Venous thromboembolic prophylaxis after simultaneous bilateral total knee arthroplasty: aspirin versus warfarin.

Science.gov (United States)

Goel, R; Fleischman, A N; Tan, T; Sterbis, E; Huang, R; Higuera, C; Parvizi, J; Rothman, R H

2018-01-01

The aims of this study were to compare the efficacy of two agents, aspirin and warfarin, for the prevention of venous thromboembolism (VTE) after simultaneous bilateral total knee arthroplasty (SBTKA), and to elucidate the risk of VTE conferred by this procedure compared with unilateral TKA (UTKA). A retrospective, multi-institutional study was conducted on 18 951 patients, 3685 who underwent SBTKA and 15 266 who underwent UTKA, using aspirin or warfarin as VTE prophylaxis. Each patient was assigned an individualised baseline VTE risk score based on a system using the Nationwide Inpatient Sample. Symptomatic VTE, including pulmonary embolism (PE) and deep vein thrombosis (DVT), were identified in the first 90 days post-operatively. Statistical analyses were performed with logistic regression accounting for baseline VTE risk. The adjusted incidence of PE following SBTKA was 1.0% (95% confidence interval (CI) 0.86 to 1.2) with aspirin and 2.2% (95% CI 2.0 to 2.4) with warfarin. Similarly, the adjusted incidence of VTE following SBTKA was 1.6% (95% CI 1.1 to 2.3) with aspirin and 2.5% (95% CI 1.9 to 3.3) with warfarin. The risk of PE and VTE were reduced by 66% (odds ratio (OR) 0.44, 95% CI 0.25 to 0.78) and 38% (OR 0.62, 95% CI 0.38 to 1.0), respectively, using aspirin. In addition, the risk of PE was 204% higher for patients undergoing SBTKA relative to those undergoing UTKA. For each ten-point increase in baseline VTE risk, the risk of PE increased by 25.5% for patients undergoing SBTKA compared with 10.5% for those undergoing UTKA. Patients with a history of myocardial infarction or peripheral vascular disease had the greatest increase in risk from undergoing SBTKA instead of UTKA. Aspirin is more effective than warfarin for the prevention of VTE following SBTKA, and serves as the more appropriate agent for VTE prophylaxis for patients in all risk categories. Furthermore, patients undergoing SBTKA are at a substantially increased risk of VTE, even more so for

Should warfarin or aspirin be stopped prior to prostate biopsy? An analysis of bleeding complications related to increasing sample number regimes

International Nuclear Information System (INIS)

Chowdhury, R.; Abbas, A.; Idriz, S.; Hoy, A.; Rutherford, E.E.; Smart, J.M.

2012-01-01

Aim: To determine whether patients undergoing transrectal ultrasound (TRUS)-guided prostate biopsy with increased sampling numbers are more likely to experience bleeding complications and whether warfarin or low-dose aspirin are independent risk factors. Materials and methods: 930 consecutive patients with suspected prostatic cancer were followed up after biopsy. Warfarin/low-dose aspirin was not stopped prior to the procedure. An eight to 10 sample regime TRUS-guided prostate biopsy was performed and patients were offered a questionnaire to complete 10 days after the procedure, to determine any immediate or delayed bleeding complications. Results: 902 patients returned completed questionnaires. 579 (64.2%) underwent eight core biopsies, 47 (5.2%) underwent nine, and 276 (30.6%) underwent 10. 68 were taking warfarin [mean international normalized ratio (INR) = 2.5], 216 were taking low-dose aspirin, one was taking both, and 617 were taking neither. 27.9% of those on warfarin and 33.8% of those on aspirin experienced haematuria. 37% of those on no blood-thinning medication experienced haematuria. 13.2% of those on warfarin and 14.4% of those on aspirin experienced rectal bleeding. 11.5% of those on no blood-thinning medication experienced rectal bleeding. 7.4% of those on warfarin and 12% of those on aspirin experienced haematospermia. 13.8% of those on neither experienced haematospermia. Regression analysis showed a significant association between increasing sampling number and occurrence of all bleeding complication types. There was no significant association between minor bleeding complications and warfarin use; however, there was a significant association between minor bleeding complications and low-dose aspirin use. There was no severe bleeding complication. Conclusion: There is an increased risk of bleeding complications following TRUS-guided prostate biopsy with increased sampling numbers but these are minor. There is also an increased risk with low

Effects of preoperative aspirin and clopidogrel therapy on perioperative blood loss and blood transfusion requirements in patients undergoing off-pump coronary artery bypass graft surgery.

Science.gov (United States)

Shim, Jae Kwang; Choi, Yong Seon; Oh, Young Jun; Bang, Sou Ouk; Yoo, Kyung Jong; Kwak, Young Lan

2007-07-01

Preoperative exposure to clopidogrel and aspirin significantly increases postoperative bleeding in patients undergoing on-pump coronary artery bypass graft surgery. Off-pump coronary bypass grafting has been proposed as an alternative technique to attenuate postoperative bleeding associated with clopidogrel. This study aimed to determine the effects of aspirin and clopidogrel therapy on perioperative blood loss and blood transfusion requirements in off-pump coronary artery bypass grafting. One hundred six patients scheduled for off-pump coronary artery bypass grafting were divided into three groups: aspirin and clopidogrel discontinued more than 6 days before surgery (group 1, n = 35), aspirin and clopidogrel continued until 3 to 5 days before surgery (group 2, n = 51), and both medications continued within 2 days of surgery (group 3, n = 20). Thromboelastographic tracings were analyzed before induction of anesthesia. Routine coagulation profiles were measured before and after surgery. A cell salvage device was used during surgery and salvaged blood was reinfused. Chest tube drainage and blood transfusion requirement were recorded postoperatively. Patient characteristics, operative data, and thromboelastographic tracings were similar among the groups. There were significant decreases in hematocrit level and platelet count and prolongation in prothrombin time postoperatively in all groups without any intergroup differences. The amounts of perioperative blood loss and blood transfusion required were all similar among the groups. Preoperative clopidogrel and aspirin exposure even within 2 days of surgery does not increase perioperative blood loss and blood transfusion requirements in patients undergoing elective off-pump coronary artery bypass grafting.

Effect of exercise on platelet activation during aspirin or clopidogrel intake in healthy men

DEFF Research Database (Denmark)

Hjorth Madsen, Esben; Christiansen, Morten Krogh; Schmidt, Erik Berg

2009-01-01

aggregometry. A significant increase in plasma von Willebrand Factor was also found in response to exercise. In conclusion, platelet activation occurs during exercise in healthy individuals. This activation is not prevented by use of aspirin or clopidogrel, and may partly be explained by an increase in plasma...

Bleeding tendency in dual antiplatelet therapy with aspirin/clopidogrel: rescue of the template bleeding time in a single-center prospective study

Directory of Open Access Journals (Sweden)

Altman Raul

2012-01-01

Full Text Available Abstract Background Patients with heightened platelet reactivity in response to antiplatelet agents are at an increased risk of recurrent ischemic events. However, there is a lack of diagnostic criteria for increased response to combined aspirin/clopidogrel therapy. The challenge is to identify patients at risk of bleeding. This study sought to characterize bleeding tendency in patients treated with aspirin and clopidogrel. Patients/methods In a single-center prospective study, 100 patients under long-term aspirin/clopidogrel treatment, the effect of therapy was assayed by template bleeding time (BT and the inhibition of platelet aggregation (IPA by light transmission aggregometry (LTA. Arachidonic acid (0.625 mmol/L and adenosine diphosphate (ADP; 2, 4, and 8 μmol/L were used as platelet agonists. Results Bleeding episodes (28 nuisance, 2 hematuria [1 severe], 1 severe proctorrhagia, 1 severe epistaxis were significantly more frequent in patients with longer BT. Template BT ≥ 24 min was associated with bleeding episodes (28 of 32. Risk of bleeding increased 17.4% for each 1 min increase in BT. Correlation was found between BT and IPAmax in response to ADP 2 μmol/L but not to ADP 4 or 8 μmol/L. Conclusion In patients treated with dual aspirin/clopidogrel therapy, nuisance and internal bleeding were significantly associated with template BT and with IPAmax in response to ADP 2 μmol/L but not in response to ADP 4 μmol/L or 8 μmol/L.

Evaluación económica del tratamiento con ácido acetilsalicílico más esomeprazol comparado con clopidogrel en la prevención de la hemorragia gastrointestinal Economic evaluation of the treatment of aspirin plus esomeprazole compared to clopidogrel in gastrointestinal bleeding prevention

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Carme Piñol

2006-02-01

Full Text Available Objetivo: Evaluar la eficiencia del ácido acetilsalicílico (AAS más esomeprazol frente a clopidogrel en la prevención de la hemorragia gastrointestinal. Métodos: Análisis coste-efectividad (árbol de decisión de 2 ramas: AAS más esomeprazol y clopidogrel respecto a la evitación de casos de hemorragia gastrointestinal en 2 años, y análisis de sensibilidad. Resultados: El coste total del tratamiento con AAS más esomeprazol (2.865 S por paciente libre de hemorragia fue inferior al clopidogrel (2.965 S. El tratamiento con AAS resultó dominante. En todos los análisis de sensibilidad la combinación siguió siendo dominante. Al sustituir esomeprazol 40 mg por omeprazol 40 mg, el coste del tratamiento combinado descendió hasta 1.934S/por episodio evitado. Conclusiones: La asociación de esomeprazol y AAS es más coste-efectiva que clopidogrel en la prevención de la hemorragia gastrointestinal. La combinación con omeprazol resulta aún más coste-efectiva.Objective: To evaluate the use of aspirin plus esomeprazole vs. clopidogrel in the prevention of gastrointestinal bleeding. Methods: We performed a cost-effectiveness analysis (two-branch decision tree: aspirin plus esomeprazole or clopidogrel of prevention of gastrointestinal bleeding over a 2-year period, as well as sensitivity analyses. Results: The total cost of aspirin plus esomeprazole treatment (2,865S/patient free of hemorrhage was lower than that of clopidogrel (2,965S. Aspirin treatment was dominant. The combination continued to be dominant in all sensitivity analyses. When esomeprazole 40 mg was substituted by omeprazole 40 mg, the cost of combination therapy decreased to 1,934 S/prevented hemorrhage. Conclusions: The association of esomeprazole and aspirin is more cost-effective than clopidogrel in preventing gastrointestinal bleeding. Aspirin plus omeprazole was even more cost-effective.

Aspirin plus dipyridamole has the highest surface under the cumulative ranking curves (SUCRA) values in terms of mortality, intracranial hemorrhage, and adverse event rate among 7 drug therapies in the treatment of cerebral infarction.

Science.gov (United States)

Zhang, Jian-Jun; Liu, Xin

2018-03-01

The standardization for the clinical use of drug therapy for cerebral infarction (CI) has not yet determined in some aspects. In this paper, we discussed the efficacies of different drug therapies (aspirin, aspirin plus dipyridamole, aspirin plus clopidogrel, aspirin plus warfarin, cilostazol, warfarin, and ticlopidine) for CI. We searched databases of PubMed and Cochrane Library from the inception to April, 2017, randomized controlled trials (RCTs) met the inclusion and exclusion criteria were enrolled in this study. The network meta-analysis integrated evidences of direct and indirect comparisons to assess odd ratios (OR) and surface under the cumulative ranking curves (SUCRA) value. Thirteen eligible RCTs including 7 drug therapies were included into this network meta-analysis. The network meta-analysis results showed that CI patients who received aspirin plus dipyridamole presented lower mortality when compared with those received aspirin plus clopidogrel (OR = 0.46, 95% CI = 0.18-0.99), indicating aspirin plus dipyridamole therapy had better efficacy for CI. As for intracranial hemorrhage (ICH), stroke recurrence, and adverse event (AE) rate, there were no significant differences of efficacy among 7 drug therapies. Besides, SUCRA values demonstrated that in the 7 drug therapies, aspirin plus dipyridamole therapy was more effective than others (mortality: 80.67%; ICH: 76.6%; AE rate: 90.2%). Our findings revealed that aspirin plus dipyridamole therapy might be the optimum one for patients with CI, which could help to improve the survival of CI patients.

Use of clopidogrel with or without aspirin in patients taking oral anticoagulant therapy and undergoing percutaneous coronary intervention: an open-label, randomised, controlled trial

NARCIS (Netherlands)

Dewilde, Willem J. M.; Oirbans, Tom; Verheugt, Freek W. A.; Kelder, Johannes C.; de Smet, Bart J. G. L.; Herrman, Jean-Paul; Adriaenssens, Tom; Vrolix, Mathias; Heestermans, Antonius A. C. M.; Vis, Marije M.; Tijsen, Jan G. P.; van 't Hof, Arnoud W.; ten Berg, Jurriën M.; Schölzel, B. E.; van den Branden, B. J.; Plokker, H. W. M.; Bosschaert, M. A.; Slagboom, T.; Vos, J.; Brueren, B. R. G.; Breet, N. J.; Sheikjoesoef, K.; Aarnoudse, W.; Rasoul, S.; van Mieghem, C.; Vandendriessche, T.; Cornelis, K.

2013-01-01

If percutaneous coronary intervention (PCI) is required in patients taking oral anticoagulants, antiplatelet therapy with aspirin and clopidogrel is indicated, but such triple therapy increases the risk of serious bleeding. We investigated the safety and efficacy of clopidogrel alone compared with

Safety of low-dose aspirin in endovascular treatment for intracranial atherosclerotic stenosis.

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Ning Ma

Full Text Available OBJECTIVES: To evaluate the safety of low-dose aspirin plus clopidogrel versus high-dose aspirin plus clopidogrel in prevention of vascular risk within 90 days of duration of dual antiplatelet therapy in patients treated with intracranial endovascular treatment. METHODS: From January 2012 to December 2013, this prospective and observational study enrolled 370 patients with symptomatic intracranial atherosclerotic stenosis of ≥70% with poor collateral undergoing intracranial endovascular treatment. Antiplatelet therapy consists of aspirin, at a low-dose of 100 mg or high-dose of 300 mg daily; clopidogrel, at a dose of 75 mg daily for 5 days before endovascular treatment. The dual antiplatelet therapy continued for 90 days after intervention. The study endpoints include acute thrombosis, subacute thrombosis, stroke or death within 90 days after intervention. RESULTS: Two hundred and seventy three patients received low-dose aspirin plus clopidogrel and 97 patients received high-dose aspirin plus clopidogrel before intracranial endovascular treatment. Within 90 days after intervention, there were 4 patients (1.5% with acute thrombosis, 5 patients (1.8% with subacute thrombosis, 17 patients (6.2% with stroke, and 2 death (0.7% in low-dose aspirin group, compared with no patient (0% with acute thrombosis, 2 patient (2.1% with subacute thrombosis, 6 patients (6.2% with stroke, and 2 death (2.1% in high-dose aspirin group, and there were no significant difference in all study endpoints between two groups. CONCLUSION: Low-dose aspirin plus clopidogrel is comparative in safety with high-dose aspirin plus clopidogrel within 90 days of duration of dual antiplatelet therapy in patients treated with intracranial endovascular treatment.

Monotherapy of aspirin or warfarin for prevention of ischemic stroke in low-risk atrial fibrillation: A Easter Asian population-based study.

Science.gov (United States)

Liu, Chieh-Yu; Chen, Hui-Chun

2018-05-02

This study aimed to investigate the effectiveness of monotherapy aspirin and warfarin for stroke prevention in low-risk atrial fibrillation (AF) by using a population-based cohort study in Taiwan. A newly diagnosed low-risk AF patient cohort were identified by using National Health Insurance Research Database (NHIRD) in Taiwan in 2008. The study cohort was observed with a follow-up of 2 years to examine the onset of ischemic stroke (IS) (to 2010). The longitudinal data were analyzed by using generalized estimation equations (GEE). A total of 8,065 newly-diagnosed low-risk AF patients were identified in 2008. 7.4% were prescribed with aspirin and 4.6% were prescribed with warfarin. The GEE results showed that low-risk AF patients with hypertension who received warfarin were associated with a statistically significant 58.4% reduction of IS risk (OR = 0.416, p = 0.024, 95% CI 0.194-0.891). Additionally, low-risk AF patients with hyperlipidemia who received warfarin were associated with a 69.3% reduction of IS risk (OR = 0.307, p = 0.044, 95% CI 0.097-0.969). Warfarin is suggested to be prescribed in preventing ischemic stroke for low-stroke-risk atrial fibrillation patients with hypertension and hyperlipidemia.

Systemic low-dose aspirin and clopidogrel independently attenuate reflex cutaneous vasodilation in middle-aged humans.

Science.gov (United States)

Holowatz, Lacy A; Jennings, John D; Lang, James A; Kenney, W Larry

2010-06-01

Chronic systemic platelet cyclooxygenase (COX) inhibition with low-dose aspirin [acetylsalicylic acid (ASA)] significantly attenuates reflex cutaneous vasodilation in middle-aged humans, whereas acute, localized, nonisoform-specific inhibition of vascular COX with intradermal administration of ketorolac does not alter skin blood flow during hyperthermia. Taken together, these data suggest that platelets may be involved in reflex cutaneous vasodilation, and this response is inhibited with systemic pharmacological platelet inhibition. We hypothesized that, similar to ASA, specific platelet ADP receptor inhibition with clopidogrel would attenuate reflex vasodilation in middle-aged skin. In a double-blind crossover design, 10 subjects (53+/-2 yr) were instrumented with four microdialysis fibers for localized drug administration and heated to increase body core temperature [oral temperature (Tor)] 1 degrees C during no systemic drug (ND), and after 7 days of systemic ASA (81 mg) and clopidogrel (75 mg) treatment. Skin blood flow (SkBF) was measured using laser-Doppler flowmetry over each site assigned as 1) control, 2) nitric oxide synthase inhibited (NOS-I; 10 mM NG-nitro-L-arginine methyl ester), 3) COX inhibited (COX-I; 10 mM ketorolac), and 4) NOS-I+COX-I. Data were normalized and presented as a percentage of maximal cutaneous vascular conductance (%CVCmax; 28 mM sodium nitroprusside+local heating to 43 degrees C). During ND conditions, SkBF with change (Delta) in Tor=1.0 degrees C was 56+/-3% CVCmax. Systemic low-dose ASA and clopidogrel both attenuated reflex vasodilation (ASA: 43+/-3; clopidogrel: 32+/-3% CVCmax; both P0.05). NOS-I attenuated vasodilation in ND and ASA (ND: 28+/-6; ASA: 25+/-4% CVCmax; both P0.05). NOS-I+COX-I was not different compared with NOS-I alone in either systemic treatment condition. Both systemic ASA and clopidogrel reduced the time required to increase Tor 1 degrees C (ND: 58+/-3 vs. ASA: 45+/-2; clopidogrel: 39+/-2 min; both Preflex

Eight-year follow-up of the Clopidogrel After Surgery for Coronary Artery Disease (CASCADE) trial.

Science.gov (United States)

Hage, Ali; Voisine, Pierre; Erthal, Fernanda; Larose, Éric; Glineur, David; Chow, Benjamin; Tremblay, Hugo; Fortier, Jacqueline; Ko, Gifferd; Une, Dai; Farkouh, Michael; Mesana, Thierry G; LeMay, Michel; Kulik, Alexander; Ruel, Marc

2018-01-01

In this 8 years' follow-up study, we evaluated the long-term outcomes of the addition of clopidogrel to aspirin during the first year after coronary artery bypass grafting, versus aspirin plus placebo, with respect to survival, major adverse cardiac, or major cerebrovascular events, including revascularization, functional status, graft patency, and native coronary artery disease progression. In the initial Clopidogrel After Surgery for Coronary Artery Disease trial, 113 patients were randomized to receive either daily clopidogrel (n = 56) or placebo (n = 57), in addition to aspirin, in a double-blind fashion for 1 year after coronary artery bypass grafting. All patients were re-evaluated to collect long-term clinical data. Surviving patients with a glomerular filtration rate > 30 mL/min were asked to undergo a coronary computed tomography angiogram to evaluate the late saphenous vein graft patency and native coronary artery disease progression. At a median follow-up of 7.6 years, survival rate was 85.5% ± 3.8% (P = .23 between the 2 groups). A trend toward enhanced freedom from all-cause death or major adverse cardiac or cerebrovascular events, including revascularization, was observed in the aspirin-clopidogrel group (P = .11). No difference in functional status or freedom from angina was observed between the 2 groups (P > .57). The long-term patency of saphenous vein graft was 89.11% in the aspirin-clopidogrel group versus 91.23% in the aspirin-placebo group (P = .79). A lower incidence of moderate to severe native disease progression was observed in the aspirin-clopidogrel group versus the aspirin-placebo group (7 out of 122 vs 13 out of 78 coronary segments that showed progression, respectively [odds ratio, 0.3 ± 0.2; 95% confidence interval, 0.1-0.8; P = .02]). At 8 years' follow-up, the addition of clopidogrel to aspirin during the first year after coronary artery bypass grafting exhibited a lower incidence of moderate to severe

Management of antithrombotic therapy during cardiac implantable device surgery.

Science.gov (United States)

AlTurki, Ahmed; Proietti, Riccardo; Birnie, David H; Essebag, Vidal

2016-06-01

Anticoagulants are commonly used drugs that are frequently encountered during device placement. Deciding when to halt or continue the use of anticoagulants is a balance between the risks of thromboembolism versus bleeding. Patients taking warfarin with a high risk of thromboembolism should continue to take their warfarin without interruption during device placement while ensuring their international normalized ratio remains below 3. For patients who are taking warfarin and have low risk of thromboembolism, either interrupted or continued warfarin may be used, with no evidence to clearly support either strategy. There is little evidence to support continuing direct acting oral anticoagulants (DOACs) for device implantation. The timing of halting these medications depends largely on renal function. If bleeding occurs, warfarin׳s anticoagulation effect is reversible with vitamin K and activated prothrombin complex concentrate. There are no DOAC reversal agents currently available, but some are under development. Regarding antiplatelet agents, aspirin alone can be safely continued while clopidogrel alone may also be continued, but with a slightly higher bleeding risk. Dual antiplatelet therapy for bare-metal stent/drug-eluting stent implanted within 4 weeks/6 months, respectively, should be continued due to high risk of stent thrombosis; however, if they are implanted after this period, then clopidogrel can be halted 5 days before the procedure and resumed soon after, while aspirin is continued. If the patient is taking both aspirin and warfarin, aspirin should be halted 5 days prior to the procedure, while warfarin is continued.

Clopidogrel discontinuation and platelet reactivity following coronary stenting

LENUS (Irish Health Repository)

2011-01-01

Summary. Aims: Antiplatelet therapy with aspirin and clopidogrel is recommended for 1 year after drug-eluting stent (DES) implantation or myocardial infarction. However, the discontinuation of antiplatelet therapy has become an important issue as recent studies have suggested a clustering of ischemic events within 90 days of clopidogrel withdrawal. The objective of this investigation was to explore the hypothesis that there is a transient ‘rebound’ increase in platelet reactivity within 3 months of clopidogrel discontinuation. Methods and Results: In this prospective study, platelet function was assessed in patients taking aspirin and clopidogrel for at least 1 year following DES implantation. Platelet aggregation was measured using a modification of light transmission aggregometry in response to multiple concentrations of adenosine diphosphate (ADP), epinephrine, arachidonic acid, thrombin receptor activating peptide and collagen. Clopidogrel was stopped and platelet function was reassessed 1 week, 1 month and 3 months later. Thirty-two patients on dual antiplatelet therapy were recruited. Discontinuation of clopidogrel increased platelet aggregation to all agonists, except arachidonic acid. Platelet aggregation in response to ADP (2.5, 5, 10, and 20 μm) and epinephrine (5 and 20 μm) was significantly increased at 1 month compared with 3 months following clopidogrel withdrawal. Thus, a transient period of increased platelet reactivity to both ADP and epinephrine was observed 1 month after clopidogrel discontinuation. Conclusions: This study demonstrates a transient increase in platelet reactivity 1 month after clopidogrel withdrawal. This phenomenon may, in part, explain the known clustering of thrombotic events observed after clopidogrel discontinuation. This observation requires confirmation in larger populations.

Clopidogrel Resistance: Current Issues

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NS Neki

2016-05-01

Full Text Available Antiplatelet agents are mainly used in the prevention and management of atherothrombotic complications. Dual antiplatelet therapy, combining aspirin and clopidogrel, is the standard care for patients having acute coronary syndromes or undergoing percutaneous coronary intervention according to the current ACC/AHA and ESC guidelines. But in spite of administration of dual antiplatelet therapy, some patients develop recurrent cardiovascular ischemic events especially stent thrombosis which is a serious clinical problem. Antiplatelet response to clopidogrel varies widely among patients based on ex vivo platelet function measurements. Clopidogrel is an effective inhibitor of platelet activation and aggregation due to its selective and irreversible blockade of the P2Y12 receptor. Patients who display little attenuation of platelet reactivity with clopidogrel therapy are labeled as low or nonresponders or clopidogrel resistant. The mechanism of clopidogrel resistance remains incompletely defined but there are certain clinical, cellular and genetic factors including polymorphisms responsible for therapeutic failure. Currently there is no standardized or widely accepted definition of clopidogrel resistance. The future may soon be realised in the routine measurement of platelet activity in the same way that blood pressure, cholesterol and blood sugar are followed to help guide the therapy, thus improving the care for millions of people. This review focuses on the methods used to identify patients with clopidogrel resistance, the underlying mechanisms, metabolism, clinical significance and current therapeutic strategies to overcome clopidogrel resistance. J Enam Med Col 2016; 6(1: 38-46

Clopidogrel plus aspirin versus aspirin alone for preventing cardiovascular events

NARCIS (Netherlands)

Squizzato, Alessandro; Bellesini, Marta; Takeda, Andrea; Middeldorp, Saskia; Donadini, Marco Paolo

2017-01-01

Aspirin is the prophylactic antiplatelet drug of choice for people with cardiovascular disease. Adding a second antiplatelet drug to aspirin may produce additional benefit for people at high risk and people with established cardiovascular disease. This is an update to a previously published review

Clopidogrel paclitaxel drug-drug interaction

DEFF Research Database (Denmark)

Agergaard, K; Mau-Sørensen, M; Stage, T B

2017-01-01

register. Peripheral sensory neuropathy was retrospectively evaluated from medical charts and compared to that of 88 age and sex matched controls treated with paclitaxel and low dose aspirin. By a cumulative dose of 1500 mg paclitaxel, 35% of the patients had developed severe neuropathy. The overall hazard...... ratio between clopidogrel use and severe paclitaxel neuropathy was 1.7 (95% CI, 0.9-3.0). Among those receiving a high dose paclitaxel regimen, the hazard ratio was 2.3 (95% CI, 1.1-4.5). Our study indicates that clopidogrel is associated with a clinically relevant increased risk of neuropathy......Paclitaxel is mainly eliminated by CYP2C8 in the liver. CYP2C8 is strongly inhibited by the clopidogrel metabolite acyl-β-D-glucuronide. To determine if this interaction has clinical relevance, we identified 48 patients treated with clopidogrel and paclitaxel using databases and a prescription...

Protocol for Birmingham Atrial Fibrillation Treatment of the Aged study (BAFTA: a randomised controlled trial of warfarin versus aspirin for stroke prevention in the management of atrial fibrillation in an elderly primary care population [ISRCTN89345269

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Fletcher Kate

2003-08-01

Full Text Available Abstract Background Atrial fibrillation (AF is an important independent risk factor for stroke. Randomised controlled trials have shown that this risk can be reduced substantially by treatment with warfarin or more modestly by treatment with aspirin. Existing trial data for the effectiveness of warfarin are drawn largely from studies in selected secondary care populations that under-represent the elderly. The Birmingham Atrial Fibrillation Treatment of the Aged (BAFTA study will provide evidence of the risks and benefits of warfarin versus aspirin for the prevention of stroke for older people with AF in a primary care setting. Study design A randomised controlled trial where older patients with AF are randomised to receive adjusted dose warfarin or aspirin. Patients will be followed up at three months post-randomisation, then at six monthly intervals there after for an average of three years by their general practitioner. Patients will also receive an annual health questionnaire. 1240 patients will be recruited from over 200 practices in England. Patients must be aged 75 years or over and have AF. Patients will be excluded if they have a history of any of the following conditions: rheumatic heart disease; major non-traumatic haemorrhage; intra-cranial haemorrhage; oesophageal varices; active endoscopically proven peptic ulcer disease; allergic hypersensitivity to warfarin or aspirin; or terminal illness. Patients will also be excluded if the GP considers that there are clinical reasons to treat a patient with warfarin in preference to aspirin (or vice versa. The primary end-point is fatal or non-fatal disabling stroke (ischaemic or haemorrhagic or significant arterial embolism. Secondary outcomes include major extra-cranial haemorrhage, death (all cause, vascular, hospital admissions (all cause, vascular, cognition, quality of life, disability and compliance with study medication.

In-hospital management and outcome of patients on warfarin undergoing coronary stent implantation: results of the multicenter, prospective WARfarin and coronary STENTing (WAR-STENT) registry.

Science.gov (United States)

Rubboli, Andrea; Sciahbasi, Alessandro; Briguori, Carlo; Saia, Francesco; Palmieri, Cataldo; Moroni, Luigi Andrea; Calabrò, Paolo; Leone, Antonio Maria; Franco, Nicoletta; Valgimigli, Marco; Varani, Elisabetta; Santi, Michela; Pasqualini, Paola; Capecchi, Alessandro; Piccalò, Giacomo; Margheri, Massimo; di Pasquale, Giuseppe; Galvani, Marcello; Bolognese, Leonardo; Gonzini, Lucio; Maggioni, Aldo Pietro

2013-04-01

The in-hospital management of patients on warfarin undergoing coronary stent implantation (PCI-S) is variable, and the in-hospital outcome incompletely defined. To determine the adherence to the current recommendations, and the incidence of adverse events, we carried out the prospective, multicenter, observational WARfarin and coronary STENTing (WAR-STENT) registry (ClinicalTrials.gov identifier NCT00722319). All consecutive patients on warfarin undergoing PCI-S at 37 Italian centers were enrolled and followed for 12 months. Outcome measures were: major adverse cardiovascular events (MACE), including cardiovascular death, non-fatal myocardial infarction, need for urgent revascularization, stroke, and venous thromboembolism, and major and minor bleeding. In this paper, we report the in-hospital findings. Out of the 411 patients enrolled, 92% were at non-low (ie, moderate or high) thromboembolic risk. The radial approach and bare-metal stents were used in 61% and 60% of cases, respectively. Drug-eluting stents were essentially reserved to patients with diabetes, which in turn, significantly predicted the implantation of drug-eluting stents (odds ratio [OR], 2.02; 95% confidence interval [CI], 1.29-3.17; P=.002). The in-hospital MACE and major bleeding rates were 2.7% and 2.1%, respectively. At discharge, triple therapy (TT) of warfarin, aspirin, and clopidogrel was prescribed to 76% of patients. Prescription of TT was significantly more frequent in the non-low thromboembolic risk group. Non-low thromboembolic risk, in turn, was a significant predictor of TT prescription (OR, 11.2; 95% CI, 4.83-26.3; P<.0001). In conclusion, real-world warfarin patients undergoing PCI-S are largely managed according to the current recommendations. As a consequence, the risk of in-hospital MACE and major bleedings appears limited and acceptable.

Comparison of Thromboemboli Prophylactic Effect of Aspirin and Low Dose Warfarin in Standard Risk Multiple Myeloma Patients that Treated with Regimens Containing Thalidomide

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Seyed Amir Dadkhahi

2017-05-01

Full Text Available Abstract Background: Most of the current regimens in the treatment of multiple myeloma include thalidomide. Thalidomide is a modulator of the immune system and according to several studies, its main complication is thromboembolism. The aim of this study is to compare the thromboemboli prophylactic effect of aspirin and low dose warfarin in standard risk multiple myeloma patients that treated with regimens containing thalidomide. Materials and Methods: In this double- blind clinical trial study, sixty-six patients with multiple myeloma under treatment with thalidomide-containing regimens with standard risk for thromboembolism who were admitted to Khansari hospital, entered the study according to inclusion and exclusion criteria. The incidence of thromboembolism in these patients was evaluated. Results: Five patients in the warfarin group and 2 patients in the aspirin group had thromboemboli. Chi square analyses showed no significant difference between groups (p=0.635. Conclusion: The results showed that both drugs are effective in preventing thromboembolism and can be used as a prophylactic treatment.

Influence of warfarin and low-dose aspirin on the outcomes of geriatric patients with traumatic intracranial hemorrhage resulting from ground-level fall.

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Inamasu, Joji; Nakatsukasa, Masashi; Miyatake, Satoru; Hirose, Yuichi

2012-10-01

Ground-level fall is the most common cause of traumatic intracranial hemorrhage (TICH) in the elderly, and is a major cause of morbidity and mortality in that population. A retrospective study was carried out to evaluate whether the use of warfarin/low-dose aspirin (LDA) is predictive of unfavorable outcomes in geriatric patients who sustain a fall-induced TICH. Charts of 76 geriatric patients (≥ 65 years-of-age) with fall-induced TICH were reviewed. The number of patients taking warfarin and LDA was 12 and 21, respectively, whereas the other 43 took neither medication (non-user group). The frequency of patients with unfavorable outcomes (Glasgow Outcome Scale score of 1-3) at discharge was calculated. Furthermore, variables predictive of unfavorable outcomes were identified by logistic regression analysis. The frequency of patients with unfavorable outcomes was 75% in the warfarin group, 33% in the LDA group and 27% in the non-user group, respectively. The risk of having unfavorable outcomes was significantly higher in the warfarin group compared with the LDA group (P = 0.03) and non-user group (P fall-induced TICH. The risk of TICH should be communicated properly to elderly taking warfarin. The information might be important not only to trauma surgeons who take care of injured elderly, but also to geriatric physicians who prescribe warfarin/LDA to them. © 2012 Japan Geriatrics Society.

Cost-effectiveness analysis of left atrial appendage occlusion compared with pharmacological strategies for stroke prevention in atrial fibrillation.

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Lee, Vivian Wing-Yan; Tsai, Ronald Bing-Ching; Chow, Ines Hang-Iao; Yan, Bryan Ping-Yen; Kaya, Mehmet Gungor; Park, Jai-Wun; Lam, Yat-Yin

2016-08-31

Transcatheter left atrial appendage occlusion (LAAO) is a promising therapy for stroke prophylaxis in non-valvular atrial fibrillation (NVAF) but its cost-effectiveness remains understudied. This study evaluated the cost-effectiveness of LAAO for stroke prophylaxis in NVAF. A Markov decision analytic model was used to compare the cost-effectiveness of LAAO with 7 pharmacological strategies: aspirin alone, clopidogrel plus aspirin, warfarin, dabigatran 110 mg, dabigatran 150 mg, apixaban, and rivaroxaban. Outcome measures included quality-adjusted life years (QALYs), lifetime costs and incremental cost-effectiveness ratios (ICERs). Base-case data were derived from ACTIVE, RE-LY, ARISTOTLE, ROCKET-AF, PROTECT-AF and PREVAIL trials. One-way sensitivity analysis varied by CHADS2 score, HAS-BLED score, time horizons, and LAAO costs; and probabilistic sensitivity analysis using 10,000 Monte Carlo simulations was conducted to assess parameter uncertainty. LAAO was considered cost-effective compared with aspirin, clopidogrel plus aspirin, and warfarin, with ICER of US$5,115, $2,447, and $6,298 per QALY gained, respectively. LAAO was dominant (i.e. less costly but more effective) compared to other strategies. Sensitivity analysis demonstrated favorable ICERs of LAAO against other strategies in varied CHADS2 score, HAS-BLED score, time horizons (5 to 15 years) and LAAO costs. LAAO was cost-effective in 86.24 % of 10,000 simulations using a threshold of US$50,000/QALY. Transcatheter LAAO is cost-effective for prevention of stroke in NVAF compared with 7 pharmacological strategies. The transcatheter left atrial appendage occlusion (LAAO) is considered cost-effective against the standard 7 oral pharmacological strategies including acetylsalicylic acid (ASA) alone, clopidogrel plus ASA, warfarin, dabigatran 110 mg, dabigatran 150 mg, apixaban, and rivaroxaban for stroke prophylaxis in non-valvular atrial fibrillation management.

ESPRIT: is aspirin plus dipyridamole superior to aspirin alone in TIA or minor stroke patients?

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Rouhl, R P W; Lodder, J

2008-11-01

Transient ischemic attack (TIA) or a (minor) ischemic stroke increases the risk of a recurrent stroke or death. Antiplatelet therapy with aspirin or clopidogrel is, in the absence of a potential cardiac embolic source, common practice to lower this risk. Until recently, adjuvant dipyridamole or low intensity oral anticoagulation were not generally prescribed in secondary prevention. In this article, we will summarize and discuss the published results of the European/Australasian Stroke Prevention in Reversible Ischemia Trial (ESPRIT). In this trial, treatments with anticoagulants, aspirin alone and the combination of aspirin plus dipyridamole were compared, in a multicenter, three-armed, randomized, open-label study in patients with TIA or minor stroke.

Mobile compression devices and aspirin for VTE prophylaxis following simultaneous bilateral total knee arthroplasty.

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Nam, Denis; Nunley, Ryan M; Johnson, Staci R; Keeney, James A; Barrack, Robert L

2015-03-01

Recently, Levy et al questioned the effectiveness of mobile compression devices (MCDs) as the sole method of thromboprophylaxis following simultaneous bilateral total knee arthroplasty (TKA). This study's purpose was to assess if the addition of aspirin to MCDs improves venous thromboembolism (VTE) prevention following simultaneous bilateral TKA. Ninety-six patients (192 TKAs) were retrospectively reviewed: 47 patients received MCDs for 10 days and aspirin for 6 weeks postoperatively based on a risk stratification protocol, while 49 patients received warfarin for 4 weeks postoperatively. One symptomatic VTE was noted in the warfarin cohort, while one patient in the MCD/aspirin cohort and three patients in the warfarin cohort were readmitted within 3 months of surgery. In appropriately selected patients, MCDs with aspirin shows promise in VTE prevention following simultaneous bilateral TKA. Copyright © 2014 Elsevier Inc. All rights reserved.

Safety and Efficacy of Warfarin Therapy in Kawasaki Disease.

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Baker, Annette L; Vanderpluym, Christina; Gauvreau, Kimberly A; Fulton, David R; de Ferranti, Sarah D; Friedman, Kevin G; Murray, Jenna M; Brown, Loren D; Almond, Christopher S; Evans-Langhorst, Margaret; Newburger, Jane W

2017-10-01

To describe the safety and efficacy of warfarin for patients with Kawasaki disease and giant coronary artery aneurysms (CAAs, ≥8 mm). Giant aneurysms are managed with combined anticoagulation and antiplatelet therapies, heightening risk of bleeding complications. We reviewed the time in therapeutic range; percentage of international normalization ratios (INRs) in range (%); bleeding events, clotting events; INRs ≥6; INRs ≥5 and warfarin therapy was 7.2 years (2.3-13.3 years). Goal INR was 2.0-3.0 (n = 6) or 2.5-3.5 (n = 3), based on CAA size and history of CAA thrombosis. All patients were treated with aspirin; 1 was on dual antiplatelet therapy and warfarin. The median time in therapeutic range was 59% (37%-85%), and median percentage of INRs in range was 68% (52%-87%). INR >6 occurred in 3 patients (4 events); INRs ≥5 warfarin and aspirin, with INRs in range only two-thirds of the time. Future studies should evaluate the use of direct oral anticoagulants in children as an alternative to warfarin. Copyright © 2017 Elsevier Inc. All rights reserved.

Efficacy And Safety of Dabigatran Etexilate Utilization With Concomitant Dual Antiplatelet Therapy In Atrial Fibrillation.

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Centurión Md PhD Facc, Osmar Antonio

2014-01-01

The necessity to add two antiplatelet agents to an oral anticoagulant (OAC) often arises in patients with atrial fibrillation (AF) in routine clinical practice. The majority of AF patients have an indication for continuous OAC, and coronary artery disease co-exists in 25% of these patients. The increasing use of drug-eluting stents to minimize intrastent restenosis necessitates long-term dual antiplatelet therapy with Aspirin plus Clopidogrel to reduce the risk of early and late stent thrombosis. Combined aspirin-clopidogrel therapy, however, is less effective in preventing stroke compared with OAC alone in AF patients, and OAC alone is insufficient to prevent stent thrombosis. The management of AF patients presenting with an acute coronary syndrome poses similar management complexities. Since AF and coronary artery disease with stent placement are common, it is relatively frequent to treat patients with both these conditions, where triple antithrombotic therapy with Aspirin, Clopidogrel and an OAC would be needed. Dabigatran etexilate, an oral direct thrombin inhibitor, has shown that compared with Warfarin given at a dose of 150 mg twice daily significantly reduces stroke with less intracranial bleeding, and at a dose of 110 mg twice daily has similar efficacy with less bleeding. Although, Dabigatran maintained its overall favorable profile compared with Warfarin in patients on dual antiplatelet therapy, we should always bear in mind for the sake of our AF patients that combining dual antiplatelet therapy with chronic anticoagulation with Dabigatran, as well as with Warfarin, significantly increases bleeding risk. This triple therapy association should be evaluated in the individual patient after carefully balancing bleeding versus thrombotic risk.

Prasugrel versus clopidogrel for patients with unstable angina or non-ST-segment elevation myocardial infarction with or without angiography

DEFF Research Database (Denmark)

Wiviott, Stephen D; White, Harvey D; Ohman, E Magnus

2013-01-01

Treatment with prasugrel and aspirin improves outcomes compared with clopidogrel and aspirin for patients with acute coronary syndrome who have had angiography and percutaneous coronary intervention; however, no clear benefit has been shown for patients managed first with drugs only. We assessed ...

Aspirin Does Not Increase Heart Failure Events in Heart Failure Patients: From the WARCEF Trial.

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Teerlink, John R; Qian, Min; Bello, Natalie A; Freudenberger, Ronald S; Levin, Bruce; Di Tullio, Marco R; Graham, Susan; Mann, Douglas L; Sacco, Ralph L; Mohr, J P; Lip, Gregory Y H; Labovitz, Arthur J; Lee, Seitetz C; Ponikowski, Piotr; Lok, Dirk J; Anker, Stefan D; Thompson, John L P; Homma, Shunichi

2017-08-01

The aim of this study was to determine whether aspirin increases heart failure (HF) hospitalization or death in patients with HF with reduced ejection fraction receiving an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB). Because of its cyclooxygenase inhibiting properties, aspirin has been postulated to increase HF events in patients treated with ACE inhibitors or ARBs. However, no large randomized trial has addressed the clinical relevance of this issue. We compared aspirin and warfarin for HF events (hospitalization, death, or both) in the 2,305 patients enrolled in the WARCEF (Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction) trial (98.6% on ACE inhibitor or ARB treatment), using conventional Cox models for time to first event (489 events). In addition, to examine multiple HF hospitalizations, we used 2 extended Cox models, a conditional model and a total time marginal model, in time to recurrent event analyses (1,078 events). After adjustment for baseline covariates, aspirin- and warfarin-treated patients did not differ in time to first HF event (adjusted hazard ratio: 0.87; 95% confidence interval: 0.72 to 1.04; p = 0.117) or first hospitalization alone (adjusted hazard ratio: 0.88; 95% confidence interval: 0.73 to 1.06; p = 0.168). The extended Cox models also found no significant differences in all HF events or in HF hospitalizations alone after adjustment for covariates. Among patients with HF with reduced ejection fraction in the WARCEF trial, there was no significant difference in risk of HF events between the aspirin and warfarin-treated patients. (Warfarin Versus Aspirin in Reduced Cardiac Ejection Fraction trial [WARCEF]; NCT00041938). Copyright © 2017 American College of Cardiology Foundation. All rights reserved.

Pharmacotherapy Evaluation and Utilization in Coronary Artery Bypass Grafting Patients in Kosovo during the Period 2016-2017

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Armond Daci

2018-03-01

CONCLUSION: The study showed that beta blockers, statins, aspirin, nitrates (before the operation, furosemide and spironolactone are the most utilized drugs. However, we found low utilization rate for ACEi, ARBs, clopidogrel, nadroparin, warfarin, xanthines, amiodarone, calcium blockers. Daily dosages were different compared to before CABG only in metoprolol, losartan, and furosemide.

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...

Relation between the Change in Mean Platelet Volume and Clopidogrel Resistance in Patients Undergoing Percutaneous Coronary Intervention.

