds with unknown activity. The models obtained showed not only statistical significance but also predictive ability. The significant molecular descriptors related to the compounds with antimalarial activity were the hydration energy (HE, the charge on the O11 oxygen atom (QO11, the torsion angle O1-O2-Fe-N2 (D2 and the maximum rate of R/Sanderson Electronegativity (RTe+. These variables led to a physical and structural explanation of the molecular properties that should be selected for when designing new ligands to be used as antimalarial agents.

  8. Deployment of ACT antimalarials for treatment of malaria: challenges and opportunities

    Directory of Open Access Journals (Sweden)

    Leslie Toby

    2008-12-01

    Full Text Available Abstract Following a long period when the effectiveness of existing mono-therapies for antimalarials was steadily declining with no clear alternative, most malaria-endemic countries in Africa and Asia have adopted artemisinin combination therapy (ACT as antimalarial drug policy. Several ACT drugs exist and others are in the pipeline. If properly targeted, they have the potential to reduce mortality from malaria substantially. The major challenge now is to get the drugs to the right people. Current evidence suggests that most of those who need the drugs do not get them. Simultaneously, a high proportion of those who are given antimalarials do not in fact have malaria. Financial and other barriers mean that, in many settings, the majority of those with malaria, particularly the poorest, do not access formal healthcare, so the provision of free antimalarials via this route has only limited impact. The higher cost of ACT creates a market for fake drugs. Addressing these problems is now a priority. This review outlines current evidence, possible solutions and research priorities.

  9. Structure-Activity Relationship of the Antimalarial Ozonide Artefenomel (OZ439).

    Science.gov (United States)

    Dong, Yuxiang; Wang, Xiaofang; Kamaraj, Sriraghavan; Bulbule, Vivek J; Chiu, Francis C K; Chollet, Jacques; Dhanasekaran, Manickam; Hein, Christopher D; Papastogiannidis, Petros; Morizzi, Julia; Shackleford, David M; Barker, Helena; Ryan, Eileen; Scheurer, Christian; Tang, Yuanqing; Zhao, Qingjie; Zhou, Lin; White, Karen L; Urwyler, Heinrich; Charman, William N; Matile, Hugues; Wittlin, Sergio; Charman, Susan A; Vennerstrom, Jonathan L

    2017-01-18

    Building on insights gained from the discovery of the antimalarial ozonide arterolane (OZ277), we now describe the structure-activity relationship (SAR) of the antimalarial ozonide artefenomel (OZ439). Primary and secondary amino ozonides had higher metabolic stabilities than tertiary amino ozonides, consistent with their higher pKa and lower log D7.4 values. For primary amino ozonides, addition of polar functional groups decreased in vivo antimalarial efficacy. For secondary amino ozonides, additional functional groups had variable effects on metabolic stability and efficacy, but the most effective members of this series also had the highest log D7.4 values. For tertiary amino ozonides, addition of polar functional groups with H-bond donors increased metabolic stability but decreased in vivo antimalarial efficacy. Primary and tertiary amino ozonides with cycloalkyl and heterocycle substructures were superior to their acyclic counterparts. The high curative efficacy of these ozonides was most often associated with high and prolonged plasma exposure, but exposure on its own did not explain the presence or absence of either curative efficacy or in vivo toxicity.

  10. A novel multiple-stage antimalarial agent that inhibits protein synthesis

    NARCIS (Netherlands)

    Baragana, B.; Hallyburton, I.; Lee, M.C.; Norcross, N.R.; Grimaldi, R.; Otto, T.D.; Proto, W.R.; Blagborough, A.M.; Meister, S.; Wirjanata, G.; Ruecker, A.; Upton, L.M.; Abraham, T.S.; Almeida, M.J.; Pradhan, A.; Porzelle, A.; Martinez, M.S.; Bolscher, J.M.; Woodland, A.; Norval, S.; Zuccotto, F.; Thomas, J.; Simeons, F.; Stojanovski, L.; Osuna-Cabello, M.; Brock, P.M.; Churcher, T.S.; Sala, K.A.; Zakutansky, S.E.; Jimenez-Diaz, M.B.; Sanz, L.M.; Riley, J.; Basak, R.; Campbell, M.; Avery, V.M.; Sauerwein, R.W.; Dechering, K.J.; Noviyanti, R.; Campo, B.; Frearson, J.A.; Angulo-Barturen, I.; Ferrer-Bazaga, S.; Gamo, F.J.; Wyatt, P.G.; Leroy, D.; Siegl, P.; Delves, M.J.; Kyle, D.E.; Wittlin, S.; Marfurt, J.; Price, R.N.; Sinden, R.E.; Winzeler, E.A.; Charman, S.A.; Bebrevska, L.; Gray, D.W.; Campbell, S.; Fairlamb, A.H.; Willis, P.A.; Rayner, J.C.; Fidock, D.A.; Read, K.D.; Gilbert, I.H.

    2015-01-01

    There is an urgent need for new drugs to treat malaria, with broad therapeutic potential and novel modes of action, to widen the scope of treatment and to overcome emerging drug resistance. Here we describe the discovery of DDD107498, a compound with a potent and novel spectrum of antimalarial activ

  11. Influence of antimalarial treatment on acquisition of immunity in Plasmodium berghei NK65 malaria.

    Science.gov (United States)

    Long, Ton That Ai; Nakazawa, Shusuke; Huaman, Maria Cecilia; Kanbara, Hiroji

    2002-07-01

    Antimalarial treatments during primary Plasmodium berghei NK65 infection in BALB/c mice influenced the acquisition of protective immunity against reinfection. Among subcurative treatments, lower doses better enable mice to acquire protective immunity than do higher doses. Eradication of parasites from the start of infection did not promote protective immunity.

  12. Fixed dose combination of arterolane and piperaquine: a newer prospect in antimalarial therapy.

    Science.gov (United States)

    Patil, Cy; Katare, Ss; Baig, Ms; Doifode, Sm

    2014-07-01

    Malaria has been very prevalent vector-borne disease in India and until date bears enormous implications on health care services of the country. Over the period of time, the development of resistance to traditional antimalarials like chloroquine has been posed as major deterrent in efforts of malaria control. As the drug resistance is today universally prevalent, especially in Plasmodium falciparum species, major burden of malarial control resides with the new artemisinin drug class. However, arterolane is one of the first fully synthetic non-artemisinin antimalarial compound with rapid schizontocidal activity, hence offering an alternative to artemisinin drugs in malaria control. Piperaquine is a synthetic bisquinoline (4-amioquinoline Antimalarial) with slow and longer schizontocidal activity. Therefore their combination has been shown to provide rapid parasitemic clearance and quick relief of most malaria-related symptoms along with prevention of recrudescences. This combination was approved by Drugs Controller General of India in 2011 for treatment of uncomplicated P. falciparum malaria. The article is aimed at to review this newer prospect in antimalarial therapy for which comprehensive database search was done in Google, Google Scholar, PubMed using the terms "Malaria," "Arterolane," "OZ277," "Piperaquine," and "Artemisinin combination therapy." A total of 323 articles were screened and 28 articles were considered for this review along with the World Health Organization and National malarial program guidelines.

  13. Evaluation of In-vivo Antimalarial Activity of Methanol Leaf Extract of ...

    African Journals Online (AJOL)

    Purpose: To evaluate the in-vivo antimalarial activity of the methanol extract of the leaves of Glyphaea brevis in Plasmodium berghei infected mice. Methods: The phytochemical profile of ethylacetate, n-butanol, and residual ... antioxidant and anti-inflammatory properties and ... Phytochemical screening to determine the.

  14. Endoscopic resection of colorectal polyps in patients on antiplatelet therapy: an evidence-based guidance for clinicians.

    Science.gov (United States)

    Plumé Gimeno, Gema; Bustamante-Balén, Marco; Satorres Paniagua, Carla; Díaz Jaime, Francia Carolina; Cejalvo Andújar, Maria José

    2017-01-01

    Due to the rising prevalence of coronary heart disease, endoscopists are more frequently performing a polypectomy in patients on antiplatelet therapy (APT) and dual antiplatelet therapy (DATP). Despite the availability of several guidelines with regard to the management of antiplatelet drugs during the periprocedure period, there is still variability in the current clinical practice. This may be influenced by the low quality of the evidence supporting recommendations, because most of the studies dealing with APT and polypectomy are observational and retrospective, and include mainly small (bleeding and thrombotic risk of the patient should be made in advance. In the case of DAPT the procedure should be postponed, at least until clopidogrel can be safely withheld. If possible, non-aspirin antiplatelet drugs should be withheld 5-7 days before the procedure. Polyp size is the main factor related with post-polypectomy bleeding and it is the factor that should drive clinical decisions regarding the resection method and the use of endoscopic prophylactic measures. Non-aspirin antiplatelet agents can be reintroduced 24-48 hours after the procedure. In conclusion, there is little data with regard to the management of DAPT in patients with a scheduled polypectomy. Large randomized controlled trials are needed to support clinical recommendations.

  15. Effect of Antiplatelet Therapy on Acute Respiratory Distress Syndrome and Mortality in Critically Ill Patients: A Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Lijun Wang

    Full Text Available Antiplatelet agents are commonly used for cardiovascular diseases, but their pleiotropic effects in critically ill patients are controversial. We therefore performed a meta-analysis of cohort studies to investigate the effect of antiplatelet therapy in the critically ill.Nine cohort studies, retrieved from PubMed and Embase before November 2015, involving 14,612 critically ill patients and 4765 cases of antiplatelet users, were meta-analysed. The main outcome was hospital or 30-day mortality. Secondary outcome was acute respiratory distress syndrome (ARDS or acute lung injury (ALI. Random- or fixed-effect models were taken for quantitative synthesis of the data.Antiplatelet therapy was associated with decreased mortality (odds ratio (OR 0.61; 95% confidence interval (CI, 0.52-0.71; I2 = 0%; P <0. 001 and ARDS/ALI (OR 0.64; 95% CI, 0.50-0.82; I2 = 0%; P <0. 001. In every stratum of subgroups, similar findings on mortality reduction were consistently observed in critically ill patients.Antiplatelet therapy is associated with reduced mortality and lower incidence of ARDS/ALI in critically ill patients, particularly those with predisposing conditions such as high-risk surgery, trauma, pneumonia, and sepsis. However, it remains unclear whether similar findings can be observed in the unselected and broad population with critical illness.