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Koh, Young-Youp; Kim, Hyung Ho; Choi, Dong-Hyun; Lee, Young-Min; Ki, Young-Jae; Kang, Seong-Ho; Park, Geon; Chung, Joong-Wha; Chang, Kyong-Sig; Hong, Soon-Pyo

2015-01-01

We aimed to determine the association between the change in mean platelet volume (MPV) over time and aspirin/ clopidogrel resistance in patients undergoing percutaneous coronary intervention (PCI). The MPV and platelet function were analysed in 302 patients who underwent PCI. MPV changes were associated with increased aspirin reaction units (ARU, r = 0.114; P = 0.047), increased P2Y12 reaction units (PRU, r = 0.193; P = 0.001), and decreased P2Y12% inhibition (PI%, r = - 0.273; P resistant group (≥235 PRU or ≤15% of PI%) showed a significantly higher positive change in MPV (ΔMPV) values than the clopidogrel responder group (0.53 ± 0.78 vs. 0.13 ± 0.69 fL, P resistant and responder groups were 72.6% and 59.3%, respectively. After adjusting for traditional risk factors, the odds ratio in the clopidogrel resistant group with ΔMPV ≥0.2 fL was 4.10 (95% confidence interval; 1.84-9.17). In conclusion, ΔMPV was associated with PRU and PI%; a positive ΔMPV was an independent predictive marker for clopidogrel resistance after PCI.

Clopidogrel and proton pump inhibitors--where do we stand in 2012?

LENUS (Irish Health Repository)

Drepper, Michael D

2012-05-14

Clopidogrel in association with aspirine is considered state of the art of medical treatment for acute coronary syndrome by reducing the risk of new ischemic events. Concomitant treatment with proton pump inhibitors in order to prevent gastrointestinal side effects is recommended by clinical guidelines. Clopidogrel needs metabolic activation predominantly by the hepatic cytochrome P450 isoenzyme Cytochrome 2C19 (CYP2C19) and proton pump inhibitors (PPIs) are extensively metabolized by the CYP2C19 isoenzyme as well. Several pharmacodynamic studies investigating a potential clopidogrel-PPI interaction found a significant decrease of the clopidogrel platelet antiaggregation effect for omeprazole, but not for pantoprazole. Initial clinical cohort studies in 2009 reported an increased risk for adverse cardiovascular events, when under clopidogrel and PPI treatment at the same time. These observations led the United States Food and Drug Administration and the European Medecines Agency to discourage the combination of clopidogrel and PPI (especially omeprazole) in the same year. In contrast, more recent retrospective cohort studies including propensity score matching and the only existing randomized trial have not shown any difference concerning adverse cardiovascular events when concomitantly on clopidogrel and PPI or only on clopidogrel. Three meta-analyses report an inverse correlation between clopidogrel-PPI interaction and study quality, with high and moderate quality studies not reporting any association, rising concern about unmeasured confounders biasing the low quality studies. Thus, no definite evidence exists for an effect on mortality. Because PPI induced risk reduction clearly overweighs the possible adverse cardiovascular risk in patients with high risk of gastrointestinal bleeding, combination of clopidogrel with the less CYP2C19 inhibiting pantoprazole should be recommended.

Interaction study of aspirin or clopidogrel on pharmacokinetics of donepezil hydrochloride in rats by HPLC-fluorescence detection.

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Wada, Mitsuhiro; Nishiwaki, Junichiro; Yamane, Tomoko; Ohwaki, Yuichi; Aboul-Enein, Hassan Y; Nakashima, Kenichiro

2007-06-01

The present study aims to investigate the possibility of interaction of aspirin (Asp) or clopidogrel (CG) on donepezil (DP) hydrochloride in rats by HPLC-fluorescence detection. The separation of DP was achieved in ca. 13 min without interference of Asp and CG on the chromatogram. DP levels in rat plasma with a single administration of DP (5 mg/kg, i.p., group I) and those with a co-administration of Asp (200 mg/kg, p.o., group II or 200 mg/kg, i.p., group III) or CG (5 mg/kg, p.o., group IV) were monitored. The DP concentrations determined in rat plasma ranged from 25.0 to 336.1 ng/mL. Pharmacokinetic parameters for these groups were calculated and compared with one another. No significant difference was observed on the comparison of group I with other groups except for the mean resident time of group IV (p = 0.012). These basic findings may help clinical inference when DP is co-administered with Asp and CG to human. Copyright 2007 John Wiley & Sons, Ltd.

Selective and rapid monitoring of dual platelet inhibition by aspirin and P2Y12 antagonists by using multiple electrode aggregometry

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Lorenz Reinhard

2010-05-01

Full Text Available Abstract Background Poor platelet inhibition by aspirin or clopidogrel has been associated with adverse outcomes in patients with cardiovascular diseases. A reliable and facile assay to measure platelet inhibition after treatment with aspirin and a P2Y12 antagonist is lacking. Multiple electrode aggregometry (MEA, which is being increasingly used in clinical studies, is sensitive to platelet inhibition by aspirin and clopidogrel, but a critical evaluation of MEA monitoring of dual anti-platelet therapy with aspirin and P2Y12 antagonists is missing. Design and Methods By performing in vitro and ex vivo experiments, we evaluated in healthy subjects the feasibility of using MEA to monitor platelet inhibition of P2Y12 antagonists (clopidogrel in vivo, cangrelor in vitro and aspirin (100 mg per day in vivo, and 1 mM or 5.4 mM in vitro alone, and in combination. Statistical analyses were performed by the Mann-Whitney rank sum test, student' t-test, analysis of variance followed by the Holm-Sidak test, where appropriate. Results ADP-induced platelet aggregation in hirudin-anticoagulated blood was inhibited by 99.3 ± 1.4% by in vitro addition of cangrelor (100 nM; p 95% and 100 ± 3.2%, respectively (p in vitro or ex vivo. Oral intake of clopidogrel did not significantly reduce AA-induced aggregation, but P2Y12 blockade by cangrelor (100 nM in vitro diminished AA-stimulated aggregation by 53 ± 26% (p Conclusions Selective platelet inhibition by aspirin and P2Y12 antagonists alone and in combination can be rapidly measured by MEA. We suggest that dual anti-platelet therapy with these two types of anti-platelet drugs can be optimized individually by measuring platelet responsiveness to ADP and AA with MEA before and after drug intake.

Effect of Co-Administration of Rivaroxaban and Clopidogrel on Bleeding Time, Pharmacodynamics and Pharmacokinetics: A Phase I Study

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Michael Becka

2012-02-01

Full Text Available Dual antiplatelet therapy with acetylsalicylic acid and a thienopyridine, such as clopidogrel, is effective for the secondary prevention of cardiovascular events in patients with acute coronary syndrome, but there is still a substantial residual risk of recurrence. Although anticoagulant therapy with a vitamin K antagonist (e.g. warfarin in conjunction with antiplatelet therapy has been shown to reduce the risk of cardiovascular events, the rates of bleeding were increased with these combination therapies; hence, triple therapy with warfarin is currently only recommended in patients at low risk of bleeding. In addition, there are other limitations associated with vitamin K antagonist therapy, including the need for routine coagulation monitoring and dose adjustment to maintain the treatment within the therapeutic range. Rivaroxaban is an oral, direct Factor Xa inhibitor; in clinical practice, it is likely that rivaroxaban will be given to patients who also receive antiplatelet therapy, such as clopidogrel. This randomized, non-blinded, three-way crossover study investigated the effect of rivaroxaban on bleeding time when co­administered with clopidogrel. In addition, the influence of clopidogrel on the safety, tolerability, pharmacodynamics and pharmacokinetics of rivaroxaban was investigated. Of 27 healthy male subjects who received a single 300 mg dose of clopidogrel, 14 were identified as clopidogrel responders and were then randomized to the following three treatments: (A two doses of clopidogrel on two consecutive days (300 mg on day 1; 75 mg on day 2; (B one dose of rivaroxaban (15 mg; or (C a combination of treatments A and B (rivaroxaban given on day 2. All treatments were well tolerated. Bleeding time with co­administration of rivaroxaban and clopidogrel was significantly prolonged in four subjects, compared with either drug alone: combination treatment increased the overall least squares-means to 3.77 times baseline (90% confidence

Edoxaban Plus Aspirin vs Dual Antiplatelet Therapy in Endovascular Treatment of Patients With Peripheral Artery Disease: Results of the ePAD Trial.

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Moll, Frans; Baumgartner, Iris; Jaff, Michael; Nwachuku, Chuke; Tangelder, Marco; Ansel, Gary; Adams, George; Zeller, Thomas; Rundback, John; Grosso, Michael; Lin, Min; Mercur, Michele F; Minar, Erich

2018-04-01

To report a randomized study that investigated the safety (risk of major bleeds) and potential efficacy of edoxaban, an oral anticoagulant that targets the major components of arterial thrombi, to prevent loss of patency following endovascular treatment (EVT). Between February 2012 and June 2014, 203 patients who underwent femoropopliteal EVT were randomized to receive aspirin plus edoxaban or aspirin plus clopidogrel for 3 months in the Edoxaban in Peripheral Arterial Disease (ePAD) study ( ClinicalTrials.gov identifier NCT01802775). Randomization assigned 101 patients (mean age 68.0±10.4 years; 67 men) to the edoxaban group and 102 patients (mean age 66.7±8.6 years; 78 men) to the clopidogrel group. The primary safety endpoint was bleeding as classified by the TIMI (Thrombolysis in Myocardial Infarction) criteria and ISTH (International Society of Thrombosis and Hemostasis) criteria; the efficacy endpoint was the rate of restenosis/reocclusion. There were no major or life-threatening bleeding events in the edoxaban group, while there were 2 major and 2 life-threatening bleeding events in the clopidogrel group by the TIMI criteria. By the ISTH classification, there was 1 major and 1 life-threatening bleeding event vs 5 major and 2 life-threatening bleeding events, respectively [relative risk (RR) 0.20, 95% confidence interval (CI) 0.02 to 1.70]. The bleeding risk was not statistically different with either treatment when assessed by TIMI or ISTH. Following 6 months of observation, there was a lower incidence of restenosis/reocclusion with edoxaban compared with clopidogrel (30.9% vs 34.7%; RR 0.89, 95% CI 0.59 to 1.34, p=0.643). These results suggest that patients who have undergone EVT have similar risks for major and life-threatening bleeding events with edoxaban and aspirin compared with clopidogrel and aspirin. The incidence of restenosis/reocclusion events, while not statistically different, was lower with edoxaban and aspirin, but an adequately sized trial

Prevalence and risk factors of clopidogrel non-response among Saudi patients undergoing coronary angiography

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Haitham I. Sakr

2016-02-01

Full Text Available Objectives: To estimate the prevalence of clopidogrel non-response and identify its risk factors among Saudi patients. Methods: This cross-sectional study was conducted at Prince Sultan Cardiac Center, Riyadh, Kingdom of Saudi Arabia between January and June 2013, to assess the degree of platelet inhibition using the VerifyNow assay (Accumetrics, San Diego, CA, USA after receiving clopidogrel standard loading dose. Clopidogrel resistance was defined as ≤15% platelet inhibition or greater than 213 P2Y12 reaction units (PRU. Results: Three hundred and four patients were included in the study. The mean age was 60.3 ± 11.4 years, and 73% were males. Clopidogrel doses were 300 mg (57%, 600 mg (27%, and 75 mg (16%. All patients used aspirin (81 mg in 94%. Approximately 66% (200/304 showed in vitro clopidogrel non-response, 54% had low platelet inhibitions, and 61% had high post-loading PRU. Using multivariate regression analysis that included all significant characteristics; only diabetes (odds ratio [OR]: 2.36, 95% confidence interval [CI]: 1.30-4.27, p=0.005 and higher preloading PRU (OR: 2.39, 95% CI: 1.40-4.11, p=0.002 remained significantly associated with higher clopidogrel non-response while myocardial infarction (OR: 0.34, 95% CI: 0.15-0.81, p=0.014 remained significantly associated with lower clopidogrel non-response. The associations of morbid obesity and diuretics use with higher clopidogrel non-response were slightly attenuated. Conclusion: Our findings indicate a high rate of clopidogrel in-vitro non-response among Saudi patients undergoing coronary angiography.

Study design and rationale of a comparison of prasugrel and clopidogrel in medically managed patients with unstable angina/non-ST-segment elevation myocardial infarction: the TaRgeted platelet Inhibition to cLarify the Optimal strateGy to medicallY manage Acute Coronary Syndromes (TRILOGY ACS

DEFF Research Database (Denmark)

Chin, Chee Tang; Roe, Matthew T; Fox, Keith A A

2010-01-01

Practice guidelines recommend dual antiplatelet therapy with aspirin and clopidogrel for patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) regardless of in-hospital management strategy. Prasugrel-a thienopyridine adenosine diphosphate receptor antagonist that provides...... higher and less variable levels of platelet inhibition than clopidogrel-has demonstrated benefit when used to treat ACS patients undergoing percutaneous coronary intervention. However, the optimal approach to antiplatelet therapy for high-risk, medically managed NSTE ACS patients remains uncertain...... revascularization procedures for their index event. Patients will be randomly allocated to prasugrel + aspirin versus clopidogrel + aspirin for a median duration of 18 months. A reduction in the maintenance dose of prasugrel for elderly patients (age >or=75 years) and those with body weight or=75 years). TRILOGY...

Stability Indicating RP-HPLC Method for Simultaneous Determination of Aspirin and Clopidrogel in Dosage Form

International Nuclear Information System (INIS)

Mohd Gousuddin; Sengupta, P.; Tripathi, V.D.; Das, A.

2016-01-01

Stability-indicating High Performance Liquid Chromatographic (HPLC) method was developed for simultaneous Aspirin and Clopidogrel, A Phenomenex Gemini C-18, 5 μm column having 250 mm x 4.6 mm i.d. in isocratic mode, with mobile phase containing buffer solution 0.3 % orthophosphoric acid : acetonitrile (65:35, v/v). The flow rate was 1 ml/ min and effluents were monitored at 266 nm. For linearity seven points calibration curve were obtained in a concentration range from 0.030-0.120 mg/ ml for aspirin and 0.015-0.060 mg/ ml for clopidogrel with correlation coefficient 0.9999. In the present study stability indicating HPLC method for the combination was tested by degrading the drugs together under various stress conditions like acid hydrolysis, base hydrolysis, oxidation, thermal and photolytic stress which is recommended by ICH guideline. (author)

Dual antiplatelet therapy in patients with aspirin resistance following coronary artery bypass grafting: study protocol for a randomized controlled trial [NCT01159639

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Gasparovic Hrvoje

2012-08-01

Full Text Available Abstract Background Coronary artery disease remains the dominant cause of mortality in developed countries. While platelets have been recognized to play a pivotal role in atherothrombosis, the ideal antiplatelet regime after coronary artery surgery remains elusive. The evolution of CABG has presently moved beyond technical improvements to involve modulation of pharmacologic management designed to improve patient outcomes. The aim of this trial will be to test the hypothesis that the addition of clopidogrel to patients with documented postoperative aspirin resistance will reduce the incidence of major cardiovascular events. Methods Patients scheduled for isolated coronary artery surgery will be eligible for the study. Patients in whom postoperative multiple electrode aggregometry documents aspirin resistance will be randomized into two groups. The control group will receive 300 mg of aspirin. The dual antiplatelet group will receive 75 mg of clopidogrel in addition to 300 mg of aspirin. Patients will be followed for 6 months. Major adverse cardiac and cerebrovascular events (death from any cause, myocardial infarction, stroke, hospitalization due to cardiovascular pathology as well as bleeding events will be recorded. Discussion This will be the first trial that will specifically address the issue of dual antiplatelet therapy in patients undergoing coronary artery surgery who have been found to be aspirin resistant. In the event that the addition of clopidogrel proves to be beneficial in this subset of surgical patients, this study could significantly impact their future antiplatelet management. This randomized controlled trial has been registered at the ClinicalTrials.gov website (Identifier NCT01159639.

Drug Resistance and Pseudoresistance: An Unintended Consequence of Enteric Coating Aspirin

Science.gov (United States)

Grosser, Tilo; Fries, Susanne; Lawson, John A.; Kapoor, Shiv C.; Grant, Gregory R.; FitzGerald, Garret A.

2013-01-01

Background Low dose aspirin reduces the secondary incidence of myocardial infarction and stroke. Drug resistance to aspirin might result in treatment failure. Despite this concern, no clear definition of “aspirin resistance” has emerged and estimates of its incidence have varied remarkably. We aimed to determine the commonality of a mechanistically consistent, stable and specific phenotype of true pharmacological resistance to aspirin – such as might be explained by genetic causes. Methods and Results Healthy volunteers (n=400) were screened for their response to a single oral dose of 325 mg immediate release or enteric coated aspirin. Response parameters reflected the activity of aspirin's molecular target, cyclooxygenase-1. Individuals who appeared “aspirin resistant” on one occasion underwent repeat testing and if still “resistant” were exposed to low dose enteric coated aspirin (81 mg) and clopidogrel (75 mg) for one week each. Variable absorption caused a high frequency of apparent resistance to a single dose of 325 mg enteric coated aspirin (up to 49%) but not to immediate release aspirin (0%). All individuals responded to aspirin upon repeated exposure, extension of the post dosing interval or addition of aspirin to their platelets ex vivo. Conclusions Pharmacological resistance to aspirin is rare; this study failed to identify a single case of true drug resistance. Pseudoresistance, reflecting delayed and reduced drug absorption, complicates enteric coated but not immediate release aspirin administration. Clinical Trial Registration Information clinicaltrials.gov. Identifier: NCT00948987. PMID:23212718

A review of antithrombotic therapy and the rationale and design of the randomized edoxaban in patients with peripheral artery disease (ePAD) trial adding edoxaban or clopidogrel to aspirin after femoropopliteal endovascular intervention.

Science.gov (United States)

Tangelder, Marco J D; Nwachuku, Chuke E; Jaff, Michael; Baumgartner, Iris; Duggal, Anil; Adams, George; Ansel, Gary; Grosso, Michael; Mercuri, Michele; Shi, Minggao; Minar, Erich; Moll, Frans L

2015-04-01

Compared with the coronary setting, knowledge about antithrombotic therapies after endovascular treatment (EVT) is inadequate in patients with peripheral artery disease (PAD). Based on a review of trials and guidelines, which is summarized in this article, there is scant evidence that antithrombotic drugs improve outcome after peripheral EVT. To address this knowledge gap, the randomized, open-label, multinational edoxaban in patients with Peripheral Artery Disease (ePAD) study (ClinicalTrials.gov identifier NCT01802775) was designed to explore the safety and efficacy of a combined regimen of antiplatelet therapy with clopidogrel and anticoagulation with edoxaban, a selective and direct factor Xa inhibitor, both combined with aspirin. As of July 2014, 203 patients (144 men; mean age 67 years) from 7 countries have been enrolled. These patients have been allocated to once-daily edoxaban [60 mg for 3 months (or 30 mg in the presence of factors associated with increased exposure)] or clopidogrel (75 mg/d for 3 months). All patients received aspirin (100 mg/d) for the 6-month duration of the study. The primary safety endpoint is major or clinically relevant nonmajor bleeding; the primary efficacy endpoint is restenosis or reocclusion at the treated segment(s) measured at 1, 3, and 6 months using duplex ultrasound scanning. All outcomes will be assessed and adjudicated centrally in a masked fashion. The ePAD study is the first of its kind to investigate a combined regimen of antiplatelet therapy and anticoagulation through factor Xa inhibition with edoxaban. © The Author(s) 2015.

Biopsy of the prostate guided by transrectal ultrasound: relation between warfarin use and incidence of bleeding complications

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Ihezue, C.U. [Department of Radiology, Southampton General Hospital (United Kingdom); Smart, J. [Department of Radiology, Southampton General Hospital (United Kingdom); Dewbury, K.C. [Department of Radiology, Southampton General Hospital (United Kingdom)]. E-mail: keith.dewbury@suht.swest.nhs.uk; Mehta, R. [Department of Radiology, Southampton General Hospital (United Kingdom); Burgess, L. [Department of Radiology, Southampton General Hospital (United Kingdom)

2005-04-01

AIM: To determine the relation between warfarin use and the frequency of bleeding complications after biopsy of the prostate guided by transrectal ultrasound (TRUS). METHODS: Overall, 1022 consecutive patients with suspected prostatic disease were followed after biopsy. Warfarin and aspirin use was determined on the day of the procedure. A TRUS-guided biopsy was performed and patients were offered a questionnaire to complete 10 days after the procedure, to determine any immediate or delayed bleeding complications. Follow-up telephone calls were made to those who had not replied within the stipulated period. RESULTS: Of the 1000 patients who replied, 49 were receiving warfarin, 220 were receiving aspirin and 731 were not receiving any anticoagulant drugs. Of the 49 subjects reporting current use of warfarin, 18 (36.7%) experienced haematuria, compared with 440 (60.2%) of the patients receiving no anti-coagulant drugs who reported haematuria. This was statistically significant (p=0.001). Of the group receiving warfarin, 4 (8.2%) experienced haematospermia whereas 153 (21%) of the group receiving no anticoagulant medication reported haematospermia. This difference also was statistically significant (p=0.030). Rectal bleeding was experienced by 7 (14.3%) of the group receiving warfarin compared with 95 (13%) in the group without anticoagulant medication, but this was not statistically significant (p=0.80). We also demonstrated that there was no statistically significant association between the severity of the bleeding complications and medication with warfarin. CONCLUSION: None of the group receiving warfarin experienced clinically important bleeding complications. Our results suggest that the frequency and severity of bleeding complications were no worse in the warfarin group than in the control group and that discontinuing anticoagulation medication before prostate biopsy may be unnecessary.

Biopsy of the prostate guided by transrectal ultrasound: relation between warfarin use and incidence of bleeding complications

International Nuclear Information System (INIS)

Ihezue, C.U.; Smart, J.; Dewbury, K.C.; Mehta, R.; Burgess, L.

2005-01-01

AIM: To determine the relation between warfarin use and the frequency of bleeding complications after biopsy of the prostate guided by transrectal ultrasound (TRUS). METHODS: Overall, 1022 consecutive patients with suspected prostatic disease were followed after biopsy. Warfarin and aspirin use was determined on the day of the procedure. A TRUS-guided biopsy was performed and patients were offered a questionnaire to complete 10 days after the procedure, to determine any immediate or delayed bleeding complications. Follow-up telephone calls were made to those who had not replied within the stipulated period. RESULTS: Of the 1000 patients who replied, 49 were receiving warfarin, 220 were receiving aspirin and 731 were not receiving any anticoagulant drugs. Of the 49 subjects reporting current use of warfarin, 18 (36.7%) experienced haematuria, compared with 440 (60.2%) of the patients receiving no anti-coagulant drugs who reported haematuria. This was statistically significant (p=0.001). Of the group receiving warfarin, 4 (8.2%) experienced haematospermia whereas 153 (21%) of the group receiving no anticoagulant medication reported haematospermia. This difference also was statistically significant (p=0.030). Rectal bleeding was experienced by 7 (14.3%) of the group receiving warfarin compared with 95 (13%) in the group without anticoagulant medication, but this was not statistically significant (p=0.80). We also demonstrated that there was no statistically significant association between the severity of the bleeding complications and medication with warfarin. CONCLUSION: None of the group receiving warfarin experienced clinically important bleeding complications. Our results suggest that the frequency and severity of bleeding complications were no worse in the warfarin group than in the control group and that discontinuing anticoagulation medication before prostate biopsy may be unnecessary

Effects of ticagrelor versus clopidogrel on platelet function in fibrinolytic-treated STEMI patients undergoing early PCI.

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Dehghani, Payam; Lavoie, Andrea; Lavi, Shahar; Crawford, Jennifer J; Harenberg, Sebastian; Zimmermann, Rodney H; Booker, Jeff; Kelly, Sheila; Cantor, Warren J; Mehta, Shamir R; Bagai, Akshay; Goodman, Shaun G; Cheema, Asim N

2017-10-01

Patients undergoing PCI early after fibrinolytic therapy are at high risk for both thrombotic and bleeding complications. We sought to assess the pharmacodynamic effects of ticagrelor versus clopidogrel in the fibrinolytic-treated STEMI patients undergoing early PCI. Patients undergoing PCI within 24 hours of tenecteplase (TNK), aspirin, and clopidogrel for STEMI were randomized to receive additional clopidogrel 300 mg followed by 75 mg daily or ticagrelor 180 mg followed by 90 mg twice daily. The platelet reactivity units (PRU) were measured with the VerifyNow Assay before study drug administration (baseline) at 4 and 24 hours post-PCI. The primary end point was PRU ≤208 at 4 hours. A total of 140 patients (74 in ticagrelor and 66 in clopidogrel group) were enrolled. The mean PRU values at baseline were similar for the 2 groups (257.8±52.9 vs 259.5±56.7, P=.85, respectively). Post-PCI, patients on ticagrelor, compared to those on clopidogrel, had significantly lower PRU at 4 hours (78.7±88 vs 193.6±86.5, respectively, PPCI frequently had PRU >208. In this high-risk population, ticagrelor provides more prompt and potent platelet inhibition compared with clopidogrel (Funded by Astra Zeneca; NCT01930591, https://clinicaltrials.gov/ct2/show/NCT01930591). Copyright © 2017 Elsevier Inc. All rights reserved.

Warfarin improves the outcome of infrainguinal vein bypass grafting at high risk for failure.

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Sarac, T P; Huber, T S; Back, M R; Ozaki, C K; Carlton, L M; Flynn, T C; Seeger, J M

1998-09-01

Patients with marginal venous conduit, poor arterial runoff, and prior failed bypass grafts are at high risk for infrainguinal graft occlusion and limb loss. We sought to evaluate the effects of anticoagulation therapy after autogenous vein infrainguinal revascularization on duration of patency, limb salvage rates, and complication rates in this subset of patients. This randomized prospective trial was performed in a university tertiary care hospital and in a Veterans Affairs Hospital. Fifty-six patients who were at high risk for graft failure were randomized to receive aspirin (24 patients, 27 bypass grafts) or aspirin and warfarin (WAR; 32 patients, 37 bypass grafts). All patients received 325 mg of aspirin each day, and the patients who were randomized to warfarin underwent anticoagulation therapy with heparin immediately after surgery and then were started on warfarin therapy to maintain an international normalized ratio between 2 and 3. Perioperative blood transfusions and complications were compared with the Student t test or with the chi2 test. Graft patency rates, limb salvage rates, and survival rates were compared with the Kaplan-Meier method and the log-rank test. Sixty-one of the 64 bypass grafts were performed for rest pain or tissue loss, and 3 were performed for short-distance claudication. There were no differences between the groups in ages, indications, bypass graft types, risk classifications (ie, conduit, runoff, or graft failure), or comorbid conditions (except diabetes mellitus). The cumulative 5-year survival rate was similar between the groups. The incidence rate of postoperative hematoma (32% vs 3.7%; P = .004) was greater in the WAR group, but no differences were seen between the WAR group and the aspirin group in the number of packed red blood cells transfused, in the incidence rate of overall nonhemorrhagic wound complications, or in the overall complication rate (62% vs 52%). The immediate postoperative primary graft patency rates (97

Clopidogrel is not associated with major bleeding complications during peripheral arterial surgery.

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Stone, David H; Goodney, Philip P; Schanzer, Andres; Nolan, Brian W; Adams, Julie E; Powell, Richard J; Walsh, Daniel B; Cronenwett, Jack L

2011-09-01

Persistent variation in practice surrounds preoperative clopidogrel management at the time of vascular surgery. While some surgeons preferentially discontinue clopidogrel citing a perceived risk of perioperative bleeding, others will proceed with surgery in patients taking clopidogrel for an appropriate indication. The purpose of this study was to determine whether preoperative clopidogrel use was associated with significant bleeding complications during peripheral arterial surgery. We reviewed a prospective regional vascular surgery registry recorded by 66 surgeons from 15 centers in New England from 2003 to 2009. Preoperative clopidogrel use within 48 hours of surgery was analyzed among patients undergoing carotid endarterectomy (CEA), lower extremity bypass (LEB), endovascular abdominal aortic aneurysm repair (EVAR), and open abdominal aortic aneurysm repair (oAAA). Ruptured AAAs were excluded. Endpoints included postoperative bleeding requiring reoperation, as well as the incidence and volume of blood transfusion. Statistical analysis was performed using analysis of variance, Fisher exact, χ(2), and Wilcoxon rank-sum tests. Over the study interval, a total of 10,406 patients underwent surgery, including 5264 CEA, 2883 LEB, 1125 EVAR, and 1134 oAAA repair. Antiplatelet use among all patients varied, with 19% (n = 2010) taking no antiplatelet agents, 69% (n = 7132) taking aspirin (ASA) alone, 2.2% (n = 229) taking clopidogrel alone, and 9.7% (n = 1017) taking both ASA and clopidogrel. Clopidogrel alone or as dual antiplatelet therapy was most frequently used prior to CEA and least frequently prior to oAAA group (CEA 16.1%, LEB 9.0%, EVAR 6.5%, oAAA 5%). Reoperation for bleeding was not significantly different among patients based on antiplatelet regimen (none 1.5%, ASA 1.3%, clopidogrel 0.9%, ASA/clopidogrel 1.5%, P = .74). When analyzed by operation type, no difference in reoperation for bleeding was seen across antiplatelet regimens. There was also no

Perioperative clopidogrel is associated with increased bleeding and blood transfusion at the time of lower extremity bypass.

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Jones, Douglas W; Schermerhorn, Marc L; Brooke, Benjamin S; Conrad, Mark F; Goodney, Philip P; Wyers, Mark C; Stone, David H

2017-06-01

Controversy persists surrounding the perceived bleeding risk associated with perioperative clopidogrel use in patients undergoing lower extremity bypass (LEB). The purpose of this study was to examine the LEB bleeding risk and clinical sequelae associated with clopidogrel. All LEBs in the Vascular Quality Initiative (VQI) from 2008 to 2014 were studied. The exposure was perioperative clopidogrel. Primary outcomes were blood transfusion, estimated blood loss ≥500 mL, and reoperation for bleeding. Secondary outcomes included mean operative time, major cardiac events, respiratory complications, infectious complications, and in-hospital mortality. Univariate and multivariable analyses were used to analyze patients on the basis of clopidogrel use and its association with outcomes. Nonparametric test for trend and Mantel-Haenszel methods were used to analyze association of clopidogrel use with blood transfusion and secondary outcomes. Among the LEB cohort (N = 9179), 28% (n = 2544) were taking clopidogrel and 72% (n = 6635) were not. Patients taking clopidogrel were more likely to have coronary disease, prior coronary intervention, abnormal findings on stress test, and aspirin use (P blood transfusion (38% vs 24%; P blood loss ≥500 mL (21% vs 12%; P blood transfusion (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.5-2.1; P 2-unit blood transfusion (OR, 2.0; 95% CI, 1.7-2.5; P blood transfusion amount revealed no remaining effect of clopidogrel on major cardiac events (OR, 1.1; P = .4) or respiratory complications (OR, 1.0; P = .8). Perioperative clopidogrel use in LEB surgery is associated with increased blood loss and blood transfusion. Associated clinical sequelae include increased cardiac and pulmonary complications. Accordingly, surgeons should consider discontinuation of perioperative clopidogrel when it is clinically appropriate unless it is strongly indicated at the time of LEB. Copyright © 2017 Society for Vascular Surgery. Published by

Pharmacokinetic drug interactions with clopidogrel: updated review and risk management in combination therapy

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Wang ZY

2015-03-01

Full Text Available Zhi-Yu Wang,1 Meng Chen,1 Ling-Ling Zhu,2 Lu-Shan Yu,3 Su Zeng,3 Mei-Xiang Xiang,4 Quan Zhou1 1Department of Pharmacy, 2VIP Care Ward, Division of Nursing, the Second Affiliated Hospital, School of Medicine, 3Department of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences, 4Department of Cardiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, People’s Republic of China Background: Coprescribing of clopidogrel and other drugs is common. Available reviews have addressed the drug–drug interactions (DDIs when clopidogrel is as an object drug, or focused on combination use of clopidogrel and a special class of drugs. Clinicians may still be ignorant of those DDIs when clopidogrel is a precipitant drug, the factors determining the degree of DDIs, and corresponding risk management.Methods: A literature search was performed using PubMed, MEDLINE, Web of Science, and the Cochrane Library to analyze the pharmacokinetic DDIs of clopidogrel and new P2Y12 receptor inhibitors.Results: Clopidogrel affects the pharmacokinetics of cerivastatin, repaglinide, ferulic acid, sibutramine, efavirenz, and omeprazole. Low efficacy of clopidogrel is anticipated in the presence of omeprazole, esomeprazole, morphine, grapefruit juice, scutellarin, fluoxetine, azole antifungals, calcium channel blockers, sulfonylureas, and ritonavir. Augmented antiplatelet effects are anticipated when clopidogrel is coprescribed with aspirin, curcumin, cyclosporin, St John’s wort, rifampicin, and angiotensin-converting enzyme inhibitors. The factors determining the degree of DDIs with clopidogrel include genetic status (eg, cytochrome P540 [CYP]2B6*6, CYP2C19 polymorphism, CYP3A5*3, CYP3A4*1G, and CYP1A2-163C>A, species differences, and dose strength. The DDI risk does not exhibit a class effect, eg, the effects of clopidogrel on cerivastatin versus other statins, the effects of proton pump

Concomitant nitrates enhance clopidogrel response during dual anti-platelet therapy.

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Lee, Dong Hyun; Kim, Moo Hyun; Guo, Long Zhe; De Jin, Cai; Cho, Young Rak; Park, Kyungil; Park, Jong Sung; Park, Tae-Ho; Serebruany, Victor

2016-01-15

Despite advances in modern anti-platelet strategies, clopidogrel still remains the cornerstone of dual anti-platelet therapy (DAPT) in patients undergoing percutaneous coronary interventions (PCI). There is some inconclusive evidence that response after clopidogrel may be impacted by concomitant medications, potentially affecting clinical outcomes. Sustained released nitrates (SRN) are commonly used together with clopidogrel in post-PCI setting for mild vasodilatation and nitric oxide-induced platelet inhibition. We prospectively enrolled 458 patients (64.5 ± 9.6 years old, and 73.4% males) following PCI undergoing DAPT with clopidogrel and aspirin. Platelet reactivity was assessed by the VerifyNow™ P2Y12 assay at the maintenance outpatient setting. Concomitant SRN (n=266) significantly (p=0.008) enhanced platelet inhibition after DAPT (251.6 ± 80.9PRU) when compared (232.1 ± 73.5PRU) to the SRN-free (n=192) patients. Multivariate logistic regression analysis with the cut-off value of 253 PRU for defining heightened platelet reactivity confirmed independent correlation of more potent platelet inhibition during DAPT and use of SRN (Relative risk=1.675; Odds ratio [1.059-2.648]; p=0.027). In contrast, statins, calcium-channel blockers, beta blockers, angiotensin receptor blockers, ACE-inhibitors, diuretics, and anti-diabetic agents did not significantly impact platelet inhibition following DAPT. The synergic ability of SRN to enhance response during DAPT may have important clinical implications with regard to better cardiovascular protection, but extra bleeding risks, requiring further confirmation in a large randomized study. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Impact of genetic polymorphisms on clinical response to antithrombotics

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Kena J Lanham

2010-06-01

Full Text Available Kena J Lanham1,2, Julie H Oestreich3, Steven P Dunn1,2, Steven R Steinhubl41Pharmacy Services, UK HealthCare, University of Kentucky, Lexington, Kentucky, USA; 2Department of Pharmacy Practice and Science, College of Pharmacy, University of Kentucky, Lexington, Kentucky, USA; 3Department of Pharmacy Practice, College of Pharmacy, University of Nebraska, Omaha, Nebraska, USA; 4The Medicines Company, Zurich, Switzerland and The Geisinger Clinic, Danville, Pennsylvania, USAAbstract: Antithrombotic therapy, including anticoagulants as well as antiplatelet drugs, is an important component in the treatment of cardiovascular disease. Variability in response to such medications, of which pharmacogenetic response is a major source, can decrease or enhance the benefits expected. This review is a comprehensive assessment of the literature published to date on the effects of genetic polymorphisms on the actions of a variety of antithrombotic medications, including warfarin, clopidogrel, prasugrel, and aspirin. Literature evaluating surrogate markers in addition to the impact of pharmacogenetics on clinical outcomes has been reviewed. The results of the studies are conflicting as to what degree pharmacogenetics will affect medication management in cardiovascular disease. Additional research is necessary to discover, characterize, and prospectively evaluate genetic and non-genetic factors that impact antithrombotic treatment in order to maximize the effectiveness and limit the harmful effects of these valuable agents.Keywords: aspirin, warfarin, clopidogrel, prasugrel, pharmacogenetic, antithrombotic, antiplatelet

Warfarin and fibrinolysis - a challenging combination: an observational cohort study

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Luurila Harri

2011-04-01

Full Text Available Abstract Background Patients presenting with ST-segment elevation myocardial infarction (STEMI frequently use warfarin. Fibrinolytic agents and warfarin both increase bleeding risk, but only a few studies have been published concerning the bleeding risk of warfarin-prescribed patients receiving fibrinolysis. The objective of this study was to define the prevalence for intracranial haemorrhage (ICH or major bleeding in patients on warfarin treatment receiving pre-hospital fibrinolysis. Methods This was an observational cohort study. Data for this retrospective case series were collected in Helsinki Emergency Medical Service catchment area from 1.1.1997 to 30.6.2010. All warfarin patients with suspected ST-segment elevation myocardial infarction (STEMI, who received pre-hospital fibrinolysis, were included. Bleeding complications were detected from Medical Records and classified as ICH, major or minor bleeding. Results Thirty-six warfarin patients received fibrinolysis during the study period. Fourteen patients had bleeding complications. One (3%, 95% CI 0-15% patient had ICH, six (17%, 95% CI 7-32% had major and seven (19%, 95% CI 9-35% had minor bleeding. The only fatal bleeding occurred in a patient with ICH. Patients' age, fibrinolytic agent used or aspirin use did not predispose to bleeding complications. High International Normalized Ratio (INR seemed to predispose to bleedings with values over 3, but no statistically significant difference was found. Conclusions Bleedings occur frequently in warfarin patients treated with fibrinolysis in the real world setting, but they are rarely fatal.

Safety and Efficacy of Acute Clopidogrel Load in Patients with Moderate and Severe Ischemic Strokes

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Amir Shaban

2016-01-01

Full Text Available Objective. To study the safety and efficacy of a clopidogrel loading dose in patients with moderate and severe acute ischemic strokes. Background. The safety of clopidogrel loading has been extensively investigated in patients with minor strokes and transient ischemic attacks. Methods. Acute ischemic stroke patients presenting consecutively to our center from 07/01/08 to 07/31/13 were screened. Clopidogrel loading was defined as at least 300 mg dose (with or without aspirin given within 6 hours of admission. We compared outcomes in patients with baseline NIHSS > 3 with and without clopidogrel loading. Results. Inclusion criteria were met for 1011 patients (43.6% females, 69.1% black, median age 63. Patients with clopidogrel loading had lower baseline NIHSS than patients who were not loaded (8 versus 9, p=0.005. The two groups had similar risk for hemorrhagic transformation (p=0.918 and symptomatic hemorrhage (p=0.599. Patients who were loaded had a lower rate of neurological worsening (38.9% versus 48.3%, p=0.031 and less in-hospital mortality (4.3% versus 13.4%, p=0.001 compared to those who were not loaded. The likelihood of having a poor functional outcome did not differ between the two groups after adjusting for NIHSS on admission (OR = 0.71, 95% CI 0.4633–1.0906, p=0.118. Conclusion. Clopidogrel loading dose was not associated with increased risk for hemorrhagic transformation or symptomatic intracranial hemorrhage in our retrospective study and was associated with reduced rates of neuroworsening following moderate and severe stroke.

Dramatic Vascular Course of Behcet's Disease

International Nuclear Information System (INIS)

Elsharawy, Mohamed A.; Hassan, Khairi A.; Al-Awami, Majed; Al-Mulhim, Fatma A.

2004-01-01

Vascular involvement in Behcet's disease is rare (approximately 14% venous and 1.6% arterial), serious and recurrent. We report a case of Behcet's disease with deep venous thrombosis and right iliac pseudoaneurysm which was repaired with polytetrafluoroethylene (PTFE) graft. The patient received warfarin, aspirin, clopidogrel, immunosupressive and corticosteroids. Two months later the patient developed manifestations of superior vena cava thrombosis and the graft was blocked. Three months later, ischemia of the right foot deteriorated and left femoral artery crossover (PTFE) graft was performed. (author)

Genetics Home Reference: clopidogrel resistance

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... Facebook Twitter Home Health Conditions Clopidogrel resistance Clopidogrel resistance Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Clopidogrel resistance is a condition in which the drug clopidogrel ...

Platelet aggregation according to body mass index in patients undergoing coronary stenting: should clopidogrel loading-dose be weight adjusted?

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Angiolillo, Dominick J; Fernández-Ortiz, Antonio; Bernardo, Esther; Barrera Ramírez, Carlos; Sabaté, Manel; Fernandez, Cristina; Hernández-Antolín, Rosana; Escaned, Javier; Alfonso, Fernando; Macaya, Carlos

2004-04-01

A 300 mg clopidogrel loading-dose (LD) is widely used as an adjunct antithrombotic treatment to reduce the risk of thrombotic events early after coronary stenting (CS). Antithrombotic drugs commonly used during percutaneous coronary interventions, such as heparin and platelet glycoprotein IIb/IIIa inhibitors, but not clopidogrel LD, are weight-adjusted, and few data are available on which is the most effective clopidogrel LD regimen. The aim of this study was to assess whether body mass index (BMI) influenced platelet response to clopidogrel LD in patients undergoing CS. Adenosine diphosphate (ADP)-induced platelet aggregation (PA) was assessed by light transmittance aggregometry in 48 patients on aspirin treatment undergoing CS receiving a 300 mg clopidogrel LD at intervention time. PA was assessed at baseline and up to 24 hours after intervention. Patients were divided into 2 groups according to BMI: overweight (BMI greater than or equal to 25 kg/m2; 29 patients) and normal weight (BMI<25 kg/m2; 19 patients). PA was significantly higher in overweight than in normal weight patients at baseline (60.1+/-18.6%; versus 47.6+/-13.5%; p=0.01), at 24 hours (42.3+/-18.4% versus 38.5+/-18.3%; p=0.02) and during the overall study time (p=0.025). Percentage of inhibition of PA 24 hours following clopidogrel LD was suboptimal (<40%) in 59% and 26% of overweight and normal weight patients, respectively (p=0.04). An elevated BMI was the only independent predictor of suboptimal platelet response. These data suggest that overweight patients may need a higher loading-dose of clopidogrel and/or an adjunct antithrombotic treatment to adequately inhibit platelet aggregation early after CS.

PlA polymorphism and platelet reactivity following clopidogrel loading dose in patients undergoing coronary stent implantation.

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Angiolillo, Dominick J; Fernandez-Ortiz, Antonio; Bernardo, Esther; Alfonso, Fernando; Sabaté, Manel; Fernández, Cristina; Stranieri, Chiara; Trabetti, Elisabetta; Pignatti, Pier Franco; Macaya, Carlos

2004-01-01

The PlA polymorphism (Leu33Pro) of the platelet glycoprotein (GP) IIIa gene has been suggested to play an important role in coronary thrombosis. In vitro studies have shown differences for this polymorphism in platelet sensitivity towards antiplatelet drugs (aspirin and abciximab), suggesting a pharmacogenetic modulation. The aim of the study was to assess the modulatory effect of the PlA polymorphism on clopidogrel-induced antiplatelet effects in 38 patients undergoing coronary stent implantation receiving a 300 mg clopidogrel loading-dose. Platelet reactivity was assessed as GPIIb/IIIa activation and P-selectin expression in platelets stimulated with 2 micromol/l adenosine diphosphate using whole blood flow cytometry. The distribution of the homozygous PlA1/A1 and heterozygous PlA1/A2 genotypes were 74 and 26%, respectively. PlA2 carriers had a higher degree of GPIIb/IIIa activation (P = 0.05) and P-selectin expression (P = 0.02) during the overall study time course and a lower antiplatelet effect to a 300 mg clopidogrel loading-dose up to 24 h following intervention (P < 0.05). In conclusion, the Pl polymorphism of the GPIIIa gene modulates platelet reactivity towards clopidogrel front loading in patients undergoing coronary stenting. This suggests the need for individualized antithrombotic regimens to optimally inhibit platelet reactivity. Copyright 2004 Lippincott Williams and Wilkins

New oral anticoagulant and antiplatelet agents for neurosurgeons.

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Kimpton, George; Dabbous, Bassam; Leach, Paul

2015-01-01

Until recently, warfarin, clopidogrel and aspirin have provided the mainstay for prevention of thrombotic disease in cardiac patients. However, new classes of drugs have recently emerged that promise better clinical outcomes and lower risks. Use of such agents has increased, but increased risk and severity of intra-cranial haemorrhage (ICH) still remain. These cases of intra-cranial bleeds present as emergencies to neurosurgical units. It is of paramount importance that neurosurgical practitioners are aware of those new drugs, useful monitoring tests and available emergency reversal options in case the patient needs emergency intervention. In this review we survey newly available agents in the U.K. at the time of publication. We look at the data provided by the manufacturers, related publications and international guidelines for their use and reversal. New anticoagulants offer a lower incidence of ICH compared with warfarin. Advanced and accurate monitoring tests are emerging, as are prospective data on reversal of anticoagulation in bleeding. Some standard coagulation tests may be of use, whilst reversal agents are available and being evaluated. The trial data shows that new antiplatelet agents have similar or increased incidence and severity of intra-cranial ICH compared with clopidogrel. There is currently limited data on monitoring or reversal. We suggest they may be managed similarly to clopidogrel by using platelet reactivity assays, optimising platelet count and using platelet transfusion with adjunctive agents.