  16. Analysis of anti-platelet aggregation components of Rhizoma Zingiberis using chicken thrombocyte extract and high performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    NIE Hong; MENG Lan-zhen; ZHANG Hui; ZHANG Jian-yu; YIN Zhen; HUANG Xue-song

    2008-01-01

    Background The conventional procedure for screening bioactive components from traditional Chinese medicine is time-consuming,expensive and low efficient.Therefore,some alternative strategies are needed urgently.A novel method for screening anti-platelet aggregation components from oleoresins was developed using chicken thrombocyte extract and high performance liquid chromatography.Methods The anti-platelet aggregation components of oleoresins were combined with receptors,channels and enzymes of chicken thrombocytes under physiological environment.Unbound substances were washed away and bound compounds were eluted using specific phosphate buffered solution(PBS).Compounds released from target sites were collected and analyzed by high performance liquid chromatography and LC-MS.The activity of three compounds which were screened from this model was confirmed using platelet aggregation pharmacology in vivo.Results There were four typical compounds that bound to the thrombocytes:6-gingerol,8-gingerol,6-shogaol and 10-gingerol,and all had shown anti-platelet aggregation activities.Eight-gingerol displayed the best anti-platelet aggregation effect.Conclusions Chicken thromobcyte extract can be used to isolate chemicals that are ligands of the receptor or other bio-targets on the platelet.This may therefore be a simple and efficient method to screen for anti-platelet aggregation compounds from traditional Chinese medicine.

  17. Current Practices Regarding Perioperative Management of Patients With Fracture on Antiplatelet Therapy: A Survey of Orthopedic Surgeons.

    Science.gov (United States)

    Pean, Christian A; Goch, Abraham; Christiano, Anthony; Konda, Sanjit; Egol, Kenneth

    2015-12-01

    There continues to be controversy over whether operative delay is necessary for patients on antiplatelet therapy, particularly for elderly patients with hip fractures. This study sought to assess current clinical practices of orthopedic surgeons regarding perioperative management of these patients. A 12-question, Web-based survey was distributed to orthopedic surgeons via e-mail. Questions regarding timing of surgery assumed patients were on antiplatelet therapy and assessed attitudes toward emergent and nonemergent orthopedic cases as well as operative delay for specific closed fracture types. Responses were compared using unpaired, 2-tailed Student t tests for continuous variables and Pearson chi-square tests with odds ratios (ORs) and 95% confidence intervals (CIs) for categorical variables. Statistical significance was defined as a P value antiplatelet therapy with closed hip fractures did not require operative delay. Surgeons who opted for surgical delay in hip fractures were more likely to delay surgery in other lower extremity fracture types (OR = 16.4, 95% CI 4.48-60.61, P antiplatelet therapy. Over a quarter of surgeons continue to opt for surgical delay in patients with hip fracture. This survey highlights the need to formulate and better disseminate practice management guidelines for patients with fracture on antiplatelet therapy, particularly given the aging population in the United States.

  18. Risk factors for the effect of anticoagulant and antiplatelet agents on perioperative blood loss following proximal femoral fractures.

    Science.gov (United States)

    Akaoka, Yusuke; Yamazaki, Hiroshi; Kodaira, Hiroyuki; Kato, Hiroyuki

    2016-07-01

    To examine the effect of oral anticoagulant and antiplatelet agents on perioperative blood loss following proximal femoral fractures and to identify the risk factors associated with perioperative blood loss.Retrospective cross-sectional study.In a retrospective cross-sectional study, we treated 334 consecutive patients with proximal femoral fractures (100 who received anticoagulant or antiplatelet drugs and 234 who did not) and an overall mean age of 85.5 years (standard deviation 8.2 years). We performed retrospective multivariate analysis to determine the independent factors related to perioperative decreases in the hemoglobin (Hb) level, a proxy for blood loss.Multivariate analysis confirmed that anticoagulant or antiplatelet drugs significantly affected decreases in the Hb level (regression coefficient [RC], 0.61; 95% confidence interval [CI], 0.14-1.08; P = 0.01). In addition to anticoagulant or antiplatelet drugs, multivariate analysis confirmed that the fracture type (Orthopedic Trauma Association classification A2: RC, 1.19; 95% CI, 0.71-1.67; P anticoagulants and antiplatelet agents is an independent risk factor for perioperative blood loss following proximal femoral fractures. Fracture type, platelet count, and operative time also affect perioperative blood loss. The fracture type was the greatest contributing factor to perioperative blood loss.Level of evidence grade: Prognostic level III.

  19. Evaluation of Bleeding Events Requiring Hospitalization in Patients With Atrial Fibrillation Receiving Dabigatran, Warfarin, or Antiplatelet Therapy.

    Science.gov (United States)

    Riley, Tanya R; Gauthier-Lewis, Mary L; Sanchez, Chelsea K; Riley, Treavor T

    2017-04-01

    To determine the incidence and severity of bleeding events requiring hospitalization among patients with atrial fibrillation (AF) receiving anticoagulants (dabigatran or warfarin) or antiplatelet agents (eg, aspirin and clopidogrel). This was a single-center, retrospective cohort study involving 1494 patients with AF hospitalized from November 1, 2010, to November 1, 2011, with prior warfarin, dabigatran, or antiplatelet therapy. Overall bleeding events in the dabigatran group compared to the warfarin group were 24% and 12%, respectively ( P = .004). Of these events, individually, there were no significant differences in major (56% vs 58%, P = .88), life-threatening (25% vs 36%, P = .38), or minor bleeding (44% vs 42%, P = .06). Gastrointestinal (GI) bleeding occurred more in the dabigatran group compared to the warfarin group ( P = .02). Intracranial bleeding occurred in 15% of patients in the warfarin group and did not occur at all in the dabigatran group. Warfarin patients had significantly more overall bleeding events compared to antiplatelet therapy ( P bleeding ( P = .06). GI bleeding, however, favored the warfarin group over the antiplatelet group (48% vs 73%, P = .04). Anticoagulation with dabigatran was associated with an overall increased occurrence of bleeding requiring hospital admission compared to warfarin. GI bleeding was more prevalent with dabigatran and antiplatelets than with warfarin. There were more intracranial hemorrhages seen in the warfarin group.

  20. In silico and in vivo anti-malarial studies of 18β glycyrrhetinic acid from Glycyrrhiza glabra.

    Directory of Open Access Journals (Sweden)

    Komal Kalani

    Full Text Available Malaria is one of the most prevailing fatal diseases causing between 1.2 and 2.7 million deaths all over the world each year. Further, development of resistance against the frontline anti-malarial drugs has created an alarming situation, which requires intensive drug discovery to develop new, more effective, affordable and accessible anti-malarial agents possessing novel modes of action. Over the past few years triterpenoids from higher plants have shown a wide range of anti-malarial activities. As a part of our drug discovery program for anti-malarial agents from Indian medicinal plants, roots of Glycyrrhizaglabra were chemically investigated, which resulted in the isolation and characterization of 18β-glycyrrhetinic acid (GA as a major constituent. The in vitro studies against P. falciparum showed significant (IC50 1.69 µg/ml anti-malarial potential for GA. Similarly, the molecular docking studies showed adequate docking (LibDock score of 71.18 for GA and 131.15 for standard anti-malarial drug chloroquine. Further, in silico pharmacokinetic and drug-likeness studies showed that GA possesses drug-like properties. Finally, in vivo evaluation showed a dose dependent anti-malarial activity ranging from 68-100% at doses of 62.5-250 mg/kg on day 8. To the best of our knowledge this is the first ever report on the anti-malarial potential of GA. Further work on optimization of the anti-malarial lead is under progress.

  1. Compound antimalarial ethosomal cataplasm: preparation, evaluation, and mechanism of penetration enhancement

    Directory of Open Access Journals (Sweden)

    Shen S

    2015-06-01

    Full Text Available Shuo Shen, Shu-Zhi Liu, Yu-Shi Zhang, Mao-Bo Du, Ai-Hua Liang, Li-Hua Song, Zu-Guang Ye Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, People’s Republic of China Abstract: Malaria is still a serious public health problem in some parts of the world. The problems of recurrence and drug resistance are increasingly more serious. Thus, it is necessary to develop a novel antimalarial agent. The objectives of this study were to construct a novel compound antimalarial transdermal nanosystem–ethosomal cataplasm, to investigate its characteristics and efficiency, and to systematically explore the penetration-enhancing mechanisms of ethosomal cataplasm. Artesunate-loaded ethosomes and febrifugine-loaded ethosomes were prepared, and their characteristics were evaluated. Drug-loaded ethosomes were incorporated in the matrix of cataplasm to form the compound antimalarial ethosomal cataplasm. With the help of ethosomal technology, the accumulated permeation quantity of artesunate significantly increased at 8 hours after administration, which was 1.57 times as much as that of conventional cataplasm. Soon after administration, the ethosomal cataplasm could make a large quantity of antimalarial drug quickly penetrate through skin, then the remaining drug in the ethosomal cataplasm could be steadily released. These characteristics of ethosomal cataplasm are favorable for antimalarial drugs to kill Plasmodium spp. quickly and prevent the resurgence of Plasmodium spp. As expected, the ethosomal cataplasm showed good antimalarial efficiency in this experiment. The negative conversion rates were 100% and the recurrence rates were 0% at all dosages. The mechanism of penetration enhancement of the ethosomal cataplasm was systematically explored using an optics microscope, polarization microscope, and transmission electron microscopy. The microstructure, ultrastructure, and birefringent structure in skin were observed. Data