Prasugrel but not high dose clopidogrel overcomes the lansoprazole neutralizing effect of P2Y12 inhibition: Results of the randomized DOSAPI study.

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Collet, Jean-Philippe; Hulot, Jean-Sébastien; Abtan, Jérémie; Anzaha, Ghalia; Kerneis, Mathieu; Silvain, Johanne; Cayla, Guillaume; O'Connor, Stephen A; Barthélémy, Olivier; Beygui, Farzin; Galier, Sophie; Brugier, Delphine; Stanek, Eric J; Charland, Scott L; Gallois, Vanessa; Montalescot, Gilles

2014-09-01

The potential negative metabolic interaction between proton pump inhibitors and clopidogrel is an unsolved issue. We hypothesized that doubling the clopidogrel maintenance dose (150 mg) would be less effective than switching to prasugrel 10 mg maintenance dose (MD) to overcome this negative interaction. In a randomized study with a factorial design, 82 stable coronary artery disease patients treated with 75 mg clopidogrel MD and aspirin were assigned to receive in a double blind fashion lansoprazole (30 mg/day) or placebo and to receive in an open fashion 150 mg clopidogrel MD or 10 mg prasugrel MD. The primary endpoint was the relative change in residual platelet reactivity over the 14-day study period [(RPA14day-RPAbaseline)/RPAbaseline]. The effect of doubling the clopidogrel MD on relative change in RPA was neutralized by lansoprazole (-53.6±48.4% versus +0.8±53.7% without and with lansoprazole, respectively, p = 0.02) whereas 10 mg of prasugrel MD dramatically reduced RPA irrespective of lansoprazole co-administration (-81.8 %±24.8% vs. -72.9%±32.9% without and with lansoprazole, respectively, p = NS). Lansoprazole exposure was the only parameter with a significant interaction with RPA among subgroups. The higher platelet inhibitory effect obtained by doubling the clopidogrel MD was totally neutralized by the co-administration of lansoprazole. This drug interaction was not observed with prasugrel 10 mg.

Antithrombotic Utilization Trends after Noncardioembolic Ischemic Stroke or TIA in the Setting of Large Antithrombotic Trials (2002–2009)

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Khan, Amir S.; Qureshi, Adnan I.

2015-01-01

Background and Purpose Several large trials published over the last decade have significantly altered recommended guidelines for therapy following a noncardioembolic ischemic stroke or transient ischemic attack (TIA). The impact of these studies on patient usage of alternative antithrombotic agents has hitherto not been evaluated. We examined the usage of these agents in the United States over the last decade, with regard to the publication of the Management of Atherothrombosis with Clopidogrel in High-Risk Patients (MATCH), European/Australasian Stroke Prevention in Reversible Ischaemia Trial (ESPRIT), and Prevention Regimen for Effectively Avoiding Second Strokes (PRoFESS) clinical trials, in order to test the hypothesis that resulting recommendations are reflected in usage trends. Methods Antithrombotic utilization was prospectively collected as part of the National Ambulatory Medical Care Survey (NAMCS) on a total of 53,608,351 patients in the United States between 2002 and 2009. Patients with a history of ischemic stroke or TIA were included. Patients were excluded if there was a prior history of subarachnoid or intracerebral hemorrhage, or if other indications for antithrombotic treatment were present, including deep venous thrombosis, pulmonary embolism, atrial fibrillation or flutter, mechanical cardiac valve replacement, congestive heart failure, coronary artery disease, peripheral arterial disease, and rheumatoid arthritis. Annual utilization of the following antithrombotic strategies was compared in 53,608,351 patients: 1) aspirin monotherapy, 2) clopidogrel monotherapy, 3) combined clopidogrel and aspirin, 4) combined extended-release dipyridamole (ERDP) and aspirin, and 5) warfarin. Annual utilization was compared before and after publication of MATCH, ESPRIT, and PRoFESS in 2004, 2006, and 2008, respectively. Trend analysis was performed with the Mantel–Haenszel test for trends. Sensitivity analysis of demographic and clinical characteristics

Clopidogrel reloading for patients with acute myocardial infarction already on clopidogrel therapy.

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Doll, Jacob A; Li, Shuang; Chiswell, Karen; Roe, Matthew T; Kosiborod, Mikhail; Scirica, Benjamin M; Wang, Tracy Y

2018-01-14

We sought to determine the association of clopidogrel reloading with in-hospital bleeding and mortality in contemporary practice. We examined clopidogrel reloading for ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) patients on pre-admission clopidogrel therapy in the ACTION Registry-GWTG from 2009 to 2014. We used inverse probability weighted propensity adjustment to compare in-hospital mortality and major bleeding risks between patients reloaded in the first 24 h with ≥300 mg of clopidogrel vs. those continued on a maintenance (therapy who were admitted with STEMI, 9369 (75.8%) received a loading dose. Of 39 158 patients with NSTEMI, 10 144 (25.9%) were reloaded. Reloaded patients were younger, had fewer comorbid conditions, and were more likely to be treated with primary PCI (STEMI) or an early invasive strategy (NSTEMI). Risks of major bleeding were not significantly different between patients with and without reloading, whether presenting with STEMI (OR 0.98, 95% CI 0.85-1.13) or NSTEMI (OR 1.00, 95% CI 0.90-1.11). Among STEMI patients, clopidogrel reloading was associated with lower risks of in-hospital mortality (OR 0.80, 95% CI 0.66-0.96), however no significant mortality difference was observed among NSTEMI patients (OR 1.13, 95% CI 0.93-1.37). Clopidogrel reloading occurs frequently among MI patients who are on pre-admission clopidogrel therapy, particularly among STEMI patients. We did not observe increased bleeding or mortality risk with clopidogrel reloading, and therefore reloading could be safe for most MI patients. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Dual Antithrombotic Therapy with Dabigatran after PCI in Atrial Fibrillation.

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Cannon, Christopher P; Bhatt, Deepak L; Oldgren, Jonas; Lip, Gregory Y H; Ellis, Stephen G; Kimura, Takeshi; Maeng, Michael; Merkely, Bela; Zeymer, Uwe; Gropper, Savion; Nordaby, Matias; Kleine, Eva; Harper, Ruth; Manassie, Jenny; Januzzi, James L; Ten Berg, Jurrien M; Steg, P Gabriel; Hohnloser, Stefan H

2017-10-19

Triple antithrombotic therapy with warfarin plus two antiplatelet agents is the standard of care after percutaneous coronary intervention (PCI) for patients with atrial fibrillation, but this therapy is associated with a high risk of bleeding. In this multicenter trial, we randomly assigned 2725 patients with atrial fibrillation who had undergone PCI to triple therapy with warfarin plus a P2Y 12 inhibitor (clopidogrel or ticagrelor) and aspirin (for 1 to 3 months) (triple-therapy group) or dual therapy with dabigatran (110 mg or 150 mg twice daily) plus a P2Y 12 inhibitor (clopidogrel or ticagrelor) and no aspirin (110-mg and 150-mg dual-therapy groups). Outside the United States, elderly patients (≥80 years of age; ≥70 years of age in Japan) were randomly assigned to the 110-mg dual-therapy group or the triple-therapy group. The primary end point was a major or clinically relevant nonmajor bleeding event during follow-up (mean follow-up, 14 months). The trial also tested for the noninferiority of dual therapy with dabigatran (both doses combined) to triple therapy with warfarin with respect to the incidence of a composite efficacy end point of thromboembolic events (myocardial infarction, stroke, or systemic embolism), death, or unplanned revascularization. The incidence of the primary end point was 15.4% in the 110-mg dual-therapy group as compared with 26.9% in the triple-therapy group (hazard ratio, 0.52; 95% confidence interval [CI], 0.42 to 0.63; Pdual-therapy group as compared with 25.7% in the corresponding triple-therapy group, which did not include elderly patients outside the United States (hazard ratio, 0.72; 95% CI, 0.58 to 0.88; Pdual-therapy groups combined as compared with 13.4% in the triple-therapy group (hazard ratio, 1.04; 95% CI, 0.84 to 1.29; P=0.005 for noninferiority). The rate of serious adverse events did not differ significantly among the groups. Among patients with atrial fibrillation who had undergone PCI, the risk of bleeding was

The difference in association between aspirin use and other thrombocyte aggregation inhibitors and survival in patients with colorectal cancer.

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Frouws, M A; Rademaker, E; Bastiaannet, E; van Herk-Sukel, M P P; Lemmens, V E; Van de Velde, C J H; Portielje, J E A; Liefers, G J

2017-05-01

Several studies have suggested that the association between aspirin and improved cancer survival is mediated through the mechanism of aspirin as thrombocyte aggregation inhibitors (TAI). The aim of this study was to provide epidemiological evidence for this mechanism assessing the association between overall survival and the use of aspirin and non-aspirin TAI in patients with colorectal cancer. In this observational study, data from the Netherlands Comprehensive Cancer Organisation were linked to PHARMO Database Network. Patients using aspirin or aspirin in combination with non-aspirin TAI (dual users) were selected and compared with non-users. The association between overall survival and the use of (non-)aspirin TAI was analysed using Cox regression models with the use of (non-)aspirin TAI as a time-varying covariate. In total, 9196 patients were identified with colorectal cancer and 1766 patients used TAI after diagnosis. Non-aspirin TAI were mostly clopidogrel and dipyridamole. Aspirin use was associated with a significant increased overall survival and hazard ratio (HR) 0.41 (95% confidence interval [CI] 0.37-0.47), and the use of non-aspirin TAI was not associated with survival of HR 0.92 (95% CI 0.70-1.22). Dual users did not have an improved overall survival when compared with patients using solely aspirin. Aspirin use after diagnosis of colorectal cancer was associated with significantly lower mortality rates and this effect remained significant after adjusting for potential confounders. No additional survival benefit was observed in patients using both aspirin and another TAI. Copyright © 2017 Elsevier Ltd. All rights reserved.

Proton pump inhibitor use and risk of adverse cardiovascular events in aspirin treated patients with first time myocardial infarction: nationwide propensity score matched study

DEFF Research Database (Denmark)

Charlot, Mette; Grove, Erik; Hansen, Peter Riis

2011-01-01

: All aspirin treated patients surviving 30 days after a first myocardial infarction from 1997 to 2006, with follow-up for one year. Patients treated with clopidogrel were excluded. MAIN OUTCOME MEASURES: The risk of the combined end point of cardiovascular death, myocardial infarction, or stroke...... associated with use of proton pump inhibitors was analysed using Kaplan-Meier analysis, Cox proportional hazard models, and propensity score matched Cox proportional hazard models. Results 3366 of 19 925 (16.9%) aspirin treated patients experienced recurrent myocardial infarction, stroke, or cardiovascular...

Bleeding Risk with Long-Term Low-Dose Aspirin: A Systematic Review of Observational Studies

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García Rodríguez, Luis A.; Martín-Pérez, Mar; Hennekens, Charles H.; Rothwell, Peter M.; Lanas, Angel

2016-01-01

Background Low-dose aspirin has proven effectiveness in secondary and primary prevention of cardiovascular events, but is also associated with an increased risk of major bleeding events. For primary prevention, this absolute risk must be carefully weighed against the benefits of aspirin; such assessments are currently limited by a lack of data from general populations. Methods Systematic searches of Medline and Embase were conducted to identify observational studies published between 1946 and 4 March 2015 that reported the risks of gastrointestinal (GI) bleeding or intracranial hemorrhage (ICH) with long-term, low-dose aspirin (75–325 mg/day). Pooled estimates of the relative risk (RR) for bleeding events with aspirin versus non-use were calculated using random-effects models, based on reported estimates of RR (including odds ratios, hazard ratios, incidence rate ratios and standardized incidence ratios) in 39 articles. Findings The incidence of GI bleeding with low-dose aspirin was 0.48–3.64 cases per 1000 person-years, and the overall pooled estimate of the RR with low-dose aspirin was 1.4 (95% confidence interval [CI]: 1.2–1.7). For upper and lower GI bleeding, the RRs with low-dose aspirin were 2.3 (2.0–2.6) and 1.8 (1.1–3.0), respectively. Neither aspirin dose nor duration of use had consistent effects on RRs for upper GI bleeding. The estimated RR for ICH with low-dose aspirin was 1.4 (1.2–1.7) overall. Aspirin was associated with increased bleeding risks when combined with non-steroidal anti-inflammatory drugs, clopidogrel and selective serotonin reuptake inhibitors compared with monotherapy. By contrast, concomitant use of proton pump inhibitors decreased upper GI bleeding risks relative to aspirin monotherapy. Conclusions The risks of major bleeding with low-dose aspirin in real-world settings are of a similar magnitude to those reported in randomized trials. These data will help inform clinical judgements regarding the use of low-dose aspirin

Assessment of platelet function in healthy cats in response to commonly prescribed antiplatelet drugs using three point-of-care platelet function tests.

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Ho, Kimberly K; Abrams-Ogg, Anthony Cg; Wood, R Darren; O'Sullivan, M Lynne; Kirby, Gordon M; Blois, Shauna L

2017-06-01

Objectives The objective was to determine if decreased platelet function could be detected after treatment with aspirin and/or clopidogrel in healthy cats using three point-of-care platelet function tests that evaluate platelet function by different methods: Multiplate (by impedance), Platelet Function Analyzer 100 (by mechanical aperture closure) and Plateletworks (by platelet counting). Methods Thirty-six healthy cats were randomly assigned to receive one of three oral treatments over an 8 day period: (1) aspirin 5 mg q72h; (2) aspirin 20.25 mg q72h; or (3) clopidogrel 18.75 mg q24h. Cats treated with 5 and 20.25 mg aspirin also received clopidogrel on days 4-8. Platelet aggregation in response to adenosine diphosphate and collagen ± arachidonic acid was assessed on days 1 (baseline), 4 and 8. Aspirin and clopidogrel metabolites were measured by high-performance liquid chromatography. Platelet function in response to treatment was analyzed by ANCOVA, linear regression and Spearman correlation. Results The only solitary aspirin effect was detected using Plateletworks with collagen in cats treated with 20.25 mg. The only effect detected by Multiplate was using arachidonic acid in cats treated with both aspirin 20.25 mg and clopidogrel. All clopidogrel treatment effects were detected by Platelet Function Analyzer 100, Plateletworks (adenosine diphosphate) and Plateletworks (collagen). Drug metabolites were present in all cats, but concentrations were minimally correlated to platelet function test results. Conclusions and relevance Platelet Function Analyzer 100 and Plateletworks using adenosine diphosphate ± collagen agonists may be used to detect decreased platelet function in response to clopidogrel treatment. Either aspirin is not as effective an antiplatelet drug as clopidogrel, or the tests used were not optimal to measure aspirin effect. Cats with heart disease are commonly prescribed antiplatelet drugs to decrease the risk of aortic thromboembolism

Is aspirin still the drug of choice for management of patients with peripheral arterial disease?

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Poredos, Pavel; Jezovnik, Mateja K

2013-03-01

Antiplatelet drugs represent one of the basic options for management of patients with different atherosclerotic diseases. Aspirin is the oldest and most often prescribed antiplatelet drug. The efficacy of aspirin depends on the clinical characteristics of the treated population and probably also on the type or location of atherosclerotic disease. It seems that it is most effective in coronary patients with clinically unstable disease, less effective in prevention of cerebrovascular incidents, and its efficacy is uncertain in peripheral artery disease (PAD) patients. One of the first meta-analyses (Antithrombotic Trialists' Collaboration - ATC) indicated that antiplatelet drugs also significantly reduce cardiovascular events in patients with PAD. However, only one third of the PAD patients included were treated with aspirin, while the rest received other anti-platelet drugs. The latest ATC meta-analysis of randomized control trials of aspirin therapy involving patients with diabetes and PAD demonstrated no benefit of aspirin in reducing cardiovascular events. Also in patients with preclinical PAD (pathological ankle brachial index) aspirin did not result in a significant reduction of vascular events. The new anti-platelet drugs prasugrel, ticagrelor and picotamide seem to be more effective than aspirin in PAD patients, particularly in diabetic patients with PAD. In conclusion, antiplatelet drugs are effective in prevention of cardiovascular events in different atherosclerotic diseases, including PAD. However, recent studies indicated that in PAD patients aspirin is less effective than in coronary artery disease. New anti-platelet drugs showed marginal superiority over aspirin without definite advantages. Aspirin thus remains the first line of antiplatelet drug for secondary prevention of cardiovascular events in PAD patients and clopidogrel as its effective alternative. Further, new studies on PAD patients are necessary to better define the role of anti

Aspirin for the prevention of recurrent venous thromboembolism: the INSPIRE collaboration.

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Simes, John; Becattini, Cecilia; Agnelli, Giancarlo; Eikelboom, John W; Kirby, Adrienne C; Mister, Rebecca; Prandoni, Paolo; Brighton, Timothy A

2014-09-23

In patients with a first unprovoked venous thromboembolism (VTE) the risk of recurrent VTE remains high after anticoagulant treatment is discontinued. The Aspirin for the Prevention of Recurrent Venous Thromboembolism (the Warfarin and Aspirin [WARFASA]) and the Aspirin to Prevent Recurrent Venous Thromboembolism (ASPIRE) trials showed that aspirin reduces this risk, but they were not individually powered to detect treatment effects for particular outcomes or subgroups. An individual patient data analysis of these trials was planned, before their results were known, to assess the effect of aspirin versus placebo on recurrent VTE, major vascular events (recurrent VTE, myocardial infarction, stroke, and cardiovascular disease death) and bleeding, overall and within predefined subgroups. The primary analysis, for VTE, was by intention to treat using time-to-event data. Of 1224 patients, 193 had recurrent VTE over 30.4 months' median follow-up. Aspirin reduced recurrent VTE (7.5%/yr versus 5.1%/yr; hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.51-0.90; P=0.008), including both deep-vein thrombosis (HR, 0.66; 95% CI, 0.47-0.92; P=0.01) and pulmonary embolism (HR, 0.66; 95% CI, 0.41-1.06; P=0.08). Aspirin reduced major vascular events (8.7%/yr versus 5.7%/yr; HR, 0.66; 95% CI, 0.50-0.86; P=0.002). The major bleeding rate was low (0.4%/yr for placebo and 0.5%/yr for aspirin). After adjustment for treatment adherence, recurrent VTE was reduced by 42% (HR, 0.58; 95% CI, 0.40-0.85; P=0.005). Prespecified subgroup analyses indicate similar relative, but larger absolute, risk reductions in men and older patients. Aspirin after anticoagulant treatment reduces the overall risk of recurrence by more than a third in a broad cross-section of patients with a first unprovoked VTE, without significantly increasing the risk of bleeding. www.anzctr.org.au. Unique identifier: ACTRN12611000684921. © 2014 American Heart Association, Inc.

Warfarin use and the risk of mortality, stroke, and bleeding in hemodialysis patients with atrial fibrillation.

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Kai, Brandon; Bogorad, Yuliya; Nguyen, Leigh-Anh N; Yang, Su-Jau; Chen, Wansu; Spencer, Hillard T; Shen, Albert Y-J; Lee, Ming-Sum

2017-05-01

The optimal management of stroke prophylaxis in hemodialysis patients with atrial fibrillation is controversial. The purpose of this study was to determine the risk of mortality, stroke, and bleeding associated with the use of warfarin in hemodialysis patients with atrial fibrillation. This was a retrospective, population-based study of hemodialysis patients with atrial fibrillation between January 1, 2006, and September 30, 2015. Association of warfarin use with mortality, stroke, and bleeding was determined by propensity score-matched, Cox proportional hazard models. Among the 4286 patients with atrial fibrillation on hemodialysis, 989 (23%) were prescribed warfarin. Propensity score matching was used to identify 888 matched pairs with similar baseline characteristics. Warfarin use was associated with lower risk of all-cause death (hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.69-0.84) and lower risk of ischemic stroke (HR 0.68, 95% CI 0.52-0.91). Warfarin use was not associated with a higher risk of hemorrhagic stroke (HR 1.2, 95% CI 0.6-2.2) or gastrointestinal bleeding (HR 0.97, 95% CI 0.77-1.2). The treatment effect was largest in the group with the best international normalized ratio control as measured by time in therapeutic range. Subgroup analyses showed warfarin use was associated with survival benefit in most subgroups. The 2 subgroups that did not benefit were patients with a history of hemorrhagic stroke and patients with concurrent aspirin use. Warfarin use is associated with lower all-cause mortality and ischemic stroke, without significantly increasing the risk of bleeding in hemodialysis patients with atrial fibrillation. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Combining aspirin with angiotensin converting enzyme inhibitors in heart failure: how safe is it?

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Mehta, H; Mahajan, A; Bansal, N; Vaidya, S; Pathak, L

1998-11-01

The above discussion on the interaction of aspirin and ACE inhibitors seems to suggest that aspirin in high doses may have adverse interaction with ACE inhibitors in patients with heart failure but the data obtained is not sufficient or conclusive to recommended omission of aspirin in patients with heart failure. This raises a query in the mind of the physician whether to use a combination or not? The role of aspirin in the early period after myocardial infarction is well established so is the role of ACE inhibitors. Hence in patients with myocardial infarction and preserved left ventricular function it would not be wrong to administer combination of ACE inhibitors and aspirin. Albeit at a lower dose. In patients with large myocardial infarction or heart failure, warfarin may be an option but still needs to be documented in large trials. As suggested long term use of aspirin after infarction is still ambiguous and may be harmful in patients with heart failure with its anticedent side effects. But long term benefits of ACE inhibitors in heart failure are well documented. Hence if a choice has to be made whether to discontinue either of the two drugs it would be preferable to stop the aspirin. To answer the issue of use of aspirin in patients with heart failure it would be essential to conduct a double blind randomized trial comparing known anti-thrombotic treatment, aspirin and anti-coagulants on mortality in patients with heart failure, especially caused by coronary artery disease. Such a trial is underway at the present and till the results are available it should be left to clinical judgement of the physician whether to administer aspirin in patients with heart failure after weighing the benefits versus risk.

The importance of bioequivalence study: focus on clopidogrel

Directory of Open Access Journals (Sweden)

Arini Setiawati

2011-05-01

Full Text Available Bioequivalence (BE study is required to show whether a generic copy product can be interchangeable with the brand innovator product. The aim of this article is to provide the rationale for conducting BE studies, the main products requiring BE studies, the design and conduct of BE studies in general, with focus on clopidogrel. All of the clopidogrel generic products in Indonesia have been shown to be BE to the innovator product Plavix® and they contain API (active pharmaceutical ingredient clopidogrel form 1 that complies with USP 30, 1997 requirements: the R-enantiomer content is not more than 1%. A proof that bioequivalence (BE means therapeutic equivalence (TE is also provided for cardiovascular drugs. Clopidogrel has 2 polymorphic forms, form 1 and form 2, which have the same indications. At least one pivotal study of clopidogrel, CAPRIE, used clopidogrel form 1. An atherothrombotic event may be associated with clopidogrel resistance, which occur in about 4 to 30% of patients treated with conventional doses of clopidogrel. (Med J Indones 2011; 20:149-53Keywords: bioequivalent, clopidogrel

Apixaban versus warfarin in patients with atrial fibrillation.

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Granger, Christopher B; Alexander, John H; McMurray, John J V; Lopes, Renato D; Hylek, Elaine M; Hanna, Michael; Al-Khalidi, Hussein R; Ansell, Jack; Atar, Dan; Avezum, Alvaro; Bahit, M Cecilia; Diaz, Rafael; Easton, J Donald; Ezekowitz, Justin A; Flaker, Greg; Garcia, David; Geraldes, Margarida; Gersh, Bernard J; Golitsyn, Sergey; Goto, Shinya; Hermosillo, Antonio G; Hohnloser, Stefan H; Horowitz, John; Mohan, Puneet; Jansky, Petr; Lewis, Basil S; Lopez-Sendon, Jose Luis; Pais, Prem; Parkhomenko, Alexander; Verheugt, Freek W A; Zhu, Jun; Wallentin, Lars

2011-09-15

Vitamin K antagonists are highly effective in preventing stroke in patients with atrial fibrillation but have several limitations. Apixaban is a novel oral direct factor Xa inhibitor that has been shown to reduce the risk of stroke in a similar population in comparison with aspirin. In this randomized, double-blind trial, we compared apixaban (at a dose of 5 mg twice daily) with warfarin (target international normalized ratio, 2.0 to 3.0) in 18,201 patients with atrial fibrillation and at least one additional risk factor for stroke. The primary outcome was ischemic or hemorrhagic stroke or systemic embolism. The trial was designed to test for noninferiority, with key secondary objectives of testing for superiority with respect to the primary outcome and to the rates of major bleeding and death from any cause. The median duration of follow-up was 1.8 years. The rate of the primary outcome was 1.27% per year in the apixaban group, as compared with 1.60% per year in the warfarin group (hazard ratio with apixaban, 0.79; 95% confidence interval [CI], 0.66 to 0.95; P<0.001 for noninferiority; P=0.01 for superiority). The rate of major bleeding was 2.13% per year in the apixaban group, as compared with 3.09% per year in the warfarin group (hazard ratio, 0.69; 95% CI, 0.60 to 0.80; P<0.001), and the rates of death from any cause were 3.52% and 3.94%, respectively (hazard ratio, 0.89; 95% CI, 0.80 to 0.99; P=0.047). The rate of hemorrhagic stroke was 0.24% per year in the apixaban group, as compared with 0.47% per year in the warfarin group (hazard ratio, 0.51; 95% CI, 0.35 to 0.75; P<0.001), and the rate of ischemic or uncertain type of stroke was 0.97% per year in the apixaban group and 1.05% per year in the warfarin group (hazard ratio, 0.92; 95% CI, 0.74 to 1.13; P=0.42). In patients with atrial fibrillation, apixaban was superior to warfarin in preventing stroke or systemic embolism, caused less bleeding, and resulted in lower mortality. (Funded by Bristol-Myers Squibb

Antiplatelet Regimen for Patients With Breakthrough Strokes While on Aspirin: A Systematic Review and Meta-Analysis.

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Lee, Meng; Saver, Jeffrey L; Hong, Keun-Sik; Rao, Neal M; Wu, Yi-Ling; Ovbiagele, Bruce

2017-09-01

Optimal antiplatelet therapy after an ischemic stroke or transient ischemic attack while on aspirin is uncertain. We, therefore, conducted a systematic review and meta-analysis. We searched PubMed (1966 to August 2016) and bibliographies of relevant published original studies to identify randomized trials and cohort studies reporting patients who were on aspirin at the time of an index ischemic stroke or transient ischemic attack and reported hazard ratio for major adverse cardiovascular events or recurrent stroke associated with a switch to or addition of another antiplatelet agent versus maintaining aspirin monotherapy. Estimates were combined using a random effects model. Five studies with 8723 patients with ischemic stroke or transient ischemic attack were identified. Clopidogrel was used in 4 cohorts, and ticagrelor was used in 1 cohort. Pooling results showed that addition of or a switch to another antiplatelet agent, versus aspirin monotherapy, was associated with reduced risks of major adverse cardiovascular events (hazard ratio, 0.68; 95% confidence interval, 0.54-0.85) and recurrent stroke (hazard ratio, 0.70; 95% confidence interval, 0.54-0.92). Each of the strategies of addition of and switching another antiplatelet agent showed benefit versus continued aspirin monotherapy, and studies with regimen initiation in the first days after index event showed more homogenous evidence of benefit. Among patients who experience an ischemic stroke or transient ischemic attack while on aspirin monotherapy, the addition of or a switch to another antiplatelet agent, especially in the first days after index event, is associated with fewer future vascular events, including stroke. © 2017 American Heart Association, Inc.

Predictors of perioperative major bleeding in patients who interrupt warfarin for an elective surgery or procedure: Analysis of the BRIDGE trial.

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Clark, Nathan P; Douketis, James D; Hasselblad, Vic; Schulman, Sam; Kindzelski, Andrei L; Ortel, Thomas L

2018-01-01

The use of low-molecular weight heparin bridge therapy during warfarin interruption for elective surgery/procedures increases bleeding. Other predictors of bleeding in this setting are not well described. BRIDGE was a randomized, double-blind, placebo-controlled trial of bridge therapy with dalteparin 100 IU/kg twice daily in patients with atrial fibrillation requiring warfarin interruption. Bleeding outcomes were documented from the time of warfarin interruption until up to 37 days postprocedure. Multiple logistic regression and time-dependent hazard models were used to identify major bleeding predictors. We analyzed 1,813 patients of whom 895 received bridging and 918 received placebo. Median patient age was 72.6 years, and 73.3% were male. Forty-one major bleeding events occurred at a median time of 7.0 days (interquartile range, 4.0-18.0 days) postprocedure. Bridge therapy was a baseline predictor of major bleeding (odds ratio [OR]=2.4, 95% CI: 1.2-4.8), as were a history of renal disease (OR=2.9, 95% CI: 1.4-6.0), and high-bleeding risk procedures (vs low-bleeding risk procedures) (OR=2.9, 95% CI: 1.4-5.9). Perioperative aspirin use (OR=3.6, 95% CI: 1.1-11.9) and postprocedure international normalized ratio >3.0 (OR=2.1, 95% CI: 1.5-3.1) were time-dependent predictors of major bleeding. Major bleeding was most common in the first 10 days compared with 11-37 days postprocedure (OR=3.5, 95% CI: 1.8-6.9). In addition to bridge therapy, perioperative aspirin use, postprocedure international normalized ratio >3.0, a history of renal failure, and having a high-bleeding risk procedure increase the risk of major bleeding around the time of an elective surgery/procedure requiring warfarin interruption. Copyright © 2017 Elsevier Inc. All rights reserved.

Warfarin

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Warfarin comes as a tablet to take by mouth. It is usually taken once a day with or without food. Take warfarin at around the ... Banzel); certain medications to treat tuberculosis such as isoniazid (in Rifamate, Rifater) and rifampin (Rifadin, in Rifamate, ...

Taking warfarin (Coumadin)

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... page: //medlineplus.gov/ency/patientinstructions/000292.htm Taking warfarin (Coumadin) To use the sharing features on this ... form a clot or have bleeding problems. Taking Warfarin It is important that you take warfarin exactly ...

Warfarin Pharmacogenetics

Science.gov (United States)

Johnson, Julie A.; Cavallari, Larisa H.

2014-01-01

The cytochrome P450 (CYP) 2C9 and vitamin K epoxide reductase complex 1 (VKORC1) genotypes have been strongly and consistently associated with warfarin dose requirements, and dosing algorithms incorporating genetic and clinical information have been shown to be predictive of stable warfarin dose. However, clinical trials evaluating genotype-guided warfarin dosing produced mixed results, calling into question the utility of this approach. Recent trials used surrogate markers as endpoints rather than clinical endpoints, further complicating translation of the data to clinical practice. The present data do not support genetic testing to guide warfarin dosing, but in the setting where genotype data are available, use of such data in those of European ancestry is reasonable. Outcomes data are expected from an on-going trial, observational studies continue, and more work is needed to define dosing algorithms that incorporate appropriate variants in minority populations; all these will further shape guidelines and recommendations on the clinical utility of genotype-guided warfarin dosing. PMID:25282448

Haplotype of platelet receptor P2RY12 gene is associated with residual clopidogrel on-treatment platelet reactivity.

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Nie, Xiao-Yan; Li, Jun-Lei; Zhang, Yong; Xu, Yang; Yang, Xue-Li; Fu, Yu; Liang, Guang-Kai; Lu, Yun; Liu, Jian; Shi, Lu-Wen

To investigate a possible association between common variations of the P2RY12 and the residual clopidogrel on-treatment platelet reactivity after adjusting for the influence of CYP2C19 tested by thromboelastography (TEG). One hundred and eighty patients with acute coronary syndrome (ACS) treated with clopidogrel and aspirin were included and platelet function was assessed by TEG. Five selected P2RY12 single nucleotide polymorphisms (SNPs; rs6798347, rs6787801, rs6801273, rs6785930, and rs2046934), which cover the common variations in the P2RY12 gene and its regulatory regions, and three CYP2C19 SNPs ( * 2, * 3, * 17) were genotyped and possible haplotypes were analyzed. The high on-treatment platelet reactivity (HTPR) prevalence defined by a platelet inhibition rate <30% by TEG in adenosine diphosphate (ADP)-channel was 69 (38.33%). Six common haplotypes were inferred from four of the selected P2RY12 SNPs (denoted H 0 to H 5 ) according to the linkage disequilibrium R square (except for rs2046934). Haplotype H 1 showed a significantly lower incidence of HTPR than the reference haplotype (H 0 ) in the total study population while haplotypes H 1 and H 2 showed significantly lower incidences of HTPR than H 0 in the nonsmoker subgroup after adjusting for CYP2C19 effects and demographic characteristics. rs2046934 (T744C) did not show any significant association with HTPR. The combination of common P2RY12 variations including regulatory regions rather than rs2046934 (T744C) that related to pharmacodynamics of clopidogrel in patients with ACS was independently associated with residual on-clopidogrel platelet reactivity. This is apart from the established association of the CYP2C19. This association seemed more important in the subgroup defined by smoking.

Safety of carotid endarterectomy in patients concurrently on clopidogrel.

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Fleming, Mark D; Stone, William M; Scott, Paul; Chapital, Alyssa B; Fowl, Richard J; Money, Samuel R

2009-01-01

Clopidogrel (Plavix) usage is increasing, primarily for the management of patients with cerebrovascular symptoms and for those receiving drug-eluting coronary artery stents. A significant percentage of these patients will require carotid endarterectomy (CEA) while they are receiving clopidogrel. Recent data have demonstrated an increased incidence of coronary stent thrombosis when clopidogrel is discontinued. The objective of this study was to determine if CEA could be performed safely while patients are continued on clopidogrel therapy. A retrospective cohort design was employed to review consecutive patients who underwent CEA over a 24-month period ending March 2007. Patients were divided into two groups based on the perioperative use of clopidogrel. Preoperative demographics and postoperative results were compared between the two groups and statistically analyzed. Of the 100 patients who underwent CEA, 19 were taking clopidogrel within 5 days of surgery. This comprised the study group. The control group consisted of the 81 patients who did not receive clopidogrel. Heparin anticoagulation was routinely utilized prior to clamping in both groups. Demographics were similar between the groups. There were no statistical differences in morbidity or mortality between the control group and the clopidogrel group. Combined stroke/death rates were equivalent between the two groups (1.2% control vs. 0% clopidogrel). One hematoma developed in the control group, which did not require operative intervention. In this series, our results suggest that patients concurrently on clopidogrel can safely undergo CEA without increased risk of hematoma or neurological complications. In view of recent data demonstrating adverse outcomes in patients discontinuing clopidogrel, this study is useful in optimally managing this group of patients.

Diagnosis, management and prevention of ischemic stroke for non-neurologists

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Kavian Ghandehari

2011-07-01

Full Text Available Background: Stroke is the third common cause of disability and death. Diagnosis of stroke is based on its clinical manifestations and/or observation of infarct in the neuroimaging. Standard battery of diagnostic investigations and classification criteria is required for detection of stroke etiology. Materials and Method: This review article deals with the diagnosis and management of brain infarction particularly in our country and is provided for non-neurologists. Using online scientific search engines and in some parts referring to laboratory archives constituted base of this review article.Results: Acute stroke management is almost similar in its various etiologies. Neuroprotective drugs have little value in acute stroke management. At present time, a few Iranian medical centers have infrastructure of thrombolysis therapy. Prevention of stroke is based on the detection and control of its risk factors. Aspirin, 80 mg per day is the most common drug for stroke prevention. Co-administration of aspirin 80 mg/d and Dipyridamole 200-400 mg/d increases the preventive effects of aspirin. Clopidogrel 75 mg/d is the stroke preventive drug of choice in patients with peptic ulcer and coronary artery disease. Co-administration of aspirin and clopidogrel is more effective in stroke prevention but has more hemorrhagic complications. Using warfarin for stroke prevention is suggested only in patients who have facilities for repetitive coagulation tests. Carotid endarterectomy is indicated in symptomatic patients with more than 70% stenosis of extracranial internal carotid artery, if performed only by vascular surgeons experienced in carotid surgery.Conclusion: Many stroke patients are managed by general practitioners and non-neurologists, e.g. internists, cardiologists and neurosurgeons. This review article provides continuous medical education according to Iranian medical curriculum

Chromatographic determination of clopidogrel bisulfate; detection and quantification of counterfeit Plavix® tablets

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Mona E. ElTantawy

2014-06-01

Full Text Available Counterfeiting of pharmaceutical products is a global problem. Upon using quality-ensuring methods of international pharmacopoeias, additional impurities and the low content of the active pharmaceutical ingredients were detected. In this paper, two chromatographic HPLC and TLC-densitometric methods were proposed as fast and reliable methods for detection and quantitation of counterfeit Plavix® tablets. These tablets were chemically counterfeited by aspirin, its degradate salicylic acid and metronidazole which were separated, besides the active ingredient clopidogrel bisulfate, by the proposed methods. Also, counterfeit was in packaging, strips and tablets’ color and these could be seen by visual inspection compared to original drug. The proposed methods can easily differentiate genuine from counterfeited tablets without need of prior separation. The proposed methods were validated according to ICH guidelines and applied to eleven batches, also were compared statistically with the reported one.

[Retrospective analysis of correlative factors between digestive system injury and anticoagulant or antiplatelet-agents].

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Cui, Ning; Luo, Hesheng

2014-05-27

To explore the correlative factors and clinical characteristics of digestive system injury during the treatment of anticoagulant and (or) antiplatelet-agents. A total of 1 443 hospitalized patients on anticoagulant and (or) antiplatelet-agents from January 2010 to December 2013 at Renmin Hospital of Wuhan University were analyzed retrospectively. Their length of hospital stay was from 5 to 27 days. Most of them were elderly males (n = 880, 61.0%) with an average age of (62 ± 6) years. 1 138 patients (78.9%) were farmers, workers or someone without a specific occupation. During the treatment of anticoagulant/antiplatelet-agents, statistical difference existed (P = 0.01) between positively and negatively previous digestive disease groups for actively newly occurring digestive system injury (16.0% (41/256) vs 15.9% (189/1 187)). After the dosing of anticoagulant and (or) antiplatelet-agents, 57 (66.3%, 57/86) patients were complicated by hemorrhage of digestive tract, taking 62.9% (61/97) of all positive result patients for Helicobacter pylori test. Comparing preventive PPI group with no PPI group, there was no marked statistical differences (P = 2.67) for digestive system complication (including hemorrhage of digestive tract) while receiving anticoagulant and (or) antiplatelet-agents (13.9% (74/533) vs 17.1% (156/910)). During anticoagulant and/or antiplatelet-agent therapy, 185 patients (12.8%) were complicated by peptic ulcer or peptic ulcer with bleeding, 40 patients (2.8%) had erosive gastritis and 5 (0.3%) developed acute gastric mucosal lesions. And 42 of 76 patients complicated by hemorrhage of digestive tract underwent endoscopic hemostasis while 2 patients were operated. Ninety-seven patients (6.7%) died, including 61 (62.9%, 61/97) from hemorrhage of digestive tract. The remainder became cured, improved and discharged. Moreover, no significant statistical differences existed (P = 2.29) among three combination group (aspirin, clopidogrel, warfarin), two

Influence of Sampling on the Determination of Warfarin and Warfarin Alcohols in Oral Fluid

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Lomonaco, Tommaso; Ghimenti, Silvia; Piga, Isabella; Biagini, Denise; Onor, Massimo; Fuoco, Roger; Di Francesco, Fabio

2014-01-01

Background and Objective The determination of warfarin, RS/SR- and RR/SS-warfarin alcohols in oral fluid may offer additional information to the INR assay. This study aimed to establish an optimized sampling technique providing the best correlation between the oral fluid and the unbound plasma concentrations of these compounds. Materials and Methods Samples of non-stimulated and stimulated oral fluid, and blood were collected from 14 patients undergoing warfarin therapy. After acidification, analytes were extracted with a dichloromethane/hexane mixture and determined by HPLC with fluorescence detection. Plasma samples were also ultrafiltered for the determination of the unbound fraction. The chromatographic separation was carried out in isocratic conditions with a phosphate buffer/methanol mobile phase on a C-18 reversed-phase column. The absence of interfering compounds was verified by HPLC-ESI-Q-TOF. Results Stimulation generally increased the oral fluid pH to values close to blood pH in about 6 minutes. The concentration of warfarin and RS/SR-warfarin alcohols in oral fluid followed the same trend, whereas the concentration of RR/SS-warfarin alcohols was not affected. Six minute stimulation with chewing gum followed by collection with a polyester swab was the best sampling procedure, with a good repeatability (RSD warfarin (r  =  0.92, p warfarin alcohols (r  =  0.84, p warfarin (r  =  0.78, p warfarin alcohols (r  =  0.81, p warfarin and RS/SR-warfarin alcohols suggests that oral fluid analysis could provide clinically useful information for the monitoring of anticoagulant therapy, complementary to the INR assay. PMID:25478864

Desensitization to clopidogrel: a tailor-made protocol.

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Barreira, P; Cadinha, S; Malheiro, D; Moreira da Silva, J P

2014-01-01

Clopidogrel is an antiplatelet drug widely used for treatment and prevention of a variety of cardiovascular diseases. We report a successful desensitization to clopidogrel in a 70-year-old Caucasian man with delayed hypersensitivity (HS) reaction. He developed lip, hand and foot swelling, erythematous papular non-pruritic lesions and arthralgias 2 weeks after starting treatment with clopidogrel 75 mg/d. A 3-hour desensitization protocol was started, achieving a cumulative dose of 154 mg without any reaction, and a daily dose of 75 mg was recommended. On the 4th day, the patient developed skin lesions similar to the previously described. He was treated with topical steroids and oral antihistamines, and the daily dose of clopidogrel was reduced to 20 mg. A new desensitization protocol was established, with a slow dose increment, according to the patient's response. It was only possible to achieve the dose of 75 mg/d after 2 months. Although well tolerated by most patients, HS reactions with clopidogrel may occur and desensitization is rising as a safe alternative in those patients. In delayed reactions with cutaneous lesions, a slower desensitization protocol may be necessary, as in this case.

Increased platelet expression of glycoprotein IIIa following aspirin treatment in aspirin-resistant but not aspirin-sensitive subjects

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Floyd, Christopher N; Goodman, Timothy; Becker, Silke; Chen, Nan; Mustafa, Agnesa; Schofield, Emma; Campbell, James; Ward, Malcolm; Sharma, Pankaj; Ferro, Albert

2014-01-01

Aims Aspirin is widely used as an anti-platelet agent for cardiovascular prophylaxis. Despite aspirin treatment, many patients experience recurrent thrombotic events, and aspirin resistance may contribute to this. We examined the prevalence of aspirin resistance in a healthy population, and investigated whether the platelet proteome differed in aspirin-resistant subjects. Methods Ninety-three healthy subjects received aspirin 300 mg daily for 28 days. Before and at the end of treatment, urine was taken to determine 11-dehydrothromboxane B2, and blood was taken to measure arachidonic acid (AA)-induced aggregation of platelet-rich plasma and to interrogate the platelet proteome by mass spectrometric analysis with further confirmation of findings using Western blotting. Results In two of the 93 subjects, neither AA-induced aggregation nor urinary 11-dehydrothromboxane B2 was effectively suppressed by aspirin, despite measurable plasma salicylate concentrations, suggesting the presence of true aspirin resistance. Despite no detectable differences in the platelet proteome at baseline, following aspirin a marked increase was seen in platelet glycoprotein IIIa expression in the aspirin-resistant but not aspirin-sensitive subjects. An increase in platelet glycoprotein IIIa expression with aspirin resistance was confirmed in a separate cohort of 17 patients with stable coronary artery disease on long term aspirin treatment, four of whom exhibited aspirin resistance. Conclusions In a healthy population, true aspirin resistance is uncommon but exists. Resistance is associated with an increase in platelet glycoprotein IIIa expression in response to aspirin. These data shed new light on the mechanism of aspirin resistance, and provide the potential to identify aspirin-resistant subjects using a novel biomarker. PMID:25099258

Warfarin Pharmacogenomics in Diverse Populations.

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Kaye, Justin B; Schultz, Lauren E; Steiner, Heidi E; Kittles, Rick A; Cavallari, Larisa H; Karnes, Jason H

2017-09-01

Genotype-guided warfarin dosing algorithms are a rational approach to optimize warfarin dosing and potentially reduce adverse drug events. Diverse populations, such as African Americans and Latinos, have greater variability in warfarin dose requirements and are at greater risk for experiencing warfarin-related adverse events compared with individuals of European ancestry. Although these data suggest that patients of diverse populations may benefit from improved warfarin dose estimation, the vast majority of literature on genotype-guided warfarin dosing, including data from prospective randomized trials, is in populations of European ancestry. Despite differing frequencies of variants by race/ethnicity, most evidence in diverse populations evaluates variants that are most common in populations of European ancestry. Algorithms that do not include variants important across race/ethnic groups are unlikely to benefit diverse populations. In some race/ethnic groups, development of race-specific or admixture-based algorithms may facilitate improved genotype-guided warfarin dosing algorithms above and beyond that seen in individuals of European ancestry. These observations should be considered in the interpretation of literature evaluating the clinical utility of genotype-guided warfarin dosing. Careful consideration of race/ethnicity and additional evidence focused on improving warfarin dosing algorithms across race/ethnic groups will be necessary for successful clinical implementation of warfarin pharmacogenomics. The evidence for warfarin pharmacogenomics has a broad significance for pharmacogenomic testing, emphasizing the consideration of race/ethnicity in discovery of gene-drug pairs and development of clinical recommendations for pharmacogenetic testing. © 2017 Pharmacotherapy Publications, Inc.

[The current role of warfarin].

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Michalcová, Jana; Buliková, Alena; Zavřelová, Jiřina; Prudková, Marie; Penka, Miroslav

Well-managed warfarin therapy remains an important method of anticoagulation in the 21st century, despite the introduction of new antithrombotics into the clinical practice. The main advantages of warfarin are decades of treatment experience, the possibility to monitor its anticoagulant effect using the INR and the last, but not least, the low cost. Currently, approximately 75 % of anticoagulated patients in the Czech Republic are treated with warfarin and warfarin remains the only option for oral anticoagulant therapy in certain clinical conditions (particularly in patients with valvular atrial fibrillation or mechanical heart valves). For physicians across specialties it is still indispensable to master the basics of safe and effective warfarin therapy, including the management of treatment complications.Key words: anticoagulant therapy - INR - thrombosis - warfarin.

Prospective randomized evaluation of the watchman left atrial appendage closure device in patients with atrial fibrillation versus long-term warfarin therapy: The PREVAIL trial.

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Belgaid, Djouhar Roufeida; Khan, Zara; Zaidi, Mariam; Hobbs, Adrian

2016-09-15

Assessing the safety and effectiveness of left atrial appendage (LAA) (pouch found in the upper chambers of the heart) occlusion, using the Watchman device compared to long term warfarin therapy (drug that reduces clot formation), in preventing the risk of stroke in patients with atrial fibrillation (most common type of irregular heart beat). 90% of strokes in atrial fibrillation arise from clots forming in this pouch. By mechanically blocking it using the device less clots are suggested to be formed. This is an alternative to taking warfarin especially in patients who cannot take it. 50 sites in the United States enrolled 407 participants. After being randomly allocated, the device group had 269 participants and warfarin group (comparator)had 138 participants. Patients with atrial fibrillation and at high risk of stroke were randomly allocated a group after they were deemed eligible. Patients in the device group had to take warfarin and aspirin for 45days till the complete closure of the LAA. The oral anticoagulant was followed by dual antiplatelet therapy until 6months and then ASA. Patients in the warfarin group have to take it for life and were continually monitored. The study ran for 26months. The trial assessed the rate of adverse events using three endpoints: The PREVAIL trial was not designed to show superiority, but non-inferiority. It met the safety endpoint and one efficacy endpoint for the watchman device compared to long term warfarin for overall efficacy of the device. The results established that LAA occlusion is not worse than warfarin intake for the prevention of stroke more than 1week after randomization. Compared to previous trials, the safety of the device has also improved. LAA occlusion is a reasonable alternative to chronic warfarin therapy in stroke prevention for patients with atrial fibrillation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Systematic review and network meta-analysis of stroke prevention treatments in patients with atrial fibrillation

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Tawfik A

2016-08-01

Full Text Available Amy Tawfik,1,2 Joanna M Bielecki,2 Murray Krahn,1,2 Paul Dorian,3,4 Jeffrey S Hoch,1,3,5 Heather Boon,1 Don Husereau,6 Petros Pechlivanoglou2 1Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, 2Toronto Health Economics and Technology Assessment (THETA Collaborative, University of Toronto, 3Centre for Excellence in Economic Analysis Research (CLEAR, Li Ka Shing Knowledge Institute, St Michael’s Hospital, 4Department of Medicine and Cardiology, University of Toronto, 5Pharmacoeconomics Research Unit, Cancer Care Ontario, Toronto, ON, 6Institute of Health Economics, Edmonton, AB, Canada Background: In the last 4 years, four novel oral anticoagulants have been developed as alternatives to warfarin and antiplatelet agents for stroke prevention in atrial fibrillation (AF patients. The objective of this review was to estimate the comparative effectiveness of all antithrombotic treatments for AF patients.Materials and methods: Data sources were Medline Ovid (1946 to October 2015, Embase Ovid (1980 to October 2015, and the Cochrane Central Register of Controlled Trials (­CENTRAL, Issue 9, 2015. Randomized controlled trials of AF patients were selected if they compared at least two of the following: placebo, aspirin, aspirin and clopidogrel combination therapy, adjusted-dose warfarin (target international normalized ratio 2.0–3.0, dabigatran, rivaroxaban, apixaban, and edoxaban. Bayesian network meta-analyses were conducted for outcomes of interest (all stroke, ischemic stroke, myocardial infarction, overall mortality, major bleeding, and intracranial hemorrhage.Results: Based on 16 randomized controlled trials of 96,826 patients, all oral anticoagulants were more effective than antiplatelet agents at reducing the risk of ischemic stroke and all strokes. Compared to warfarin, dabigatran 150 mg (rate ratio 0.65, 95% credible interval 0.52–0.82 and apixaban (rate ratio 0.82, 95% credible interval 0.69–0.97 reduced the risk of

Genetics Home Reference: warfarin sensitivity

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... Email Facebook Twitter Home Health Conditions Warfarin sensitivity Warfarin sensitivity Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Warfarin sensitivity is a condition in which individuals have ...

Genetics Home Reference: warfarin resistance

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... Email Facebook Twitter Home Health Conditions Warfarin resistance Warfarin resistance Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Warfarin resistance is a condition in which individuals have ...

Performing Aspirin Desensitization in Aspirin-Exacerbated Respiratory Disease.

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Waldram, Jeremy D; Simon, Ronald A

2016-11-01

Aspirin-exacerbated respiratory disease (AERD) is characterized by chronic rhinosinusitis with nasal polyps, asthma, and reactions to cyclooxygenase-1-inhibiting drugs. This condition is often refractory to standard medical treatments and results in aggressive nasal polyposis that often requires multiple sinus surgeries. Aspirin desensitization followed by daily aspirin therapy is an important treatment option, and its efficacy has been validated in multiple research studies. Aspirin desensitization is not without risk, but specific protocols and recommendations exist to mitigate the risk. Most patients with AERD can undergo aspirin desensitization in an outpatient setting under the supervision of an allergist. Copyright © 2016 Elsevier Inc. All rights reserved.

Aspirin Desensitization

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... Nerve Decompression Dacryocystorhinostomy (DCR) Disclosure Statement Printer Friendly Aspirin Desensitization Kevin C. Welch, MD Zara Patel, MD Introduction The term "aspirin-sensitive asthma" (also known as "aspirin triad" or " ...

Dermatotoxicity of epicutaneously applied anticoagulant warfarin

International Nuclear Information System (INIS)

Kataranovski, Milena; Prokic, Vera; Kataranovski, Dragan; Zolotarevski, Lidija; Majstorovic, Ivana

2005-01-01

Dermatotoxic effects of epicutaneous application of a first-generation anticoagulant, warfarin (WF) were examined in rats. Selected parameters of skin activity were determined 24 h following warfarin application, including metabolic viability of skin explants, some aspects of oxidative activity in skin tissue homogenates and inflammatory/immune relevant activity of epidermal cells from warfarin-treated skin. No changes in skin metabolic viability (MTT reduction) were noted ex vivo following WF application, suggesting the absence of immediate toxicity for skin. In contrast, increased formation of malondialdehyde (MDA), with a decrease in protein and non-protein thiols in homogenates of warfarin-treated skin was demonstrated, pointing to prooxidant activity in warfarin-treated skin. Increased costimulatory activity of epidermal cells isolated from warfarin-exposed skin in Con-A-stimulated T-cell activation/proliferation assay was noted, reflecting proinflammatory and immune-modulating capacity of warfarin for epidermis. No evident differences in skin histology between control and warfarin-treated skin were found at that time point, while striking changes in tissue integrity, cellularity and appearance 72 h following WF application were noted. The observed histological picture probably reflects a regenerative/inflammatory program related to oxidant/inflammation-type warfarin-evoked injury to the skin. Presented data demonstrate the potential of epicutaneously applied warfarin to modulate local skin activity in rats

Characterization of human warfarin reductase

OpenAIRE

Sokolová, Simona

2016-01-01

Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Simona Sokolová Supervisor: PharmDr. Petra Malátková, Ph.D. Title of diploma thesis: Characterization of human warfarin reductase Warfarin is widely used anticoagulant drug. Considering the narrow therapeutic window of warfarin, it is important to fully understand its metabolism in human body. Oxidative, reductive and conjugation reactions are involved in warfarin metabolism. Howev...

Does "smoker's paradox" exist in clopidogrel-treated Turkish patients with acute coronary syndrome.

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Edem, Efe; Kirdök, Ali Hikmet; Kınay, Ahmet Ozan; Tekin, Ümit İlker; Taş, Sedat; Alpaslan, Erkan; Pabuccu, Mustafa Türker; Akdeniz, Bahri

2016-01-01

Previously conducted studies revealed that smoking enhanced the efficacy of clopidogrel by increasing formation of the active metabolite (AM) from the prodrug through induction of the cytochrome CYP1A2. The expression of cytochrome enzymes depends on genotype and no data exists in literature conducted in Turkish patients comparing the clopidogrel responsiveness between active smokers and non-active smokers treated with clopidogrel. In this study, our aim was to investigate the clopidogrel responsiveness in clopidogrel-treated Turkish acute coronary syndrome (ACS) patients according to their smoking status. We retrospectively enrolled 258 patients who were hospitalized due to ACS. Clinical variables of the patients, especially smoking status were recorded. Clopidogrel resistance was evaluated by using adenosine diphosphate (ADP) induced platelet aggregometry. Clopidogrel resistance was detected as a change in maximal aggregation ≤20% from baseline. A total of 139 patients were active smokers while 12 were former smokers. 107 patients did not have a history of smoking. Ten of the smokers were hyporesponsive to clopidogrel, whereas 36 of non-smokers were hyporesponsive to clopidogrel (p value >612.5 predicted the clopidogrel resistance with a sensitivity of 60% (OR: 100.65, %95 CI = 19.996-506.615 p paradox" probably exists in Turkish ACS patients.

Aspirin overdose

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... this page: //medlineplus.gov/ency/article/002542.htm Aspirin overdose To use the sharing features on this page, please enable JavaScript. An overdose of aspirin means you have too much aspirin in your ...

Warfarin for venous thromboembolism prophylaxis after elective hip or knee arthroplasty: exploring the evidence, guidelines, and challenges remaining.

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Dager, William E

2012-01-01

Guidelines for the prevention of venous thromboembolism (VTE) after elective total hip or knee arthroplasty (THA/TKA) have been developed separately by the American Academy of Orthopaedic Surgeons (AAOS) and the American College of Chest Physicians (ACCP). Differences exist in approaches to preventing postoperative VTE through prophylaxis. To compare trials using vitamin K antagonists (VKAs) and differences in guidelines to determine the benefits and drawbacks of warfarin for VTE prophylaxis following THA/TKA. Guidelines from the AAOS published in 2009 and revised in 2011 and from the ACCP published in 2008 were compared for recommendations on the use of VKAs. A MEDLINE search from 1960 to November 2009 was conducted to identify pertinent articles on the use of warfarin or VKAs for VTE prophylaxis following THA/TKA. Search terms included warfarin, vitamin K antagonist, total hip or total knee replacement, and total hip or total knee arthroplasty. Only clinical trials in which warfarin was the primary agent for prophylaxis compared to other anticoagulants were included. Data on differences between guideline recommendations for the use of VKAs and the importance of a deep vein thrombosis or asymptomatic events were extracted. Thirteen comparative trials using VKAs for VTE prophylaxis and international normalized ratio (INR) targets were assessed. Overall, the incidence of bleeding tended to be lower with the use of VKAs, but thrombosis when including asymptomatic events was numerically higher when comparing INR targets. However, INR targets varied, with no comparative trials assessing the AAOS 2009 recommended INR target of 1.5-2.0. The AAOS guidelines initially recommended a longer duration of therapy and expressed stronger support for the use of aspirin for prophylaxis; however, in 2011, its guidelines were revised, with no specific recommendations as to agent, dose, or INR target goal. Warfarin is an effective agent to prevent VTE after elective THA/TKA. The most

Pharmacogenetics of warfarin: challenges and opportunities

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Ta Michael Lee, Ming; Klein, Teri E

2014-01-01

Since the introduction in the 1950s, warfarin has become the commonly used oral anticoagulant for the prevention of thromboembolism in patients with deep vein thrombosis, atrial fibrillation or prosthetic heart valve replacement. Warfarin is highly efficacious; however, achieving the desired anticoagulation is difficult because of its narrow therapeutic window and highly variable dose response among individuals. Bleeding is often associated with overdose of warfarin. There is overwhelming evidence that an individual's warfarin maintenance is associated with clinical factors and genetic variations, most notably polymorphisms in cytochrome P450 2C9 and vitamin K epoxide reductase subunit 1. Numerous dose-prediction algorithms incorporating both genetic and clinical factors have been developed and tested clinically. However, results from major clinical trials are not available yet. This review aims to provide an overview of the field of warfarin which includes information about the drug, genetics of warfarin dose requirements, dosing algorithms developed and the challenges for the clinical implementation of warfarin pharmacogenetics. PMID:23657428

Warfarin Side Effects: Watch for Interactions

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Warfarin side effects: Watch for interactions Although commonly used to treat blood clots, warfarin (Coumadin, Jantoven) can have dangerous side effects or ... bleeding. Here are precautions to take to avoid warfarin side effects. By Mayo Clinic Staff If you' ...

Comparative bioavailability of two oral formulations of clopidogrel: Determination of clopidogrel and its carboxylic acid metabolite (SR26334 under fasting and fed conditions in healthy subjects

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Brvar Nina

2014-03-01

Full Text Available Two randomized, single dose, 2-period, 2-sequence crossover studies were conducted to evaluate the comparative bioavailability of two clopidogrel formulations under fasting and fed conditions. Assessment of bioequivalence was based upon measurement of plasma concentrations of the parent drug, clopidogrel, and its major (inactive metabolite, clopidogrel carboxylic acid, using improved methanol-free extraction. Bioequivalence of Krka’s formulation to the innovator’s formulation was demonstrated under both fasting and fed conditions on 205 volunteers. Confidence intervals for AUC0-t, AUC0-inf and Cmax of clopidogrel and its main metabolite were well within the acceptance range of 80.00 to 125.00 %. Food substantially increased the bioavailability of clopidogrel from both formulations, while no effect of food on the extent and rate of exposure to the metabolite was observed. The effect of food was comparable between the two formulations, as indicated by the same direction and rank of food impact on the bioavailability of both formulations.

Chondrodysplasia punctata after warfarin

International Nuclear Information System (INIS)

Tamburrini, O.; Bartolomeo-De Iuri, A.; Di Guglielmo, G.L.

1987-01-01

Administration of warfarin during pregnancy may cause a rare syndrome characterized by nasal hypoplasia, usually associated with stippled epiphyseal and extraepiphyseal calcifications ressembling chondrodysplasia punctata. A case of chondrodysplasia punctata after warfarin with 18 months follow-up is reported. (orig.)

Warfarin-Associated Diaphragmatic Hernia: An Unusual Diagnosis

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Cristina Vilhena

2015-01-01

Full Text Available Fetal warfarin syndrome is a consequence of maternal intake of warfarin during pregnancy and comprises a wide range of manifestations, including some typical facial dysmorphologic features. The authors report a case of prenatal ultrasonographic diagnosis of warfarin embryopathy in an obese woman on unsupervised warfarin prophylaxis at the 16th week of gestation. The fetus presented with facial dysmorphism, pectus excavatum, diaphragmatic hernia, and pulmonary hypoplasia. To the best of our knowledge, this is the second reported case of warfarin-associated diaphragmatic hernia.

CYP2C19*17 increases clopidogrel-mediated platelet inhibition but does not alter the pharmacokinetics of the active metabolite of clopidogrel

DEFF Research Database (Denmark)

Pedersen, Rasmus Steen; Nielsen, Flemming; Stage, Tore Bjerregaard

2014-01-01

*1/*1, 11 CYP2C19*1/*17 and nine CYP2C19*17/*17). In Phase A, the pharmacokinetics of the derivatized active metabolite of clopidogrel (CAMD) and platelet function were determined after administration of a single oral dose of 600 mg clopidogrel (Plavix; Sanofi-Avensis, Horsholm, Denmark). In Phase B...

ANTI-INFLAMMATORY EFFECT OF CLOPIDOGREL IN ATHEROSCLEROSIS

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L. I. Buriachkovskaia

2011-01-01

Full Text Available Aim. To analyze the literary and own data about clopidogrel influence on platelets during inflammation and to reveal particularities of its usage in ischemic heart disease (IHD patients with active inflammation. Material and methods. The platelet morphology and a number of leukocyte-platelet aggregates (LTA were investigated with scanning electron microscopy in 110 patients with stable angina pectoris of I-III functional class and 18 healthy volunteers. Spontaneous and ADP-induced platelet aggregation were assessed with laser aggregatometre manufactured by LLC “BIOLA”. Mean platelet volume (MPV was estimated with the hematological analyzer . All investigations were performed in IHD patients before and after 2 months of clopidogrel treatment 75 mg a day. Results. IHD patients demonstrated appearance of LTA and big reticular platelets in the blood, increase in MPV and spontaneous aggregation. ADP-induced platelet aggregation was rarely increased probably due to acetylsalicylic acid therapy in all IHD patients. These platelet activity changes are connected with increased risk of thrombotic events and correlated with inflammation markers levels. After 2 months of clopidogrel treatment LTA number reduced in 4 times and big reticular platelets number decreased in 2.5 times as well as MPV and spontaneous aggregation achieved the normal ranges. Conclusion. Clopidogrel has not only antithrombotic effect but also can diminish platelets morphological and functional changes connected with inflammation.

Medications Containing Aspirin (Acetylsalicylate) and Aspirin-Like Products

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updated 3/10/08 Medications Containing Aspirin (Acetylsalicylate) and Aspirin-Like Products © National Reye's Syndrome Foundation Inc. 2008 Epidemiologic research has shown an association between the development of Reye's ...

Effect of scutellarin on the metabolism and pharmacokinetics of clopidogrel in rats.

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Chen, Xinmeng; Jin, Jing; Chen, Yaobin; Peng, Lingling; Zhong, Guoping; Li, Jiali; Bi, Huichang; Cai, Yefeng; Huang, Min

2015-01-01

Erigeron breviscapus (Vant.) Hand-Mazz, a traditional Chinese medicine, is often co-prescribed with clopidogrel for the treatment of ischemic vascular diseases. Scutellarin is the representative bioactive flavonoid isolated from this herb. The aim of this study was to explore the effect of scutellarin on the metabolism and pharmacokinetics of clopidogrel. The in vitro studies using rat liver microsomes showed that scutellarin significantly inhibited the metabolism of clopidogrel. The IC50 value was 2.1 µM. Ten male rats were employed to investigate the effect of scutellarin on the pharmacokinetics of clopidogrel in vivo. After pretreatment with scutellarin, there were significant increases in the AUC0-∞ (from 0.9 ± 0.4 to 1.7 ± 0.6 ng/ml h; p <0.05) and Cmax (from 0.4 ± 0.1 to 0.9 ± 0.1 ng/ml; p <0.05) of clopidogrel. The pharmacokinetic data for clopidogrel active metabolite showed significant decreases in AUC0-∞ (18.2 ± 5.6 to 11.4 ± 3.7 ng/ml h; p <0.05) and Cmax (from 8.2 ± 1.2 to 4.3 ± 0.3 ng/ml; p <0.05) after pretreatment with scutellarin. Collectively, the metabolism and pharmacokinetics of clopidogrel were significantly affected by scutellarin. This study indicated that potential herb-drug interaction between scutellarin and clopidogrel should be taken into consideration in clinical use. Copyright © 2014 John Wiley & Sons, Ltd.

New in vitro effects of clopidogrel on platelets in hyperlipidemic and healthy subjects

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Derya Özsavcı

2010-06-01

Full Text Available Objective: We aimed to detect novel in vitro effects of clopidogrel on platelets by assessment of the following parameters: malondialdehyde, glutathione, nitrite, aggregation response, and expressions of P-selectin, fibrinogen, apolipoprotein A1, apolipoprotein B, and phosphatidylserine.Materials and Methods: Platelets were obtained from healthy (n: 9 and hyperlipidemic (n: 9 volunteers. Expressions of P-selectin, fibrinogen, apolipoproteins A1/B and phosphatidylserine with and without clopidogrel were assayed by flow cytometry. Malondialdehyde, glutathione, aggregation and nitrite levels were also assayed. Results: Without clopidogrel, the baseline values of platelet aggregation, malondialdehyde, and expressions of P-selectin, fibrinogen and phosphatidylserine were significantly higher, whereas nitrite and expression of apolipoproteins A1/B were significantly lower in hyperlipidemics than in the healthy group. In both groups, clopidogrel significantly reduced aggregation and expression of fibrinogen, but it elevated nitrite levels. Clopidogrel significantly decreased P-selectin and phosphatidylserine expression and malondialdehyde but increased expressions of apolipoproteins A1/B only in hyperlipidemics. Conclusion: It seems that clopidogrel has some new in vitro antiplatelet effects. The present study is a basic in vitro study to suggest new insights into the effects of clopidogrel on platelet functions.

Aspirin and Omeprazole

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The combination of aspirin and omeprazole is used to reduce the risk of stroke or heart attack in patients who have had or ... risk of developing a stomach ulcer when taking aspirin. Aspirin is in a class of medications called ...

Effects of clopidogrel on the pharmacokinetics of sibutramine and its active metabolites.

Science.gov (United States)

Bae, Jung-Woo; Jang, Choon-Gon; Lee, Seok-Young

2011-12-01

Sibutramine is metabolized by the enzymes CYP2B6 and CYP2C19 into 2 active metabolites, M1 (mono-desmethyl sibutramine) and M2 (di-desmethyl sibutramine). Clopidogrel is a mechanism-based inhibitor of CYP2B6 and CYP2C19. In this study, 13 extensive metabolizers of CYP2B6 and CYP2C19 were evaluated to clarify whether clopidogrel inhibits the formation of the active metabolites of sibutramine. In the control phase, each subject received a 15-mg oral dose of sibutramine. After a washout period of 2 weeks, in the clopidogrel phase, the subjects received 300 mg of clopidogrel on the first day and then 75-mg once daily for 6 days. One hour after the last dosing of clopidogrel, all subjects received 15-mg of sibutramine. Compared with the control phase, the mean sibutramine and M1 plasma concentrations were higher after clopidogrel treatment. Clopidogrel significantly increased the half-life (242% of control phase) and area under the plasma concentration-time curve from 0 to infinity (AUC(inf)) (227% of control phase) of sibutramine and decreased the apparent oral clearance (31% of control phase) of sibutramine. Pharmacokinetic analysis showed significant increases in the AUC(inf) (162% of control phase) of M1. The CYP2B6 and CYP2C19 inhibitor clopidogrel significantly inhibited the formations of M1 from sibutramine and M2 from sibutramine by 37% and 64%, respectively. Therefore, CYP2B6 and CYP2C19 are in vivo catalysts for the formation of the 2 active metabolites of sibutramine.

Dabigatran for the prevention of stroke and systemic embolism in atrial fibrillation: A NICE single technology appraisal.

Science.gov (United States)

Faria, Rita; Spackman, Eldon; Burch, Jane; Corbacho, Belen; Todd, Derick; Pepper, Chris; Woolacott, Nerys; Palmer, Stephen

2013-07-01

. The economic evaluation compared the costs and outcomes of DBG110, DBG150 and DBG sequential against warfarin, aspirin, and aspirin plus clopidogrel. Across the three dosing regimens, dabigatran was associated with greater costs and better health outcomes than warfarin; however, DBG150 offered the most benefits and dominated DBG110 and DBG sequential (i.e. less costly and more effective). The cost-effectiveness of DBG150 was less favourable for patients well controlled on warfarin. In the first appraisal meeting, the committee issued a 'minded no' decision until additional analyses on the licensed DBG sequential regimen were presented by the manufacturer. These additional analyses indicated that the incremental cost-effectiveness ratio (ICER) of the DBG sequential regimen compared with warfarin ranged from £8,388 to £18,987 per quality-adjusted life year (QALY) gained depending on the level of monitoring costs assumed for warfarin. Patients on warfarin would need to be within therapeutic range 83-85 % of the time for the ICER to exceed £30,000 per additional QALY. Following consideration of the additional evidence and the responses from a large number of consultees and commentators, the committee recommended dabigatran as DBG sequential as an option for the prevention of stroke and systemic embolism in people with non-valvular AF with one or more risk factors for ischaemic stroke.

Trends in Ambulatory Prescribing of Antiplatelet Therapy among US Ischemic Stroke Patients: 2000–2007

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Sudeep Karve

2012-01-01

Full Text Available Objective. Study objectives were to assess temporal trends and identify patient- and practice-level predictors of the prescription of antiplatelet medications in a national sample of ischemic stroke (IS patients seeking ambulatory care. Methods. IS-related outpatient visits by adults were identified using the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey for the years 2000–2007. We assessed prescribing of antiplatelet medications using the generic drug code and drug entry codes in these data. Temporal trends in antiplatelet prescribing were assessed using the Cochran-Mantel-Haenszel test for trend. Results. We identified 9.5 million IS-related ambulatory visits. Antiplatelet medications were prescribed at 35.5% of visits. Physician office prescribing of the clopidogrel-aspirin combination increased significantly from 0.5% in 2000 to 22.0% in 2007 (P=0.05, whereas prescribing of aspirin decreased from 17.9% to 7.0% (P=0.50 during the same period. Conclusion. We observed a continued increase in prescription of the aspirin-clopidogrel combination from 2000 to 2007. Clinical trial evidence suggests that the aspirin-clopidogrel combination does not provide any additional benefit compared with clopidogrel alone; however, our study findings indicate that even with lack of adequate clinical evidence physician prescribing of this combination has increased in real-world community settings.

Anticoagulation After Biological Aortic Valve Replacement: Is There An Optimal Regimen?

Science.gov (United States)

Owais, Tamer; Rouman, Mina; Breuer, Martin; Hüter, Lars; Fuchs, Jürgen; Lauer, Bernward; Kuntze, Thomas

2016-03-01

The anticoagulation of biological heart valves remains a 'hot spot' of discussion in various domains due to the risk of developing valve thrombosis and arterial thromboembolism. The situation has always been controversial, especially during the early postoperative phase. The American College of Cardiology/ American Heart Association and European Society of Cardiology guidelines recommend the use of warfarin for the first three months after biological aortic valve replacement (BAVR), although the American College of Chest Physicians guidelines suggest that these recommendations are experience-based and that the risk/benefit is unclear. The aim of the present study was to compare the efficacy of aspirin and warfarin in patients after BAVR. A total of 863 patients who underwent BAVR between 2008 and 2015 was allocated to two groups. Each group was managed with a specific anticoagulation regimen, with 430 patients receiving warfarin during the first three postoperative months, and 433 receiving aspirin. The major study end points were bleeding, cerebral ischemic events, and survival. In total, 10 and 15 postoperative cerebral ischemic events occurred between 24 h and three months after surgery in patients treated with aspirin and warfarin, respectively. After three months the incidence of cerebral ischemic events did not differ greatly between the two groups. The rate of major bleeding events and rates of stroke-free survival and overall survival were not statistically significant between the warfarin and aspirin groups. Plasma anticoagulation with warfarin during the early postoperative phase was shown statistically to be inferior to platelet aggregation inhibition by aspirin with regards to postoperative bleeding risk, cerebral ischemic events, and survival.

Predictors of premature clopidogrel discontinuation within 30 days of successful coronary artery stenting

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Çayan Cakir

2018-01-01

Full Text Available Objective: We aimed to determine the prevalence, predictors, and mortality rate of premature clopidogrel discontinuation within 30 days of successful coronary stenting. Methods: All consecutive patients who underwent successful coronary stent implantation at our hospital between December 2006 and December 2007 were prospectively included in this study. Patients were interviewed by telephone 30 days after stent implantation. Premature clopidogrel discontinuation was defined as follows: patients who did not continue clopidogrel after discharge were defined as “never used” and patients who received clopidogrel for <20 days or interrupted therapy for at least 5 successive days within the first 30 days were defined as “partially used.” Results: Follow-up data were available for 381 patients and 58 (15.2% patients reported premature clopidogrel discontinuation. No mortality and only 1 (0.3% stent thrombosis occurred in adherent patients, whereas there were 2 (3.4% mortalities and 6 (10.3% stent thrombosis in the patients who prematurely discontinued clopidogrel. Those who discontinued clopidogrel therapy were older (P = 0.02, more likely to be female (P = 0.02, single (P = 0.03, of lower economic (P < 0.05 and educational status (P < 0.01, more likely to have chronic disease (P = 0.04, less likely to have undergone previous stenting (P = 0.01, and were more likely to be receiving a larger number of drugs (P < 0.05. In multivariate analysis, low- or intermediate-economic status, no history of previous stent implantation, and total number of prescribed drugs using were factors independently associated with premature clopidogrel discontinuation. Conclusion: This study demonstrates several predictors of premature clopidogrel discontinuation. This data may help clinicians pay particular attention to these patients in an attempt to improve the outcomes of coronary stenting.

Strokes attributable to underuse of warfarin and antiplatelets

DEFF Research Database (Denmark)

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

2007-01-01

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...... 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...... not received warfarin or antiplatelets on admission, 27 had not received warfarin but had received antiplatelets, and 11 had received warfarin. Assuming that warfarin and antiplatelets reduces the risk of stroke by 66% and 25%, respectively, it was calculated that between 6 and 12 of these strokes with atrial...

Generic switching of warfarin and risk of excessive anticoagulation

DEFF Research Database (Denmark)

Hellfritzsch, Maja; Rathe, Jette; Stage, Tore Bjerregaard

2016-01-01

PURPOSE: Generic switching of warfarin was recently repealed in Denmark, as adverse drug reaction (ADR) reports suggested risk of excessive anticoagulation following switches from branded to generic warfarin. We investigated this putative association in a formalized pharmacoepidemiological analysis....... METHODS: We conducted a nationwide cohort study based on Danish healthcare registries, including data from the introduction of generic warfarin until the repeal (January 2011-April 2015). We followed Danish warfarin users over time and compared the rate of incident hospitalizations due to excessive...... anticoagulation (i.e. increased INR or any bleeding requiring hospitalization) in periods following a recent switch to generic warfarin to the rate in periods without a recent switch. RESULTS: We included 105,751 warfarin users, filling a total of 1,539,640 prescriptions for warfarin (2.5% for generic warfarin...

Updates on the Clinical Evidenced Herb-Warfarin Interactions

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Beikang Ge

2014-01-01

Full Text Available Increasing and inadvertent use of herbs makes herb-drug interactions a focus of research. Concomitant use of warfarin, a highly efficacious oral anticoagulant, and herbs causes major safety concerns due to the narrow therapeutic window of warfarin. This paper presents an update overview of clinical findings regarding herb-warfarin interaction, highlighting clinical outcomes, severity of documented interactions, and quality of clinical evidence. Among thirty-eight herbs, Cannabis, Chamomile, Cranberry, Garlic, Ginkgo, Grapefruit, Lycium, Red clover, and St. John’s wort were evaluated to have major severity interaction with warfarin. Herbs were also classified on account of the likelihood of their supporting evidences for interaction. Four herbs were considered as highly probable to interact with warfarin (level I, three were estimated as probable (level II, and ten and twenty-one were possible (level III and doubtful (level IV, respectively. The general mechanism of herb-warfarin interaction almost remains unknown, yet several pharmacokinetic and pharmacodynamic factors were estimated to influence the effectiveness of warfarin. Based on limited literature and information reported, we identified corresponding mechanisms of interactions for a small amount of “interacting herbs.” In summary, herb-warfarin interaction, especially the clinical effects of herbs on warfarin therapy should be further investigated through multicenter studies with larger sample sizes.

Graves’ Disease and Treatment Effects on Warfarin Anticoagulation

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Amanda Howard-Thompson

2014-01-01

Full Text Available Background. Hyperthyroidism causes an increased hypoprothrombinemic response to warfarin anticoagulation. Previous studies have demonstrated that patients with hyperthyroidism require lower dosages of warfarin to achieve a therapeutic effect. As hyperthyroidism is treated and euthyroidism is approached, patients may require increasing warfarin dosages to maintain appropriate anticoagulation. We describe a patient’s varying response to warfarin during treatment of Graves’ disease. Case Presentation. A 48-year-old African American female presented to the emergency room with tachycardia, new onset bilateral lower extremity edema, gradual weight loss, palpable goiter, and generalized sweating over the prior 4 months. She was admitted with Graves’ disease and new onset atrial fibrillation. Primary stroke prophylaxis was started using warfarin; the patient developed a markedly supratherapeutic INR likely due to hyperthyroidism. After starting methimazole, her free thyroxine approached euthyroid levels and the INR became subtherapeutic. She remained subtherapeutic over several months despite steadily increasing dosages of warfarin. Immediately following thyroid radioablation and discontinuation of methimazole, the patient’s warfarin dose and INR stabilized. Conclusion. Clinicians should expect an increased response to warfarin in patients with hyperthyroidism and close monitoring of the INR is imperative to prevent adverse effects. As patients approach euthyroidism, insufficient anticoagulation is likely without vigilant follow-up, INR monitoring, and increasing warfarin dosages.

Influence of aspirin and non-aspirin NSAID use on ovarian and endometrial cancer

DEFF Research Database (Denmark)

Verdoodt, F.; Kjaer, S. K.; Friis, S.

2017-01-01

Increasing evidence supports a role for aspirin use in reducing the incidence and mortality of several cancer types. This has spurred a new wave of interest in this widely used drug. In this review, we present and evaluate the epidemiologic evidence of the association between the use of aspirin....... Overall, observational studies indicate modest reductions in risk of ovarian and endometrial cancer with aspirin use, whereas the results for non-aspirin NSAID use are equivocal. The strongest inverse associations have been reported for long-term consistent aspirin use, notably among subgroups of users (e.......g., those with high body mass index). Few studies have evaluated the influence of NSAID use on the mortality of ovarian or endometrial cancer, and substantial heterogeneity of study characteristics and results preclude any conclusions. Additional studies of aspirin and non-aspirin NSAID use and ovarian...

Risk of Hemorrhage during Needle-Based Ophthalmic Regional Anesthesia in Patients Taking Antithrombotics: A Systematic Review.

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Augusto Takaschima

Full Text Available Patients undergoing ophthalmic surgery are usually elderly and, due to systemic disease, may be on long-term therapy, such as antithrombotic agents. Rates of hemorrhagic complications associated with invasive procedures may be increased by the use of anticoagulants and antiplatelet agents.To compare the incidence of hemorrhagic complications in patients undergoing needle-based ophthalmic regional anesthesia between patients on antithrombotic therapy and those not on such therapy.A systematic review was conducted by two independent reviewers based on searches of Cochrane, LILACS, PubMed, Scopus, Web of Science, and the "gray" literature (Google Scholar. The end search date was May 8, 2015, across all databases.Five studies met the eligibility criteria. In three studies, individual risk of bias was low, and in two of them, moderate. In all studies, no differences regarding mild to moderate incidence of hemorrhagic complications were found between patients using antithrombotics (aspirin, clopidogrel, and warfarin and those not using them. Rates of severe hemorrhagic complication were very low (0.04% in both groups, supporting the safety of needle blocks, even in patients using antithrombotics. High heterogeneity across studies prevented meta-analysis. Limitations to these results include low statistical power in three experimental studies and a large 95% confidence interval in the two retrospective cohorts.In this review, none of the selected studies showed significant bleeding related to needle-based ophthalmic regional anesthesia in association with the use of aspirin, clopidogrel, or vitamin K inhibitors. Since the available data is not powerful enough to provide a reliable evaluation of the true effect of antithrombotics in this setting, new studies to address these limitations are necessary.

Increased platelet aggregation and turnover in the acute phase of ST-elevation myocardial infarction

DEFF Research Database (Denmark)

Jensen, Kristian Løkke Funck; Dalsgaard, Jens; Grove, Erik Lerkevang

2013-01-01

Newly produced platelets are present in the acute phase of ST-elevation myocardial infarction (STEMI). This may influence the antiplatelet effect of aspirin and clopidogrel administered prior to primary percutaneous coronary intervention (PPCI). The aims of this study were to investigate the anti...... turnover may partly explain the reduced efficacy of antiplatelet drugs in the acute phase of STEMI....... the antiplatelet effect of aspirin and clopidogrel and evaluate platelet turnover in the acute phase of STEMI compared to a stable phase 3 months later. In this observational follow-up study on 48 STEMI patients transferred for PPCI, loading doses of aspirin (300 mg) and clopidogrel (600 mg) were given orally...... in the ambulance. Blood samples were obtained immediately prior to PPCI, at 4 and 12 hours after administration of bolus doses and at follow-up after 3 months. Residual platelet aggregation was evaluated by Multiplate® and VerifyNow® aggregometry. Platelet turnover was evaluated by automated flow cytometry...

Warfarin-induced leukocytoclastic vasculitis and proteinuria

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Khalid Jumean

2016-01-01

Full Text Available Warfarin is typically prescribed for patients with thromboembolic diseases and atrial fibrillation. In addition to the complications of bleeding, allergic skin reaction is one of its rare adverse effects. We herein report a case of a 79 year old male patient with leukocytoclastic vasculitis and proteinuria secondary to warfarin. The warfarin was discontinued and oral prednisone therapy was initiated. The cutaneous lesions and the proteinuria resolved thereafter.

Warfarin Poisoning with Delayed Rebound Toxicity.

Science.gov (United States)

Berling, Ingrid; Mostafa, Ahmed; Grice, Jeffrey E; Roberts, Michael S; Isbister, Geoffrey K

2017-02-01

Intentional poisoning with warfarin is not the same as over-anticoagulation, for which guidelines exist. The coagulopathy resulting from a warfarin overdose is reversed with vitamin K 1 , the dose and timing of which is often guided by experience with the management of over-anticoagulation with warfarin therapy, rather than acute overdose. We report a case of a 50-year-old man who ingested an unknown amount of his warfarin, venlafaxine, and paracetamol. He presented with an international normalized ratio (INR) of 2.5, which steadily increased over 24 h to 7, despite receiving an initial 1 mg of vitamin K 1 . He was then treated with 5 mg vitamin K 1 , and once the INR returned to 4.5, 40 h post ingestion, he was discharged home. He was also treated with a full course of acetylcysteine for the paracetamol overdose. The following day his INR rebounded to 8.5 and he suffered a spontaneous epistaxis requiring readmission; he was treated with low titrated doses of vitamin K 1 . The warfarin concentration was 74.6 μg/mL 26 h post ingestion and decreased to 3.7 μg/mL over 72 h. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Our case highlights the risk of a rebound elevated INR even 3 days after acute warfarin overdose despite treatment with vitamin K 1 . Understanding the pharmacokinetics of vitamin K 1 in comparison with warfarin, repeat INR testing, and continued treatment with oral vitamin K 1 may help avoid complications of rebound coagulopathy in warfarin overdose. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Preliminary clinical evaluation of a noninvasive device for the measurement of coagulability in the elderly.

Science.gov (United States)

Lerman, Yaffa; Werber, Moshe M; Fine, Ilya; Kemelman, Polina

2011-01-01

The feasibility of the noninvasive assessment of blood 'coagulability' (the tendency to coagulate) has been tested by using a novel device, the Thrombo-Monitor. It monitors, by using the principles of near infra-red (NIR) dynamic light scattering, the tendency of blood to create clots. The Thrombo-Monitor observes the very initial changes of blood viscosity, which occurs due to the temporarily induced stasis of capillary blood of the finger. One hundred and fifteen patients aged >65 years (matched by age and sex) participated in the study. Patients were initially divided into four groups based on the patient's medical therapy. The study groups were: warfarin, enoxaparin, aspirin and/or clopidogrel, and a control group. The medications were given according to the patient's comorbidities (eg, atrial fibrillation [AF], status post pulmonary embolism [S/p PE], status post cerebrovascular accident [S/p CVA]). The Thrombo-Monitor Index (TMI) is a noninvasive index, derived on the basis of laboratory test results of international normalized ratio (INR) and prothrombin time (PT) values. For the group of patients who were treated only with warfarin, TMI was adjusted by using the jackknife statistical approach to create maximum correlation and linearity with INR and PT values that ranged from 1.1 to 5.0. For all warfarin patients (N = 35) the TMI was found to have a good correlation with INR and PT values (R(2) = 0.64, P index is significantly correlated with INR and PT values.

Longitudinal assessment of thrombin generation potential in response to alteration of antiplatelet therapy after TIA or ischaemic stroke.

LENUS (Irish Health Repository)

Tobin, W O

2013-02-01

The impact of changing antiplatelet therapy on thrombin generation potential in patients with ischaemic cerebrovascular disease (CVD) is unclear. We assessed patients within 4 weeks of TIA or ischaemic stroke (baseline), and then 14 days (14d) and >90 days (90d) after altering antiplatelet therapy. Thrombin generation was assessed in platelet poor plasma. Ninety-one patients were recruited. Twenty-four were initially assessed on no antiplatelet therapy, and then after 14d (N = 23) and 90d (N = 8) on aspirin monotherapy; 52 were assessed on aspirin monotherapy, and after 14 and 90 days on aspirin and dipyridamole combination therapy; 21 patients were assessed on aspirin and after 14 days (N = 21) and 90 days (N = 19) on clopidogrel. Peak thrombin generation and endogenous thrombin potential were reduced at 14 and 90 days (p ≤ 0.04) in the overall cohort. We assessed the impact of individual antiplatelet regimens on thrombin generation parameters to investigate the cause of this effect. Lag time and time-to-peak thrombin generation were unchanged at 14 days, but reduced 90 days after commencing aspirin (p ≤ 0.009). Lag time, peak thrombin generation and endogenous thrombin potential were reduced at both 14 and 90 days after adding dipyridamole to aspirin (p ≤ 0.01). Lag time was reduced 14 days after changing from aspirin to clopidogrel (p = 0.045), but this effect was not maintained at 90 days (p = 0.2). This pilot study did not show any consistent effects of commencing aspirin, or of changing from aspirin to clopidogrel on thrombin generation potential during follow-up. The addition of dipyridamole to aspirin led to a persistent reduction in peak and total thrombin generation ex vivo, and illustrates the diverse, potentially beneficial, newly recognised \\'anti-coagulant\\' effects of dipyridamole in ischaemic CVD.

Prevalence of Ex Vivo High On-treatment Platelet Reactivity on Antiplatelet Therapy after Transient Ischemic Attack or Ischemic Stroke on the PFA-100(®) and VerifyNow(®).

LENUS (Irish Health Repository)

Kinsella, Justin A

2012-09-12

BACKGROUND: The prevalence of ex vivo high on-treatment platelet reactivity (HTPR) to commonly prescribed antiplatelet regimens after transient ischemic attack (TIA) or ischemic stroke is uncertain. METHODS: Platelet function inhibition was simultaneously assessed with modified light transmission aggregometry (VerifyNow; Accumetrics Inc, San Diego, CA) and with a moderately high shear stress platelet function analyzer (PFA-100; Siemens Medical Solutions USA, Inc, Malvern, PA) in a pilot, cross-sectional study of TIA or ischemic stroke patients. Patients were assessed on aspirin-dipyridamole combination therapy (n = 51) or clopidogrel monotherapy (n = 25). RESULTS: On the VerifyNow, HTPR on aspirin was identified in 4 of 51 patients (8%) on aspirin-dipyridamole combination therapy (≥550 aspirin reaction units on the aspirin cartridge). Eleven of 25 (44%) patients had HTPR on clopidogrel (≥194 P2Y12 reaction units on the P2Y12 cartridge). On the PFA-100, 21 of 51 patients (41%) on aspirin-dipyridamole combination therapy had HTPR on the collagen-epinephrine (C-EPI) cartridge. Twenty-three of 25 patients (92%) on clopidogrel had HTPR on the collagen-adenosine diphosphate (C-ADP) cartridge. The proportion of patients with antiplatelet HTPR was lower on the VerifyNow than PFA-100 in patients on both regimens (P < .001). CONCLUSIONS: The prevalence of ex vivo antiplatelet HTPR after TIA or ischemic stroke is markedly influenced by the method used to assess platelet reactivity. The PFA-100 C-ADP cartridge is not sensitive at detecting the antiplatelet effects of clopidogrel ex vivo. Larger prospective studies with the VerifyNow and with the PFA-100 C-EPI and recently released Innovance PFA P2Y cartridges (Siemens Medical Solutions USA, Inc) in addition to newer tests of platelet function are warranted to assess whether platelet function monitoring predicts clinical outcome in ischemic cerebrovascular disease.