  2. Hyperparasitaemia and low dosing are an important source of anti-malarial drug resistance

    Directory of Open Access Journals (Sweden)

    Lee Sue J

    2009-11-01

    Full Text Available Abstract Background Preventing the emergence of anti-malarial drug resistance is critical for the success of current malaria elimination efforts. Prevention strategies have focused predominantly on qualitative factors, such as choice of drugs, use of combinations and deployment of multiple first-line treatments. The importance of anti-malarial treatment dosing has been underappreciated. Treatment recommendations are often for the lowest doses that produce "satisfactory" results. Methods The probability of de-novo resistant malaria parasites surviving and transmitting depends on the relationship between their degree of resistance and the blood concentration profiles of the anti-malarial drug to which they are exposed. The conditions required for the in-vivo selection of de-novo emergent resistant malaria parasites were examined and relative probabilities assessed. Results Recrudescence is essential for the transmission of de-novo resistance. For rapidly eliminated anti-malarials high-grade resistance can arise from a single drug exposure, but low-grade resistance can arise only from repeated inadequate treatments. Resistance to artemisinins is, therefore, unlikely to emerge with single drug exposures. Hyperparasitaemic patients are an important source of de-novo anti-malarial drug resistance. Their parasite populations are larger, their control of the infection insufficient, and their rates of recrudescence following anti-malarial treatment are high. As use of substandard drugs, poor adherence, unusual pharmacokinetics, and inadequate immune responses are host characteristics, likely to pertain to each recurrence of infection, a small subgroup of patients provides the particular circumstances conducive to de-novo resistance selection and transmission. Conclusion Current dosing recommendations provide a resistance selection opportunity in those patients with low drug levels and high parasite burdens (often children or pregnant women. Patients with

  3. Synthesis of 4-hydroxy-2(1H)-quinolone derived chalcones, pyrazolines and their antimicrobial, in silico antimalarial evaluations.

    Science.gov (United States)

    Sarveswari, S; Vijayakumar, V; Siva, R; Priya, R

    2015-01-01

    A few derivatives of 3-(4,5-dihydro-5-aryl-1-phenyl-1H-pyrazol-3-yl)-4-hydroxyquinolin-2(1H)-ones (5a-j) that are synthesized from 4-hydroxy-3-(3-arylacryloyl)quinolin-2(1H)-ones (4a-j) by microwave-assisted synthesis are screened for their antimicrobial, in silico antimalarial activities. Among the tested compounds 4h and 5d were found to have a potent antimalarial activity than the standards, and the others are found to show considerable antimalarial activity and moderate antimicrobial activity.

  4. Poor quality vital anti-malarials in Africa - an urgent neglected public health priority

    Directory of Open Access Journals (Sweden)

    Newton Paul N

    2011-12-01

    Full Text Available Abstract Background Plasmodium falciparum malaria remains a major public health problem. A vital component of malaria control rests on the availability of good quality artemisinin-derivative based combination therapy (ACT at the correct dose. However, there are increasing reports of poor quality anti-malarials in Africa. Methods Seven collections of artemisinin derivative monotherapies, ACT and halofantrine anti-malarials of suspicious quality were collected in 2002/10 in eleven African countries and in Asia en route to Africa. Packaging, chemical composition (high performance liquid chromatography, direct ionization mass spectrometry, X-ray diffractometry, stable isotope analysis and botanical investigations were performed. Results Counterfeit artesunate containing chloroquine, counterfeit dihydroartemisinin (DHA containing paracetamol (acetaminophen, counterfeit DHA-piperaquine containing sildenafil, counterfeit artemether-lumefantrine containing pyrimethamine, counterfeit halofantrine containing artemisinin, and substandard/counterfeit or degraded artesunate and artesunate+amodiaquine in eight countries are described. Pollen analysis was consistent with manufacture of counterfeits in eastern Asia. These data do not allow estimation of the frequency of poor quality anti-malarials in Africa. Conclusions Criminals are producing diverse harmful anti-malarial counterfeits with important public health consequences. The presence of artesunate monotherapy, substandard and/or degraded and counterfeit medicines containing sub-therapeutic amounts of unexpected anti-malarials will engender drug resistance. With the threatening spread of artemisinin resistance to Africa, much greater investment is required to ensure the quality of ACTs and removal of artemisinin monotherapies. The International Health Regulations may need to be invoked to counter these serious public health problems.

  5. Ameliorative antimalarial effects of the combination of rutin and swertiamarin on malarial parasites

    Directory of Open Access Journals (Sweden)

    Divya Shitlani

    2016-06-01

    Full Text Available Objective: To ameliorate the antimalarial activity via the combination of rutin (flavonoid and swertiamarin (glycoside. Methods: The antimalarial effects were assessed by in vitro and in vivo methodology. In vitro antiplasmodial activity was assessed by using Plasmodium falciparum cultured media and determined the IC 50 value of individual drugs and their combinations. In in vivo methodology, antimalarial effects of rutin, swertiamarin (200–280 mg/kg/day, p.o. and their combination in 1:1, 1:2 and 2:1 ratios were investigated early and established malaria infections using Swiss albino mice infected with Plasmodium berghei. Chloroquine phosphate (5 mg/kg/day, p.o. was used as the standard drug. Results: IC 50 values of the rutin and swertiamarin via in vitro study revealed (9.50 ± 0.29 µg/ mL and (8.17 ± 0.17 µg/mL respectively. Whereas, the combination in 1:1 ratio [IC50 of (5.51 ± 0.18 µg/mL] showed better antiplasmodial activity against Plasmodium falciparum. In vivo results showed that rutin and swertiamarin had chemosuppressant effects in a dose-dependent manner, whereas, combination in 1:1 ratio possessed potential antimalarial activity similar to chloroquine phosphate. The drug interaction between rutin and swertiamarin revealed the synergistic effect on 1:1 ratio and additive effect on 1:2 and 2:1 ratios. Conclusions: The results of the in vitro and in vivo study clearly indicate that the combination (1:1 of rutin and swertiamarin showed potential antimalarial activity rather than an individual of each and their combinations 1:2 and 2:1.

  6. In vitro antimalarial activity of extracts of some plants from a biological reserve in Costa Rica

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    Misael Chinchilla

    2012-06-01

    Full Text Available Treatment with the usual antimalarial drugs, have induced parasite resistance, reinforcing the need to finding natural antimalarial components that would be found on plants from the forest. Therefore, we decided to look for these components in Costa Rican plants from a protected forest area. Fresh and dry extracts of roots, bark, leaves, flowers and fruits of 25 plants from a biological reserve in Costa Rica, Reserva Biológica Alberto Manuel Brenes (REBAMB, were studied in vitro for the presence of substances with antimalarial activity. By studying the inhibition of P. berghei schizogony, we assessed the antimalarial activity of several plant extracts: Aphelandra aurantiaca, A. tridentata (Acanthaceae; Xanthosoma undipes (Araceae; Iriartea deltoidea (Arecaceae; Neurolaena lobata (Asteraceae; Senna papillosa, Pterocarpus hayessi, Lonchocarpus pentaphyllus (Fabaceae; Nectandra membranacea, Persea povedae, Cinamomum chavarrianum (Lauraceae; Hampea appendiculata (Malvaceae; Ruagea glabra, Guarea glabra (Meliaceae; Psidium guajava (Myrtaceae; Bocconia frutescens (Papaveraceae; Piper friedrichsthalii (Piperaceae; Clematis dioica (Ranunculaceae; Prunus annularis (Rosaceae; Siparuna thecaphora (Siparunaceae; Solanum arboreum, Witheringia solanácea (Solanaceae; Ticodendrum incognitum (Ticodendraceae; Heliocarpus appendiculatus (Tiliaceae and Myriocarpa longipes (Urticaceae. We used different parts of the plants as well as fresh and dried extracts for testing IC50. The solid content of the extracts ranged from 1-71.9μg/mL. The fresh extracts showed stronger activity than the dry ones. Since the plants showing the strongest antimalarial activity are very common in Central America, and some similar genera of these plants have shown positives results in South America, we considered important to present these findings for discussion. On the other hand, this is the first systematic study of this kind ever realized in a circumscribed and protected area of

  7. Substandard artemisinin-based antimalarial medicines in licensed retail pharmaceutical outlets in Ghana

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    M. El-Duah & K. Ofori-Kwakye

    2012-09-01

    Full Text Available Background & objectives: The artemisinin-based antimalarial medicines are first line medicines in the treatmentof severe and uncomplicated falciparum malaria. Numerous brands of these medicines manufactured in variouscountries are available in the Ghanaian market. The study was aimed at evaluating the authenticity and qualityof selected brands of artemisinin-based antimalarial medicines marketed in Ghana.Methods: In all, 14 artemisinin-based antimalarial medicines were purchased from pharmacies (P and licensedchemical shops (LCSs in the Kumasi metropolis, Ghana. Simple field tests based on colorimetry and thin layerchromatography were employed in determining the authenticity of the samples. Important quality assessmenttests, namely uniformity of mass, crushing strength, disintegration time, and the percentage content of activepharmaceutical ingredients (APIs were determined.Results: All the brands tested contained the stipulated APIs. Artesunate tablet AT2 failed the uniformity of masstest while artesunate tablets AT3 & AT4 as well as amodiaquine tablets AM4 & AM6 failed the crushing strengthtest. All the six artemether-lumefantrine tablet brands passed the uniformity of mass, crushing strength anddisintegration tests. Only artemether-lumefantrine tablet brand AL1 contained the correct amount of the drugs.The other 13 artemisinin products contained either a lower (underdose or higher (overdose amount of thespecified drug. Artesunate monotherapy tablets were readily available in pharmacies and licensed chemicalshops.Interpretation & conclusion: All the artemisinin-based medicines tested (except AL1 were of substandardquality. The results demonstrate the need for continuous monitoring and evaluation of the quality of artemisininbased antimalarials in the Ghanaian market. Also, the practice of artemisinin antimalarial monotherapy is prevalentin Ghana. Determined efforts should, therefore, be made to eradicate the practice to prevent the development

  8. Chronic antiplatelet therapy is not associated with alterations in the presentation, outcome, or host response biomarkers during sepsis: a propensity-matched analysis.