EVALUATION OF COST-EFFECTIVENESS OF PLATELET REACTIVITY ANALYSIS USING THE VERIFYNOW P2Y12 ASSAY IN PATIENTS AFTER ACUTE CORONARY SYNDROME

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A. V. Rudakova

2015-09-01

Full Text Available Dual antiplatelet therapy, including clopidogrel and aspirin, in a significant share of patients after acute coronary syndrome (ACS is characterized by high level of platelet reactivity, which is associated with an increased incidence of cardiovascular events. Perhaps it will make reasonable the prescription of new antiplatelet drugs, particularly the combination of ticagrelor with aspirin.Aim. To assess the cost-effectiveness of VerifyNow P2Y12 platelet reactivity testing in patients after ACS.Material and methods. The analysis was performed for patients aged 55 years after ACS by modeling based on the results of the PLATO trial considering Russian epidemiological data. The time horizon of simulation was 5 years. It was assumed that the patients were receiving either generic clopidogrel or ticagrelor for 1 year, or before maintenance treatment VerifyNow P2Y12 assay had been performed, and the patients with platelet reactivity index >230 24-48 hours after ACS were receiving ticagrelor and the remaining patients - generic clopidogrel. It was expected that after 1 year the patients would discontinue treatment with clopidogrel or ticagrelor, and hereafter additional therapeutic effect of their use would be absent. The costs of antiplatelet agents in the reference case corresponded to the weighted average price of public procurement in 2013 in Russia. The costs of treatment of complications corresponded to the compulsory health insurance rates for St. Petersburg in 2014. The cost and life expectancy were discounted at 3.5% per year.Results. The platelet reactivity test and the prescription by its results of the combination of clopidogrel plus aspirin or ticagrelor plus aspirin can prevent 5 myocardial infarction and 6 deaths per 1000 patients additionally as compared with the prescription of clopidogrel plus aspirin combination to all patients. The costs for one additional year of life as compared with the combination of clopidogrel plus aspirin

ORIGINAL ARTICLES Warfarin-induced skin necrosis in HIV-1 ...

African Journals Online (AJOL)

F Bhaijee, H Wainwright, G Meintjes, R J Wilkinson, G Todd, E de Vries, D J Pepper. Warfarin-induced skin necrosis (WISN) is a rare complication of warfarin ..... first few days of warfarin therapy.2,11 Warfarin is a vitamin K antagonist and ...

Use of warfarin in long-term care: a systematic review

Science.gov (United States)

2012-01-01

Background The use of warfarin in older patients requires special consideration because of concerns with comorbidities, interacting medications, and the risk of bleeding. Several studies have suggested that warfarin may be underused or inconsistently prescribed in long-term care (LTC); no published systematic review has evaluated warfarin use for stroke prevention in this setting. This review was conducted to summarize the body of published original research regarding the use of warfarin in the LTC population. Methods A systematic literature search of the PubMed, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Library was conducted from January 1985 to August 2010 to identify studies that reported warfarin use in LTC. Studies were grouped by (1) rates of warfarin use and prescribing patterns, (2) association of resident and institutional characteristics with warfarin prescribing, (3) prescriber attitudes and concerns about warfarin use, (4) warfarin management and monitoring, and (5) warfarin-related adverse events. Summaries of study findings and quality assessments of each study were developed. Results Twenty-two studies met the inclusion criteria for this review. Atrial fibrillation (AF) was the most common indication for warfarin use in LTC and use of warfarin for stroke survivors was common. Rates of warfarin use in AF were low in 5 studies, ranging from 17% to 57%. These usage rates were low even among residents with high stroke risk and low bleeding risk. Scored bleeding risk had no apparent association with warfarin use in AF. In physician surveys, factors associated with not prescribing warfarin included risk of falls, dementia, short life expectancy, and history of bleeding. International normalized ratio was in the target range approximately half of the time. The combined overall rate of warfarin-related adverse events and potential events was 25.5 per 100 resident months on warfarin therapy. Conclusions Among residents with AF

Aspirin induces IL-4 production: augmented IL-4 production in aspirin-exacerbated respiratory disease

Science.gov (United States)

Kong, Su-Kang; Soo Kim, Byung; Gi Uhm, Tae; Soo Chang, Hun; Sook Park, Jong; Woo Park, Sung; Park, Choon-Sik; Chung, Il Yup

2016-01-01

Aspirin hypersensitivity is a hallmark of aspirin-exacerbated respiratory disease (AERD), a clinical syndrome characterized by the severe inflammation of the respiratory tract after ingestion of cyclooxygenase-1 inhibitors. We investigated the capacity of aspirin to induce interleukin-4 (IL-4) production in inflammatory cells relevant to AERD pathogenesis and examined the associated biochemical and molecular pathways. We also compared IL-4 production in peripheral blood mononuclear cells (PBMCs) from patients with AERD vs aspirin-tolerant asthma (ATA) upon exposure to aspirin. Aspirin induced IL-4 expression and activated the IL-4 promoter in a report assay. The capacity of aspirin to induce IL-4 expression correlated with its activity to activate mitogen-activated protein kinases, to form DNA–protein complexes on P elements in the IL-4 promoter and to synthesize nuclear factor of activated T cells, critical transcription factors for IL-4 transcription. Of clinical importance, aspirin upregulated IL-4 production twice as much in PBMCs from patients with AERD compared with PBMCs from patients with ATA. Our results suggest that IL-4 is an inflammatory component mediating intolerance reactions to aspirin, and thus is crucial for AERD pathogenesis. PMID:27534531

Laboratory assessment of anti-thrombotic therapy in heart failure, atrial fibrillation and coronary artery disease: insights using thrombelastography and a micro-titre plate assay of thrombogenesis and fibrinolysis.

Science.gov (United States)

Lau, Y C; Xiong, Q; Ranjit, P; Lip, G Y H; Blann, A D

2016-08-01

As heart failure, coronary artery disease and atrial fibrillation all bring a risk of thrombosis, anti-thrombotic therapy is recommended. Despite such treatment, major cardiovascular events such as myocardial infarction and stroke still occur, implying inadequate suppression of thrombus formation. Accordingly, identification of patients whose haemostasis remains unimpaired by treatment is valuable. We compared indices for assessing thrombogenesis and fibrinolysis by two different techniques in patients on different anti-thrombotic agents, i.e. aspirin or warfarin. We determined fibrin clot formation and fibrinolysis by a microplate assay and thromboelastography, and platelet marker soluble P selectin in 181 patients with acute or chronic heart failure, coronary artery disease who were taking either aspirin or warfarin. Five thromboelastograph indices and four microplate assay indices were different on aspirin versus warfarin (p indices rate of clot formation and rate of clot dissolution were independently related to aspirin or warfarin use (p ≤ 0.001). Five microplate assay indices, but no thrombelastograph index, were different (p indices were different (p ≤ 0.002) in warfarin users. The microplate assay indices of lag time and rate of clot formation were abnormal in chronic heart failure patients on aspirin, suggesting increased risk of thrombosis despite anti-platelet use. Soluble P selectin was lower in patients on aspirin (p = 0.0175) but failed to correlate with any other index of haemostasis. The microplate assay shows promise as a tool for dissecting thrombogenesis and fibrinolysis in cardiovascular disease, and the impact of antithrombotic therapy. Prospective studies are required to determine a role in predicting thrombotic risk.

[Aspirin and colorectal cancer].

Science.gov (United States)

Grancher, Adrien; Michel, Pierre; Di Fiore, Frédéric; Sefrioui, David

2018-02-01

Colorectal cancer is a worldwide public health problem. Aspirin has been identified as a protective factor against the apparition of colorectal cancer. There are several mechanisms about the actions by aspirin on colorectal tumorogenesis. These are not perfectly known nowadays. On one hand, there are direct mechanisms on colorectal mucosa, on the other hand there are indirect mechanisms through platelet functions. Aspirin also plays a role by its anti-inflammatory action and the stimulation of antitumor immunity. Several studies show that long-term treatment with low-doses of aspirin decreases the incidence of adenomas and colorectal cancers. In the United States, aspirin is currently recommended for primary prevention of the risk of colorectal cancer in all patients aged 50 to 59, with a 10-year risk of cardiovascular event greater than 10 %. However, primary prevention with aspirin should not be a substitute for screening in colorectal cancer. Furthermore, aspirin seems to be beneficial when used in post-diagnosis of colorectal cancer. It could actually decrease the risk of metastasis in case of a localized colorectal cancer, and increase the survival in particular, concerning PIK3CA mutated tumors. The association of aspirin with neoadjuvant treatment of colorectal cancer by radiochimiotherapy seems to have beneficial effects. French prospective randomized study is currently being conducted to investigate postoperative aspirin in colorectal cancers with a PIK3CA mutation. Copyright © 2017 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

A Novel Multiplex HRM Assay to Detect Clopidogrel Resistance.

Science.gov (United States)

Zhang, Lichen; Ma, Xiaowei; You, Guoling; Zhang, Xiaoqing; Fu, Qihua

2017-11-22

Clopidogrel is an antiplatelet medicine used to prevent blood clots in patients who have had a heart attack, stroke, or other symptoms. Variability in the clinical response to clopidogrel treatment has been attributed to genetic factors. In particular, five SNPs of rs4244285, rs4986893, rs12248560, rs662 and rs1045642 have been associated with resistance to clopidogrel therapy in Chinese population. This work involves the development of a multiplex high-resolution melting (HRM) assay to genotype all five of these loci in 2 tubes. Amplicons corresponding to distinct SNPs in a common tube were designed with the aid of uMelt prediction software to have different melting temperatures Tm by addition of a GC-rich tail to the 5' end of the certain primers. Two kinds of commercial methods, Digital Fluorescence Molecular Hybridization (DFMH) and Sanger sequencing, were used as a control. Three hundred sixteen DFMH pretested samples from consecutive acute coronary syndrome patients were used for a blinded study of multiplex HRM. The sensitivity of HRM was 100% and the specificity was 99.93% reflecting detection of variants other than the known resistance SNPs. Multiplex HRM is an effective closed-tube, highly accurate, fast, and inexpensive method for genotyping the 5 clopidogrel resistance associated SNPs.

Feasibility of implementing a comprehensive warfarin pharmacogenetics service.

Science.gov (United States)

Nutescu, Edith A; Drozda, Katarzyna; Bress, Adam P; Galanter, William L; Stevenson, James; Stamos, Thomas D; Desai, Ankit A; Duarte, Julio D; Gordeuk, Victor; Peace, David; Kadkol, Shrihari S; Dodge, Carol; Saraf, Santosh; Garofalo, John; Krishnan, Jerry A; Garcia, Joe G N; Cavallari, Larisa H

2013-11-01

To determine the procedural feasibility of a pharmacist-led interdisciplinary service for providing genotype-guided warfarin dosing for hospitalized patients newly starting warfarin. Prospective observational study. A 438-bed tertiary care hospital affiliated with a large academic institution. Eighty patients who started warfarin therapy and were managed by a newly implemented pharmacogenetics service. All patients received routine warfarin genotyping and clinical pharmacogenetics consultation. The primary outcomes were percentage of genotype-guided dose recommendations available prior to the second warfarin dose and adherence of the medical staff to doses recommended by the pharmacogenetics service. Of 436 genotype orders placed during the first 6 months of the service, 190 (44%) were deemed appropriate. For the 80 patients on the service who consented to data collection, 76% of the genotypes were available prior to the second warfarin dose. The median (range) time from genotype order to genotype result was 26 hours (7-80 hrs), and the time to genotype-guided dose recommendation was 30 hours (7-80 hrs). A total of 73% of warfarin doses ordered by the medical staff were within 0.5 mg of the daily dose recommended by the pharmacogenetics consult service. Providing routine genotype-guided warfarin dosing supported by a pharmacogenetics consult service is feasible from a procedural standpoint, with most genotypes available prior to the second warfarin dose and good adherence to genotype-guided dose recommendations by the medical staff. © 2013 Pharmacotherapy Publications, Inc.

Long-term sinonasal outcomes of aspirin desensitization in aspirin exacerbated respiratory disease.

Science.gov (United States)

Cho, Kyu-Sup; Soudry, Ethan; Psaltis, Alkis J; Nadeau, Kari C; McGhee, Sean A; Nayak, Jayakar V; Hwang, Peter H

2014-10-01

This study aimed to assess sinonasal outcomes in patients with aspirin exacerbated respiratory disease (AERD) undergoing aspirin desensitization following endoscopic sinus surgery (ESS). Case series with chart review. University hospital. A retrospective review of sinonasal outcomes was conducted for 30 AERD patients undergoing aspirin desensitization and maintenance therapy following ESS. Sinonasal outcomes were prospectively assessed by the Sinonasal Outcomes Test-22 (SNOT-22) and endoscopic polyp grading system. Data were collected preoperatively, 1 and 4 weeks postsurgery (before desensitization), and 1, 6, 12, 18, 24, and 30 months after aspirin desensitization. Twenty-eight of 30 patients (93.3%) successfully completed aspirin desensitization, whereas 2 of 30 (6.7%) were unable to complete desensitization due to respiratory intolerance. Of the 21 patients who successfully completed a minimum of 24 weeks of follow-up, 20 (95.2%) patients demonstrated sustained endoscopic and symptomatic improvement for a median follow-up period of 33 months. After surgical treatment but before desensitization, patients experienced significant reductions in SNOT-22 and polyp grade scores. In the first 6 months after aspirin desensitization, patients experienced further significant reductions in SNOT-22 scores, whereas polyp grade remained stable. The improvements in symptom endoscopic scores were preserved throughout the follow-up period after desensitization. No patients required additional sinus surgery. One patient had to discontinue aspirin therapy due to gastrointestinal side effects. No other adverse reactions to aspirin were noted. Aspirin desensitization following ESS appears to be a well-tolerated and effective adjunctive therapy for long-term control of nasal polyposis in patients with AERD. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

Validation of Clinical Testing for Warfarin Sensitivity

Science.gov (United States)

Langley, Michael R.; Booker, Jessica K.; Evans, James P.; McLeod, Howard L.; Weck, Karen E.

2009-01-01

Responses to warfarin (Coumadin) anticoagulation therapy are affected by genetic variability in both the CYP2C9 and VKORC1 genes. Validation of pharmacogenetic testing for warfarin responses includes demonstration of analytical validity of testing platforms and of the clinical validity of testing. We compared four platforms for determining the relevant single nucleotide polymorphisms (SNPs) in both CYP2C9 and VKORC1 that are associated with warfarin sensitivity (Third Wave Invader Plus, ParagonDx/Cepheid Smart Cycler, Idaho Technology LightCycler, and AutoGenomics Infiniti). Each method was examined for accuracy, cost, and turnaround time. All genotyping methods demonstrated greater than 95% accuracy for identifying the relevant SNPs (CYP2C9 *2 and *3; VKORC1 −1639 or 1173). The ParagonDx and Idaho Technology assays had the shortest turnaround and hands-on times. The Third Wave assay was readily scalable to higher test volumes but had the longest hands-on time. The AutoGenomics assay interrogated the largest number of SNPs but had the longest turnaround time. Four published warfarin-dosing algorithms (Washington University, UCSF, Louisville, and Newcastle) were compared for accuracy for predicting warfarin dose in a retrospective analysis of a local patient population on long-term, stable warfarin therapy. The predicted doses from both the Washington University and UCSF algorithms demonstrated the best correlation with actual warfarin doses. PMID:19324988

COST-EFFECTIVENESS OF APIXABAN AS COMPARED WITH WARFARIN AND ACETYLSALICYLIC ACID IN PATIENTS WITH NON-VALVULAR ATRIAL FIBRILLATION IN THE RUSSIAN FEDERATION

Directory of Open Access Journals (Sweden)

A. V. Rudakova

2015-09-01

-adjusted life year (QALY gained and corresponded to the three times GDP per capita in 2013 in the Russian Federation. Sensitivity analysis explored the impact of the treatment discontinuation rates, patients’ age and quality of INR monitoring on the cost-effectiveness of apixaban.Results. In the base case analysis it was demonstrated that apixaban as compared with warfarin and acetylsalicylic acid provided additional 0.187 and 0.255 life years as well as additional 0.187 and 0.214 QALYs respectively. Over lifetime horizon apixaban as compared with warfarin and aspirin required additional treatment costs equal to 112.72 and 101.35 thousands rubles, respectively. With that estimated incremental cost-effectiveness ratio for apixaban as compared with warfarin and acetylsalicylic acid was 603.92 and 473.02 thousands rubles per QALY respectively. The results were robust in sensitivity analysis.Conclusions. Apixaban is expected to be a cost-effective alternative to warfarin and acetylsalicylic acid in patients with NVAF from the Russian Federation national health care system perspective. Apixaban may be recommended for inclusion into formulary reimbursement lists as an alternative to warfarin.

COST-EFFECTIVENESS OF APIXABAN AS COMPARED WITH WARFARIN AND ACETYLSALICYLIC ACID IN PATIENTS WITH NON-VALVULAR ATRIAL FIBRILLATION IN THE RUSSIAN FEDERATION

Directory of Open Access Journals (Sweden)

A. V. Rudakova

2014-01-01

-adjusted life year (QALY gained and corresponded to the three times GDP per capita in 2013 in the Russian Federation. Sensitivity analysis explored the impact of the treatment discontinuation rates, patients’ age and quality of INR monitoring on the cost-effectiveness of apixaban.Results. In the base case analysis it was demonstrated that apixaban as compared with warfarin and acetylsalicylic acid provided additional 0.187 and 0.255 life years as well as additional 0.187 and 0.214 QALYs respectively. Over lifetime horizon apixaban as compared with warfarin and aspirin required additional treatment costs equal to 112.72 and 101.35 thousands rubles, respectively. With that estimated incremental cost-effectiveness ratio for apixaban as compared with warfarin and acetylsalicylic acid was 603.92 and 473.02 thousands rubles per QALY respectively. The results were robust in sensitivity analysis.Conclusions. Apixaban is expected to be a cost-effective alternative to warfarin and acetylsalicylic acid in patients with NVAF from the Russian Federation national health care system perspective. Apixaban may be recommended for inclusion into formulary reimbursement lists as an alternative to warfarin.

Optimal initial dose adjustment of warfarin in orthopedic patients.

Science.gov (United States)

Lenzini, Petra A; Grice, Gloria R; Milligan, Paul E; Gatchel, Susan K; Deych, Elena; Eby, Charles S; Burnett, R Stephen J; Clohisy, John C; Barrack, Robert L; Gage, Brian F

2007-11-01

Warfarin sodium is commonly prescribed for the prophylaxis and treatment of venous thromboembolism. Dosing algorithms have not been widely adopted because they require a fixed initial warfarin dose (eg, 5 mg) and are not tailored to other factors that may affect the international normalized ratio (INR). To develop an algorithm that could predict a therapeutic warfarin dose based on drug interactions, INR response after the initial warfarin doses, and other clinical factors. We used stepwise regression to quantify the relationship between these factors in patients beginning prophylactic warfarin therapy immediately prior to joint replacement. In the derivation cohort (n = 271), we separately modeled the therapeutic dose after 2 and 3 initial doses. We prospectively validated these 2 models in an independent cohort (n = 105). About half of the therapeutic dose variability was predictable after 3 days of therapy: R2 was 53% in the derivation cohort and 42% in the validation cohort. INR response after 3 warfarin doses (INR3) inversely correlated with therapeutic dose (p < 0.001). Intraoperative blood loss transiently, but significantly, elevated the postoperative INR values. Other significant (p < 0.03) predictors were the first and second warfarin doses (+7% and +6%, respectively, per 1 mg), and statin use (-15.0%). The model derived after 2 warfarin doses explained 32% of the variability in therapeutic dose. We developed and validated algorithms that estimate therapeutic warfarin doses based on clinical factors and INR response available after 2-3 days of warfarin therapy. The algorithms are implemented online at www.WarfarinDosing.org.

[Enantioselective determinination of R-warfarin/S-warfarin in human plasma using liquid chromatography-tandem mass spectrometry and its application in a drug-drug interaction study].

Science.gov (United States)

Jin, Shu; Zhang, Yi-Fan; Chen, Xiao-Yan; Liu, Ke; Zhong, Da-Fang

2012-01-01

To study the drug-drug interaction of morinidazole and warfarin and its application, a sensitive and rapid liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of R-warfarin/S-warfarin in human plasma. In a random, two-period crossover study, 12 healthy volunteers received a single oral dose of 5 mg racemic warfarin in the absence and presence of morinidazole. Blood samples were collected according to a pre-designed time schedule. R-warfarin, S-warfarin and methyclothiazide were extracted with ethylether : methylenechloride (3 : 2), then separated on a Astec Chirobiotic V (150 mm x 4.6 mm ID, 5 microm) column using 5 mmol x L(-1) ammonium acetate (pH 4.0) - acetonitrile as mobile phase at a flow-rate of 1.5 mL x min(-1). The mobile phase was splitted and 0.5 mL x min(-1) was introduced into MS. A tandem mass spectrometer equipped with electrospray ionization source was used as detector and operated in the negative ion mode. Quantification was performed using multiple reaction monitoring (MRM). The resolution of warfarin enantiomers is 1.56. The linear calibration curves for R-warfarin and S-warfarin both were obtained in the concentration range of 5 - 1 000 ng x mL(-1). Intra- and inter-day relative standard deviation (RSD) for R-warfarin and S-warfarin over the entire concentration range across three validation runs was both less than 10%, and relative error (RE) ranged from -4.9% to 0.7%, separately. The method herein described is effective and convenient, and suitable for the study of metabolic interaction between morinidazole and warfarin. The results showed that coadministration of warfarin with morinidazole did not affect the pharmacokinetics of either R-warfarin or S-warfarin.

Warfarin use in hemodialysis patients: what is the risk?

LENUS (Irish Health Repository)

Phelan, P J

2011-03-01

Background: There is a paucity of data concerning the risks associated with warfarin in hemodialysis (HD) patients. We compared major bleeding episodes in this group with HD patients not receiving warfarin and with a cohort of non-HD patients receiving warfarin. Methods: A retrospective review of 141 HD patients on warfarin (HDW), 704 HD patients not on warfarin (HDNW) and 3,266 non-dialysis warfarin patients (NDW) was performed. Hospital admissions for hemorrhagic events and ischemic strokes were examined as was hospital length of stay and blood product use. INR variability was also assessed. Results: The incidence rates for major hemorrhage per 100 patient years was 10.8 in the HDW group as compared to 8.0 in the HDNW (p = 0.593) and 2.1 in the NDW (p < 0.001) groups. Mean units of red blood cell transfusions required was higher in patients on dialysis with no significant difference between HDW and HDNW groups. The risk of ischemic stroke per 100 patient years was 1.7 in the HDW group as compared to 0.7 in the HDNW groups (p = 0.636) and 0.4 in the NDW (p = 0.003). The HDW group had higher inter-measurement INR variability compared to the NDW group (p = 0.034). In patients with atrial fibrillation, HDW group had a higher incidence of ischemic stroke than the NDW group (2.2 versus 0.4 events per 100 patient years; p = 0.024). Conclusions: This study confirms the higher bleeding risk associated with HD\\/ESRD but suggests that warfarin use in these patients may not add significantly to this risk. We also demonstrated high rates of ischemic stroke in HD patients despite warfarin use. Summary: Our study compares the frequency of major hemorrhage and secondarily, ischemic stroke in HD patients receiving or not receiving warfarin, with non-HD patients receiving warfarin. The major finding was that frequency of hemorrhage was higher in HD patients receiving warfarin than in non-HD patients receiving warfarin, but not different in HD patients with or without warfarin. A

Warfarin use in hemodialysis patients: what is the risk?

LENUS (Irish Health Repository)

Phelan, P J

2012-02-01

BACKGROUND: There is a paucity of data concerning the risks associated with warfarin in hemodialysis (HD) patients. We compared major bleeding episodes in this group with HD patients not receiving warfarin and with a cohort of non-HD patients receiving warfarin. METHODS: A retrospective review of 141 HD patients on warfarin (HDW), 704 HD patients not on warfarin (HDNW) and 3,266 non-dialysis warfarin patients (NDW) was performed. Hospital admissions for hemorrhagic events and ischemic strokes were examined as was hospital length of stay and blood product use. INR variability was also assessed. RESULTS: The incidence rates for major hemorrhage per 100 patient years was 10.8 in the HDW group as compared to 8.0 in the HDNW (p = 0.593) and 2.1 in the NDW (p < 0.001) groups. Mean units of red blood cell transfusions required was higher in patients on dialysis with no significant difference between HDW and HDNW groups. The risk of ischemic stroke per 100 patient years was 1.7 in the HDW group as compared to 0.7 in the HDNW groups (p = 0.636) and 0.4 in the NDW (p = 0.003). The HDW group had higher inter-measurement INR variability compared to the NDW group (p = 0.034). In patients with atrial fibrillation, HDW group had a higher incidence of ischemic stroke than the NDW group (2.2 versus 0.4 events per 100 patient years; p = 0.024). CONCLUSIONS: This study confirms the higher bleeding risk associated with HD\\/ESRD but suggests that warfarin use in these patients may not add significantly to this risk. We also demonstrated high rates of ischemic stroke in HD patients despite warfarin use. SUMMARY: Our study compares the frequency of major hemorrhage and secondarily, ischemic stroke in HD patients receiving or not receiving warfarin, with non-HD patients receiving warfarin. The major finding was that frequency of hemorrhage was higher in HD patients receiving warfarin than in non-HD patients receiving warfarin, but not different in HD patients with or without warfarin. A

Interaktion mellem warfarin og oral miconazol-gel

DEFF Research Database (Denmark)

Ogard, C G; Vestergaard, Henrik

2000-01-01

We report a case of a 76 year-old woman who had been taking warfarin for seven years because of relapsing deep venous thrombosis. Her daily maintenance dose was 5 mg. Monthly measurements of international normalised ratio (INR) were stable between 2-3. She developed oral candidiasis and miconazole...... gel was prescribed. One week later she developed bleeding gums. Eight days later she was admitted to the hospital with haematuria. INR was > 10. Warfarin and the miconazole gel were withdrawn. She was treated with phytonadione. INR normalised after four days and she continued warfarin treatment....... Caution should be exercised whenever the combination of warfarin and miconazole gel are prescribed....

Aspirin resistance following pediatric cardiac surgery.

Science.gov (United States)

Cholette, Jill M; Mamikonian, Lara; Alfieris, George M; Blumberg, Neil; Lerner, Norma B

2010-09-01

Aspirin is often used to prevent thrombosis in pediatric cardiac surgery. The primary study aim was to assess aspirin resistance in this context. Secondary aims were to evaluate (1) the relationship between elevated inflammatory markers and thrombosis and (2) aspirin's effect on these levels. This was a prospective observational study of children undergoing cardiac surgery managed with and without aspirin. Aspirin response was assessed using the VerifyNow system and urinary 11-dehydrothromboxane B2 (uTxB2) measurements. Laboratory studies of inflammation were also obtained. 101 subjects were studied; 50 received aspirin. Six subjects (5.9%), 5 aspirin-treated, experienced symptomatic thrombosis. When measured by VerifyNow resistance was 43% after aspirin suppositories and 14% after additional days of oral aspirin. There was no correlation with thrombosis. Upper quartile post-operative day (POD) #5 uTxB2 was correlated with thrombosis in aspirin treated subjects (pchildren with high levels of uTxB2 despite aspirin therapy and/or those with elevated preoperative CRP are at increased risk for thrombosis. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Population pharmacokinetic analysis of clopidogrel in healthy Jordanian subjects with emphasis optimal sampling strategy.

Science.gov (United States)

Yousef, A M; Melhem, M; Xue, B; Arafat, T; Reynolds, D K; Van Wart, S A

2013-05-01

Clopidogrel is metabolized primarily into an inactive carboxyl metabolite (clopidogrel-IM) or to a lesser extent an active thiol metabolite. A population pharmacokinetic (PK) model was developed using NONMEM(®) to describe the time course of clopidogrel-IM in plasma and to design a sparse-sampling strategy to predict clopidogrel-IM exposures for use in characterizing anti-platelet activity. Serial blood samples from 76 healthy Jordanian subjects administered a single 75 mg oral dose of clopidogrel were collected and assayed for clopidogrel-IM using reverse phase high performance liquid chromatography. A two-compartment (2-CMT) PK model with first-order absorption and elimination plus an absorption lag-time was evaluated, as well as a variation of this model designed to mimic enterohepatic recycling (EHC). Optimal PK sampling strategies (OSS) were determined using WinPOPT based upon collection of 3-12 post-dose samples. A two-compartment model with EHC provided the best fit and reduced bias in C(max) (median prediction error (PE%) of 9.58% versus 12.2%) relative to the basic two-compartment model, AUC(0-24) was similar for both models (median PE% = 1.39%). The OSS for fitting the two-compartment model with EHC required the collection of seven samples (0.25, 1, 2, 4, 5, 6 and 12 h). Reasonably unbiased and precise exposures were obtained when re-fitting this model to a reduced dataset considering only these sampling times. A two-compartment model considering EHC best characterized the time course of clopidogrel-IM in plasma. Use of the suggested OSS will allow for the collection of fewer PK samples when assessing clopidogrel-IM exposures. Copyright © 2013 John Wiley & Sons, Ltd.

Optimizing clopidogrel dose response: a new clinical algorithm comprising CYP2C19 pharmacogenetics and drug interactions

Directory of Open Access Journals (Sweden)

Saab YB

2015-09-01

Full Text Available Yolande B Saab,1 Rony Zeenny,2 Wijdan H Ramadan2 1School of Pharmacy, Pharmaceutical Sciences Department, 2School of Pharmacy, Pharmacy Practice Department, Lebanese American University, Byblos, Lebanon Purpose: Response to clopidogrel varies widely with nonresponse rates ranging from 4% to 30%. A reduced function of the gene variant of the CYP2C19 has been associated with lower drug metabolite levels, and hence diminished platelet inhibition. Drugs that alter CYP2C19 activity may also mimic genetic variants. The aim of the study is to investigate the cumulative effect of CYP2C19 gene polymorphisms and drug interactions that affects clopidogrel dosing, and apply it into a new clinical-pharmacogenetic algorithm that can be used by clinicians in optimizing clopidogrel-based treatment. Method: Clopidogrel dose optimization was analyzed based on two main parameters that affect clopidogrel metabolite area under the curve: different CYP2C19 genotypes and concomitant drug intake. Clopidogrel adjusted dose was computed based on area under the curve ratios for different CYP2C19 genotypes when a drug interacting with CYP2C19 is added to clopidogrel treatment. A clinical-pharmacogenetic algorithm was developed based on whether clopidogrel shows 1 expected effect as per indication, 2 little or no effect, or 3 clinical features that patients experience and fit with clopidogrel adverse drug reactions. Results: The study results show that all patients under clopidogrel treatment, whose genotypes are different from *1*1, and concomitantly taking other drugs metabolized by CYP2C19 require clopidogrel dose adjustment. To get a therapeutic effect and avoid adverse drug reactions, therapeutic dose of 75 mg clopidogrel, for example, should be lowered to 6 mg or increased to 215 mg in patients with different genotypes. Conclusion: The implementation of clopidogrel new algorithm has the potential to maximize the benefit of clopidogrel pharmacological therapy

Topical Antimycotics for Oral Candidiasis in Warfarin Users.

Science.gov (United States)

Hellfritzsch, Maja; Pottegård, Anton; Pedersen, Andreas James Thestrup; Burghle, Alaa; Mouaanaki, Fatima; Hallas, Jesper; Grove, Erik Lerkevang; Damkier, Per

2017-04-01

Treatment for oral candidiasis in warfarin users may be complicated by drug-drug interactions (DDIs) between warfarin and topically applied antimycotics. However, current knowledge of these putative DDIs is merely based on case series. We therefore performed a cohort cross-over study with the objective to evaluate the potential DDIs between warfarin and miconazole oral gel or nystatin oral solution. The cohort consisted of individuals using warfarin in the period of 1998-2012 (n ≈ 7400). We collected data on cohort members' measurements of the international normalized ratio (INR) from a clinical database, and obtained information on their use of topically applied miconazole and nystatin from a regional prescription register. Potential DDIs were assessed by comparing INR values before and after initiation of an antimycotic drug. Among 17 warfarin users exposed to miconazole oral gel, the mean INR increased from 2.5 (95% CI: 2.1-2.8) to 3.8 (95% CI: 2.8-4.8) after exposure, corresponding to a mean INR increase of 1.4 (95% CI: 0.3-2.4). Among 30 warfarin users exposed to nystatin oral solution, the mean INR was 2.7 (95% CI: 2.3-3.1) before and 2.5 (95% CI: 2.2-2.9) after exposure. In conclusion, we found evidence supporting a clinically relevant drug-drug interaction between warfarin and miconazole oral gel. In contrast, we did not find any indication of an interaction between warfarin and nystatin oral solution. Nystatin rather than miconazole should be preferred when treating warfarin users for oral candidiasis. © 2016 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

Factors influencing warfarin control in Australia and Singapore.

Science.gov (United States)

Bernaitis, Nijole; Ching, Chi Keong; Teo, Siew Chong; Chen, Liping; Badrick, Tony; Davey, Andrew K; Crilly, Julia; Anoopkumar-Dukie, Shailendra

2017-09-01

Warfarin is widely used for patients with non-valvular atrial fibrillation (NVAF). Variations in warfarin control, as measured by time in therapeutic range (TTR), have been reported across different regions and ethnicities, particularly between Western and Asian countries. However, there is limited data on comparative factors influencing warfarin control in Caucasian and Asian patients. Therefore, the aim of this study was to determine warfarin control and potential factors influencing this in patients with NVAF in Australia and Singapore. Retrospective data was collected for patients receiving warfarin for January to June 2014 in Australia and Singapore. TTR was calculated for individuals with mean patient TTR used for analysis. Possible influential factors on TTR were analysed including age, gender, concurrent co-morbidities, and concurrent medication. The mean TTR was significantly higher in Australia (82%) than Singapore (58%). At both sites, chronic kidney disease significantly lowered this TTR. Further factors influencing control were anaemia and ageWarfarin control was significantly higher in Australia compared to Singapore, however chronic kidney disease reduced control at both sites. The different levels of control in these two countries, together with patient factors further reducing control may impact on anticoagulant choice in these countries with better outcomes from warfarin in Australia compared to Singapore. Copyright © 2017 Elsevier Ltd. All rights reserved.

New high-performance liquid chromatography method for the determination of (R)-warfarin and (S)-warfarin using chiral separation on a glycopeptide-based stationary phase.

Science.gov (United States)

Malakova, Jana; Pavek, Petr; Svecova, Lucie; Jokesova, Iveta; Zivny, Pavel; Palicka, Vladimir

2009-10-01

Warfarin is a well-known anticoagulant agent that occurs in two enantiomers, (R)-(+)-warfarin and (S)-(-)-warfarin. A new liquid chromatography method for the determination of both enantiomers was developed, validated and applied in in vitro studies with the aim of evaluating the accumulation of (R)-warfarin and (S)-warfarin in the hepatoma HepG2 cell line. OptiMEM cell cultivation medium samples and cellular lysates were purified using Waters Oasis MAX extraction cartridges. The chiral separation of warfarin and the internal standard p-chlorowarfarin enantiomers was performed on an Astec Chirobiotic V2 column at a flow rate of 1.2mL/min. The mobile phase was composed of 31% acetonitrile, 5% of methanol and 64% of ammonium acetate buffer (10mmol/L, pH 4.1). The enantiomers were quantified using a fluorescence detector (lambda(excit)=320nm, lambda(emiss)=415nm). The limit of detection was found to be 0.121micromol/L of (S)-warfarin and 0.109micromol/L of (R)-warfarin. The range of applicability and linearity was estimated from 0.25 to 100micromol/L. The precision ranged from 1.3% to 12.2% of the relative standard deviation, and the accuracy reached acceptable values from 95.5% to 108.4%. The new bioanalytical method confirmed the same accumulation of (R)-warfarin and (S)-warfarin in the hepatoma HepG2 cell line.

The effect anticoagulation status on geriatric fall trauma patients.

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Coleman, Julia; Baldawi, Mustafa; Heidt, David

2016-12-01

This research study aims to identify the effect of anticoagulation status on hospital course, complications, and outcomes among geriatric fall trauma patients. The study design is a retrospective cohort study, looking at fall trauma among patients aged 60 to 80 years from 2009 to 2013 at a university hospital in the United States. The statistical analysis, conducted with SPSS software with a threshold for statistical significance of P patients included in this study was 1,121. Compared with patients not on anticoagulation, there was a higher LOS among patients on anticoagulation (6.3 ± 6.2 vs 4.9 ± 5.2, P = .001). A higher LOS (7.2 ± 6.8 vs 5.0 ± 5.3, P = .001) and days in the ICU (2.1 ± 5.4 vs 1.1 ± 3.8, P = .010) was observed in patients on warfarin. A higher mortality (7.1% vs 2.8%, P = .013), LOS (6.3 ± 6.2 vs 5.1 ± 5.396, P = .036), and complication rate (49.1 vs 36.7, P = .010) was observed among patients on clopidogrel. In this study, a higher mortality and complication rate were seen among clopidogrel, and a greater LOS and number of days in the ICU were seen in patients on warfarin. These differences are important, as they can serve as a screening tool for triaging the severity of a geriatric trauma patient's condition and complication risk. For patients on clopidogrel, it is essential that these patients are recognized early as high-risk patients who will need to be monitored more closely. For patients on clopidogrel or warfarin, bridging a patient's anticoagulation should be initiated as soon as possible to prevent unnecessary increased LOS. At last, these data also provide support against prescribing patients clopidogrel when other anticoagulation options are available. Published by Elsevier Inc.

Taking Aspirin to Protect Your Heart

Science.gov (United States)

Toolkit No. 23 Taking Aspirin to Protect Your Heart What can taking aspirin do for me? If you are at high risk for or if you have heart disease, taking a low dose aspirin every day may help. Aspirin can also help ...

Awareness of antiplatelet resistance in patient with repeated episodes of thrombotic events

Science.gov (United States)

Dalimunthe, N. N.; Hamonangan, R.; Antono, D.; Prasetya, I.; Rusdi, L.

2018-03-01

Antiplatelet has been the cornerstones management of acute coronary syndrome. However, numbers of patients on these agents had episodes of adverse cardiovascular events. A 65-year-old woman post cardiac coronary bypass surgery on dual antiplatelet therapy, Aspirin, and Clopidogrel underwent several episodes of thrombotic events despite good adhered to thedailyantiplatelet regimen.These recurrent events had led to clinical suspicious of antiplatelet resistance. Platelet function test was performed which indicates a poor platelet response to Clopidogrel. Clopidogrelwas discontinued and Ticagrelor was prescribed together with Aspirin. During two months of follow up, there is no episode of chest discomfort.

Aspirin increases mitochondrial fatty acid oxidation

International Nuclear Information System (INIS)

Uppala, Radha; Dudiak, Brianne; Beck, Megan E.; Bharathi, Sivakama S.; Zhang, Yuxun; Stolz, Donna B.; Goetzman, Eric S.

2017-01-01

The metabolic effects of salicylates are poorly understood. This study investigated the effects of aspirin on fatty acid oxidation. Aspirin increased mitochondrial long-chain fatty acid oxidation, but inhibited peroxisomal fatty acid oxidation, in two different cell lines. Aspirin increased mitochondrial protein acetylation and was found to be a stronger acetylating agent in vitro than acetyl-CoA. However, aspirin-induced acetylation did not alter the activity of fatty acid oxidation proteins, and knocking out the mitochondrial deacetylase SIRT3 did not affect the induction of long-chain fatty acid oxidation by aspirin. Aspirin did not change oxidation of medium-chain fatty acids, which can freely traverse the mitochondrial membrane. Together, these data indicate that aspirin does not directly alter mitochondrial matrix fatty acid oxidation enzymes, but most likely exerts its effects at the level of long-chain fatty acid transport into mitochondria. The drive on mitochondrial fatty acid oxidation may be a compensatory response to altered mitochondrial morphology and inhibited electron transport chain function, both of which were observed after 24 h incubation of cells with aspirin. These studies provide insight into the pathophysiology of Reye Syndrome, which is known to be triggered by aspirin ingestion in patients with fatty acid oxidation disorders. - Highlights: • Aspirin increases mitochondrial—but inhibits peroxisomal—fatty acid oxidation. • Aspirin acetylates mitochondrial proteins including fatty acid oxidation enzymes. • SIRT3 does not influence the effect of aspirin on fatty acid oxidation. • Increased fatty acid oxidation is likely due to altered mitochondrial morphology and respiration.

The Active Metabolite of Warfarin (3'-Hydroxywarfarin) and Correlation with INR, Warfarin and Drug Weekly Dosage in Patients under Oral Anticoagulant Therapy: A Pharmacogenetics Study.

Science.gov (United States)

Gemmati, Donato; Burini, Francesco; Talarico, Anna; Fabbri, Matteo; Bertocco, Cesare; Vigliano, Marco; Moratelli, Stefano; Cuneo, Antonio; Serino, Maria Luisa; Avato, Francesco Maria; Tisato, Veronica; Gaudio, Rosa Maria

2016-01-01

Warfarin oral anticoagulant therapy (OAT) requires regular and frequent drug adjustment monitored by INR. Interindividual variability, drug and diet interferences, and genetics (VKORC1 and CYP2C9) make the maintenance/reaching of stable INR a not so easy task. HPLC assessment of warfarin/enantiomers was suggested as a valid monitoring-tool along with INR, but definite results are still lacking. We evaluated possible correlations between INR, warfarin/3'-hydroxywarfarin, and drug weekly dosage aimed at searching novel alternatives to OAT monitoring. VKORC1/CYP2C9 pharmacogenetics investigation was performed to account for the known influence on warfarin homeostasis. 133 OAT patients were recruited and assessed for warfarin/3'-hydroxywarfarin serum levels (HPLC), INR, and VKORC1 and CYP2C9 genotypes. A subgroup of 52 patients were monitored in detail (5 consecutive controls; c0-c4) till the target INR was reached. Correlation analyses were performed in both groups. In the whole OAT group both warfarin and 3'-hydroxywarfarin correlate with INR at comparable degree (r2 = 0.0388 and 0.0362 respectively). Conversely, warfarin weekly dosage better correlates with warfarin than with 3'-hydroxywarfarin (r2 = 0.0975 and r2 = 0.0381 respectively), but considering together warfarin plus 3'-hydroxywarfarin the correlation strongly increased (r2 = 0.1114; ppharmacogenetics studies confirmed that patients carrying the VKORC1 variant-allele required lower warfarin maintenance dosage and that the combination of VKORC1 and CYP2C9 yielded a warfarin responsive index (WRI) inversely related to the number variant alleles. Our results overall suggest that 3'-hydroxywarfarin monitoring could be of great advantage in INR monitoring respect to classical warfarin assessment showing significant contribution also in multivariate analysis. Therefore, additional active metabolites should be recognized and investigated as novel useful indicators.

Aspirin for Primary Prevention.

Science.gov (United States)

Richman, Ilana B; Owens, Douglas K

2017-07-01

Aspirin reduces the risk of nonfatal myocardial infarction and stroke, and the risk of colorectal cancer. Aspirin increases the risk of gastrointestinal and intracranial bleeding. The best available evidence supports initiating aspirin in select populations. In 2016, the US Preventive Services Task Force recommended initiating aspirin for the primary prevention of both cardiovascular disease and colorectal cancer among adults ages 50 to 59 who are at increased risk for cardiovascular disease. Adults 60 to 69 who are at increased cardiovascular disease risk may also benefit. There remains considerable uncertainty about whether younger and older patients may benefit. Copyright © 2017 Elsevier Inc. All rights reserved.

Validation of clinical testing for warfarin sensitivity: comparison of CYP2C9-VKORC1 genotyping assays and warfarin-dosing algorithms.

Science.gov (United States)

Langley, Michael R; Booker, Jessica K; Evans, James P; McLeod, Howard L; Weck, Karen E

2009-05-01

Responses to warfarin (Coumadin) anticoagulation therapy are affected by genetic variability in both the CYP2C9 and VKORC1 genes. Validation of pharmacogenetic testing for warfarin responses includes demonstration of analytical validity of testing platforms and of the clinical validity of testing. We compared four platforms for determining the relevant single nucleotide polymorphisms (SNPs) in both CYP2C9 and VKORC1 that are associated with warfarin sensitivity (Third Wave Invader Plus, ParagonDx/Cepheid Smart Cycler, Idaho Technology LightCycler, and AutoGenomics Infiniti). Each method was examined for accuracy, cost, and turnaround time. All genotyping methods demonstrated greater than 95% accuracy for identifying the relevant SNPs (CYP2C9 *2 and *3; VKORC1 -1639 or 1173). The ParagonDx and Idaho Technology assays had the shortest turnaround and hands-on times. The Third Wave assay was readily scalable to higher test volumes but had the longest hands-on time. The AutoGenomics assay interrogated the largest number of SNPs but had the longest turnaround time. Four published warfarin-dosing algorithms (Washington University, UCSF, Louisville, and Newcastle) were compared for accuracy for predicting warfarin dose in a retrospective analysis of a local patient population on long-term, stable warfarin therapy. The predicted doses from both the Washington University and UCSF algorithms demonstrated the best correlation with actual warfarin doses.

Effect of age and sex on warfarin dosing

Directory of Open Access Journals (Sweden)

Khoury G

2014-07-01

Full Text Available Ghada Khoury,1 Marwan Sheikh-Taha2 1School of Pharmacy, 2Department of Pharmacy Practice, Lebanese American University, Byblos, Lebanon Objective: We examined the potential effect of sex and age on warfarin dosing in ambulatory adult patients. Methods: We conducted a retrospective chart review of patients attending an anticoagulation clinic. We included patients anticoagulated with warfarin for atrial fibrillation or venous thromboembolism who had a therapeutic international normalized ratio of 2–3 for 2 consecutive months. We excluded patients who had been on any drug that is known to have a major interaction with warfarin, smokers, and heavy alcohol consumers. Out of 340 screened medical records, 96 met the predetermined inclusion criteria. The primary outcome assessed was warfarin total weekly dose (TWD. Results: There was a statistically significant difference in the TWD among the ages (P<0.01; older patients required lower doses. However there was no statistically significant difference in the TWD between sexes (P=0.281. Conclusion: Age was found to have a significant effect on warfarin dosing. Even though women did require a lower TWD than men, this observation was not statistically significant. Keywords: warfarin, INR, anticoagulation, vitamin K antagonists, age

Warfarin: do we need genotype-based dose prediction?

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Yenny Yenny

2016-02-01

Full Text Available For the treatment and prevention of thrombo-embolic disease, the most frequently used anticoagulant drug worldwide is warfarin, an oral coumarin derivative, with more than 30 million prescriptions written for this drug in the United States in 2004.(1 The drug has a narrow therapeutic index and its metabolism varies by as much as a factor of 10 among individual patients, making warfarin therapy difficult to manage. Hemorrhagic complication rates of warfarin are estimated to be 5-7.9% for major (life threatening hemorrhage and 14-36% for minor hemorrhage (e.g. nosebleeds, microscopic hematuria.(2 This condition makes it difficult to establish the appropriate dose of warfarin.

Association of platelet responsiveness with clopidogrel metabolism: role of compliance in the assessment of "resistance".

Science.gov (United States)

Serebruany, Victor; Cherala, Ganesh; Williams, Craig; Surigin, Serge; Booze, Christopher; Kuliczkowski, Wiktor; Atar, Dan

2009-12-01

Noncompliance is probably the major cause of clopidogrel "resistance." However, noncompliance is difficult to prove without confirming that the drug has been administered. Therefore, detection of plasma clopidogrel and/or metabolite(s) as the reliable objective method to confirm compliance is important. We sought to correlate the inhibition of platelet aggregation (IPA) with plasma levels of unchanged clopidogrel (UC), active thiol metabolite (ATM), and inactive carboxyl metabolite (ICM) in a large cohort of patients with coronary artery disease and ischemic stroke treated with clopidogrel. We conducted secondary post-hoc analyses of IPA and plasma UC, ATM, and ICM in a dataset consisting of presumably compliant patients with coronary disease (n = 422) and post-stroke (n = 209). Overall noncompliance rate was 22% (n = 138), while such risks were significantly higher in stroke survivors (n = 79, or 38%) when compared to patients with coronary disease (14%; n = 59; P = .001). Only ICM (19,154 +/- 7,228 ng/ml) was suitable for detecting compliance, while UC (15.2 +/- 9.4 ng/ml), and ATM (8.1 +/- 3.7 ng/ml) in most cases are barely detectable, and diminish over time in the stored samples. The best correlation with IPA (r2 = 0.847) was observed for active metabolite, followed by unchanged clopidogrel (r2 = 0.602), and finally inactive metabolite (r2 = 0.529). The predictive value for noncompliance was also high for inactive metabolite (c-statistic = 0.911). Therapy with clopidogrel is associated with double-digit underestimated risks for noncompliance, especially in stroke survivors, supporting the hypothesis that lack of IPA, and clopidogrel "resistance" are attributed to hidden noncompliance. Plasma ICM, but not UC, or ATM is a useful marker to monitor compliance to clopidogrel in registries and clinical trials.

Use of clopidogrel in the reduction of myocardial damage during percutaneous coronary intervention

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Arijit Dasgupta

2009-03-01

Full Text Available Arijit Dasgupta, Debabrata MukherjeeGill Heart Institute, University of Kentucky, Lexington, KY, USAAbstract: It is estimated that approximately a quarter of patients undergoing coronary intervention may have significant post-procedural creatinine (CK/creatinine kinase myocardial band (CK-MB elevations and approximately half may have post-procedural troponin elevations. Current data suggest that periprocedural infarction is associated with short-, intermediate-, and long-term adverse outcomes, most notably mortality. This review examines the role of clopidogrel in decreasing periprocedural myonecrosis following percutaneous coronary intervention (PCI. Clopidogrel is an important pharmacologic agent used to reduce myocardial infarction post-coronary intervention as assessed directly by the evaluation of cardiac biomarkers and indirectly by the evaluation of short-term ischemic events. The optimal dose of clopidogrel is considered to be at least 300 mg given 6 to 15 hours prior to PCI but there is considerable evidence to suggest that a loading dose of 600 mg given 2 to 6 hours prior to PCI may be more efficacious in limiting post-coronary intervention events. The benefit obtained from clopidogrel appears independent of and incremental to that of other antiplatelet and antithrombotic agents used during and after coronary intervention.Keywords: percutaneous coronary intervention, myonecrosis, clopidogrel, antiplatelet agents, myocardial infarction 

LBA50 - Influence of concomitant clopidogrel consumption on development of paclitaxel-associated toxicity: A pharmacoepidemiological study

DEFF Research Database (Denmark)

K, Agergaard; Mau-Sørensen, M; Stage, Tore Bjerregaard

clopidogrel to a metabolite, which is a strong inhibitor of CYP2C8. To determine if this interaction has clinical relevance, we investigated whether concomitant clopidogrel and paclitaxel was associated with severe paclitaxel toxicity, primarily peripheral sensory neuropathy. Methods Patients concomitantly...... from medical charts by reviewers partially blinded to clopidogrel exposure. The association of clopidogrel use and development of paclitaxel induced neuropathy was evaluated over accumulated paclitaxel dose with censoring after 1500 mg using Cox-regression analysis with adjustment for high intensity...... neuropathy or worse. Clopidogrel use was associated with increased risk of neuropathy with hazard ratios of 1.7 (95% CI 0.9-3.0), 2.0 (1.0-3.9) and 2.3 (1.1-4.5) in overall unadjusted, high intensity paclitaxel unadjusted and high intensity paclitaxel full adjusted analyses, respectively. Conclusions...

Compound list: aspirin [Open TG-GATEs

Lifescience Database Archive (English)

Full Text Available aspirin ASA 00014 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/in_vitro/aspirin....Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vitro/aspirin....Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Single/aspirin....Rat.in_vivo.Liver.Single.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/aspirin.Rat.in_vivo.Liver.Repeat.zip ...

Topical Antimycotics for Oral Candidiasis in Warfarin Users

DEFF Research Database (Denmark)

Hellfritzsch, Maja; Pottegård, Anton; Pedersen, Andreas James Thestrup

2017-01-01

Treatment for oral candidiasis in warfarin users may be complicated by drug-drug interactions (DDIs) between warfarin and topically applied antimycotics. However, current knowledge of these putative DDIs is merely based on case series. We therefore performed a cohort cross-over study with the obj......Treatment for oral candidiasis in warfarin users may be complicated by drug-drug interactions (DDIs) between warfarin and topically applied antimycotics. However, current knowledge of these putative DDIs is merely based on case series. We therefore performed a cohort cross-over study...... increased from 2.5 (95% CI: 2.1-2.8) to 3.8 (95% CI: 2.8-4.8) after exposure, corresponding to a mean INR increase of 1.4 (95% CI: 0.3-2.4). Among 30 warfarin users exposed to nystatin oral solution, the mean INR was 2.7 (95% CI: 2.3-3.1) before and 2.5 (95% CI: 2.2-2.9) after exposure. In conclusion, we...

Warfarin dosage response related pharmacogenetics in Chinese population.

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Siyue Li

Full Text Available As the most frequently prescribed anticoagulant, warfarin has large inter-individual variability in dosage. Genetic polymorphisms could largely explain the differences in dosage requirement. rs9923231 (VKORC1, rs7294 (VKORC1, rs1057910 (CYP2C9, rs2108622 (CYP4F2, and rs699664 (GGCX involved in the warfarin action mechanism and the circulatory vitamin K were selected to investigate their polymorphism characteristics and their effects on the pharmacodynamics and pharmacokinetics of warfarin in Chinese population.220 patients with cardiac valve replacement were recruited. International normalized ratio and plasma warfarin concentrations were determined. The five genetic polymorphisms were genotyping by pyro-sequencing. The relationships of maintenance dose, plasma warfarin concentration and INR were assessed among groups categorized by genotypes.rs9923231 and rs7294 in VKORC1 had the analogous genotype frequencies (D': 0.969. 158 of 220 recruited individuals had the target INR (1.5-2.5. Patients with AA of rs9923231 and CC of rs7294 required a significantly lower maintenance dose and plasma concentration than those with AG and TC, respectively. The mean weekly maintenance dose was also significantly lower in CYP2C9 rs1057910 mutated heterozygote than in patients with the wild homozygote. Eliminating the influence from environment factors (age, body weight and gender, rs9923231 and rs1057910 could explain about 32.0% of the variability in warfarin maintenance dose; rs7294 could explain 26.7% of the variability in plasma concentration. For patients with allele G of rs9923231 and allele T of rs7294, higher plasma concentration was needed to achieve the similar goal INR.A better understanding of the genetic variants in individuals can be the foundation of warfarin dosing algorithm and facilitate the reasonable and effective use of warfarin in Chinese.

Aspirin in patients undergoing noncardiac surgery

DEFF Research Database (Denmark)

Devereaux, P J; Mrkobrada, Marko; Sessler, Daniel I

2014-01-01

BACKGROUND: There is substantial variability in the perioperative administration of aspirin in patients undergoing noncardiac surgery, both among patients who are already on an aspirin regimen and among those who are not. METHODS: Using a 2-by-2 factorial trial design, we randomly assigned 10......,010 patients who were preparing to undergo noncardiac surgery and were at risk for vascular complications to receive aspirin or placebo and clonidine or placebo. The results of the aspirin trial are reported here. The patients were stratified according to whether they had not been taking aspirin before...... the study (initiation stratum, with 5628 patients) or they were already on an aspirin regimen (continuation stratum, with 4382 patients). Patients started taking aspirin (at a dose of 200 mg) or placebo just before surgery and continued it daily (at a dose of 100 mg) for 30 days in the initiation stratum...

ANTICOAGULANT TREATMENT OF AF: FOCUS ON THE WARFARIN DOSAGE

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Y. Kovbasniuk

2015-10-01

  Summary Authors analyzed the results of some studies of AF and warfarin dosing. Than investigation of 75 patient with AF (permanent type was performed. According to demographic, anthropometric data and related conditions (diabetes mellitus type 2, myocardial infarction, acute cerebrovascular ischemia, pulmonary embolism, alcohol abuse - drinking more than one ounce of ≥3 weekly predictive model of warfarin dosing was developed: warfarin dose = 0.097 * BMI - 0.03 * AGE + 0.30 *ASS.Status+ 0.02 *WC+ 1, 88. After testing of final model authors concluded what derived formula was representative, to determine the optimal dose of warfarin given to patient based on demographic characteristics. Considering all of the abovementioned, this model can be recommended for use determining the treatment strategy in patients with AF. Keywords: anticoagulant treatment, warfarin, atrial fibrillation.

Evaluation of the effect of torsemide on warfarin dosage requirements.

Science.gov (United States)

Lai, Sophia; Momper, Jeremiah D; Yam, Felix K

2017-08-01

Background According to drug interaction databases, torsemide may potentiate the effects of warfarin. Evidence for this drug-drug interaction, however, is conflicting and the clinical significance is unknown. Objective The aim of this study is to evaluate the impact of torsemide initiation on warfarin dosage requirements. Setting This study was conducted at the Veterans Affairs Healthcare System in San Diego, California. Method A retrospective cohort study was conducted using Veterans Affairs data from patients who were converted from bumetanide to torsemide between March 2014 and July 2014. Patients were also prescribed and taking warfarin during the observation period. Warfarin dosage requirements were evaluated to determine if any changes occurred within the first 3 months of starting torsemide. Main outcome measure The primary outcome was the average weekly warfarin dose before and after torsemide initiation. Results Eighteen patients met study inclusion criteria. The weekly warfarin dose before and after initiation of torsemide was not significantly different (34 ± 15 and 34 ± 13 mg, p > 0.05). Of those eighteen patients, only two experienced elevations in INR that required a decrease in warfarin dosage after torsemide initiation. Between those two patients, dosage reductions ranged from 5.3 to 18%. Conclusion These results indicated that most patients did not require any warfarin dosage adjustments after torsemide was initiated. The potential for interaction, however, still exists. While empiric warfarin dosage adjustments are not recommended when initiating torsemide, increased monitoring is warranted to minimize the risk of adverse effects.

The Active Metabolite of Warfarin (3'-Hydroxywarfarin) and Correlation with INR, Warfarin and Drug Weekly Dosage in Patients under Oral Anticoagulant Therapy: A Pharmacogenetics Study

Science.gov (United States)

Talarico, Anna; Fabbri, Matteo; Bertocco, Cesare; Vigliano, Marco; Moratelli, Stefano; Cuneo, Antonio; Serino, Maria Luisa; Avato, Francesco Maria

2016-01-01

Objectives Warfarin oral anticoagulant therapy (OAT) requires regular and frequent drug adjustment monitored by INR. Interindividual variability, drug and diet interferences, and genetics (VKORC1 and CYP2C9) make the maintenance/reaching of stable INR a not so easy task. HPLC assessment of warfarin/enantiomers was suggested as a valid monitoring-tool along with INR, but definite results are still lacking. We evaluated possible correlations between INR, warfarin/3’-hydroxywarfarin, and drug weekly dosage aimed at searching novel alternatives to OAT monitoring. VKORC1/CYP2C9 pharmacogenetics investigation was performed to account for the known influence on warfarin homeostasis. Methods 133 OAT patients were recruited and assessed for warfarin/3’-hydroxywarfarin serum levels (HPLC), INR, and VKORC1 and CYP2C9 genotypes. A subgroup of 52 patients were monitored in detail (5 consecutive controls; c0-c4) till the target INR was reached. Correlation analyses were performed in both groups Results In the whole OAT group both warfarin and 3’-hydroxywarfarin correlate with INR at comparable degree (r2 = 0.0388 and 0.0362 respectively). Conversely, warfarin weekly dosage better correlates with warfarin than with 3’-hydroxywarfarin (r2 = 0.0975 and r2 = 0.0381 respectively), but considering together warfarin plus 3’-hydroxywarfarin the correlation strongly increased (r2 = 0.1114; pwarfarin (r2 = 0.2157 and r2 = 0.0549; p = 0.0005 and p = 0.0944 respectively) seeming less affected by drug adjustments in the subgroup of 52 patients who started OAT. The multivariate analyses aimed at estimating the true contribution of 3’-hydroxywarfarin on INR value ascribed it the unique significant value (p = 0.0021) in spite of warfarin who lost association. The pharmacogenetics studies confirmed that patients carrying the VKORC1 variant-allele required lower warfarin maintenance dosage and that the combination of VKORC1 and CYP2C9 yielded a warfarin responsive index (WRI

Effect of aspirin desensitization on T-cell cytokines and plasma lipoxins in aspirin-exacerbated respiratory disease.

Science.gov (United States)

Aksu, Kurtuluş; Kurt, Emel; Alatas, Özkan; Gülbas, Zafer

2014-01-01

The pathogenesis of aspirin-exacerbated respiratory disease (AERD) is thought to be based on, mainly, overproduction of eicosanoid lipid mediators and on defective anti-inflammatory regulators. Aspirin desensitization treatment, the mainstay of controlling asthma and rhinitis in AERD patients, however, is the least understood aspect of the disease. The study was designed to determine the effect of aspirin desensitization on T-lymphocyte cytokine expression and on plasma lipoxin levels in AERD. Spirometry, skin-prick test and asthma control test were documented and intracellular cytokine expression in T lymphocytes and plasma lipoxin levels were measured in 23 AERD patients, 17 aspirin-tolerant asthmatic (ATA) patients, and 16 healthy controls. In the AERD group nasal symptom and smell scores were assessed. Of the 23 AERD patients 15 accepted to undergo aspirin desensitization protocol and 14 of them were desensitized successfully. In the desensitized AERD group, cytokine and lipoxin measurements were repeated after 1-month aspirin treatment. CD4(+) IL-10 levels were higher in AERD patients than in healthy controls and CD4(+) interferon (IFN) gamma levels were higher in AERD and ATA patients than in controls. Plasma lipoxin-A4 and 15-epi-lipoxin-A4 levels were similar among the three study groups. In the AERD group, subjects underwent aspirin desensitization followed by a 1-month aspirin treatment. Clinical parameters improved and CD4(+) IFN-gamma levels decreased significantly. No significant change in lipoxin levels was recorded. CD4(+) IFN-gamma and CD4(+) IL-10 levels in AERD patients after 1-month aspirin desensitization treatment were similar to the healthy controls. The study confirms aspirin desensitization is effective clinically in AERD patients and suggests that IFN gamma and IL-10 expression in CD4(+) T lymphocytes may be related to the mechanism of action.

Determination of total and unbound warfarin and warfarin alcohols in human plasma by high performance liquid chromatography with fluorescence detection.

Science.gov (United States)

Lomonaco, Tommaso; Ghimenti, Silvia; Piga, Isabella; Onor, Massimo; Melai, Bernardo; Fuoco, Roger; Di Francesco, Fabio

2013-11-01

Two analytical procedures are presented for the determination of the total content and unbound fraction of both warfarin and warfarin alcohols in human plasma. Chromatographic separation was carried out in isocratic conditions at 25°C on a C-18 reversed-phase column with a mobile phase consisting of a 70% buffer phosphate 25mM at pH=7, 25% methanol and 5% acetonitrile at a flow rate of 1.2mL/min. Fluorescence detection was performed at 390nm (excitation wavelength 310nm). Neither method showed any detectable interference or matrix effect. Inter-day recovery of the total warfarin and warfarin alcohols at a concentration level of 1000ng/mL was 89±3% and 73±3%, respectively, whereas for their unbound fraction (at a concentration level of 10ng/mL) was 66±8% and 90±7%, respectively. The intra- and inter-day precision (assessed as relative standard deviation) was alcohols, respectively. The methods were successfully applied to a pooled plasma sample obtained from 69 patients undergoing warfarin therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparative bioequivalence assessment of aspirin tablets marketed ...

African Journals Online (AJOL)

Purpose: In the last few years, aspirin has become a life saver against cardiovascular accidents. This investigation was carried out to determine possible bioequivalence between regular aspirin and soluble aspirin tablets marketed in Nigeria. Methods: The in vivo bioavailability profiles of three commercial brands of aspirin ...

Effect of Smoking on Pharmacokinetics of Clopidogrel, an ...

African Journals Online (AJOL)

... in patients undergoing PCI. Keywords: Antiplatelet, Clopidogrel, Pharmacokinetics, Smoking, Cigarette ..... regimen of choice to prevent thrombotic complications. [2,16]. ... either the parent drug [19] or the carboxylic acid metabolite as an ...

Clopidogrel, a P2Y12 receptor antagonist, potentiates the inflammatory response in a rat model of peptidoglycan polysaccharide-induced arthritis.

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Analia E Garcia

Full Text Available The P2Y12 receptor plays a crucial role in the regulation of platelet activation by several agonists, which is irreversibly antagonized by the active metabolite of clopidogrel, a widely used anti-thrombotic drug. In this study, we investigated whether reduction of platelet reactivity leads to reduced inflammatory responses using a rat model of erosive arthritis. We evaluated the effect of clopidogrel on inflammation in Lewis rats in a peptidoglycan polysaccharide (PG-PS-induced arthritis model with four groups of rats: 1 untreated, 2 clopidogrel-treated, 3 PG-PS-induced, and 4 PG-PS-induced and clopidogrel-treated. There were significant differences between the PG-PS+clopidogrel group when compared to the PG-PS group including: increased joint diameter and clinical manifestations of inflammation, elevated plasma levels of pro-inflammatory cytokines (IL-1 beta, interferon (IFN gamma, and IL-6, an elevated neutrophil blood count and an increased circulating platelet count. Plasma levels of IL-10 were significantly lower in the PG-PS+clopidogrel group compared to the PG-PS group. Plasma levels of platelet factor 4 (PF4 were elevated in both the PG-PS and the PG-PS+clopidogrel groups, however PF4 levels showed no difference upon clopidogrel treatment, suggesting that the pro- inflammatory effect of clopidogrel may be due to its action on cells other than platelets. Histology indicated an increase in leukocyte infiltration at the inflammatory area of the joint, increased pannus formation, blood vessel proliferation, subsynovial fibrosis and cartilage erosion upon treatment with clopidogrel in PG-PS-induced arthritis animals. In summary, animals treated with clopidogrel showed a pro-inflammatory effect in the PG-PS-induced arthritis animal model, which might not be mediated by platelets. Elucidation of the mechanism of clopidogrel-induced cell responses is important to understand the role of the P2Y12 receptor in inflammation.

Clopidogrel, a P2Y12 receptor antagonist, potentiates the inflammatory response in a rat model of peptidoglycan polysaccharide-induced arthritis.

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Garcia, Analia E; Mada, Sripal R; Rico, Mario C; Dela Cadena, Raul A; Kunapuli, Satya P

2011-01-01

The P2Y12 receptor plays a crucial role in the regulation of platelet activation by several agonists, which is irreversibly antagonized by the active metabolite of clopidogrel, a widely used anti-thrombotic drug. In this study, we investigated whether reduction of platelet reactivity leads to reduced inflammatory responses using a rat model of erosive arthritis. We evaluated the effect of clopidogrel on inflammation in Lewis rats in a peptidoglycan polysaccharide (PG-PS)-induced arthritis model with four groups of rats: 1) untreated, 2) clopidogrel-treated, 3) PG-PS-induced, and 4) PG-PS-induced and clopidogrel-treated. There were significant differences between the PG-PS+clopidogrel group when compared to the PG-PS group including: increased joint diameter and clinical manifestations of inflammation, elevated plasma levels of pro-inflammatory cytokines (IL-1 beta, interferon (IFN) gamma, and IL-6), an elevated neutrophil blood count and an increased circulating platelet count. Plasma levels of IL-10 were significantly lower in the PG-PS+clopidogrel group compared to the PG-PS group. Plasma levels of platelet factor 4 (PF4) were elevated in both the PG-PS and the PG-PS+clopidogrel groups, however PF4 levels showed no difference upon clopidogrel treatment, suggesting that the pro- inflammatory effect of clopidogrel may be due to its action on cells other than platelets. Histology indicated an increase in leukocyte infiltration at the inflammatory area of the joint, increased pannus formation, blood vessel proliferation, subsynovial fibrosis and cartilage erosion upon treatment with clopidogrel in PG-PS-induced arthritis animals. In summary, animals treated with clopidogrel showed a pro-inflammatory effect in the PG-PS-induced arthritis animal model, which might not be mediated by platelets. Elucidation of the mechanism of clopidogrel-induced cell responses is important to understand the role of the P2Y12 receptor in inflammation.

Warfarin resumption following anticoagulant-associated intracranial hemorrhage: A systematic review and meta-analysis.

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Chai-Adisaksopha, Chatree; Iorio, Alfonso; Hillis, Christopher; Siegal, Deborah; Witt, Daniel M; Schulman, Sam; Crowther, Mark

2017-12-01

This study aims to assess the effect of warfarin resumption in patients who experienced warfarin-associated intracranial hemorrhage (ICH). We conducted a systematic review and meta-analysis of studies evaluating the outcomes of adult patients who survived warfarin-associated ICH. We included studies that compared patients who resumed warfarin versus those who did not. Of 3145 studies screened, ten observational studies were included in the final analysis. Death occurred in 181 of 968 patients (18.7%) who resumed warfarin and 834 of 2579 (32.3%) who did not resume warfarin (RR 0.51, 95% CI 0.34 to 0.76, P=0.0009). Ischemic stroke occurred in 32 of 902 (3.5%) patients who resumed warfarin and 172 of 2467 (7.0%) patients who did not resume warfarin (RR 0.56, 95% CI 0.39 to 0.82, P=0.002). Venous thromboembolism occurred in 4 of 224 (1.8%) patients who resumed warfarin and of 33 of 681 (4.8%) patients who did not resume warfarin (RR 0.39, 95% CI, 0.15 to 1.03, P=0.06). Recurrent ICH occurred in 200 of 2994 (6.7%) patients who resumed warfarin and 358 of 4652 (7.7%) patients who did not resume warfarin (RR 0.89, 95% CI 0.65 to 1.23, P=0.49). The study suggests that warfarin resumption is associated with significant reduction in ischemic stroke and venous thromboembolism when compared to no warfarin resumption in patients who experience warfarin-associated ICH. Although these results are strongly supportive of restarting anticoagulation, prospective studies are required to confirm our results due to the high likelihood of bias in the included studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aspirin, Butalbital, and Caffeine

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The combination of aspirin, butalbital, and caffeine comes as a capsule and tablet to take by mouth. It usually is taken every 4 ... explain any part you do not understand. Take aspirin, butalbital, and caffeine exactly as directed. Do not ...

Cytokine expression before and after aspirin desensitization therapy in aspirin-exacerbated respiratory disease.

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Aktas, Ayse; Kurt, Emel; Gulbas, Zafer

2013-12-01

Aspirin exacerbated respiratory disease (AERD) is induced by acetylsalicylic acid (ASA) and/or nonsteroidal antiinflammatory drugs (NSAIDs). Effects of desensitization on many mediators have been examined previously, but few studies addressed the influence of desensitization on T lymphocytes and T lymphocyte-derived cytokines. This study was performed to examine peripheral blood lymphocyte (PBL) cytokine expression in aspirin-sensitive patients who have asthma before and after aspirin desensitization. In this study, the release of interleukin-2 (IL-2), interleukin-4 (IL-4), and interferon-gamma (IFN-γ) by CD4+ T lymphocytes prior to aspirin desensitization were also measured at intracellular levels, and expression of these cytokines after 1 month aspirin desensitization was evaluated. Twelve patients with AERD were included in the study. Two different control groups were formed, one consisted of 15 healthy people and second 12 aspirin tolerant asthmatic (ATA) patients using aspirin. A blood sample was collected prior to desensitization, and the tests were repeated by taking a second blood sample 1 month after the 4-day desensitization treatment. The proportion of lymphocytes secreting IFN-γ in the study group was 15.61 ± 4.40 % before desensitization and 15.08 ± 5.89 % after desensitization. The rate of IFN-γ secreting CD4+ T lymphocytes was 20.51 ± 4.41 % in the normal control group and 16.07 ± 5.7 % in the ATA group (p = 0.021). The ratio of CD4+ T lymphocyte secreting IFN-γ was reduced in patients with AERD before desensitization compared to normal control group (p = 0.040). The levels of IL-2, IL-4, and the subsets of lymphocyte were not different before and after desensitization compared to control groups.

Clinical determinants of clopidogrel responsiveness in a heterogeneous cohort of Puerto Rican Hispanics.

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Hernandez-Suarez, Dagmar F; Scott, Stuart A; Tomey, Matthew I; Melin, Kyle; Lopez-Candales, Angel; Buckley, Charlotte E; Duconge, Jorge

2017-09-01

Clopidogrel is by far the most prescribed platelet adenosine diphosphate (ADP) antagonist in Puerto Rico despite the advent of newer agents (prasugrel and ticagrelor). Given the paucity of data on clopidogrel responsiveness in Hispanics, we sought to determine the association between clinical characteristics and platelet reactivity in Puerto Rican patients on clopidogrel therapy. A total of 100 Puerto Rican patients on clopidogrel therapy were enrolled and allocated into two groups: Group I, without high on-treatment platelet reactivity (HTPR); and Group II, with HTPR. Platelet function was measured ex vivo using the VerifyNow® P2Y12 assay. The cohort was comprised of Hispanic patients with coronary artery disease (57%), peripheral artery disease (32%), carotid artery stenosis (7%), cerebral artery aneurysm (2%), and stroke (2%). Mean platelet reactivity was 200 ± 61 P2Y12 reaction units (PRUs) (range: 8-324), and 35% of patients had HTPR (PRUs ⩾ 230). Multivariable logistic regression analysis determined that diabetes mellitus (DM) [odds ratio (OR) = 3.27; 95% confidence interval (CI): 1.20-8.96], use of proton-pump inhibitors (PPIs) (OR = 3.60; 95% CI: 1.09-11.82), and calcium channel blockers (CCBs) (OR = 3.10; 95% CI: 1.09-8.83) were independent predictors of HTPR ( p Puerto Rican Hispanic patients on clopidogrel, 35% had HTPR. Furthermore, DM, PPIs and CCBs predicted HTPR. Clinical outcome data are needed to identify appropriate PRU thresholds for risk prediction in the Puerto Rican population.

Triple antithrombotic therapy in patients with atrial fibrillation undergoing coronary artery stenting: hovering among bleeding risk, thromboembolic events, and stent thrombosis

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Menozzi Mila

2012-10-01

Full Text Available Abstract Dual antiplatelet treatment with aspirin and clopidogrel is the antithrombotic treatment recommended after an acute coronary syndrome and/or coronary artery stenting. The evidence for optimal antiplatelet therapy for patients, in whom long-term treatment oral anticoagulation is mandatory, is however scarce. To evaluate the safety and efficacy of the various antithrombotic strategies adopted in this population, we reviewed the available evidence on the management of patients receiving oral anticoagulation, such as a vitamin-k-antagonists, referred for coronary artery stenting. Atrial fibrillation is the most frequent indication for oral anticoagulation. The need of starting antiplatelet therapy in this clinical scenario raises concerns about the combination to choose: triple therapy with warfarin, aspirin, and a thienopyridine being the most frequent and advised. The safety of this regimen appeared suboptimal because of an increased risk in hemorrhagic complications. On the other hand, the combination of oral anticoagulation and an antiplatelet agent is suboptimal in preventing thromboembolic events and stent thrombosis; dual antiplatelet therapy may be considered only when a high hemorrhagic risk and low thromboembolic risk are perceived. Indeed, the need for prolonged multiple-drug antithrombotic therapy increases the bleeding risks when drug eluting stents are used. Since current evidence derives mainly from small, single-center and retrospective studies, large-scale prospective multicenter studies are urgently needed.

Aspirin plus dipyridamole versus aspirin alone after cerebral ischaemia of arterial origin (ESPRIT): randomised controlled trial.

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Halkes, P H A; van Gijn, J; Kappelle, L J; Koudstaal, P J; Algra, A

2006-05-20

Results of trials of aspirin and dipyridamole combined versus aspirin alone for the secondary prevention of vascular events after ischaemic stroke of presumed arterial origin are inconsistent. Our aim was to resolve this uncertainty. We did a randomised controlled trial in which we assigned patients to aspirin (30-325 mg daily) with (n=1363) or without (n=1376) dipyridamole (200 mg twice daily) within 6 months of a transient ischaemic attack or minor stroke of presumed arterial origin. Our primary outcome event was the composite of death from all vascular causes, non-fatal stroke, non-fatal myocardial infarction, or major bleeding complication, whichever happened first. Treatment was open, but auditing of outcome events was blinded. Primary analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial (number ISRCTN73824458) and with (NCT00161070). Mean follow-up was 3.5 years (SD 2.0). Median aspirin dose was 75 mg in both treatment groups (range 30-325); extended-release dipyridamole was used by 83% (n=1131) of patients on the combination regimen. Primary outcome events arose in 173 (13%) patients on aspirin and dipyridamole and in 216 (16%) on aspirin alone (hazard ratio 0.80, 95% CI 0.66-0.98; absolute risk reduction 1.0% per year, 95% CI 0.1-1.8). Addition of the ESPRIT data to the meta-analysis of previous trials resulted in an overall risk ratio for the composite of vascular death, stroke, or myocardial infarction of 0.82 (95% CI 0.74-0.91). Patients on aspirin and dipyridamole discontinued trial medication more often than those on aspirin alone (470 vs 184), mainly because of headache. The ESPRIT results, combined with the results of previous trials, provide sufficient evidence to prefer the combination regimen of aspirin plus dipyridamole over aspirin alone as antithrombotic therapy after cerebral ischaemia of arterial origin.

The potential drug-drug interaction between proton pump inhibitors and warfarin

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Henriksen, Daniel Pilsgaard; Stage, Tore Bjerregaard; Hansen, Morten Rix

2015-01-01

BACKGROUND: Proton pump inhibitors (PPIs) have been suggested to increase the effect of warfarin, and clinical guidelines recommend careful monitoring of international normalized ratio (INR) when initiating PPI among warfarin users. However, this drug-drug interaction is sparsely investigated...... in a clinical setting. The aim was to assess whether initiation of PPI treatment among users of warfarin leads to increased INR values. METHODS: The study was an observational self-controlled study from 1998 to 2012 leveraging data on INR measurements on patients treated with warfarin from primary care...... and outpatient clinics and their use of prescription drugs. Data were analyzed in 2015. We assessed INR, warfarin dose, and dose/INR ratio before and after initiating PPI treatment using the paired student's t-test. RESULTS: We identified 305 warfarin users initiating treatment with PPIs. The median age was 71...

Efficacy of Clopidogrel and Clinical Outcome When Clopidogrel Is Coadministered With Atorvastatin and Lansoprazole

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Zhang, Jian-rong; Wang, Di-qing; Du, Jun; Qu, Guang-su; Du, Jian-lin; Deng, Song-bai; Liu, Ya-jie; Cai, Jin-xi; She, Qiang

2015-01-01

Abstract This prospective, randomized, nonblind, controlled trial evaluated the effects of clopidogrel on platelet function upon coadministration with atorvastatin and lansoprazole. One hundred four adult patients with non-ST-segment elevated acute coronary syndrome (NSTE-ACS) who underwent percutaneous coronary intervention (PCI) with drug-eluting stent implantation were included. All patients were treated with standard dual antiplatelet therapy (DAPT) plus rosuvastatin 10 mg daily after the operation. On the sixth day after PCI, patients were randomly divided into 4 groups, Group A: DAPT + atorvastatin 20 mg daily (a change from rosuvastatin to atorvastatin) + lansoprazole 30 mg daily, Group B: DAPT + atorvastatin 20 mg daily (a change from rosuvastatin to atorvastatin), Group C: DAPT + lansoprazole 30 mg daily (continuing to take rosuvastatin), Group D is the control group. Additional drugs were used according to the situation of patients. Platelet function and concentrations of platelet activation markers (granular membrane protein 140 (P-selectin), thromboxane B2 (TXB2), and human soluble cluster of differentiation 40 ligand (sCD40L)) were assessed before randomization and at 15- and 30-day follow-up visits. All patients were maintained on treatment for 6 months and observed for bleeding and ischemic events. A total of 104 patients were enrolled, 27 patients in group A, 26 patients in Group B/C, 25 patients in Group D separately, and all the patients were analyzed. There were no differences in platelet function and the levels of platelet activation markers (P-selectin, TXB2, and sCD40L) among or within the 4 groups at the 3 time points of interest (P > 0.05). In the subsequent 6 months, no significant bleeding events occurred, and 12 patients experienced ischemic events, these results were also not significantly different among the groups (P > 0.05). In patients diagnosed with NSTE-ACS who have had drug-eluting stent

Effects of etravirine on the pharmacokinetics and pharmacodynamics of warfarin in rats

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John, J; John, M; Wu, L; Hsiao, C; Abobo, CV; Liang, D

2013-01-01

Background and Purpose Warfarin is often used with etravirine (ETV) to prevent HIV-related thromboembolic events. As both warfarin and ETV bind to plasma proteins and are metabolized by hepatic cytochrome P450s, they are likely to interact. Hence, we evaluated the effect of ETV on the pharmacokinetics and blood clotting time of racemic warfarin in rats. Experimental Approach Two groups of male Sprague-Dawley rats, in which the jugular vein had been cannulated, were studied. The control group (n = 10) received 1 mg·kg−1 racemic warfarin i.v., and the test group (n = 13) 1 mg·kg−1 of racemic warfarin followed by 25 mg·kg−1 ETV i.v. Serial blood samples were collected for up to 144 h and the blood clotting time (calculated as international normalized ratio [INR]) measured in blood plasma at each sample point. Plasma concentrations of R-warfarin, S-warfarin, R-7-hydroxywarfarin and S-7-hydroxywarfarin were measured by a LC/MS/MS method using a chiral lux cellulose-1 column. Pharmacokinetic parameters were analysed using non-compartmental methods. Key Results ETV significantly increased, by threefold, the systemic clearance and volume of distribution of S-warfarin, but not those of R-warfarin. ETV decreased the total AUC of warfarin, but had no effect on its elimination half-life. ETV also increased the systemic clearance of both R-7-hydroxywarfarin and S-7-hydroxywarfarin but only increased the volume of distribution of R-7-hydroxywarfarin. Interestingly, the effect of warfarin on blood clotting time (INR) was significantly increased in the presence of etravirine. Conclusion and Implications Our data suggest that etravirine may potentiate the anticoagulant effect of warfarin and this could have clinical significance. PMID:23215758

Long-term efficacy of aspirin desensitization in aspirin-exacerbated respiratory disease. Review of two clinical cases

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Julio César Cambray-Gutiérrez

2016-05-01

Clinical cases: two patients diagnosed with respiratory disease exacerbated by aspirin, with poor asthma control and need for multiple polypectomies, despite optimal pharmacological management, carrying out protocol desensitization to aspirin (AAS successful, now after 4 years of having carried out, they have adequate asthma control without need for polypectomies with a maintenance dose of aspirin 150 mg/day.

Population Impact of Drug Interactions with Warfarin

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Martín-Pérez, Mar; Gaist, David; de Abajo, Francisco J

2018-01-01

OBJECTIVE:  To investigate the population impact of previously reported interactions between warfarin and other drugs on international normalized ratio (INR) levels. METHODS:  Using The Health Improvement Network (THIN), a United Kingdom primary care database, a cohort of warfarin users between.......55) and in the proportion of patients with INR levels out of therapeutic range (population...

Aspirin challenge and desensitization: how, when and why.

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Cortellini, Gabriele; Caruso, Cristiano; Romano, Antonino

2017-08-01

To investigate the current approach to aspirin challenge (drug provocation) and/or desensitization in patients with histories of hypersensitivity reactions to it, particularly in those with cardiovascular diseases. The literature indicates that patients with coronary artery disease (CAD), including those with an acute coronary syndrome, may safely undergo low-dose aspirin challenge and/or desensitization. Recently, flowcharts regarding challenge/desensitization procedures with aspirin in patients with CAD and histories of aspirin hypersensitivity reactions have become available. Aspirin desensitization and continuous aspirin therapy constitute an effective option in patients with nonsteroidal anti-inflammatory drug-exacerbated respiratory diseases (NERD) who have suboptimally controlled asthma or rhinosinusitis, or require multiple revision polypectomies. The use of aspirin has proven to reduce morbidity and mortality associated with CAD. There is a general consensus on aspirin's effectiveness in secondary prevention of CAD. Therefore, aspirin desensitization is necessary in patients with CAD and histories of hypersensitivity reactions to it. The effectiveness of aspirin desensitization and continuous therapy in patients with NERD has been shown in numerous studies. However, shared selection criteria of candidates for aspirin challenge/desensitization procedures, and simple and homogeneous protocols are necessary. Moreover, preventive safety measures are still needed in order to reduce the potential risks of these procedures.

Daily Aspirin Therapy: Understand the Benefits and Risks

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Daily aspirin therapy: Understand the benefits and risks Daily aspirin therapy can be a lifesaving option, but it's not ... everyone. Get the facts before considering a daily aspirin. By Mayo Clinic Staff Daily aspirin therapy may ...

The Clopidogrel-PPI Interaction

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Juel, Jacob; Pareek, Manan; Jensen, Svend Eggert

2014-01-01

the potential for PPIs, especially omeprazole, to decrease the efficacy of clopidogrel, and both the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) have issued warnings regarding the concomitant use of these medications. A review of the literature revealed that the pharmacodynamic...... studies support an interaction, whereas the clinical evidence, which is mainly based on nonrandomized, observational studies and secondary analyses of randomized trials, is conflicting. We conclude that PPIs should be prescribed together with DAPT for patients in whom they are recommended according...

Warfarin accelerated vascular calcification and worsened cardiac dysfunction in remnant kidney mice

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Ming-Tsun Tsai

2018-04-01

Full Text Available Background: Vascular calcification is highly prevalent in end-stage renal disease (ESRD and is a significant risk factor for future cardiovascular events and death. Warfarin use results in dysfunction of matrix Gla protein, an inhibitor of vascular calcification. However, the effect of warfarin on vascular calcification in patients with ESRD is still not well characterized. Thus we investigated whether arterial calcification can be accelerated by warfarin treatment both in vitro and in vivo using a mouse remnant kidney model. Methods: Human aortic smooth muscle cells (HASMC were cultured in medium supplemented with warfarin and phosphate to investigate the potential role of this drug in osteoblast transdifferentiation. For in vivo study, adult male C57BL/6 mice underwent 5/6 nephrectomy were treated with active vitamin D3 plus warfarin to determine the extent of vascular calcification and parameters of cardiovascular function. Results: We found that the expressions of Runx2 and osteocalcin in HASMC were markedly enhanced in the culture medium containing warfarin and high phosphate concentration. Warfarin induced calcification of cultured HASMC in the presence of high phosphate levels, and this effect is inhibited by vitamin K2. Severe aortic calcification and reduced left ventricular ejection fractions were also noted in 5/6 nephrectomy mice treated with warfarin and active vitamin D3. Conclusion: Warfarin treatment contributes to the accelerated vascular calcification in animal models of advanced chronic kidney disease. Clinicians should therefore be aware of the profound risk of warfarin use on vascular calcification and cardiac dysfunction in patients with ESRD and atrial fibrillation. Keywords: Left ventricular dysfunction, Uremia, Vascular calcification, Warfarin

Update on antiplatelet agents, including MATCH, CHARISMA, and ESPRIT.

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Skliut, Maryna; Jamieson, Dara G

2008-02-01

Despite recent advances in the acute treatment of stroke, prevention and risk factor modification remain the mainstays of management for patients with ischemic stroke and transient ischemic attack. The majority of noncardioembolic ischemic strokes are atherothrombotic, presumed to be associated with the activation and aggregation of platelets. Antiplatelet medications have been shown to be effective in the secondary prevention of stroke of presumed arterial origin, both as monotherapy and in combination. Among combination of antiplatelet agents, aspirin plus extended-release dipyridamole has demonstrated statistically significant additive benefit over monotherapy with each agent. Clopidogrel plus aspirin does not prevent recurrent ischemic stroke over each component individually, and the combination increases the risk of hemorrhagic side effects. This article reviews the most recent studies on antiplatelet medications, including the combination of aspirin and clopidogrel or extended-release dipyridamole, and discusses some of the controversies that still exist with the use of antiplatelet agents.

Pharmacokinetics of warfarin in rats: role of serum protein binding and tissue distribution

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Cheung, W.K.

1985-01-01

The purpose of this study was to explore the role of serum protein binding and tissue distribution in the non-linear pharmacokinetics of warfarin in rats. The first phase of the research was an attempt to elucidate the causes of intersubject differences in serum protein binding of warfarin in rats. It was found that the distribution of S-warfarin between blood and liver, kidneys, muscle, or fatty tissue was non-linear. Based on the tissue distribution data obtained, a physiologically-based pharmacokinetic model was developed to describe the time course of S-warfarin concentrations in the serum and tissues of rats. The proposed model was able to display the dose-dependent pharmacokinetics of warfarin in rats. Namely a lower clearance and a smaller apparent volume of distribution with increasing dose, which appear to be due to the presence of capacity-limited, high-affinity binding sites for warfarin in various tissues. To determine if the binding of warfarin to the high-affinity binding sites in the liver of rats is reversible, concentrations of S-warfarin in the liver and serum of rats were monitored for a very long time after an intravenous injection of a 1 mg/kg dose. In another study in rats, non-radioactive warfarin was found to be able to displace tissue-bound C 14 -warfarin which was administered about 200 hours before the i.v. injection of the non-radioactive warfarin, showing that the binding of warfarin to the high-affinity binding sites in the body is persistent and reversible

A pharmacogenetics-based warfarin maintenance dosing algorithm from Northern Chinese patients.