    Science.gov (United States)

    Wiewel, Maryse A; de Stoppelaar, Sacha F; van Vught, Lonneke A; Frencken, Jos F; Hoogendijk, Arie J; Klein Klouwenberg, Peter M C; Horn, Janneke; Bonten, Marc J; Zwinderman, Aeilko H; Cremer, Olaf L; Schultz, Marcus J; van der Poll, Tom

    2016-03-01

    Sepsis is a major health burden worldwide. Preclinical investigations in animals and retrospective studies in patients have suggested that inhibition of platelets may improve the outcome of sepsis. In this study we investigated whether chronic antiplatelet therapy impacts on the presentation and outcome of sepsis, and the host response. We performed a prospective observational study in 972 patients admitted with sepsis to the mixed intensive care units (ICUs) of two hospitals in the Netherlands between January 2011 and July 2013. Of them, 267 patients (27.5%) were on antiplatelet therapy (95.9% acetylsalicylic acid) before admission. To account for differential likelihoods of receiving antiplatelet therapy, a propensity score was constructed, including variables associated with use of antiplatelet therapy. Cox proportional hazards regression was used to estimate the association of antiplatelet therapy with mortality. Antiplatelet therapy was not associated with sepsis severity at presentation, the primary source of infection, causative pathogens, the development of organ failure or shock during ICU stay, or mortality up to 90 days after admission, in either unmatched or propensity-matched analyses. Antiplatelet therapy did not modify the values of 19 biomarkers providing insight into hallmark host responses to sepsis, including activation of the coagulation system, the vascular endothelium, the cytokine network, and renal function, during the first 4 days after ICU admission. Pre-existing antiplatelet therapy is not associated with alterations in the presentation or outcome of sepsis, or the host response.

  9. Impact of the additive effect of angiotensin-converting enzyme inhibitors and /or statins with antiplatelet medication on mortality after acute ischaemic stroke.

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    Hassan, Yahaya; Al-Jabi, Samah W; Aziz, Noorizan Abd; Looi, Irene; Zyoud, Sa'ed H

    2012-04-01

    There has been recent interest in combining antiplatelets, angiotensin-converting enzyme inhibitors (ACEIs) and statins in primary and secondary ischaemic stroke prevention. This observational study was performed to evaluate the impact of adding ACEIs and/or statins to antiplatelets on post-stroke in-hospital mortality. Ischaemic stroke patients attending a hospital in Malaysia over an 18-month period were evaluated. Patients were categorized according to their vital status at discharge. Data included demographic information, risk factors, clinical characteristics and previous medications with particular attention on antiplatelets, ACEIs and statins. In-hospital mortality was compared among patients who were not taking antiplatelets, ACEIs or statins before stroke onset versus those who were taking antiplatelets alone or in combination with either ACEIs, statins or both. Data analysis was performed using SPSS version 15. Overall, 637 patients met the study inclusion criteria. After controlling for the effects of confounders, adding ACEIs or statins to antiplatelets significantly decreased the incidence of death after stroke attack by 68% (p = 0.036) and 81% (p = 0.010), respectively, compared to patients on antiplatelets alone or none of these medications. Additionally, the addition of both ACEIs and statins to antiplatelet medication resulted in the highest reduction (by 94%) of the occurrence of death after stroke attack (p rate of ischaemic stroke morbidity and mortality by enhancing the application of specific therapeutic and management strategies for patients at a high risk of acute stroke.

  10. A prospective randomized antiplatelet trial of cilostazol versus clopidogrel in patients with bare metal stent

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    CHEN Yun-dai; LU Yan-ling; JIN Ze-ning; YUAN Fei; L(U) Shu-zheng

    2006-01-01

    Background Cilostazol is a newly developed antiplatelet drug that has been widely applied for clinical use. Its antiplatelet action appears to be mainly related to inhibition of intracellular phosphodiesterase activity. Recently,cilostazol has been used for antiplatelet therapy after coronary bare metal stent implantation for thrombosis and restenosis prevention. This prospective randomized and double blind trial was designed to investigate the safety and efficacy of cilostazol for the prevention of late restenosis and acute or subacute stent thrombosis.Methods One hundred and twenty patients who underwent elective stent were randomly assigned to treatment group with cilostazol 200 mg/d (n = 60), clopidogrel 75 mg/d and aspirin 100 mg/d or to control group with clopidogrel treatment 75 mg/d (n = 60) and aspirin 100 mg/d. Follow-up coronary angiography was performed 6-9 months later.Results Nine months major adverse cardio-cerebral event (MACCE) were lower in treatment groups (P<0.05).The quantitative coronary angiography (QCA) at 6 months follow-up showed that minimum lumen diameter(MLD) was higher in treatment group than that of control group [(2.14±0.52)mm vs (1.82 ±0.36)mm, P<0.05].Late lumen loss (LL) [(0.82 ± 0.42)mm vs (1.31 ± 0.58)mm; P<0.01 ], restenosis rate (RR) (14% vs 32%; P<0.05)and target lesion revascularizaion (TLR) rate (5% vs 17%; P<0.05) were lower in treatment group than in control group.Conclusion Cilostazol therapy is an effective regimen for prevention not only stent thrombosis but also RR and TLR through reducing MLD without the risk of increasing bleeding.

  11. Effect of Desmopressin in Reducing Bleeding after Cardiac Surgery in Patients Receiving Anti-Platelet Agents

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    Kamran Shadvar

    2016-07-01

    Full Text Available Background: Severe bleeding is an important cause of morbidity and mortality in cardiac surgery using the cardiopulmonary bypass (CPB pump. Desmopressin, a synthetic analogue of vasopressin, is used to prevent postoperative bleeding in patients with renal insufficiency. The aim of the present study was to evaluate the effect of desmopressin in reducing blood loss after cardiac surgery in patients receiving antiplatelet drugs. Methods: In this prospective clinical trial, 40 patients undergoing coronary artery bypass grafting (CABG surgery with CPB, aged over 18 years, and on antiplatelet therapy for a week before surgery were divided in two groups. Case and control groups received nasal desmopressin spray and nasal normal saline spray, respectively. Patient vital signs, blood loss, administration of blood products, prescription drugs to improve the coagulation status, serum and whole intake and output of patients, need for a second surgery to control the bleeding, remaining sternum open, mortality due to bleeding, duration of intensive care unit (ICU stay and mechanical ventilation were recorded. Results: In the case and control groups there were no differences in duration of operation, mechanical ventilation and length of ICU stay. There was no significant difference in terms of postoperative bleeding and intake of blood products between two groups (P>0.05. Reoperation due to bleeding in the case and control groups was observed in 3 (15%, and 1 (5% patient(s, respectively (P=0.3. Conclusion: Desmopressin has no significant effect on reducing the amount of bleeding after cardiac surgery in patients receiving anti-platelet agents.   Keywords: CABG; cardio pulmonary bypass pump; hemorrhage; desmopressin

  12. Antiplatelet therapy versus observation in low-risk essential thrombocythemia with a CALR mutation

    Science.gov (United States)

    Alvarez-Larrán, Alberto; Pereira, Arturo; Guglielmelli, Paola; Hernández-Boluda, Juan Carlos; Arellano-Rodrigo, Eduardo; Ferrer-Marín, Francisca; Samah, Alimam; Griesshammer, Martin; Kerguelen, Ana; Andreasson, Bjorn; Burgaleta, Carmen; Schwarz, Jiri; García-Gutiérrez, Valentín; Ayala, Rosa; Barba, Pere; Gómez-Casares, María Teresa; Paoli, Chiara; Drexler, Beatrice; Zweegman, Sonja; McMullin, Mary F.; Samuelsson, Jan; Harrison, Claire; Cervantes, Francisco; Vannucchi, Alessandro M.; Besses, Carlos

    2016-01-01

    The role of antiplatelet therapy as primary prophylaxis of thrombosis in low-risk essential thrombocythemia has not been studied in randomized clinical trials. We assessed the benefit/risk of low-dose aspirin in 433 patients with low-risk essential thrombocythemia (271 with a CALR mutation, 162 with a JAK2V617F mutation) who were on antiplatelet therapy or observation only. After a follow up of 2215 person-years free from cytoreduction, 25 thrombotic and 17 bleeding episodes were recorded. In CALR-mutated patients, antiplatelet therapy did not affect the risk of thrombosis but was associated with a higher incidence of bleeding (12.9 versus 1.8 episodes per 1000 patient-years, P=0.03). In JAK2V617F-mutated patients, low-dose aspirin was associated with a reduced incidence of venous thrombosis with no effect on the risk of bleeding. Coexistence of JAK2V617F-mutation and cardiovascular risk factors increased the risk of thrombosis, even after adjusting for treatment with low-dose aspirin (incidence rate ratio: 9.8; 95% confidence interval: 2.3–42.3; P=0.02). Time free from cytoreduction was significantly shorter in CALR-mutated patients with essential thrombocythemia than in JAK2V617F-mutated ones (median time 5 years and 9.8 years, respectively; P=0.0002) and cytoreduction was usually necessary to control extreme thrombocytosis. In conclusion, in patients with low-risk, CALR-mutated essential thrombocythemia, low-dose aspirin does not reduce the risk of thrombosis and may increase the risk of bleeding. PMID:27175028

  13. The Pharmacogenomics of Anti-Platelet Intervention (PAPI) Study: Variation in Platelet Response to Clopidogrel and Aspirin.