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Jinxing Chen

Full Text Available Inconsistent associations with warfarin dose were observed in genetic variants except VKORC1 haplotype and CYP2C9*3 in Chinese people, and few studies on warfarin dose algorithm was performed in a large Chinese Han population lived in Northern China. Of 787 consenting patients with heart-valve replacements who were receiving long-term warfarin maintenance therapy, 20 related Single nucleotide polymorphisms were genotyped. Only VKORC1 and CYP2C9 SNPs were observed to be significantly associated with warfarin dose. In the derivation cohort (n = 551, warfarin dose variability was influenced, in decreasing order, by VKORC1 rs7294 (27.3%, CYP2C9*3(7.0%, body surface area(4.2%, age(2.7%, target INR(1.4%, CYP4F2 rs2108622 (0.7%, amiodarone use(0.6%, diabetes mellitus(0.6%, and digoxin use(0.5%, which account for 45.1% of the warfarin dose variability. In the validation cohort (n = 236, the actual maintenance dose was significantly correlated with predicted dose (r = 0.609, P<0.001. Our algorithm could improve the personalized management of warfarin use in Northern Chinese patients.

P2Y12 Receptor Antagonist, Clopidogrel, Does Not Contribute to Risk of Osteoporotic Fractures in Stroke Patients

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Jørgensen, Niklas R; Schwarz, Peter; Iversen, Helle K

2017-01-01

Background: Stroke is a leading cause of mortality and morbidity. It is associated with excessive bone loss and risk of fracture in stroke patients is high. The P2Y12R antagonist and platelet inhibitor, clopidogrel, is widely used for secondary prevention after a stroke. However, recent studies...... have shown that clopidogrel has negative effects on bone and that long-term clopidogrel use is associated with increased fracture risk. The purpose of the current study was therefore to investigate the association of clopidogrel treatment with risk of fractures in stroke and TIA patients.......Methods:The study was a cohort study including all subjects who were prescribed clopidogrel between 1996 and 2008 in Denmark (n= 77,503). Age- and gender matched controls (n= 232,510) were randomly selected from the background population. The study end-points were occurrence of stroke or TIA and occurrence...

Pharmacogenetic testing for clopidogrel using the rapid INFINITI analyzer: a dose-escalation study.

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Gladding, Patrick; White, Harvey; Voss, Jamie; Ormiston, John; Stewart, Jim; Ruygrok, Peter; Bvaldivia, Badi; Baak, Ruth; White, Catherine; Webster, Mark

2009-11-01

Our aim was to assess whether a higher clopidogrel maintenance dose has a greater antiplatelet effect in CYP2C19*2 allele carriers compared with noncarriers. Clopidogrel is a prodrug that is biotransformed by the cytochrome P450 enzymes CYP2C19, 2C9, and 3A4, 2B6, 1A2. The CYPC219*2 loss of function variant has been associated with a reduced antiplatelet response to clopidogrel and a 3-fold risk of stent thrombosis. Forty patients on standard maintenance dosage clopidogrel (75 mg), for 9.4 +/- 9.2 weeks, were enrolled into a dose escalation study. Platelet function was assessed at baseline and after 1 week of 150 mg once daily using the VerifyNow platelet function analyzer (Accumetrics Ltd., San Diego, California). Genomic DNA was hybridized to a BioFilmChip microarray on the INFINITI analyzer (AutoGenomics Inc., Carlsbad, California) and analyzed for the CYP19*2, *4, *17, and CYP2C9*2, *3 polymorphisms. Platelet inhibition increased over 1 week, mean +8.6 +/- 13.5% (p = 0.0003). Carriers of the CYP2C19*2 allele had significantly reduced platelet inhibition at baseline (median 18%, range 0% to 72%) compared with wildtype (wt) (median 59%, range 11% to 95%, p = 0.01) and at 1 week (p = 0.03). CYP2C19*2 allele carriers had an increase in platelet inhibition of (mean +9 +/- 11%, p = 0.03) and reduction in platelet reactivity (mean -26 +/- 38 platelet response unit, p = 0.04) with a higher dose. Together CYP2C19*2 and CYP2C9*3 loss of function carriers had a greater change in platelet inhibition with 150 mg daily than wt/wt (+10.9% vs. +0.7%, p = 0.04). Increasing the dose of clopidogrel in patients with nonresponder polymorphisms can increase antiplatelet response. Personalizing clopidogrel dosing using pharmacogenomics may be an effective method of optimizing treatment.

Clinical and Genetic Determinants of Warfarin Pharmacokinetics and Pharmacodynamics during Treatment Initiation

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Gong, Inna Y.; Schwarz, Ute I.; Crown, Natalie; Dresser, George K.; Lazo-Langner, Alejandro; Zou, GuangYong; Roden, Dan M.; Stein, C. Michael; Rodger, Marc; Wells, Philip S.; Kim, Richard B.; Tirona, Rommel G.

2011-01-01

Variable warfarin response during treatment initiation poses a significant challenge to providing optimal anticoagulation therapy. We investigated the determinants of initial warfarin response in a cohort of 167 patients. During the first nine days of treatment with pharmacogenetics-guided dosing, S-warfarin plasma levels and international normalized ratio were obtained to serve as inputs to a pharmacokinetic-pharmacodynamic (PK-PD) model. Individual PK (S-warfarin clearance) and PD (Imax) parameter values were estimated. Regression analysis demonstrated that CYP2C9 genotype, kidney function, and gender were independent determinants of S-warfarin clearance. The values for Imax were dependent on VKORC1 and CYP4F2 genotypes, vitamin K status (as measured by plasma concentrations of proteins induced by vitamin K absence, PIVKA-II) and weight. Importantly, indication for warfarin was a major independent determinant of Imax during initiation, where PD sensitivity was greater in atrial fibrillation than venous thromboembolism. To demonstrate the utility of the global PK-PD model, we compared the predicted initial anticoagulation responses with previously established warfarin dosing algorithms. These insights and modeling approaches have application to personalized warfarin therapy. PMID:22114699

Comparison and analysis on the serum-binding characteristics of aspirin-zinc complex and aspirin.

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Zhang, Hua-Xin; Zhang, Qun; Wang, Hong-Lin; Li, Li-Wei

2017-09-01

This study was designed to compare the protein-binding characteristics of aspirin-zinc complex (AZN) with those of aspirin itself. AZN was synthesized and interacted with a model transport protein, human serum albumin (HSA). Three-dimensional fluorescence, ultraviolet-visible and circular dichroism (CD) spectra were used to characterize the interaction of AZN with HSA under physiological conditions. The interaction mechanism was explored using a fluorescence quenching method and thermodynamic calculation. The binding site and binding locality of AZN on HSA were demonstrated using a fluorescence probe technique and Förster non-radiation energy transfer theory. Synchronous fluorescence and CD spectra were employed to reveal the effect of AZN on the native conformation of the protein. The HSA-binding results for AZN were compared with those for aspirin under consistent experimental conditions, and indicated that aspirin acts as a guide in AZN when binding to Sudlow's site I, in subdomain IIA of the HSA molecule. Moreover, compared with aspirin, AZN showed greater observed binding constants with, but smaller changes in the α-helicity of, HSA, which proved that AZN might be easier to transport and have less toxicity in vivo. Copyright © 2017 John Wiley & Sons, Ltd.

Comparative effects of aspirin and enteric-coated aspirin on loss of chromium 51-labeled erythrocytes from the gastrointestinal tract

International Nuclear Information System (INIS)

Robbins, D.C.; Schwartz, R.S.; Kutny, K.; Vallejo, G.; Horton, E.S.; Cotter, J.M.

1984-01-01

Sodium chromate Cr 51 was used to label red blood cells of 19 healthy male volunteers, whose stools were collected for four days before and four days during oral administration of either uncoated (N . 9) or enteric-coated (N . 10) aspirin. Each subject received 2.925 gm/day of aspirin, in three equal doses separated by eight-hour intervals, for a total of seven days. During drug use, stools were collected on days 4 through 7. Fecal blood content, estimated by measuring radioactivity in the stools, was significantly higher (P less than 0.001) during use of either type of aspirin than at baseline, but losses measured during use of the coated aspirin (mean, 1.54 ml/day) were significantly lower (P less than 0.001) than those measured during use of the uncoated aspirin (mean, 4.33 ml/day). The two types of aspirin produced equivalent serum concentrations of salicylates. We conclude that enteric-coated aspirin reduces gastrointestinal blood loss

Healthcare utilization and costs for patients initiating Dabigatran or Warfarin.

Science.gov (United States)

Reynolds, Shannon L; Ghate, Sameer R; Sheer, Richard; Gandhi, Pranav K; Moretz, Chad; Wang, Cheng; Sander, Stephen; Costantino, Mary E; Annavarapu, Srinivas; Andrews, George

2017-06-21

Novel oral anticoagulants (NOAC) such as dabigatran, when compared to warfarin, have been shown to potentially reduce the risk of stroke in patients with non-valvular atrial fibrillation (NVAF) together with lower healthcare resource utilization (HCRU) and similar total costs. This study expands on previous work by comparing HCRU and costs for patients newly diagnosed with NVAF and newly initiated on dabigatran or warfarin, and is the first study specifically in a Medicare population. A retrospective matched-cohort study was conducted using data from administrative health care claims during the study period 01/01/2010-12/31/2012. Cox regression analyses were used to compare all-cause risk of first hospitalizations and emergency room (ER) visits. Medical, pharmacy, and total costs per-patient-per-month (PPPM) were compared between dabigatran and warfarin users. A total of 1110 patients initiated on dabigatran were propensity score-matched with corresponding patients initiated on warfarin. The mean number of hospitalizations (0.92 vs. 1.13, P = 0.012), ER visits (1.32 vs. 1.56, P warfarin users. Patients initiated on dabigatran had significantly lower risk of first all-cause ER visits [hazard ratio (HR): 0.84, 95% confidence interval (CI): 0.73-0.98] compared to those initiated on warfarin. Adjusted mean pharmacy costs PPPM were significantly greater for dabigatran users ($510 vs. $250, P warfarin users. Dabigatran users had significantly lower HCRU compared to warfarin users. In addition, dabigatran users had lower risk of all-cause ER visits. Despite higher pharmacy costs, the two cohorts did not differ significantly in medical or total all-cause costs.

Assessment of analytical techniques for characterization of crystalline clopidogrel forms in patent applications

Directory of Open Access Journals (Sweden)

Luiz Marcelo Lira

2014-04-01

Full Text Available The aim of this study was to evaluate two important aspects of patent applications of crystalline forms of drugs: (i the physicochemical characterization of the crystalline forms; and (ii the procedure for preparing crystals of the blockbuster drug clopidogrel. To this end, searches were conducted using online patent databases. The results showed that: (i the majority of patent applications for clopidogrel crystalline forms failed to comply with proposed Brazilian Patent Office guidelines. This was primarily due to insufficient number of analytical techniques evaluating the crystalline phase. In addition, some patent applications lacked assessment of chemical/crystallography purity; (ii use of more than two analytical techniques is important; and (iii the crystallization procedure for clopidogrel bisulfate form II were irreproducible based on the procedure given in the patent application.

Synthesis of 13C warfarin labelled at the hemiketal carbon, and its resolution

International Nuclear Information System (INIS)

Savell, V.H. Jr.; Valente, E.J.; Eggleston, D.S.

1989-01-01

Warfarin (cyclic hemiketal form: 2-hydroxy-2-methyl-4-phenyl-3,4-dihydro-2H,5H-pyrano[3,2-c][1]benz opyran-5-one) is labeled with 98+% 13 C at the anomeric carbon (C2) and resolved into its enantiomers. Acetone-2- 13 C(98.6%) condenses with benzaldehyde in aqueous base to produce 4-phenyl-3-buten-2-one-2- 13 C(98+%). Michael-type addition of this to 4-hydroxycoumarin in methanol produces the labeled diastereomeric warfarin methyl ketals which on deprotection form racemic warfarin-2- 13 C(98+%). Classical resolution of labeled warfarin with quinidine produces partly resolved (S)-(-)-warfarin-2- 13 C(98+%). Labeled warfarin is a suitable probe for warfarin configuration for which three distinct isomeric forms are known. (Author)

Warfarin binding to plasma of workers exposed to toluene diisocyanate

Energy Technology Data Exchange (ETDEWEB)

Bachmann, K.; Shapiro, R.; Forney, R.B. Jr.

1982-02-01

The extent of (14)C-warfarin binding to plasma proteins was evaluated in a group of normal, healthy volunteers and in two groups of individuals occupationally exposed to toluene diisocyanate (TDI). Plasma binding was assessed by ultrafiltration after the addition of racemic (14)C-warfarin to a final concentration of 0.8 microgram/ml. Chronic occupational exposure to TDI did not affect the extent of warfarin binding since warfarin free fractions (normalized to an albumin concentration of 4.5 g/dl) were 1.09 +/- 0.23 (mean +/- SD), 0.98 +/- 0.19, and 0.97 +/- 0.15 for controls and the two groups of TDI-exposed individuals, respectively.

Preventing AVF thrombosis: the rationale and design of the Omega-3 fatty acids (Fish Oils and Aspirin in Vascular access OUtcomes in REnal Disease (FAVOURED study

Directory of Open Access Journals (Sweden)

Rosman Johan

2009-01-01

Full Text Available Abstract Background Haemodialysis (HD is critically dependent on the availability of adequate access to the systemic circulation, ideally via a native arteriovenous fistula (AVF. The Primary failure rate of an AVF ranges between 20–54%, due to thrombosis or failure of maturation. There remains limited evidence for the use of anti-platelet agents and uncertainty as to choice of agent(s for the prevention of AVF thrombosis. We present the study protocol for a randomised, double-blind, placebo-controlled, clinical trial examining whether the use of the anti-platelet agents, aspirin and omega-3 fatty acids, either alone or in combination, will effectively reduce the risk of early thrombosis in de novo AVF. Methods/Design The study population is adult patients with stage IV or V chronic kidney disease (CKD currently on HD or where HD is planned to start within 6 months in whom a planned upper or lower arm AVF is to be the primary HD access. Using a factorial-design trial, patients will be randomised to aspirin or matching placebo, and also to omega-3 fatty acids or matching placebo, resulting in four treatment groups (aspirin placebo/omega-3 fatty acid placebo, aspirin/omega-3 fatty acid placebo, aspirin placebo/omega-3 fatty acid, aspirin/omega-3 fatty acid. Randomisation will be achieved using a dynamic balancing method over the two stratification factors of study site and upper versus lower arm AVF. The medication will be commenced pre-operatively and continued for 3 months post surgery. The primary outcome is patency of the AVF at three months after randomisation. Secondary outcome measures will include functional patency at six and twelve months, primary patency time, secondary (assisted patency time, and adverse events, particularly bleeding. Discussion This multicentre Australian and New Zealand study has been designed to determine whether the outcome of surgery to create de novo AVF can be improved by the use of aspirin and/or omega-3 fatty

Preventing AVF thrombosis: the rationale and design of the Omega-3 fatty acids (Fish Oils) and Aspirin in Vascular access OUtcomes in REnal Disease (FAVOURED) study.

Science.gov (United States)

Irish, Ashley; Dogra, Gursharan; Mori, Trevor; Beller, Elaine; Heritier, Stephane; Hawley, Carmel; Kerr, Peter; Robertson, Amanda; Rosman, Johan; Paul-Brent, Peta-Anne; Starfield, Melissa; Polkinghorne, Kevan; Cass, Alan

2009-01-21

Haemodialysis (HD) is critically dependent on the availability of adequate access to the systemic circulation, ideally via a native arteriovenous fistula (AVF). The Primary failure rate of an AVF ranges between 20-54%, due to thrombosis or failure of maturation. There remains limited evidence for the use of anti-platelet agents and uncertainty as to choice of agent(s) for the prevention of AVF thrombosis. We present the study protocol for a randomised, double-blind, placebo-controlled, clinical trial examining whether the use of the anti-platelet agents, aspirin and omega-3 fatty acids, either alone or in combination, will effectively reduce the risk of early thrombosis in de novo AVF. The study population is adult patients with stage IV or V chronic kidney disease (CKD) currently on HD or where HD is planned to start within 6 months in whom a planned upper or lower arm AVF is to be the primary HD access. Using a factorial-design trial, patients will be randomised to aspirin or matching placebo, and also to omega-3 fatty acids or matching placebo, resulting in four treatment groups (aspirin placebo/omega-3 fatty acid placebo, aspirin/omega-3 fatty acid placebo, aspirin placebo/omega-3 fatty acid, aspirin/omega-3 fatty acid). Randomisation will be achieved using a dynamic balancing method over the two stratification factors of study site and upper versus lower arm AVF. The medication will be commenced pre-operatively and continued for 3 months post surgery. The primary outcome is patency of the AVF at three months after randomisation. Secondary outcome measures will include functional patency at six and twelve months, primary patency time, secondary (assisted) patency time, and adverse events, particularly bleeding. This multicentre Australian and New Zealand study has been designed to determine whether the outcome of surgery to create de novo AVF can be improved by the use of aspirin and/or omega-3 fatty acids. Recently a placebo-controlled trial has shown that

Mechanisms of aspirin-sensitive asthma

Directory of Open Access Journals (Sweden)

Sun Ying

2004-01-01

Full Text Available It is now widely accepted that aspirin, along with other non-steroidal anti-inflammatory drugs (NSAIDs, may precipitate asthma attacks in a minority of susceptible individuals. The syndrome is part of a mucosal inflammatory disease that typically affects the nasal, as well as the bronchial, mucosa and sometimes the gut and skin also. Although the mucosal cellular infiltrate in aspirin-sensitive asthma and rhinitis resembles that of asthma and rhinitis in general, there is evidence of increased expression of asthma-relevant cytokines, such as interleukin-5 and granulocyte–macrophage colony stimulating factor, and a more intense infiltrate of mast cells and eosinophils. One key feature of aspirin-sensitive asthma is thought to be the overproduction of cysteinyl leukotrienes, principally by these local mast cells and eosinophils, but whether this represents a fundamental abnormality or is simply a consequence of greater numbers and activation of inflammatory cells is unclear. Genetic polymorphisms of the leukotriene C4 synthase gene, which result in elevated expression of this enzyme, may also play a role. In addition, overexpression of cysteinyl leukotriene receptors, particularly CysLT1, may contribute to an enhanced response of local inflammatory and structural cells to cysteinyl leukotrienes. Aspirin challenge in these patients is accompanied by acute further elevation of the already elevated baseline cysteinyl leukotriene synthesis, a phenomenon that is most closely related to the ability of aspirin and related NSAIDs to inhibit the cyclooxygenase enzyme COX-1. The reason for this is unknown, although it has been suggested that the COX-1 product prostaglandin E2 (PGE2 serves as a ‘brake’ to leukotriene synthesis and that somehow this mechanism is deficient in aspirin-sensitive asthmatics. A better understanding of the pathogenesis of aspirin-sensitive asthma will undoubtedly lead to better approaches to treatment. Aside from the use of

Costs and consequences of direct-to-consumer advertising for clopidogrel in Medicaid.

Science.gov (United States)

Law, Michael R; Soumerai, Stephen B; Adams, Alyce S; Majumdar, Sumit R

2009-11-23

Direct-to-consumer advertising (DTCA) is assumed to be a major driver of rising pharmaceutical costs. Yet, research on how it affects costs is limited. Therefore, we studied clopidogrel, a commonly used and heavily marketed antiplatelet agent, which was first sold in 1998 and first direct-to-consumer advertised in 2001. We examined pharmacy data from 27 Medicaid programs from 1999 through 2005. We used interrupted time series analysis to analyze changes in the number of units dispensed, cost per unit dispensed, and total pharmacy expenditures after DTCA initiation. In 1999 and 2000, there was no DTCA for clopidogrel; from 2001 through 2005, DTCA spending exceeded $350 million. Direct-to-consumer advertising did not change the preexisting trend in the number of clopidogrel units dispensed per 1000 enrollees (P = .10). However, there was a sudden and sustained increase in cost per unit of $0.40 after DTCA initiation (95% confidence interval, $0.31-$0.49; P consumer advertising was not associated with an increase in clopidogrel use over and above preexisting trends. However, Medicaid pharmacy expenditures increased substantially after the initiation of DTCA because of a concomitant increase in the cost per unit. If drug price increases after DTCA initiation are common, there are important implications for payers and for policy makers in the United States and elsewhere.

Thrombotic Management of Antiphospholipid Syndrome: Towards Novel Targeted Therapies.

Science.gov (United States)

Islam, Md Asiful; Alam, Fahmida; Wong, Kah Keng; Kamal, Mohammad Amjad; Gan, Siew Hua

2017-01-01

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by thrombosis and/or pregnancy morbidity with persistent levels of antiphospholipid antibodies (aPLs). The development of thrombosis in APS is mediated by aPLs and contributes to the high mortality rate in APS patients. However, although APS has been reported for more than 30 years, there has been no optimal regimen for its prevention or for the management of thrombosis, mainly because the mainstay treatment strategies for managing APS are not targeted towards aPL-mediated thrombotic pathophysiology. Instead, the treatments commonly used are aimed at general thrombotic disorders. Warfarin is the most commonly used vitamin K antagonist (VKA), in addition to anti-platelet medications, such as aspirin and clopidogrel. Over the last decade, novel non-VKA oral anticoagulants, including rivaroxaban, apixaban and dabigatran, as well as immunomodulatory agents, such as rituximab, eculizumab, hydroxychloroquine, statins and sirolimus, have also been used. In this review, we discuss the current treatment strategies and future treatment outlook for thrombotic APS. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Aspirin provocation increases 8-iso-PGE2 in exhaled breath condensate of aspirin-hypersensitive asthmatics.

Science.gov (United States)

Mastalerz, Lucyna; Januszek, Rafał; Kaszuba, Marek; Wójcik, Krzysztof; Celejewska-Wójcik, Natalia; Gielicz, Anna; Plutecka, Hanna; Oleś, Krzysztof; Stręk, Paweł; Sanak, Marek

2015-09-01

Isoprostanes are bioactive compounds formed by non-enzymatic oxidation of polyunsaturated fatty acids, mostly arachidonic, and markers of free radical generation during inflammation. In aspirin exacerbated respiratory disease (AERD), asthmatic symptoms are precipitated by ingestion of non-steroid anti-inflammatory drugs capable for pharmacologic inhibition of cyclooxygenase-1 isoenzyme. We investigated whether aspirin-provoked bronchoconstriction is accompanied by changes of isoprostanes in exhaled breath condensate (EBC). EBC was collected from 28 AERD subjects and 25 aspirin-tolerant asthmatics before and after inhalatory aspirin challenge. Concentrations of 8-iso-PGF2α, 8-iso-PGE2, and prostaglandin E2 were measured using gas chromatography/mass spectrometry. Leukotriene E4 was measured by immunoassay in urine samples collected before and after the challenge. Before the challenge, exhaled 8-iso-PGF2α, 8-iso-PGE2, and PGE2 levels did not differ between the study groups. 8-iso-PGE2 level increased in AERD group only (p=0.014) as a result of the aspirin challenge. Urinary LTE4 was elevated in AERD, both in baseline and post-challenge samples. Post-challenge airways 8-iso-PGE2 correlated positively with urinary LTE4 level (p=0.046), whereas it correlated negatively with the provocative dose of aspirin (p=0.027). A significant increase of exhaled 8-iso-PGE2 after inhalatory challenge with aspirin was selective and not present for the other isoprostane measured. This is a novel finding in AERD, suggesting that inhibition of cyclooxygenase may elicit 8-iso-PGE2 production in a specific mechanism, contributing to bronchoconstriction and systemic overproduction of cysteinyl leukotrienes. Copyright © 2015 Elsevier Inc. All rights reserved.

Use of low-dose aspirin and non-aspirin nonsteroidal anti-inflammatory drugs and risk of glioma

DEFF Research Database (Denmark)

Gaist, David; García-Rodríguez, L A; Sørensen, H T

2013-01-01

Background:Few studies have examined the association between use of aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs) and risk of glioma and the results have been equivocal. We therefore investigated the influence of NSAID use on glioma risk in a nationwide setting.Methods:We used...... exposure to low-dose aspirin or non-aspirin (NA) NSAIDs into ever use or long-term use, defined as continuous use for 5 years. Conditional logistic regression was used to compute odds ratios (ORs), with 95% confidence intervals (CIs), for glioma associated with NSAID use, adjusted for potential...... confounders.Results:A total of 2688 glioma cases and 18 848 population controls were included in the study. Ever use of low-dose aspirin (OR=0.90; 95% CI: 0.77-1.04) or NA-NSAIDs (OR=1.05; 95% CI: 0.96-1.14) was not associated with glioma risk. Compared with never use, long-term use of low-dose aspirin...

Comparison of effect of locally available brands of clopidogrel on platelet aggregation in patients with coronary disease

International Nuclear Information System (INIS)

Khan, S.B.; Hameedullah; Noor, L.; Awan, Z.A.; Din, S.U.; Muhammad Hafeezullah, M.

2010-01-01

Background: Anticoagulant effect of clopidogrel is of utmost importance in coronary artery disease, especially in prevention of coronary stent thrombosis. Recently, many new local brands of clopidogrel have been launched, with unknown efficacy. This study was conducted with the aim to compare two locally prepared clopidogrel brands, in terms of the effect of a loading dose of 600 mg on inhibition of platelet aggregation in patients with coronary artery disease. Methods: This was a double blind randomised study. Sample population consisting of 35 patients, were admitted at Lady Reading Hospital, Peshawar, for the management of coronary artery disease. Baseline platelet aggregation of all these patients was measured. These patients were divided in two groups randomly. Group-A consisting of 18 patients was given brand 'A' clopidogrel 600 mg, while Group-B consisting of 17 patients was give brand 'B' of clopidogrel 600 mg. The platelet aggregation of both groups was then measured at baseline, and at 2, 4, and 6 hours after taking the loading dose of 600 mg. Results: Platelet aggregation time at baseline in Group-A was 2.61+- 2.28 sec. and in Group-B it was 2.24 +- 1.52 sec. (p=0.57). After 2 hours of clopidogrel administration in Group-A the platelet aggregation time was 1.44 +- 1.58 sec. and in Group-B it was 1.53 +- 1.107 sec. (p=0.85). Platelet aggregation time after 4 hours in Group-A was 0.28 +- 0.57 sec. and in Group-B 1.06 +- 1.03 sec. (p=0.009), and after 6 hours it was 0.00 +- 0.00 sec. in Group-A and in Group-B it was 0.59 +- 0.71 sec. (p=0.001). Conclusion: The two brands of clopidogrel had a significant difference in their effect on inhibition of platelet aggregation. Different brands of clopidogrel may not be equally effective. (author)

Policy objective of generic medicines from the investment perspective: The case of clopidogrel.

Science.gov (United States)

Elek, Péter; Harsányi, András; Zelei, Tamás; Csetneki, Kata; Kaló, Zoltán

2017-05-01

The objective of generic drug policies in most countries is defined from a disinvestment perspective: reduction in expenditures without compromising health outcomes. However, in countries with restricted access of patients to original patented drugs, the objective of generic drug policies can also be defined from an investment perspective: health gain by improved patient access without need for additional health budget. This study examines the investment aspect of generic medicines by analyzing clopidogrel utilization in European countries between 2004 and 2014 using multilevel panel data models. We find that clopidogrel consumption was strongly affected by affordability constraints before the generic entry around 2009, but this effect decayed by 2014. After controlling for other variables, utilization had a substantially larger trend increase in lower-income European countries than in the higher-income ones. Generic entry increased clopidogrel consumption only in lower- and average-income countries but not in the highest-income ones. An earlier generic entry was associated with a larger effect. The case of clopidogrel indicates that the entrance of generics may increase patient access to effective medicines, most notably in lower-income countries, thereby reducing inequalities between European patients. Policymakers should also consider this investment aspect of generic medicines when designing pharmaceutical policies. Copyright © 2017 Elsevier B.V. All rights reserved.

The role of aspirin desensitization in patients with aspirin-exacerbated respiratory disease (AERD).

Science.gov (United States)

Spies, Jonas Willian; Valera, Fabiana Cardoso Pereira; Cordeiro, Daniel Loiola; de Mendonça, Taís Nociti; Leite, Marcelo Gonçalves Junqueira; Tamashiro, Edwin; Arruda, Luiza Karla; Anselmo-Lima, Wilma Terezinha

2016-01-01

Aspirin-exacerbated respiratory disease (AERD) consists of a classic tetrad: moderate/severe asthma, chronic rhinosinusitis, nasal polyps, and intolerance to aspirin or other nonsteroidal anti-inflammatory drugs. Clinical control with drugs, surgery, and desensitization are treatment options. To evaluate the efficacy and tolerability of aspirin desensitization in patients with AERD. Periodic symptom assessment and endoscopy in patients with AERD undergoing surgery who were desensitized. Seventeen patients were desensitized. Eight patients completed the desensitization and were followed for a minimum of a one-year period (mean 3.1 years). These patients showed improvement in all symptoms. Moreover, surgical reassessment was not indicated in any of these patients and there was a decrease in costs with medication and procedures. Eight patients did not complete desensitization, mainly due to procedure intolerance and uncontrolled asthma, whereas another patient was lost to follow-up. Aspirin desensitization, when tolerated, was effective in patients with AERD and with poor clinical/surgical response. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Attenuated expression of the tight junction proteins is involved in clopidogrel-induced gastric injury through p38 MAPK activation

International Nuclear Information System (INIS)

Wu, Hai-Lu; Gao, Xin; Jiang, Zong-Dan; Duan, Zhao-Tao; Wang, Shu-Kui; He, Bang-Shun; Zhang, Zhen-Yu; Xie, Hong-Guang

2013-01-01

Highlights: ► Clopidogrel suppressed GES-1 cell viability in a concentration- and time-dependent manner. ► Clopidogrel significantly increased dextran permeability, reduced occludin and ZO-1 expression, and induced cell apoptosis. ► Clopidogrel activated p38 MAPK signaling pathway. ► Activation of p38 activity was involved in clopidogrel-induced increase in gastric epithelial cells permeability and disruption of TJ. -- Abstract: Bleeding complications and delayed healing of gastric ulcer associated with use of clopidogrel is a common clinical concern; however, the underlying mechanisms remain to be determined. This study aimed to clarify whether clopidogrel could cause the damage of the human gastric epithelial cells and to further elucidate the mechanisms involved. After human gastric epithelial cell line GES-1 had been treated with clopidogrel (0.5–2.5 mM), the cell proliferation was examined by MTT assay, apoptosis was measured with DAPI staining and flow cytometry analysis, and the barrier function of the tight junctions (TJ) was evaluated by permeability measurement and transmission electron microscopy. Moreover, expression of the TJ proteins occludin and ZO-1 and the phosphorylation of the mitogen-activated protein kinases (MAPK) p38, ERK, and JNK were examined by western blot. In addition, three MAPK inhibitors specific to p38, ERK and JNK were used, respectively, to verify the signaling pathways responsible for regulating the expression of the TJ proteins being tested. Results showed that clopidogrel significantly increased dextran permeability, induced apoptosis, suppressed GES-1 cell viability, and reduced the expression of the TJ proteins (occludin and ZO-1), acting through p38 MAPK phosphorylation. Furthermore, these observed effects were partially abolished by SB-203580 (a p38 MAPK inhibitor), rather than by either U-0126 (an ERK inhibitor) or SP-600125 (a JNK inhibitor), suggesting that clopidogrel-induced disruption in the gastric

Effect of Clopidogrel on Platelet CD Markers in Normal Individuals and in Patients with Untreated Type 2 Diabetes Mellitus

International Nuclear Information System (INIS)

Saboor, M.; Moinuddin, M.; Ilyas, S.

2015-01-01

The objective of this study was to evaluate the effect of clopidogrel response in patients with untreated type 2 diabetes mellitus as compared with normal individuals. One hundred and seven subjects i.e. 32 normal and 75 patients with untreated type 2 diabetes mellitus were enrolled in this study. In the first step, normal subjects as well as diabetic patients were selected and tested for various laboratory parameters and platelets flow cytometry. In the second step, an antiplatelet drug (clopidogrel) was administered for 10 days to each individual enrolled in the study. After 10 days blood samples were collected for platelets flow cytometry. CD41 and CD61 did not show any change after the administration of clopidogrel in resting and activated platelets. CD63 and CD62p positivity was increased in normal and in diabetic patients' platelets after activation with ADP before clopidogrel. It was decreased in normal resting and ADP stimulated platelets after clopidogrel treatment. CD63 and CD62p positivity in resting and ADP stimulated patients platelets was also decreased after clopidogrel treatment. The change was, however, not as marked as in normal subjects. (author)

Selective macrophage inhibition abolishes warfarin-induced reduction of metastasis

NARCIS (Netherlands)

Maat, B.

1980-01-01

Warfarin administered to tumor-bearing mice reduces the number of spontaneous lung metastases. Both macrophage inhibitors silica and carrageenan abolish the warfarin-induced decrease in tumour metastasis, which strongly supports the concept that the antitumour effect of coumarin derivatives is

Interaction between gemfibrozil and warfarin: case report and review of the literature.

Science.gov (United States)

Dixon, Dave L; Williams, Virginia G

2009-06-01

Possible procoagulant effects can occur when lipid-lowering fibric acid derivatives, such as gemfibrozil and fenofibrate, are taken concomitantly with warfarin. Although there are several detailed reports of fenofibrate potentiating the anticoagulant effects of warfarin, few case reports have been published regarding an interaction between gemfibrozil and warfarin. We describe a 62-year-old man who was taking warfarin for paroxysmal atrial fibrillation and came to the anticoagulation clinic for a routine follow-up. For 9 months, the patient's international normalized ratio (INR) had been stable (target range 2.0-3.0) with warfarin 45 mg/week. At this clinic visit, however, his INR was supratherapeutic at 5.8; the only identified change in his drug therapy was the addition of gemfibrozil 600 mg twice/day, started 3 weeks earlier. The patient denied any changes in his dietary intake of vitamin K, alcohol use, or addition of nonprescription or herbal agents. Recent laboratory tests revealed no signs of thyroid abnormalities and only an insignificant elevation in his alanine aminotransferase level. His warfarin dose was decreased to 35-37.5 mg/week (a 22% reduction), and a therapeutic INR was maintained until gemfibrozil was later discontinued because of myalgia. After consecutive subtherapeutic INRs, his warfarin dose was increased to 45 mg/week and a therapeutic INR was maintained. Use of the Drug Interaction Probability Scale indicated that the likelihood of the gemfibrozil-warfarin interaction was probable. The exact mechanism of the proposed interactions between fibric acid derivatives and warfarin remains unknown but may be multifactorial through inhibition of cytochrome P450 isoenzymes, displacement from protein binding sites, or changes in coagulation factor synthesis. Regardless of the fibric acid derivative chosen, an empiric dosage reduction of 20% and close INR monitoring are warranted in patients receiving warfarin.

Edoxaban versus Warfarin in Patients with Atrial Fibrillation

DEFF Research Database (Denmark)

Giugliano, Robert P; Ruff, Christian T; Braunwald, Eugene

2013-01-01

. The principal safety end point was major bleeding. RESULTS: The annualized rate of the primary end point during treatment was 1.50% with warfarin (median time in the therapeutic range, 68.4%), as compared with 1.18% with high-dose edoxaban (hazard ratio, 0.79; 97.5% confidence interval [CI], 0.63 to 0.99; P....001 for noninferiority) and 1.61% with low-dose edoxaban (hazard ratio, 1.07; 97.5% CI, 0.87 to 1.31; P=0.005 for noninferiority). In the intention-to-treat analysis, there was a trend favoring high-dose edoxaban versus warfarin (hazard ratio, 0.87; 97.5% CI, 0.73 to 1.04; P=0.08) and an unfavorable trend with low......-dose edoxaban versus warfarin (hazard ratio, 1.13; 97.5% CI, 0.96 to 1.34; P=0.10). The annualized rate of major bleeding was 3.43% with warfarin versus 2.75% with high-dose edoxaban (hazard ratio, 0.80; 95% CI, 0.71 to 0.91; PP...

Warfarin: pharmacological profile and drug interactions with antidepressants

Directory of Open Access Journals (Sweden)

Juliana Souto Teles

2012-03-01

Full Text Available Oral anticoagulants are among the drugs with the greatest numberof drug interactions. The concomitant use of several medications isa common practice in patients with cardiovascular problems, whooften also present with depression; therefore, the probability of aninteraction occurring between warfarin and the antidepressants ishigh, and may result in increased or decreased anticoagulant activity.Since the possible interactions between these two classes of drugshave been poorly explored in literature, with a risk to the patients who use them, we reviewed the pharmacology of warfarin and its possible interactions with antidepressants. Of the antidepressants analyzed, those that showed relevant effects on the interaction with warfarin were, in decreasing order: paroxetine, venlafaxine, fluoxetine, and duloxetine.

Aspirin overutilization for the primary prevention of cardiovascular disease

Directory of Open Access Journals (Sweden)

VanWormer JJ

2014-12-01

Full Text Available Jeffrey J VanWormer,1 Aaron W Miller,2 Shereif H Rezkalla3 1Center for Clinical Epidemiology and Population Health, 2Biomedical Informatics Research Center, Marshfield Clinic Research Foundation, Marshfield, WI, USA; 3Department of Cardiology, Marshfield Clinic, Marshfield, WI, USA Background: Aspirin is commonly used for the primary prevention of cardiovascular disease (CVD in the US. Previous research has observed significant levels of inappropriate aspirin use for primary CVD prevention in some European populations, but the degree to which aspirin is overutilized in the US remains unknown. This study examined the association between regular aspirin use and demographic/clinical factors in a population-based sample of adults without a clinical indication for aspirin for primary prevention.Methods: A cross-sectional analysis was performed using 2010–2012 data from individuals aged 30–79 years in the Marshfield Epidemiologic Study Area (WI, USA. Regular aspirin users included those who took aspirin at least every other day.Results: There were 16,922 individuals who were not clinically indicated for aspirin therapy for primary CVD prevention. Of these, 19% were regular aspirin users. In the final adjusted model, participants who were older, male, lived in northern Wisconsin, had more frequent medical visits, and had greater body mass index had significantly higher odds of regular aspirin use (P<0.001 for all. Race/ethnicity, health insurance, smoking, blood pressure, and lipid levels had negligible influence on aspirin use. A sensitivity analysis found a significant interaction between age and number of medical visits, indicating progressively more aspirin use in older age groups who visited their provider frequently.Conclusion: There was evidence of aspirin overutilization in this US population without CVD. Older age and more frequent provider visits were the strongest predictors of inappropriate aspirin use. Obesity was the only significant

Antiplatelet therapy for recurrent stroke prevention: newer perspectives based on (MATCH), (CHARISMA), and (ESPRIT).

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Gorelick, Philip B

2008-01-01

Antiplatelet therapy is an important component of our armamentarium for recurrent stroke prevention. Aspirin is a safe and effective antiplatelet drug for recurrent stroke prevention, however, it has been challenged recently by the thienopyridine derivative, clopidogrel, and the combination agent, aspirin plus extended release dipyridamole. In this review, we discuss recent studies of thienopyridine derivatives and aspirin plus extended-release dipyridamole in stroke prevention and evidence-based guidelines for the administration of these agents in practice for recurrent stroke prevention.

Synthesis of [sup 13]C warfarin labelled at the hemiketal carbon, and its resolution

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Savell, V.H. Jr.; Valente, E.J. (Mississippi College, Clinton. MS (United States). Dept. of Chemistry); Eggleston, D.S. (Smith, Kline and French Labs., King of Prussia, PA (United States). Physical and Structural Chemistry)

1989-06-01

Warfarin (cyclic hemiketal form: 2-hydroxy-2-methyl-4-phenyl-3,4-dihydro-2H,5H-pyrano[3,2-c][1]benz opyran-5-one) is labeled with 98+% [sup 13]C at the anomeric carbon (C2) and resolved into its enantiomers. Acetone-2-[sup 13]C(98.6%) condenses with benzaldehyde in aqueous base to produce 4-phenyl-3-buten-2-one-2-[sup 13]C(98+%). Michael-type addition of this to 4-hydroxycoumarin in methanol produces the labeled diastereomeric warfarin methyl ketals which on deprotection form racemic warfarin-2-[sup 13]C(98+%). Classical resolution of labeled warfarin with quinidine produces partly resolved (S)-(-)-warfarin-2-[sup 13]C(98+%). Labeled warfarin is a suitable probe for warfarin configuration for which three distinct isomeric forms are known. (Author).

Vascular access site complication in transfemoral coronary angiography between uninterrupted warfarin and heparin bridging.

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Wongcharoen, Wanwarang; Pinyosamosorn, Kittipong; Gunaparn, Siriluck; Boonnayhun, Suchada; Thonghong, Tasalak; Suwannasom, Pannipa; Phrommintikul, Arintaya

2017-08-01

Warfarin discontinuation with heparin bridging is a common practice in patients receiving warfarin prior to elective coronary angiography (CAG). The uninterrupted warfarin strategy has been suggested to be alternative option for patients with high thromboembolic risk. Therefore, we aimed to assess the safety of elective transfemoral CAG during uninterrupted warfarin therapy compared to heparin bridging. This study was a randomized open-label design with blinded event evaluation. The 110 consecutive patients (age ≥ 18 years) receiving warfarin before the planned transfemoral CAG were randomly assigned to either heparin bridging or uninterrupted warfarin with targeted INR (2.0-3.0). The primary outcome was the incidence of major vascular access site complications. The baseline characteristics were comparable between two groups (mean age was 60.1 ± 7.8 years, 49 males). The mean INR on the day of CAG of heparin bridging and uninterrupted warfarin groups was 1.2 ± 0.3 and 2.2 ± 0.5 (P warfarin patients (P = 0.243). The total vascular access site complications occurred in 6 (10.9%) heparin-bridging and one (1.8%) uninterrupted warfarin patients (P = 0.113). No patient developed either other bleeding or thromboembolic events during 7 days after CAG. We demonstrated that an uninterrupted warfarin strategy did not increase vascular access site complications in patients undergoing transfemoral CAG compared to heparin bridging therapy. Due to the safety and the ease of uninterrupted warfarin strategy, this approach should be encouraged in patients receiving long-term warfarin who undergo elective transfemoral CAG. © 2017, Wiley Periodicals, Inc.

Clinical outcomes, health resource use, and cost in patients with early versus late dual or triple anti-platelet treatment for acute coronary syndrome.

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Friedman, Howard; Mollon, Patrick; Lian, Jean; Navaratnam, Prakash

2013-08-01

Acute coronary syndrome (ACS) guidelines recommend early dual anti-platelet therapy (thienopyridines + acetylsalicylic acid [aspirin]). However, triple therapy (thienopyridines + aspirin + glycoprotein IIb/IIIa receptor inhibitors [GRIs]) has shown benefit in clinical trials. This study assessed real-world ACS treatment patterns and outcomes in the acute care setting. A retrospective analysis of patients admitted to hospital with ACS (index event) from January 2007 to December 2009 was conducted (Thomson's MarketScan Hospital Drug Database). Eligible patients were ≥18 years of age, of either sex, and had primary admission and discharge diagnoses of ACS. Cohorts were defined by anti-platelet treatment and then by the timing of treatment initiation (early initiation: within ≤2 days of admission; late initiation: ≥2 days post-admission). Patient characteristics, clinical outcomes, resource utilization, and costs were assessed using descriptive statistics. A total of 249,907 eligible patients were placed into four treatment cohorts (aspirin assumed for all patients): aspirin only; clopidogrel only (dual therapy); GRI only (dual therapy); and clopidogrel + GRI (triple therapy). Patients in the 'clopidogrel-only' cohort were more likely to be older, female, and have more co-morbidities than those in other cohorts; stroke (6.2 %) and re-hospitalization (15.4 %) rates were higher than in the 'GRI-only' and 'triple therapy' cohorts. The GRI-only cohort had higher major bleeding rates (3.3 %), mortality (7.6 %), and costs ($US21,975 [year 2010 values]) than the clopidogrel-only and triple-therapy cohorts. Late initiation cohorts were more likely to be older, female, and have more co-morbidities than early initiation cohorts. Major bleeding was more likely with GRI-only patients (regardless of initiation timing) than with other cohorts. Late-treated clopidogrel-only patients had higher rates of stroke (6.9 %), ACS-related re-admissions (6.1 %), and all

Oral warfarin intake affects skin inflammatory cytokine responses in rats.