    Science.gov (United States)

    Bozzi, Laura M; Mitchell, Braxton D; Lewis, Joshua P; Ryan, Kathy A; Herzog, William R; O'Connell, Jeffrey R; Horenstein, Richard B; Shuldiner, Alan R; Yerges-Armstrong, Laura M

    2016-01-01

    Clopidogrel and aspirin are commonly prescribed anti-platelet medications indicated for patients who have experienced, or are at risk for, ischemic cardiovascular events. The Pharmacogenomics of Anti-Platelet Intervention (PAPI) Study was designed to characterize determinants of clopidogrel and dual anti-platelet therapy (DAPT) response in a healthy cohort of Old Order Amish from Lancaster, PA. Following a loading dose, clopidogrel was taken once a day for 7 days. One hour after the last dose of clopidogrel, 325 mg of aspirin was given. Ex vivo platelet aggregometry was performed at baseline, post-clopidogrel, and post-DAPT. Platelet aggregation measurements were significantly lower after both interventions for all agonists tested (p pharmacogenomics studies.

  14. Risks and Benefits Associated With Prestroke Antiplatelet Therapy Among Patients With Acute Ischemic Stroke Treated With Intravenous Tissue Plasminogen Activator.

    Science.gov (United States)

    Xian, Ying; Federspiel, Jerome J; Grau-Sepulveda, Maria; Hernandez, Adrian F; Schwamm, Lee H; Bhatt, Deepak L; Smith, Eric E; Reeves, Mathew J; Thomas, Laine; Webb, Laura; Bettger, Janet Prvu; Laskowitz, Daniel T; Fonarow, Gregg C; Peterson, Eric D

    2016-01-01

    Intravenous tissue plasminogen activator (tPA) is known to improve outcomes in ischemic stroke; however, many patients may have been receiving antiplatelet therapy before acute ischemic stroke and could face an increased risk for bleeding when treated with tPA. To assess the risks and benefits associated with prestroke antiplatelet therapy among patients with ischemic stroke who receive intravenous tPA. This observational study used data from the American Heart Association and American Stroke Association Get With the Guidelines-Stroke registry, which included 85 072 adult patients with ischemic stroke who received intravenous tPA in 1545 registry hospitals from January 1, 2009, through March 31, 2015. Data were analyzed during the same period. Prestroke antiplatelet therapy before tPA administration for acute ischemic stroke. Symptomatic intracranial hemorrhage (sICH), in-hospital mortality, discharge ambulatory status, and modified Rankin Scale score (range, 0 [no symptoms] to 6 [death]). Of the 85 072 registry patients, 38 844 (45.7%) were receiving antiplatelet therapy before admission; 46 228 patients (54.3%) were not. Patients receiving antiplatelet therapy were older (median [25th-75th percentile] age, 76 [65-84] vs 68 [56-80] years) and had a higher prevalence of cardiovascular risk factors. The unadjusted rate of sICH was higher in patients receiving antiplatelet therapy (5.0% vs 3.7%). After risk adjustment, prior use of antiplatelet agents remained associated with higher odds of sICH compared with no use (adjusted odds ratio [AOR], 1.18 [95% CI, 1.10-1.28]; absolute difference, +0.68% [95% CI, 0.36%-1.01%]; number needed to harm [NNH], 147). Among patients enrolled on October 1, 2012, or later, the highest odds (95% CIs) of sICH were found in 15 116 patients receiving aspirin alone (AOR, 1.19 [1.06- 1.34]; absolute difference [95% CI], +0.68% [0.21%-1.20%]; NNH, 147) and 2397 patients receiving dual antiplatelet treatment of aspirin and clopidogrel

  15. Anti-Platelet Aggregation and Vasorelaxing Effects of the Constituents of the Rhizomes of Zingiber officinale

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    Tian-Shung Wu

    2012-07-01

    Full Text Available In the present study, the chemical investigation of the bioactive fractions of the rhizomes of Zingiber officinale has resulted in the identification of twenty-nine compounds including one new compound, O-methyldehydrogingerol (1. Some of the isolates were subjected into the evaluation of their antiplatelet aggregation and vasorelaxing bioactivities. Among the tested compounds, [6]-gingerol (13 and [6]-shogaol (17 exhibited potent anti-platelet aggregation bioactivity. In addition, [10]-gingerol (15 inhibited the Ca2+-dependent contractions in high K+ medium. According to the results in the present research, the bioactivity of ginger could be related to the anti-platelet aggregation and vasorelaxing mechanism.

  16. Impact of Optimal Medical Therapy in the Dual Antiplatelet Therapy (DAPT) Study

    Science.gov (United States)

    Resor, Charles D; Nathan, Ashwin; Kereiakes, Dean J; Yeh, Robert W; Massaro, Joseph M; Cutlip, Donald E; Steg, P. Gabriel; Hsieh, Wen-Hua; Mauri, Laura

    2017-01-01

    Background Continued dual antiplatelet therapy and optimal medical therapy (OMT) improve outcomes in selected patient populations with established coronary heart disease, but whether OMT modifies the treatment effect of dual antiplatelet therapy is unknown. Methods The Dual Antiplatelet Therapy Study, a double-blind trial, randomized 11,648 patients who had undergone coronary stenting and completed 1 year of dual antiplatelet therapy without major bleeding or ischemic events to an additional 18 months of continued thienopyridine or placebo. OMT was defined as a combination of statin, beta blocker and angiotensin converting enzyme inhibitor/angiotensin receptor blocker use in patients with an ACC/AHA class I indication for each medication. Per protocol, all patients were treated with aspirin 75–325 mg daily. Endpoints included myocardial infarction (MI), major adverse cardiovascular and cerebrovascular events (MACCE) and GUSTO moderate or severe bleeding events. Results Of 11,643 randomized patients with complete medication data, 63% were on OMT. Between 12 and 30 months, continued thienopyridine reduced MI compared with placebo in both groups (on OMT 2.1% vs 3.3%, HR 0.64, CI 0.48–0.86, p=0.003; off OMT 2.2% vs 5.2%, HR 0.41, CI 0.29–0.58, p OMT (HR 0.82, CI 0.66–1.02, p=0.077) and 4.5% vs 7.0% among those off OMT (HR 0.63, CI 0.49–0.82, pOMT were 2.2% vs 1.0% (HR 2.13, CI 1.43–3.17, pOMT were 2.8% vs 2.2% (HR 1.30, CI 0.88–1.92, p=0.189; interaction p=0.073). Overall, patients on OMT had lower rates of MI (2.7% vs 3.7%, p=0.003), MACCE (4.6% vs 5.7%, p=0.007) and bleeding (1.6% vs 2.5%, pOMT. Rates of stent thrombosis (0.8% vs 1.0%, p=0.171) and death (1.6% vs 1.9%, p=0.155) did not differ. Conclusions Continued thienopyridine therapy reduced the rate of MI regardless of OMT status and had consistent effects on reduction in MACCE and increased bleeding. Trial Registration https://clinicaltrials.gov, #NCT00977938 PMID:27576774

  17. Triple antiplatelet therapy for preventing vascular events: a systematic review and meta-analysis

    Science.gov (United States)

    2010-01-01

    Background Dual antiplatelet therapy is usually superior to mono therapy in preventing recurrent vascular events (VEs). This systematic review assesses the safety and efficacy of triple antiplatelet therapy in comparison with dual therapy in reducing recurrent vascular events. Methods Completed randomized controlled trials investigating the effect of triple versus dual antiplatelet therapy in patients with ischaemic heart disease (IHD), cerebrovascular disease or peripheral vascular disease were identified using electronic bibliographic searches. Data were extracted on composite VEs, myocardial infarction (MI), stroke, death and bleeding and analysed with Cochrane Review Manager software. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using random effects models. Results Twenty-five completed randomized trials (17,383 patients with IHD) were included which involving the use of intravenous (iv) GP IIb/IIIa inhibitors (abciximab, eptifibatide, tirofiban), aspirin, clopidogrel and/or cilostazol. In comparison with aspirin-based therapy, triple therapy using an intravenous GP IIb/IIIa inhibitor significantly reduced composite VEs and MI in patients with non-ST elevation acute coronary syndromes (NSTE-ACS) (VE: OR 0.69, 95% CI 0.55-0.86; MI: OR 0.70, 95% CI 0.56-0.88) and ST elevation myocardial infarction (STEMI) (VE: OR 0.39, 95% CI 0.30-0.51; MI: OR 0.26, 95% CI 0.17-0.38). A significant reduction in death was also noted in STEMI patients treated with GP IIb/IIIa based triple therapy (OR 0.69, 95% CI 0.49-0.99). Increased minor bleeding was noted in STEMI and elective percutaneous coronary intervention (PCI) patients treated with GP IIb/IIIa based triple therapy. Stroke events were too infrequent for us to be able to identify meaningful trends and no data were available for patients recruited into trials on the basis of stroke or peripheral vascular disease. Conclusions Triple antiplatelet therapy based on iv GPIIb/IIIa inhibitors was more

  18. Haemorrhagic shock due to spontaneous splenic haemorrhage complicating antiplatelet therapy: endovascular management

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    Garge S Shaileshkumar

    2015-01-01

    Full Text Available Spontaneous splenic haemorrahge and rupture is a rare but life-threatening condition requiring urgent diagnosis and treatment. Splenic haemorrhage and rupture precipitated by thrombolytic or antiocoagulant therapy has been reported frequently in the literature, but only two cases due to ticlopidine and one case due to salicyclate have been reported. We report the case of a 54-year-old man with haemorrhagic shock due to spontaneous splenic haemorrhage and rupture following dual antiplatelet (aspirin and clopidogrel therapy. He was successfully treated with selective angioembolization of the bleeding branch of the splenic artery.

  19. Triple antiplatelet therapy for preventing vascular events: a systematic review and meta-analysis

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    Bath Philip MW

    2010-06-01

    Full Text Available Abstract Background Dual antiplatelet therapy is usually superior to mono therapy in preventing recurrent vascular events (VEs. This systematic review assesses the safety and efficacy of triple antiplatelet therapy in comparison with dual therapy in reducing recurrent vascular events. Methods Completed randomized controlled trials investigating the effect of triple versus dual antiplatelet therapy in patients with ischaemic heart disease (IHD, cerebrovascular disease or peripheral vascular disease were identified using electronic bibliographic searches. Data were extracted on composite VEs, myocardial infarction (MI, stroke, death and bleeding and analysed with Cochrane Review Manager software. Odds ratios (OR and 95% confidence intervals (CI were calculated using random effects models. Results Twenty-five completed randomized trials (17,383 patients with IHD were included which involving the use of intravenous (iv GP IIb/IIIa inhibitors (abciximab, eptifibatide, tirofiban, aspirin, clopidogrel and/or cilostazol. In comparison with aspirin-based therapy, triple therapy using an intravenous GP IIb/IIIa inhibitor significantly reduced composite VEs and MI in patients with non-ST elevation acute coronary syndromes (NSTE-ACS (VE: OR 0.69, 95% CI 0.55-0.86; MI: OR 0.70, 95% CI 0.56-0.88 and ST elevation myocardial infarction (STEMI (VE: OR 0.39, 95% CI 0.30-0.51; MI: OR 0.26, 95% CI 0.17-0.38. A significant reduction in death was also noted in STEMI patients treated with GP IIb/IIIa based triple therapy (OR 0.69, 95% CI 0.49-0.99. Increased minor bleeding was noted in STEMI and elective percutaneous coronary intervention (PCI patients treated with GP IIb/IIIa based triple therapy. Stroke events were too infrequent for us to be able to identify meaningful trends and no data were available for patients recruited into trials on the basis of stroke or peripheral vascular disease. Conclusions Triple antiplatelet therapy based on iv GPIIb/IIIa inhibitors

  20. A review of potential harmful interactions between anticoagulant/antiplatelet agents and Chinese herbal medicines.

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    Hsin-Hui Tsai

    Full Text Available BACKGROUND: The risks attributed to drug-herb interactions, even when known, are often ignored or underestimated, especially for those involving anti-clotting drugs and Chinese medicines. The aim of this study was to structurally search and evaluate the existing evidence-based data associated with potential drug interactions between anticoagulant/antiplatelet drugs and Chinese herbal medicines (CHMs and evaluate the documented mechanisms, consequences, and/or severity of interactions. METHODOLOGY AND FINDINGS: Information related to anticoagulant/antiplatelet drug-CHM interactions was retrieved from eight interaction-based textbooks, four web resources and available primary biomedical literature. The primary literature searches were conducted in English and/or Chinese from January 2000 through December 2011 using the secondary databases (e.g., PubMed, Airiti Library, China Journal full-text database. The search terms included the corresponding medical subject headings and key words. Herbs or natural products not used as a single entity CHM or in Chinese Medicinal Prescriptions were excluded from further review. The corresponding mechanisms and severity ratings of interactions were retrieved using MicroMedex®, Lexicomp® and Natural Medicines Comprehensive Database®. Finally, we found 90 single entity CHMs contributed to 306 documented drug-CHM interactions. A total of 194 (63.4% interactions were verified for its evidence describing possible mechanisms and severity. Of them, 155 interactions (79.9% were attributable to pharmacodynamic interactions, and almost all were rated as moderate to severe interactions. The major consequences of these interactions were increased bleeding risks due to the additive anticoagulant or antiplatelet effects of the CHMs, specifically danshen, dong quai, ginger, ginkgo, licorice, and turmeric. CONCLUSIONS/SIGNIFICANCE: Conventional anticoagulants and antiplatelet drugs were documented to have harmful interactions

  1. Non-Vitamin K Antagonist Oral Anticoagulants and Antiplatelet Therapy for Stroke Prevention in Patients With Atrial Fibrillation: A Meta-Analysis of Randomized Controlled Trials.

    Science.gov (United States)

    Kumar, Shashi; Danik, Stephan B; Altman, Robert K; Barrett, Conor D; Lip, Gregory Y H; Chatterjee, Saurav; Roubin, Gary S; Natale, Andrea; Danik, Jacqueline S

    2016-01-01

    Non-vitamin K antagonist oral anticoagulants (NOACs) are frequently used to prevent stroke in patients with atrial fibrillation. These patients are often also on aspirin or other antiplatelet agents. It is possible that treatment with both NOACs and aspirin or other antiplatelet drug may be effective in decreasing stroke, but data are sparse regarding the efficacy and safety of using both agents for stroke prevention. To address these issues, data were pooled from the 4 recent randomized, controlled trials of NOACs: apixaban, rivaroxaban, dabigatran, and edoxaban, which included 42,411 patients; 14,148 (33.4%) were also on aspirin or other antiplatelet drug. The number of thromboembolic events among participants on NOAC and aspirin/antiplatelet was compared with the number of events in patients on NOAC alone. Bleeding rates were also compared between those on NOAC + aspirin/antiplatelet and on NOAC alone. These results were compared with thromboembolic and bleeding events in the warfarin + aspirin/antiplatelet versus warfarin alone. No greater risk for thromboembolism was seen in patients on NOACs compared with patients on both NOACs and aspirin/antiplatelet drug. In this nonrandomized comparison, there was initially a signal toward higher thromboembolic rates among NOAC users also on aspirin/antiplatelet drugs (relative risk, 1.16; 95% confidence intervals, 1.05, 1.29) when compared with NOAC alone. This likely reflected the higher CHADS2 scores of those on aspirin/antiplatelet drugs. When the analysis was limited to studies that included aspirin rather than other antiplatelet drugs, no difference was seen for thromboembolic rates comparing dual therapy to NOAC alone (relative risk, 1.02; 95% confidence intervals, 0.90, 1.15). Higher rates of bleeding were seen with aspirin/antiplatelet drug in conjunction with NOAC. In this meta-analysis and nonrandomized comparison of aspirin/antiplatelet users and nonusers also on anticoagulation, there was no additional

  2. Intermittent preventive antimalarial treatment for children with anaemia.

    Science.gov (United States)

    Athuman, Mwaka; Kabanywanyi, Abdunoor M; Rohwer, Anke C

    2015-01-13

    Anaemia is a global public health problem. Children under five years of age living in developing countries (mostly Africa and South-East Asia) are highly affected. Although the causes for anaemia are multifactorial, malaria has been linked to anaemia in children living in malaria-endemic areas. Administering intermittent preventive antimalarial treatment (IPT) to children might reduce anaemia, since it could protect children from new Plasmodium parasite infection (the parasites that cause malaria) and allow their haemoglobin levels to recover. To assess the effect of IPT for children with anaemia living in malaria-endemic areas. We searched the Cochrane Infectious Diseases Group Specialized Register, Cochrane Central of Controlled Trials (CENTRAL), published in The Cochrane Library; MEDLINE; EMBASE; and LILACS. We also searched the World Health Organization (WHO) International Clinical Trial Registry Platform and metaRegister of Controlled Trials (mRCT) for ongoing trials up to 4 December 2014. Randomized controlled trials (RCTs) evaluating the effect of IPT on children with anaemia. Two review authors independently extracted data and assessed risk of bias. We analysed data by conducting meta-analyses, stratifying data according to whether participants received iron supplements or not. We used GRADE to assess the quality of evidence. Six trials with 3847 participants met our inclusion criteria. Trials were conducted in areas of low malaria endemicity (three trials), and moderate to high endemicity (three trials). Four trials were in areas of seasonal malaria transmission. Iron was given to all children in two trials, and evaluated in a factorial design in a further two trials.IPT for children with anaemia probably has little or no effect on the proportion anaemic at 12 weeks follow-up (four trials, 2237 participants, (moderate quality evidence).IPT in anaemic children probably increases the mean change in haemoglobin levels from baseline to follow-up at 12 weeks on

  3. Risk Factors for Suboptimal Utilization of Statins and Antiplatelet Therapy in Patients Undergoing Revascularization for Symptomatic Peripheral Arterial Disease.

    Science.gov (United States)

    Meltzer, Andrew J; Sedrakyan, Art; Connolly, Peter H; Ellozy, Sharif; Schneider, Darren B

    2017-06-08

    The objective of this study was to identify risk factors for suboptimal medical therapy (defined as reported antiplatelet and statin use) among patients undergoing lower extremity bypass (LEB) and peripheral vascular interventions (PVIs) for symptomatic peripheral arterial disease (PAD). The Vascular Study Group of Greater New York (VSGGNY) database was used to identify all patients undergoing PVI or LEB for PAD (2011-2013). Bivariate analyses were performed to identify characteristics of patients who were not prescribed statins and/or antiplatelet agents before revascularization. Multivariate relative risk regression models were developed to identify patients at risk for suboptimal therapy, with regards to antiplatelet and statin therapy. About 1,030 patients underwent endovascular therapy (n = 822; 80%) or surgical bypass (n = 208; 20%) for symptomatic PAD (57.2% claudication; 15% rest pain and 27.8% tissue loss). Overall, preoperative statin use was observed in 59%. Preoperative antiplatelet therapy was observed in 79% of patients. Bivariate analysis revealed comparatively reduced statin use among patients without other cardiovascular risk factors including hypertension (63% vs. 39.3%; P antiplatelet therapy use was associated with CAD and/or prior CABG/PCI (1.11 [1.04-1.17]; P = 0.0015) and prior peripheral revascularization (1.07 [1.01-1.13]; P = 0.03). Patients with symptomatic PAD, but without an antecedent cardiovascular history, are less likely to be optimally managed with statins and antiplatelet therapy preoperatively. Given the established role of these medications in the optimal medical management of patients with PAD, this presents an opportunity for improvement in the overall vascular care of patients undergoing intervention for symptomatic PAD at VSGGNY centers. Copyright © 2017. Published by Elsevier Inc.

  4. Prediction models for intracranial hemorrhage or major bleeding in patients on antiplatelet therapy: a systematic review and external validation study.

    Science.gov (United States)

    Hilkens, N A; Algra, A; Greving, J P

    2016-01-01

    ESSENTIALS: Prediction models may help to identify patients at high risk of bleeding on antiplatelet therapy. We identified existing prediction models for bleeding and validated them in patients with cerebral ischemia. Five prediction models were identified, all of which had some methodological shortcomings. Performance in patients with cerebral ischemia was poor. Background Antiplatelet therapy is widely used in secondary prevention after a transient ischemic attack (TIA) or ischemic stroke. Bleeding is the main adverse effect of antiplatelet therapy and is potentially life threatening. Identification of patients at increased risk of bleeding may help target antiplatelet therapy. This study sought to identify existing prediction models for intracranial hemorrhage or major bleeding in patients on antiplatelet therapy and evaluate their performance in patients with cerebral ischemia. We systematically searched PubMed and Embase for existing prediction models up to December 2014. The methodological quality of the included studies was assessed with the CHARMS checklist. Prediction models were externally validated in the European Stroke Prevention Study 2, comprising 6602 patients with a TIA or ischemic stroke. We assessed discrimination and calibration of included prediction models. Five prediction models were identified, of which two were developed in patients with previous cerebral ischemia. Three studies assessed major bleeding, one studied intracerebral hemorrhage and one gastrointestinal bleeding. None of the studies met all criteria of good quality. External validation showed poor discriminative performance, with c-statistics ranging from 0.53 to 0.64 and poor calibration. A limited number of prediction models is available that predict intracranial hemorrhage or major bleeding in patients on antiplatelet therapy. The methodological quality of the models varied, but was generally low. Predictive performance in patients with cerebral ischemia was poor. In order to

  5. Prevalence of Bleeding Complications Following Ultrasound-Guided Botulinum Toxin Injections in Patients on Anticoagulation or Antiplatelet Therapy.

    Science.gov (United States)

    LaVallee, Jeffrey; Royer, Regan; Smith, Geoffrey

    2017-06-16

    Patients on anticoagulation or antiplatelet therapy may be at higher risk for bleeding complications following intramuscular chemodenervation injections. Musculoskeletal ultrasound may be able to reduce the risk of bleeding complications by providing real-time visualization of vascular structures and postinjection monitoring. Limited data exist addressing the risk of bleeding complications following ultrasound-guided botulinum neurotoxin intramuscular chemodenervation procedures in the setting of anticoagulation or antiplatelet therapy. To provide initial outcome data regarding bleeding complications in patients on anticoagulation or antiplatelet therapy who have received ultrasound-guided botulinum neurotoxin intramuscular chemodenervation procedures. Retrospective, medical record review. Academic institution outpatient spasticity clinic. Total of 328 ultrasound-guided intramuscular botulinum toxin injections performed in 15 patients (mean age 53.8 years) with the predominant indication for chemodenervation being spastic paresis secondary to stroke. The medical records of all patients receiving ultrasound-guided intramuscular chemodenervation procedures performed between July 1, 2011, and October 16, 2015, were reviewed for demographic information, details regarding anticoagulation therapy, procedure specifics, and postinjection bleeding complications. All patients had a postinjection ultrasound to screen for hematoma. Prevalence of clinically significant bleeding complications and of sonographically documented subclinical bleeding complications following ultrasound-guided chemodenervation procedures in patients on anticoagulation or antiplatelet therapy. Of 328 procedures, only 2 subclinical hematomas were detected, resulting in a bleeding complication rate of 0.61% in this patient population. The target muscles in these cases were tibialis posterior and pronator teres, and both cases were in patients on anticoagulation therapy (as opposed to antiplatelet

  6. Platelet reactivity-adjusted antiplatelet therapy in patients with percutaneous coronary intervention: a meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Xing, Zhenhua; Tang, Liang; Zhu, Zhaowei; Huang, Jiabing; Peng, Xiaofan; Hu, Xinqun

    2017-09-12

    Numerous number of evidences show that high on-treatment platelet reactivity is a well-known risk factor for adverse events in patients after percutaneous coronary intervention (PCI). Controversial situations still exist regarding the effectiveness of tailoring antiplatelet therapy according to platelet function monitoring. The PubMed, Embase, and Cochrane Central databases were searched for randomized trials comparing platelet reactivity-adjusted antiplatelet therapy with conventional antiplatelet therapy in patients undergoing PCI. The primary end point was all-cause mortality, major adverse cardiac events (MACE) including cardiovascular (CV) death, nonfatal myocardial infarction (MI), definite/probable stent thrombosis (ST), revascularization, and stroke or transient ischemic attack (TIA). The safety end point was defined as major bleeding events. We derived pooled risk ratios (RRs) with fixed-effect models. Six studies enrolling 6347 patients were included. Compared with conventional treatment, tailoring antiplatelet failed to reduce all-cause mortality (RR: 0.89, 95% confidence interval [CI]: 0.63-1.24, P = 0.48), MACE (RR: 1.02, 95% CI: 0.92-1.14, P = 0.69), MI (RR: 1.07, 95% CI: 0.95-1.21, P = 0.24), CV death (RR: 0.69, 95% CI: 0.40-1.19, P = 0.09), ST (RR: 0.83, 95% CI: 0.50-1.38, P = 0.23), stroke or TIA (RR: 1.08, 95% CI: 0.55-2.12, P = 0.83), revascularization (RR: 0.96, 95% CI: 0.69-1.33, P = 0.79), and major bleeding events (RR: 0.79, 95% CI: 0.53-1.17, P = 0.24). Compared with traditional antiplatelet treatment, tailoring antiplatelet therapy according to platelet reactivity testing failed to reduce all-cause mortality, MACE, and major bleeding events in patients undergoing PCI.

  7. Previous hypertensive hemorrhage increases the risk for bleeding and ischemia for PCI patients on dual antiplatelet therapy.

    Science.gov (United States)

    Qiao, Manli; Bi, Qi; Fu, Paul; Wang, Yixin; Song, Zhe; Guo, Fang

    2017-06-01

    The use of antiplatelet therapy after intracerebral hemorrhage remains controversial, while the use of dual antiplatelet therapy (DAPT) is required after cardiac stenting. In this study, we examine the risk of bleeding and ischemic events for PCI patients with a history of hypertensive hemorrhage on DAPT. A total of 128 cases and 153 controls were selected from Chinese patients with cardiac stenting on dual anti-platelet therapy for a single-center retrospective case-control study. Patients with a history of hypertensive hemorrhage were selected for the case group, while patients with a history of hypertension were chosen as control. All patients were on aspirin 100 mg and clopidogrel 75 mg after cardiac stenting, and were followed for a duration of 12-48 months. The primary outcomes were intracerebral hemorrhage, major bleeding, and major adverse cardiovascular and cerebrovascular events. A history of previous hypertensive hemorrhage was not found to be a risk factor for intracerebral hemorrhage and major bleeding while on dual anti-platelet therapy. However, a history of either hypertensive hemorrhage or coronary artery disease was independently found to be risk factors for major adverse cardiovascular and cerebrovascular events. On sub-group analysis, patients with a history of hypertensive hemorrhage within 12 months were found to be at higher risk for bleeding on dual anti-platelet therapy, while patients with history of hypertensive hemorrhage outside of 12 months on dual anti-platelet therapy did not have the same increased risk. A history of hypertensive hemorrhage and coronary heart disease were two independent risk factors for major adverse cardiovascular and cerebrovascular events in PCI patients taking DAPT. A history of hypertensive hemorrhage less than 12 months had an increased risk for recurrent intracerebral hemorrhage and major bleeding in PCI patients taking DAPT.

  8. Gastroscopy-related adverse cardiac events and bleeding complications among patients treated with coronary stents and dual antiplatelet therapy

    DEFF Research Database (Denmark)

    Egholm, Gro; Thim, Troels; Madsen, Morten

    2016-01-01

    BACKGROUND AND STUDY AIMS: Dual antiplatelet therapy (DAPT) is recommended following percutaneous coronary intervention (PCI) with drug-eluting stent (DES). DAPT is a risk factor for gastrointestinal bleeding. We aimed to quantify (1) the rate of gastroscopy within 12 months after PCI, (2) the rate...... of adverse cardiac events and gastroscopy-related bleeding complications within 30 days of gastroscopy, and (3) the association between antiplatelet therapy and these events. PATIENTS AND METHODS: Patients receiving gastroscopy within 12 months of PCI were identified and two nested case-control analyses were...

  9. Preparation, characterization and in vitro release kinetics of polyaspartamide-based conjugates containing antimalarial and anticancer agents for combination therapy

    CSIR Research Space (South Africa)

    Aderibigbe, BA

    2016-09-01

    Full Text Available Malaria is treated by combination of two drugs in order to overcome drug resistance. Antimalarials have been found to be more effective by combining them with low doses of anticancer drugs. Polymer-drug conjugates containing aminoquinoline...

  10. Synthesis and evaluation of antimalarial activity of curcumin derivatives; Sintese e avaliacao da atividade antimalarica de compostos derivados da curcumina

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Patricia Ramos; Miguel, Fabio Balbino; Almeida, Mauro Vieira de; Couri, Mara Rubia Costa [Universidade Federal de Juiz de Fora (UFSJ), MG (Brazil). Instituto de Ciencias Exatas. Departamento de Quimica; Oliveira, Michael Eder de; Ferreira, Vanessa Viana; Guimaraes, Daniel Silqueira Martins; Lima, Aline Brito de; Barbosa, Camila de Souza; Oliveira, Mariana Amorim de; Almeida, Mauro Vieira de; Viana, Gustavo Henrique Ribeiro; Varotti, Fernando de Pilla, E-mail: varotti@ufsj.edu.br [Universidade Federal de Sao Joao Del Rei (UFSJ), MG (Brazil). Centro de Ciencias da Saude; and others

    2014-05-15

    ne of the main challenges in the development of new antimalarial drugs is to achieve a viable lead candidate with good pharmacokinetic properties. Curcumin has a broad range of biological activities, including antimalarial activity. Herein, we report the antimalarial activity of six curcumin derivatives (6-12) and an initial analysis of their pharmacokinetic properties. Five compounds have demonstrated potent activity against the P. falciparum in vitro (IC{sub 50} values ranging from 1.7 to 15.2 μg mL{sup -1}), with moderate or low cytotoxicity against the HeLa cell line. The substitution of the carbonyl group in 6 by a 2,4-dinitrophenylhydrazone group (to afford 11) increases the Selective Index. These preliminary results indicate curcumin derivatives as potential antimalarial compounds. (author)

  11. Outcome of Triple Antiplatelet Therapy Including Cilostazol in Elderly Patients with ST-Elevation Myocardial Infarction who Underwent Primary Percutaneous Coronary Intervention: Results from the INTERSTELLAR Registry.

    Science.gov (United States)

    Jang, Ho-Jun; Park, Sang-Don; Park, Hyun Woo; Suh, Jon; Oh, Pyung Chun; Moon, Jeonggeun; Lee, Kyounghoon; Kang, Woong Chol; Kwon, Sung Woo; Kim, Tae-Hoon

    2017-06-01

    Compared with dual antiplatelet therapy including aspirin and clopidogrel, triple antiplatelet therapy including cilostazol has a mortality benefit in patients with ST-segment elevation myocardial infarction. However, whether the mortality benefit persists in elderly patients is not clear. From 2007 to 2014, 1278 patients with ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention were retrospectively analyzed. The patients were divided into four groups by age (antiplatelet strategy (triple or dual antiplatelet therapy). We compared the mortality rates between the triple and dual antiplatelet therapy groups. There were 1052 (male, 85%; mean age, 56.3 ± 10.4 years) patients in the young group and 241 (male, 52.7%; mean age, 80.3 ± 4.5 years) patients in the elderly group. In the young and elderly groups, 220 (20.9%) and 28 (12.3%) patients were treated with triple antiplatelet therapy. During a 1-year follow-up period, 80 patients died (4.2% in the young group vs. 15.5% in the elderly group). Kaplan-Meier survival analysis revealed that triple antiplatelet therapy was associated with a lower mortality rate in the young group (log-rank, p = 0.005). Although there were more angiographic high-risk patients in the elderly group, similar mortality rates were reported (log-rank, p = 0.803) without increased bleeding rates (1 vs. 3.6% in the elderly group, p = 0.217). Triple antiplatelet therapy might be a better antiplatelet regimen than dual antiplatelet therapy for patients with ST-segment elevation myocardial infarction. Although this benefit was strong in patients aged <75 years, no definite increase in major bleeding was seen for elderly patients (aged ≥75 years).

  12. Assessing the quality of anti-malarial drugs from Gabonese pharmacies using the MiniLab®: a field study.

    Science.gov (United States)

    Visser, Benjamin J; Meerveld-Gerrits, Janneke; Kroon, Daniëlle; Mougoula, Judith; Vingerling, Rieke; Bache, Emmanuel; Boersma, Jimmy; van Vugt, Michèle; Agnandji, Selidji T; Kaur, Harparkash; Grobusch, Martin P

    2015-07-15

    Recent studies alluded to the alarming scale of poor anti-malarial drug quality in malaria-endemic countries, but also illustrated the major geographical gaps in data on anti-malarial drug quality from endemic countries. Data are particularly scarce from Central Africa, although it carries the highest burden of malaria. The aim of this medicine quality field survey was to determine the prevalence of poor-quality anti-malarial drugs in Gabon. A field survey of the quality of anti-malarial drugs in Gabonese pharmacies was conducted using the Global Pharma Health Fund Minilab(®) tests, following the Medicine Quality Assessment Reporting Guidelines. Anti-malarial drugs were purchased randomly from selected pharmacies in Gabon. Semi-quantitative thin-layer chromatography (TLC) and disintegration testing were carried out to measure the concentration of active pharmaceutical ingredients (APIs). The samples failing the TLC test were analysed by high-performance liquid chromatography. Following the collection of anti-malarial drugs, a street survey was conducted to understand where people purchase their anti-malarial drugs. A total of 432 samples were purchased from 41 pharmacies in 11 cities/towns in Gabon. The prevalence of poor-quality anti-malarial drugs was 0.5% (95% CI 0.08-1.84%). Two out of 432 samples failed the MiniLab(®) semi-quantitative TLC test, of which a suspected artemether-lumefantrine (AL) sample was classified as falsified and one sulfadoxine-pyrimethamine (SP) sample as substandard. High performance liquid chromatography with ultraviolet photo diode array detection analysis confirmed the absence of APIs in the AL sample, and showed that the SP sample did contain the stated APIs but the amount was half the stated dose. Of the people interviewed, 92% (187/203) purchased their anti-malarial drugs at a pharmacy. Using the GPHF Minilab(®), the prevalence of poor-quality anti-malarial drugs is far lower than anticipated. The findings emphasize the need for

  13. Case management of malaria fever in Cambodia: results from national anti-malarial outlet and household surveys

    Directory of Open Access Journals (Sweden)

    Littrell Megan

    2011-10-01

    Full Text Available Abstract Background Continued progress towards global reduction in morbidity and mortality due to malaria requires scale-up of effective case management with artemisinin-combination therapy (ACT. The first case of artemisinin resistance in Plasmodium falciparum was documented in western Cambodia. Spread of artemisinin resistance would threaten recent gains in global malaria control. As such, the anti-malarial market and malaria case management practices in Cambodia have global significance. Methods Nationally-representative household and outlet surveys were conducted in 2009 among areas in Cambodia with malaria risk. An anti-malarial audit was conducted among all public and private outlets with the potential to sell anti-malarials. Indicators on availability, price and relative volumes sold/distributed were calculated across types of anti-malarials and outlets. The household survey collected information about management of recent "malaria fevers." Case management in the public versus private sector, and anti-malarial treatment based on malaria diagnostic testing were examined. Results Most public outlets (85% and nearly half of private pharmacies, clinics and drug stores stock ACT. Oral artemisinin monotherapy was found in pharmacies/clinics (9%, drug stores (14%, mobile providers (4% and grocery stores (2%. Among total anti-malarial volumes sold/distributed nationally, 6% are artemisinin monotherapies and 72% are ACT. Only 45% of people with recent "malaria fever" reportedly receive a diagnostic test, and the most common treatment acquired is a drug cocktail containing no identifiable anti-malarial. A self-reported positive diagnostic test, particularly when received in the public sector, improves likelihood of receiving anti-malarial treatment. Nonetheless, anti-malarial treatment of reportedly positive cases is low among people who seek treatment exclusively in the public (61% and private (42% sectors. Conclusions While data on the anti-malarial

  14. Implementation of a reference standard and proficiency testing programme by the World Wide Antimalarial Resistance Network (WWARN

    Directory of Open Access Journals (Sweden)

    Barnes Karen I

    2010-12-01

    Full Text Available Abstract Background The Worldwide Antimalarial Resistance Network (WWARN is a global collaboration to support the objective that anyone affected by malaria receives effective and safe drug treatment. The Pharmacology module aims to inform optimal anti-malarial drug selection. There is an urgent need to define the drug exposure - effect relationship for most anti-malarial drugs. Few anti-malarials have had their therapeutic blood concentration levels defined. One of the main challenges in assessing safety and efficacy data in relation to drug concentrations is the comparability of data generated from different laboratories. To explain differences in anti-malarial pharmacokinetics in studies with different measurement laboratories it is necessary to confirm the accuracy of the assay methods. This requires the establishment of an external quality assurance process to assure results that can be compared. This paper describes this process. Methods The pharmacology module of WWARN has established a quality assurance/quality control (QA/QC programme consisting of two separate components: 1. A proficiency testing programme where blank human plasma spiked with certified reference material (CRM in different concentrations is sent out to participating bioanalytical laboratories. 2. A certified reference standard programme where accurately weighed amounts of certified anti-malarial reference standards, metabolites, and internal standards are sent to participating bioanalytical and in vitro laboratories. Conclusion The proficiency testing programme is designed as a cooperative effort to help participating laboratories assess their ability to carry out drug analysis, resolve any potential problem areas and to improve their results - and, in so doing, to improve the quality of anti-malarial pharmacokinetic data published and shared with WWARN. By utilizing the same source of standards for all laboratories, it is possible to minimize bias arising from poor

  15. The Emerging Role of miR-223 in Platelet Reactivity: Implications in Antiplatelet Therapy

    Directory of Open Access Journals (Sweden)

    Rui Shi

    2015-01-01

    Full Text Available Platelets are anuclear cells and are devoid of genomic DNA, but they are capable of de novo protein synthesis from mRNA derived from their progenitor cells, megakaryocytes. There is mounting evidence that microRNA (miRNA plays an important role in regulating gene expression in platelets. miR-223 is the most abundant miRNAs in megakaryocytes and platelets. One of the miR-223-regulated genes is ADP P2Y12, a key target for current antiplatelet drug therapy. Recent studies showed that a blunted response to P2Y12 antagonist, that is, high on-treatment platelet reactivity (HTPR, is a strong predictor of major cardiovascular events (MACEs in coronary heart disease (CHD patients receiving antiplatelet treatment. Recent clinical cohort study showed that the level of circulating miR-223 is inversely associated with MACE in CHD patients. In addition, our recent data demonstrated that the level of both intraplatelet and circulating miR-223 is an independent predictor for HTPR, thus providing a link between miR-223 and MACE. These lines of evidence indicate that miR-223 may serve as a potential regulatory target for HTPR, as well as a diagnostic tool for identification of HTPR in clinical settings.