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Aleksandrov, Aleksandra Popov; Mirkov, Ivana; Zolotarevski, Lidija; Ninkov, Marina; Mileusnic, Dina; Kataranovski, Dragan; Kataranovski, Milena

2017-09-01

Warfarin is an anticoagulant used in prevention/prophylaxis of thromboembolism. Besides the effects on coagulation, non-hemorrhagic reactions have also been documented. Although cutaneous reactions were reported in some patients, the impact on skin immunity was not explored. In the present paper, the effect of 30-day oral warfarin intake on skin cytokine responses in rats was analyzed. Increased release of inflammatory cytokines (TNF, IL-1β and IL-10) was noted by skin explants from rats which received warfarin, but without effect on IL-6. No impact on epidermal cell cytokine secretion was seen, except a tendency of an increase of IL-6 response to stimulation with microbial product lipopolysaccharide (LPS). Topical application of contact allergen dinitrochlorobenzene (DNCB) resulted in slight (numerical solely) increase of TNF release by skin explants of warfarin-treated animals, while epidermal cells responded by increased secretion of all four cytokines examined. The data presented provide new information on the potential of oral warfarin to modulate skin innate immune activity. Copyright © 2017 Elsevier B.V. All rights reserved.

Important Information to Know When You Are Taking: Warfarin (Coumadin) and Vitamin K

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... Important information to know when you are taking: Warfarin (Coumadin) and Vitamin K The food you eat ... provides you with information about the interaction between warfarin (Coumadin) and vitamin K. Why was warfarin (Coumadin) ...

21 CFR 520.1409 - Methylprednisolone, aspirin tablets.

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2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Methylprednisolone, aspirin tablets. 520.1409... Methylprednisolone, aspirin tablets. (a) Specifications. Each tablet contains 0.5 milligram of methylprednisolone and 300 milligrams of aspirin. (b) Sponsor. See No. 000009 in § 510.600(c) of this chapter. (c) NAS/NRC...

Rationale, design, and preliminary results of the Quebec Warfarin Cohort Study.

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Perreault, Sylvie; Shahabi, Payman; Côté, Robert; Dumas, Stéphanie; Rouleau-Mailloux, Étienne; Feroz Zada, Yassamin; Provost, Sylvie; Mongrain, Ian; Dorais, Marc; Huynh, Thao; Kouz, Simon; Diaz, Ariel; Blostein, Mark; de Denus, Simon; Turgeon, Jacques; Ginsberg, Jeffrey; Lelorier, Jacques; Lalonde, Lyne; Busque, Lambert; Kassis, Jeannine; Talajic, Mario; Tardif, Jean-Claude; Dubé, Marie-Pierre

2018-05-01

Over- and undercoagulation with warfarin are associated with hemorrhagic and thromboembolic events, respectively. Genetic and clinical factors affect warfarin response, and the causes of this variability remain unclear. We present descriptive statistics and test for predictors of poor anticoagulation control. The Quebec Warfarin Cohort (QWC) comprises 1059 new warfarin users, with prospective follow-up using telephone questionnaires every 3 months for 1 year, and using healthcare administrative databases (RAMQ and Med-Echo) for 5 years prior to cohort entry and up to 10 years following active patient participation. Genetic material was collected, and genotyping of CYP2C9 and VKORC1 genes was conducted. Measured outcomes included the percentage of time patients spent within therapeutic range, anticoagulation control, warfarin dose, bleeding, and thromboembolic events. We report baseline characteristics and outcomes after 1 year of follow-up. Poor anticoagulation control was defined as time in therapeutic range <60% in the 3- to 12-month interval. Participants had a mean age of 71 years, and 62% were men. The most common indication for warfarin was atrial fibrillation (87%). Mean time in therapeutic range was 56% (±25%) in the 3 months following warfarin initiation, and 70% (±21%) in the 3- to 12-month interval. During follow-up, the rate of stroke or systemic embolism was 1.8 events per 100 person-years; for major bleeding events, 3.3 events per 100 person-years. Independent predictors of poor anticoagulation control were chronic kidney disease, heart failure, dyslipidemia, and age. The QWC represents a good research cohort to investigate clinical and genetic factors in a warfarin-anticoagulated population. © 2018 Wiley Periodicals, Inc.

A Pharmacogenetics-Based Warfarin Maintenance Dosing Algorithm from Northern Chinese Patients

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Luo, Fang; Wang, Jin'e; Shi, Yi; Tan, Yu; Chen, Qianlong; Zhang, Yu; Hui, Rutai; Wang, Yibo

2014-01-01

Inconsistent associations with warfarin dose were observed in genetic variants except VKORC1 haplotype and CYP2C9*3 in Chinese people, and few studies on warfarin dose algorithm was performed in a large Chinese Han population lived in Northern China. Of 787 consenting patients with heart-valve replacements who were receiving long-term warfarin maintenance therapy, 20 related Single nucleotide polymorphisms were genotyped. Only VKORC1 and CYP2C9 SNPs were observed to be significantly associated with warfarin dose. In the derivation cohort (n = 551), warfarin dose variability was influenced, in decreasing order, by VKORC1 rs7294 (27.3%), CYP2C9*3(7.0%), body surface area(4.2%), age(2.7%), target INR(1.4%), CYP4F2 rs2108622 (0.7%), amiodarone use(0.6%), diabetes mellitus(0.6%), and digoxin use(0.5%), which account for 45.1% of the warfarin dose variability. In the validation cohort (n = 236), the actual maintenance dose was significantly correlated with predicted dose (r = 0.609, Pwarfarin use in Northern Chinese patients. PMID:25126975

Influence of paraoxonase-1 Q192R and cytochrome P450 2C19 polymorphisms on clopidogrel response

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Li L

2012-02-01

Full Text Available Rolf P Kreutz1,2, Perry Nystrom2, Yvonne Kreutz2, Jia Miao2, Zeruesenay Desta2, Jeffrey A Breall1, Lang Li2, ChienWei Chiang2, Richard Kovacs1, David A Flockhart2, Yan Jin21Krannert Institute of Cardiology, 2Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis, IN, USABackground: The metabolic activation of clopidogrel is a two-step process. It has been suggested that paraoxonase-1 (PON1 is a rate-limiting enzyme in the conversion of 2-oxo-clopidogrel to an active thiol metabolite. Conflicting results have been reported in regard to (1 the association of a common polymorphism of PON1 (Q192R with reduced rates of coronary stent thrombosis in patients taking clopidogrel and (2 its effects on platelet inhibition in patient populations of European descent. Methods: Blood samples from 151 subjects of mixed racial background with established coronary artery disease and who received clopidogrel were analyzed. Platelet aggregation was determined with light transmittance aggregometry and VerifyNow® P2Y12 assay. Genotyping for cytochrome P450 2C19 (CYP2C19*2 and *3 and PON1 (Q192R polymorphisms was performed.Results: Carriers of CYP2C19*2 alleles exhibited lower levels of platelet inhibition and higher on-treatment platelet aggregation than noncarriers. There was no significant difference in platelet aggregation among PON1 Q192R genotypes. Homozygous carriers of the wild-type variant of PON1 (QQ192 had similar on-treatment platelet reactivity to carriers of increased-function variant alleles during maintenance clopidogrel dosing, as well as after administration of a clopidogrel 600 mg loading dose.Conclusion: CYP2C19*2 allele is associated with impaired platelet inhibition by clopidogrel and high on-treatment platelet aggregation. PON1 (Q192R polymorphism does not appear to be a significant determinant of clopidogrel response.Keywords: PON1, platelet, aggregation, cytochrome P450 enzymes

The impact of peritransplant warfarin use on renal transplant outcome.

LENUS (Irish Health Repository)

Connaughton, Dervla M

2011-03-31

The unplanned nature of kidney transplantation necessitates that patients undergo surgery without prior cessation of warfarin. Our study analyses the impact of warfarin treatment in the peritransplant period on graft outcome and perioperative transfusion requirements.

Warfarin traps human vitamin K epoxide reductase in an intermediate state during electron transfer

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Shen, Guomin; Cui, Weidong; Zhang, Hao; Zhou, Fengbo; Huang, Wei; Liu, Qian; Yang, Yihu; Li, Shuang; Bowman, Gregory R.; Sadler, J. Evan; Gross, Michael L.; Li, Weikai

2017-01-01

Although warfarin is the most widely used anticoagulant worldwide, the mechanism by which warfarin inhibits its target, human vitamin K epoxide reductase (hVKOR), remains unclear. Here we show that warfarin blocks a dynamic electron-transfer process in hVKOR. A major fraction of cellular hVKOR is at an intermediate redox state of this process containing a Cys51-Cys132 disulfide, a characteristic accommodated by a four-transmembrane-helix structure of hVKOR. Warfarin selectively inhibits this major cellular form of hVKOR, whereas disruption of the Cys51-Cys132 disulfide impairs warfarin binding and causes warfarin resistance. Relying on binding interactions identified by cysteine alkylation footprinting and mass spectrometry coupled with mutagenesis analysis, we are able to conduct structure simulations to reveal a closed warfarin-binding pocket stabilized by the Cys51-Cys132 linkage. Understanding the selective warfarin inhibition of a specific redox state of hVKOR should enable the rational design of drugs that exploit the redox chemistry and associated conformational changes in hVKOR. PMID:27918545

Aspirin and omeprazole for secondary prevention of cardiovascular disease in patients at risk for aspirin-associated gastric ulcers.

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García-Rayado, Guillermo; Sostres, Carlos; Lanas, Angel

2017-08-01

Cardiovascular disease is the most important cause of morbidity and mortality in the world and low-dose aspirin is considered the cornerstone of the cardiovascular disease prevention. However, low-dose aspirin use is associated with gastrointestinal adverse effects in the whole gastrointestinal tract. In this setting, co-therapy with a proton pump inhibitor is the most accepted strategy to reduce aspirin related upper gastrointestinal damage. In addition, some adverse effects have been described with proton pump inhibitors long term use. Areas covered: Low-dose aspirin related beneficial and adverse effects in cardiovascular system and gastrointestinal tract are reviewed. In addition, this manuscript summarizes current data on upper gastrointestinal damage prevention and adverse events with proton pump inhibition. Finally, we discuss the benefit/risk ratio of proton pump inhibitor use in patients at risk of gastrointestinal damage taking low-dose aspirin. Expert commentary: Nowadays, with the current available evidence, the combination of low-dose aspirin with proton pump inhibitor is the most effective therapy for cardiovascular prevention in patients at high gastrointestinal risk. However, further studies are needed to discover new effective strategies with less related adverse events.

Cytochrome P450-mediated warfarin metabolic ability is not a critical determinant of warfarin sensitivity in avian species: In vitro assays in several birds and in vivo assays in chicken.

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Watanabe, Kensuke P; Kawata, Minami; Ikenaka, Yoshinori; Nakayama, Shouta M M; Ishii, Chihiro; Darwish, Wageh Sobhi; Saengtienchai, Aksorn; Mizukawa, Hazuki; Ishizuka, Mayumi

2015-10-01

Coumarin-derivative anticoagulant rodenticides used for rodent control are posing a serious risk to wild bird populations. For warfarin, a classic coumarin derivative, chickens have a high median lethal dose (LD50), whereas mammalian species generally have much lower LD50. Large interspecies differences in sensitivity to warfarin are to be expected. The authors previously reported substantial differences in warfarin metabolism among avian species; however, the actual in vivo pharmacokinetics have yet to be elucidated, even in the chicken. In the present study, the authors sought to provide an in-depth characterization of warfarin metabolism in birds using in vivo and in vitro approaches. A kinetic analysis of warfarin metabolism was performed using liver microsomes of 4 avian species, and the metabolic abilities of the chicken and crow were much higher in comparison with those of the mallard and ostrich. Analysis of in vivo metabolites from chickens showed that excretions predominantly consisted of 4'-hydroxywarfarin, which was consistent with the in vitro results. Pharmacokinetic analysis suggested that chickens have an unexpectedly long half-life despite showing high metabolic ability in vitro. The results suggest that the half-life of warfarin in other bird species could be longer than that in the chicken and that warfarin metabolism may not be a critical determinant of species differences with respect to warfarin sensitivity. © 2015 SETAC.

Monitoring the hydrolyzation of aspirin during the dissolution testing for aspirin delayed-release tablets with a fiber-optic dissolution system

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Yan Wang

2012-10-01

Full Text Available The purpose of this study was to investigate the hydrolyzation of aspirin during the process of dissolution testing for aspirin delayed-release tablets. Hydrolysis product of salicylic acid can result in adverse effects and affect the determination of dissolution rate assaying. In this study, the technique of differential spectra was employed, which made it possible to monitor the dissolution testing in situ. The results showed that the hydrolyzation of aspirin made the percentage of salicylic acid exceed the limit of free salicylic acid (4.0, and the hydrolyzation may affect the quality detection of aspirin delayed-release tablets. Keywords: Aspirin delayed-release tablets, Drug dissolution test, Fiber-optic dissolution system, UV–vis spectrum

Effect of gemfibrozil on the pharmacokinetics and pharmacodynamics of racemic warfarin in healthy subjects

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Lilja, Jari J; Backman, Janne T; Neuvonen, Pertti J

2005-01-01

Aims Case reports suggest that gemfobrozil can increase the anticoagulant effect of warfarin. Because gemfibrozil inhibits CYP2C9 in vitro, we studied its effects on the pharmacokinetics and pharmacodynamics of racemic warfarin. Methods In a randomized cross-over study, 10 healthy subjects ingested 600 mg gemfibrozil or placebo twice daily for 8 days. On day 3, they were administered a single dose of 10 mg racemic R-S-warfarin orally. The concentrations of R- and S-warfarin in plasma and thromboplastin time were monitored up to 168 h. Results Gemfibrozil decreased the mean (±SD) area under the plasma concentration-time curve [AUC(0–∞)] of S-warfarin by 11%, from 19.9 ± 5.2 mg l−1 h to 17.6 ± 4.7 mg l−1 h (95% CI on the difference −3.7, −0.78; P gemfibrozil phase to 29.5 ± 6.9 mg l−1 h during the placebo phase (95% CI −3.3, −0.33; P Gemfibrozil did not alter the anticoagulant effect of warfarin. Conclusion Unexpectedly, gemfibrozil slightly decreased the plasma concentrations of R- and S-warfarin. Displacement of warfarin from plasma albumin by gemfibrozil or its interference with the absorption of warfarin could explain the present findings. Usual therapeutic doses of gemfibrozil seem to have limited effects on the pharmacokinetics and pharmacodynamics of single dose warfarin in healthy subjects. PMID:15801938

PFA-100-measured aspirin resistance is the predominant risk factor for hospitalized cardiovascular events in aspirin-treated patients: A 5-year cohort study.

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Chen, H Y; Chou, P

2018-04-01

Aspirin therapy is the clinical gold standard for the prevention of cardiovascular events. However, cardiovascular events still develop in some patients undergoing aspirin therapy. Many laboratory methods exist for measuring aspirin resistance. Using the platelet Function Analyzer (PFA)-100 system, we aimed to determine the effect of aspirin resistance on hospitalized cardiovascular events (hCVE) in a 5-year follow-up cohort. We also sought to determine the impact of aspirin resistance on the relationship between common cardiovascular risk factors and cardiovascular hospitalization. Aspirin resistance was evaluated in aspirin-treated patients from the outpatient department. A total of 465 patients during a 5-year follow-up period were included in this study. The primary endpoint of the study was hospitalization for any acute cardiovascular event. The prevalence and associated risk factors of acute cardiovascular events were evaluated. Aspirin resistance was prevalent in 91 (20.0%) of 465 patients. Prior hospitalization history of cardiovascular events was highly associated with aspirin resistance (P = .001). At the 5-year follow-up, cardiovascular events were found to have developed in 11 patients (8 stroke and 3 myocardial infarction) who exhibited aspirin resistance (12.1%) and in 9 (4 stroke and 5 myocardial infarction) patients who did not exhibit aspirin resistance (2.4%) (P resistance and cardiovascular events (adjusted odds ratio 4.28; 95% CI: 1.64-11.20; P = .03). PFA-100 measurements of aspirin resistance correlate with hCVE, as evidenced by both the past medical history and the 5-year follow-up. The logistic regression analysis results showed that aspirin resistance plays a larger role in hospitalized cardiovascular disease than do other cardiovascular risk factors. © 2017 John Wiley & Sons Ltd.

Major bleeding in patients with atrial fibrillation receiving apixaban or warfarin: The ARISTOTLE Trial (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation): Predictors, Characteristics, and Clinical Outcomes.

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Hylek, Elaine M; Held, Claes; Alexander, John H; Lopes, Renato D; De Caterina, Raffaele; Wojdyla, Daniel M; Huber, Kurt; Jansky, Petr; Steg, Philippe Gabriel; Hanna, Michael; Thomas, Laine; Wallentin, Lars; Granger, Christopher B

2014-05-27

This study sought to characterize major bleeding on the basis of the components of the major bleeding definition, to explore major bleeding by location, to define 30-day mortality after a major bleeding event, and to identify factors associated with major bleeding. Apixaban was shown to reduce the risk of major hemorrhage among patients with atrial fibrillation in the ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation) trial. All patients who received at least 1 dose of a study drug were included. Major bleeding was defined according to the criteria of the International Society on Thrombosis and Haemostasis. Factors associated with major hemorrhage were identified using a multivariable Cox model. The on-treatment safety population included 18,140 patients. The rate of major hemorrhage among patients in the apixaban group was 2.13% per year compared with 3.09% per year in the warfarin group (hazard ratio [HR] 0.69, 95% confidence interval [CI]: 0.60 to 0.80; p < 0.001). Compared with warfarin, major extracranial hemorrhage associated with apixaban led to reduced hospitalization, medical or surgical intervention, transfusion, or change in antithrombotic therapy. Major hemorrhage followed by mortality within 30 days occurred half as often in apixaban-treated patients than in those receiving warfarin (HR 0.50, 95% CI: 0.33 to 0.74; p < 0.001). Older age, prior hemorrhage, prior stroke or transient ischemic attack, diabetes, lower creatinine clearance, decreased hematocrit, aspirin therapy, and nonsteroidal anti-inflammatory drugs were independently associated with an increased risk. Apixaban, compared with warfarin, was associated with fewer intracranial hemorrhages, less adverse consequences following extracranial hemorrhage, and a 50% reduction in fatal consequences at 30 days in cases of major hemorrhage. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

The effect of aspirin nanoemulsion on TNFα and iNOS in gastric tissue in comparison with conventional aspirin

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Mahmoud FA

2015-08-01

Full Text Available Fatma Abd Elhalim Mahmoud,1,2 Khalid S Hashem,3 Asmaa Mohammed M Hussein Elkelawy21Medical Pharmacology Department, Faculty of Medicine, Cairo University, Giza, 2Clinical Pharmacology Department, Faculty of Medicine, 3Biochemistry Department, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef, EgyptBackground: No dose of aspirin is free of bleeding risk. Even at a dose as low as 75 mg/day, the risk of upper gastrointestinal bleeding is twice as high as among nonusers. Nanoemulsions (NEs are emulsion systems with droplet size in nanometer scale in which oil or water droplets are finely dispersed in the opposite phase with the help of a suitable surfactant to stabilize the system.Objectives: The objective of this study was to determine the effect of aspirin NE in comparison to conventional aspirin.Materials and methods: A total of 24 male rats were used in the study and arbitrarily assigned to four groups. Group 1 was the control group, and was given saline. Group 2 was given blank NE 1.5 mL/kg orally. Group 3 was given aspirin 30 mg/kg body weight orally. Group 4 was given aspirin NE 30 mg/kg body weight orally. Rats were killed, and gastric tissue was quickly excised after dissection of the animals. The tissues were divided into three pieces. The first one was kept in formalin 10% for pathological investigation. The second piece was kept in liquid nitrogen for molecular investigation. The third piece was homogenized in ten volumes of ice-cold phosphate-buffered saline (pH 7 using a Teflon homogenizer until a uniform suspension was obtained. The homogenate was centrifuged at 4,000 rpm for 30 minutes at 4°C to separate the supernatant from cellular debris. The supernatant was then used for the estimation of biochemical assays.Results: The present study shows that aspirin has a toxic effect on the stomach as a result of inducing marked oxidative damage and the release of reactive oxygen species. This was shown by the significant

Sol-gel Derived Warfarin - Silica Composites for Controlled Drug Release.

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Dolinina, Ekaterina S; Parfenyuk, Elena V

2017-01-01

Warfarin, commonly used anticoagulant in clinic, has serious shortcomings due to its unsatisfactory pharmacodynamics. One of the efficient ways for the improvement of pharmacological and consumer properties of drugs is the development of optimal drug delivery systems. The aim of this work is to synthesize novel warfarin - silica composites and to study in vitro the drug release kinetics to obtain the composites with controlled release. The composites of warfarin with unmodified (UMS) and mercaptopropyl modified silica (MPMS) were synthesized by sol-gel method. The composite formation was confirmed by FTIR spectra. The concentrations of warfarin released to media with pH 1.6, 6.8 and 7.4 were measured using UV spectroscopy. The drug release profiles from the solid composites were described by a series of kinetic models which includes zero order kinetics, first order kinetics, the modified Korsmeyer-Peppas model and Hixson-Crowell model. The synthesized sol-gel composites have different kinetic behavior in the studied media. In contrast to the warfarin composite with unmodified silica, the drug release from the composite with mercaptopropyl modified silica follows zero order kinetics for 24 h irrespective to the release medium pH due to mixed mechanism (duffusion + degradation and/or disintegration of silica matrix). The obtained results showed that warfarin - silica sol-gel composites have a potential application for the development of novel oral formulation of the drug with controlled delivery. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Aspirin to Zoloft: Ways Medicines Work

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... View All Articles | Inside Life Science Home Page Aspirin to Zoloft: Ways Medicines Work By Emily Carlson ... biology of how cancer cells grow. Antihistamines, Antidepressants, Aspirin Adrenergic receptor with carazolol, a beta-blocker. View ...

Suboptimal Anticoagulant Management in Japanese Patients with Nonvalvular Atrial Fibrillation Receiving Warfarin for Stroke Prevention.

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Hirano, Teruyuki; Kaneko, Hirokazu; Mishina, Sari; Wang, Feng; Morita, Satoshi

2017-10-01

Atrial fibrillation (AF) is the most common cardiac arrhythmia, with increasing prevalence in Japan. Although prothrombin time-international normalized ratio (PT-INR) targets for monitoring warfarin therapy in patients with nonvalvular AF (NVAF) are well defined, real-world patient characteristics and PT-INR levels remain unknown among Japanese patients with NVAF who initiate and continue warfarin (warfarin maintainers) versus those who switch from warfarin to direct oral anticoagulants (DOACs; warfarin switchers). Patients with NVAF receiving oral anticoagulants between February 2013 and June 2015 were identified using a nationwide electronic medical record (EMR) database from 69 hospitals in Japan. Demographics and characteristics of patients, PT-INR, time in therapeutic range (TTR), and frequency in range (FIR) of PT-INR between warfarin maintainers and warfarin switchers were assessed. A total of 1705 patients met inclusion criteria and were examined (1501 warfarin maintainers versus 204 warfarin switchers). CHADS 2 , CHA 2 DS 2 -VASc, and HAS-BLED scores were comparable between groups. However, these scores were significantly higher among warfarin switchers at the time of switching than at the time of warfarin initiation. Furthermore, TTR and FIR of PT-INR were lower in warfarin switchers than in maintainers. Nevertheless, TTR and FIR were below 50% (PT-INR, 1.6-2.6) in both patient groups. In this EMR-based clinical study, patients who switched to DOACs had both poor or inadequate PT-INR control and higher risk factors of stroke. Many patients receiving warfarin did not achieve sufficient PT-INR therapeutic range. DOACs could be recommended in Japanese patients with NVAF with inadequate PT-INR control and increased risk of stroke. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Attempted Suicide by Massive Warfarin Ingestion Conservatively Managed Using Phytonadione

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Katherine L. March

2016-01-01

Full Text Available Treatment strategies for acute toxicity following massive ingestion of warfarin are not well described in the literature. Warfarin is the primary oral anticoagulation agent used in the treatment of thromboembolic disease, and patients with acute toxicity are at risk for life-threatening hemorrhages. Treatment options include phytonadione (vitamin K1, fresh frozen plasma (FFP, and prothrombin complex concentrates (PCCs used alone or in combination. FFP and PCC can be associated with volume complications, undesirable thromboembolic events, and increased costs. We describe the case of a 63-year-old female with acute warfarin toxicity following a massive ingestion of warfarin (420 mg–450 mg in an attempt to commit suicide. Upon arrival to the emergency department, serial INR checks were initiated to help guide dosing strategy and later adjusted based on INR response to treatment using only phytonadione.

Retrobulbar Hematoma from Warfarin Toxicity and the Limitations of Bedside Ocular Sonography

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2010-05-01

worldwide. Peer Reviewed Title: Retrobulbar Hematoma from Warfarin Toxicity and the Limitations of Bedside Ocular Sonography Journal Issue: Western...Preferred Citation: Thompson D, Stanescu C, Pryor P, Laselle B. Retrobulbar Hematoma from Warfarin Toxicity and the Limitations of Bedside Ocular...nontrauamtic retrobulbar hematoma associated with warfarin toxicity. The application and limitations of focused bedside ocular sonography for this

Algorithms for monitoring warfarin use: Results from Delphi Method.

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Kano, Eunice Kazue; Borges, Jessica Bassani; Scomparini, Erika Burim; Curi, Ana Paula; Ribeiro, Eliane

2017-10-01

Warfarin stands as the most prescribed oral anticoagulant. New oral anticoagulants have been approved recently; however, their use is limited and the reversibility techniques of the anticoagulation effect are little known. Thus, our study's purpose was to develop algorithms for therapeutic monitoring of patients taking warfarin based on the opinion of physicians who prescribe this medicine in their clinical practice. The development of the algorithm was performed in two stages, namely: (i) literature review and (ii) algorithm evaluation by physicians using a Delphi Method. Based on the articles analyzed, two algorithms were developed: "Recommendations for the use of warfarin in anticoagulation therapy" and "Recommendations for the use of warfarin in anticoagulation therapy: dose adjustment and bleeding control." Later, these algorithms were analyzed by 19 medical doctors that responded to the invitation and agreed to participate in the study. Of these, 16 responded to the first round, 11 to the second and eight to the third round. A 70% consensus or higher was reached for most issues and at least 50% for six questions. We were able to develop algorithms to monitor the use of warfarin by physicians using a Delphi Method. The proposed method is inexpensive and involves the participation of specialists, and it has proved adequate for the intended purpose. Further studies are needed to validate these algorithms, enabling them to be used in clinical practice.

Calcium-channel blockers do not alter the clinical efficacy of clopidogrel after myocardial infarction: a nationwide cohort study

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Olesen, Jonas B; Gislason, Gunnar H; Charlot, Mette G

2011-01-01

Objectives The purpose of this study was to determine the risk of adverse cardiovascular events associated with concomitant use of clopidogrel and calcium-channel blockers (CCBs) in patients with myocardial infarction (MI). Background CCBs inhibit a variety of cytochrome P-450 enzymes, some...... patients treated and not treated with clopidogrel, with a hazard ratio of 1.15 (95% confidence interval [CI]: 1.07 to 1.24) and 1.05 (95% CI: 1.01 to 1.11), respectively. The increased risk was independent of clopidogrel use; the hazard rate ratio was 1.08 (95% CI: 0.99 to 1.18). Analyses of all additional...... adverse end points and propensity score–matched models provided similar results. Conclusions The clinical efficacy of clopidogrel in patients with a recent MI is not modified by concomitant CCB treatment. This potential drug interaction is unlikely to have clinical significance....

Blødningskomplikationer ved behandling med clopidogrel og acetylsalicylsyre efter akut koronart syndrom

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Kjær, Janus; Larsen, Christian Hastrup; Poulsen, Tina Svenstrup

2006-01-01

INTRODUCTION: The Clopidogrel in Unstable Angina to Prevent Recurrent Events (CURE) study showed that patients with unstable angina pectoris (UAP) and non-ST-elevation myocardial infarction (NSTEMI) benefit from combined therapy with acetylsalicylic acid (ASA) and clopidogrel. However, only...... patients entering clinical randomized trials were studied. We sought to assess whether the risk of bleeding increased after the introduction of the CURE criteria in an unselected population of Danish patients with NSTEMI or UAP. MATERIALS AND METHODS: The CURE criteria were implemented in the Department...

Hemorrhagic Transformation After Large Cerebral Infarction in Rats Pretreated With Dabigatran or Warfarin.

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Kwon, Il; An, Sunho; Kim, Jayoung; Yang, Seung-Hee; Yoo, Joonsang; Baek, Jang-Hyun; Nam, Hyo Suk; Kim, Young Dae; Lee, Hye Sun; Choi, Hyun-Jung; Heo, Ji Hoe

2017-10-01

It is uncertain whether hemorrhagic transformation (HT) after large cerebral infarction is less frequent in dabigatran users than warfarin users. We compared the occurrence of HT after large cerebral infarction among rats pretreated with dabigatran, warfarin, or placebo. This was a triple-blind, randomized, and placebo-controlled experiment. After treatment with warfarin (0.2 mg/kg), dabigatran (20 mg/kg), or saline for 7 days, Wistar rats were subjected to transient middle cerebral artery occlusion. As the primary outcome, HT was determined by gradient-recalled echo imaging. For the secondary outcome, intracranial hemorrhage was assessed via gradient-recalled echo imaging in surviving rats and via autopsy for dead rats. Of 62 rats, there were 33 deaths (53.2%, 17 technical reasons). Of the intention-to-treat population, 33 rats underwent brain imaging. HT was less frequent in the dabigatran group than the warfarin group (placebo 2/14 [14%], dabigatran 0/10 [0%], and warfarin 9/9 [100%]; dabigatran versus warfarin; P warfarin group (19/29 [65.5%]; P =0.003), but not in the dabigatran group (6/19 [31.6%]; P =0.420). Mortality was significantly higher in the warfarin group than the dabigatran group (79.3% versus 47.4%; P =0.022), but not related to the hemorrhage frequency. The risk of HT after a large cerebral infarction was significantly increased in rats pretreated with warfarin than those with dabigatran. However, the results here may not have an exact clinical translation. © 2017 American Heart Association, Inc.

Rivaroxaban with or without aspirin in stable cardiovascular disease

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Eikelboom, John W; Connolly, Stuart J; Bosch, Jackie

2017-01-01

BACKGROUND: We evaluated whether rivaroxaban alone or in combination with aspirin would be more effective than aspirin alone for secondary cardiovascular prevention. METHODS: In this double-blind trial, we randomly assigned 27,395 participants with stable atherosclerotic vascular disease to receive...... rivaroxaban (2.5 mg twice daily) plus aspirin (100 mg once daily), rivaroxaban (5 mg twice daily), or aspirin (100 mg once daily). The primary outcome was a composite of cardiovascular death, stroke, or myocardial infarction. The study was stopped for superiority of the rivaroxaban-plus-aspirin group after...... a mean follow-up of 23 months. RESULTS: The primary outcome occurred in fewer patients in the rivaroxaban-plus-aspirin group than in the aspirin-alone group (379 patients [4.1%] vs. 496 patients [5.4%]; hazard ratio, 0.76; 95% confidence interval [CI], 0.66 to 0.86; P

Lack of a meaningful effect of anacetrapib on the pharmacokinetics and pharmacodynamics of warfarin in healthy subjects

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Krishna, Rajesh; Stypinski, Daria; Ali, Melissa; Garg, Amit; Cote, Josee; Maes, Andrea; DeGroot, Bruce; Liu, Yang; Li, Susie; Connolly, Sandra M; Wagner, John A; Stoch, S Aubrey

2012-01-01

AIM Anacetrapib is currently being developed for the treatment of dyslipidaemia. Since warfarin, an anticoagulant with a narrow therapeutic index, is expected to be commonly prescribed in this population, a drug interaction study was conducted. METHODS In a randomized, open-label, two-period fixed-sequence design, 12 healthy male subjects received two different treatments (treatment A followed by treatment B). In treatment A, a single oral dose of 30 mg warfarin (3 × 10 mg CoumadinTM) was administered on day 1. After a washout interval, subjects began treatment B, where they were given daily 100 mg doses of anacetrapib (1 × 100 mg) beginning on day −14 and continuing through day 7, with concomitant administration of 30 mg warfarin (3 × 10 mg) on day 1. All anacetrapib and warfarin doses were administered with a standard low fat breakfast. After warfarin concentrations and prothrombin time were measured, standard pharmacokinetic, pharmacodynamic and statistical (linear mixed effects model) analyses were applied. RESULTS Anacetrapib was generally well tolerated when co-administered with warfarin in the healthy males in this study. The geometric mean ratios (GMRs) for warfarin + anacetrapib : warfarin alone and 90% confidence interval (CIs) for warfarin AUC(0–∞) were 0.94 (0.90, 0.97) for the R(+) warfarin enantiomer and 0.93 (0.87, 0.98) for the S(−) warfarin enantiomer, both being contained in the interval (0.80, 1.25), supporting the primary hypothesis of the study. The GMRs warfarin + anacetrapib : warfarin alone and 90% CIs for the statistical comparison of warfarin Cmax were 1.01 (0.97, 1.05) for both the R(+) warfarin and the S(−) warfarin enantiomers, and were also contained in the interval (0.80, 1.25). The GMR (warfarin + anacetrapib : warfarin alone) and 90% CI for the statistical comparison of INR AUC(0–168 h) was 0.93 (0.89, 0.96). CONCLUSION The single dose pharmacokinetics and pharmacodynamics of orally administered warfarin were not

Antiplatelet therapy: aspirin resistance and all that jazz!

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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.

Edoxaban versus Warfarin for the Treatment of Symptomatic Venous Thromboembolism

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Büller, Harry R; Décousus, Hervé; Grosso, Michael A

2013-01-01

Whether the oral factor Xa inhibitor edoxaban can be an alternative to warfarin in patients with venous thromboembolism is unclear.......Whether the oral factor Xa inhibitor edoxaban can be an alternative to warfarin in patients with venous thromboembolism is unclear....

Preliminary clinical evaluation of a noninvasive device for the measurement of coagulability in the elderly

Directory of Open Access Journals (Sweden)

Lerman Y

2011-08-01

Full Text Available Yaffa Lerman1, Moshe M Werber2, Ilya Fine2, Polina Kemelman11Department of Geriatrics, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; 2Elfi-Tech Ltd, Rehovot, IsraelAbstract: The feasibility of the noninvasive assessment of blood ‘coagulability’ (the tendency to coagulate has been tested by using a novel device, the Thrombo-Monitor. It monitors, by using the principles of near infra-red (NIR dynamic light scattering, the tendency of blood to create clots. The Thrombo-Monitor observes the very initial changes of blood viscosity, which occurs due to the temporarily induced stasis of capillary blood of the finger. One hundred and fifteen patients aged >65 years (matched by age and sex participated in the study. Patients were initially divided into four groups based on the patient’s medical therapy. The study groups were: warfarin, enoxaparin, aspirin and/or clopidogrel, and a control group. The medications were given according to the patient’s comorbidities (eg, atrial fibrillation [AF], status post pulmonary embolism [S/p PE], status post cerebrovascular accident [S/p CVA]. The Thrombo-Monitor Index (TMI is a noninvasive index, derived on the basis of laboratory test results of international normalized ratio (INR and prothrombin time (PT values. For the group of patients who were treated only with warfarin, TMI was adjusted by using the jackknife statistical approach to create maximum correlation and linearity with INR and PT values that ranged from 1.1 to 5.0. For all warfarin patients (N = 35 the TMI was found to have a good correlation with INR and PT values (R2 = 0.64, P < 0.00001; mean TMI = 1.86 (SD = 0.91; mean INR and PT = 2.3 (SD = 0.91. The calibration curve thus generated was used to calculate the TMI for all other groups: aspirin group, mean TMI = 1.3 (SD = 0.14, N = 23, corresponding approximately to INR and PT values of 1.036; enoxaparin group (N = 24, mean TMI = 1.34 (SD

Rivaroxaban with or without Aspirin in Stable Cardiovascular Disease.

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Eikelboom, John W; Connolly, Stuart J; Bosch, Jackie; Dagenais, Gilles R; Hart, Robert G; Shestakovska, Olga; Diaz, Rafael; Alings, Marco; Lonn, Eva M; Anand, Sonia S; Widimsky, Petr; Hori, Masatsugu; Avezum, Alvaro; Piegas, Leopoldo S; Branch, Kelley R H; Probstfield, Jeffrey; Bhatt, Deepak L; Zhu, Jun; Liang, Yan; Maggioni, Aldo P; Lopez-Jaramillo, Patricio; O'Donnell, Martin; Kakkar, Ajay K; Fox, Keith A A; Parkhomenko, Alexander N; Ertl, Georg; Störk, Stefan; Keltai, Matyas; Ryden, Lars; Pogosova, Nana; Dans, Antonio L; Lanas, Fernando; Commerford, Patrick J; Torp-Pedersen, Christian; Guzik, Tomek J; Verhamme, Peter B; Vinereanu, Dragos; Kim, Jae-Hyung; Tonkin, Andrew M; Lewis, Basil S; Felix, Camilo; Yusoff, Khalid; Steg, P Gabriel; Metsarinne, Kaj P; Cook Bruns, Nancy; Misselwitz, Frank; Chen, Edmond; Leong, Darryl; Yusuf, Salim

2017-10-05

We evaluated whether rivaroxaban alone or in combination with aspirin would be more effective than aspirin alone for secondary cardiovascular prevention. In this double-blind trial, we randomly assigned 27,395 participants with stable atherosclerotic vascular disease to receive rivaroxaban (2.5 mg twice daily) plus aspirin (100 mg once daily), rivaroxaban (5 mg twice daily), or aspirin (100 mg once daily). The primary outcome was a composite of cardiovascular death, stroke, or myocardial infarction. The study was stopped for superiority of the rivaroxaban-plus-aspirin group after a mean follow-up of 23 months. The primary outcome occurred in fewer patients in the rivaroxaban-plus-aspirin group than in the aspirin-alone group (379 patients [4.1%] vs. 496 patients [5.4%]; hazard ratio, 0.76; 95% confidence interval [CI], 0.66 to 0.86; Paspirin group (288 patients [3.1%] vs. 170 patients [1.9%]; hazard ratio, 1.70; 95% CI, 1.40 to 2.05; Paspirin group as compared with 378 (4.1%) in the aspirin-alone group (hazard ratio, 0.82; 95% CI, 0.71 to 0.96; P=0.01; threshold P value for significance, 0.0025). The primary outcome did not occur in significantly fewer patients in the rivaroxaban-alone group than in the aspirin-alone group, but major bleeding events occurred in more patients in the rivaroxaban-alone group. Among patients with stable atherosclerotic vascular disease, those assigned to rivaroxaban (2.5 mg twice daily) plus aspirin had better cardiovascular outcomes and more major bleeding events than those assigned to aspirin alone. Rivaroxaban (5 mg twice daily) alone did not result in better cardiovascular outcomes than aspirin alone and resulted in more major bleeding events. (Funded by Bayer; COMPASS ClinicalTrials.gov number, NCT01776424 .).

Prospective observational study of the effect of dual antiplatelet therapy with tranexamic acid treatment on platelet function and bleeding after cardiac surgery.

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Amour, J; Garnier, M; Szymezak, J; Le Manach, Y; Helley, D; Bertil, S; Ouattara, A; Riou, B; Gaussem, P

2016-12-01

The bleeding impact of dual antiplatelet therapy (DAPT), aspirin and clopidogrel, maintained until coronary artery bypass graft surgery (CABG), is still a matter of debate. The lack of preoperative antiplatelet activity measurement and heterogeneity of antifibrinolytic protocols in prior studies make the conclusions questionable. The aim of this prospective study was to determine, after preoperative antiplatelet activity measurement, if the maintenance of DAPT until CABG increases bleeding in patients treated with tranexamic acid (TA). This observational study included 150 consecutive patients, 89 treated with aspirin and 61 treated with DAPT, undergoing a first-time planned on-pump CABG with TA treatment. Antiplatelet activity was measured with platelet aggregation tests and quantification of VASP phosphorylation. Postoperative bleeding at 24 h was recorded and propensity score analysis was performed. Based on VASP assay, 54% of patients showed high on-clopidogrel platelet activity inhibition. Postoperative bleeding at 24 h increased by 22% in the DAPT group, compared with the aspirin group (680 [95% CI: 360-1670] vs 558 [95%CI: 267-1270] ml, P < 0.01), consistent with increased blood transfusion (21% vs 7%, P = 0.01); a higher incidence of mediastinitis did not reach statistical significance (15% vs 4%, P = 0.05). Bleeding correlated with the extent of clopidogrel antiplatelet effect, with the best correlation for the VASP assay. Maintenance of DAPT until the day of CABG in patients treated with TA, increased postoperative bleeding at 24 h in parallel with preoperative antiplatelet activity induced by clopidogrel. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Role of Aspirin in Breast Cancer Survival.

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Chen, Wendy Y; Holmes, Michelle D

2017-07-01

Chemotherapy and hormonal therapy have significantly decreased breast cancer mortality, although with considerable side effects and financial costs. In the USA, over three million women are living after a breast cancer diagnosis and are eager for new treatments that are low in toxicity and cost. Multiple observational studies have reported improved breast cancer survival with regular aspirin use. Furthermore, pooled data from five large randomized trials of aspirin for cardiovascular disease showed that subjects on aspirin had decreased risk of cancer mortality and decreased risk of metastatic cancer. Although the potential mechanism for aspirin preventing breast cancer is not known, possible pathways may involve platelets, inflammation, cyclooxygenase (COX) 2, hormones, or PI3 kinase. This review article summarizes the current epidemiologic and clinical trial evidence as well as possible underlying mechanisms that justify current phase III randomized trials of aspirin to improve breast cancer survival.

Aspirin and lipid mediators in the cardiovascular system.

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Schrör, Karsten; Rauch, Bernhard H

2015-09-01

Aspirin is an unique compound because it bears two active moieties within one and the same molecule: a reactive acetyl group and the salicylate metabolite. Salicylate has some effects similar to aspirin, however only at higher concentrations, usually in the millimolar range, which are not obtained at conventional antiplatelet aspirin doses of 100-300 mg/day. Pharmacological actions of aspirin in the cardiovascular system at these doses are largely if not entirely due to target structure acetylation. Several classes of lipid mediators become affected: Best known is the cyclooxygenase-1 (COX-1) in platelets with subsequent inhibition of thromboxane and, possibly, thrombin formation. By this action, aspirin also inhibits paracrine thromboxane functions on other lipid mediators, such as the platelet storage product sphingosine-1-phosphate (S1P), an inflammatory mediator. Acetylation of COX-2 allows for generation of 15-(R)HETE and subsequent formation of "aspirin-triggered lipoxin" (ATL) by interaction with white cell lipoxygenases. In the cardiovascular system, aspirin also acetylates eNOS with subsequent upregulation of NO formation and enhanced expression of the antioxidans heme-oxygenase-1. This action is possibly also COX-2/ATL mediated. Many more acetylation targets have been identified in live cells by quantitative acid-cleavable activity-based protein profiling and might result in discovery of even more aspirin targets in the near future. Copyright © 2015 Elsevier Inc. All rights reserved.

Cost-effectiveness of clopidogrel in myocardial infarction with ST-segment elevation: a European model based on the CLARITY and COMMIT trials.

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Berg, Jenny; Lindgren, Peter; Spiesser, Julie; Parry, David; Jönsson, Bengt

2007-06-01

Several health economic studies have shown that the use of clopidogrel is cost-effective to prevent ischemic events in non-ST-segment elevation myocardial infarction (NSTEMI) and unstable angina. This study was designed to assess the cost-effectiveness of clopidogrel in short- and long-term treatment of ST-segment elevation myocardial infarction (STEMI) with the use of data from 2 trials in Sweden, Germany, and France: CLARITY (Clopidogrel as Adjunctive Reperfusion Therapy) and COMMIT (Clopidogrel and Metoprolol in Myocardial Infarction Trial). A combined decision tree and Markov model was constructed. Because existing evidence indicates similar long-term outcomes after STEMI and NSTEMI, data from the long-term NSTEMI CURE trial (Clopidogrel in Unstable Angina to Prevent Recurrent Events) were combined with 1-month data from CLARITY and COMMIT to model the effect of treatment up to 1 year. The risks of death, myocardial infarction, and stroke in an untreated population and long-term survival after all events were derived from the Swedish Hospital Discharge and Cause of Death register. The model was run separately for the 2 STEMI trials. A payer perspective was chosen for the comparative analysis, focusing on direct medical costs. Costs were derived from published sources and were converted to 2005 euros. Effectiveness was measured as the number of life-years gained (LYG) from clopidogrel treatment. In a patient cohort with the same characteristics and event rates as in the CLARITY population, treatment with clopidogrel for up to 1 year resulted in 0.144 LYG. In Sweden and France, this strategy was dominant with estimated cost savings of euro 111 and euro 367, respectively. In Germany, clopidogrel treatment had an incremental cost-effectiveness ratio (ICER) of euro 92/LYG. Data from the COMMIT study showed that clopidogrel treatment resulted in 0.194 LYG at an incremental cost of euro 538 in Sweden, euro 798 in Germany, and euro 545 in France. The corresponding

Safety and feasibility of liver resection with continued antiplatelet therapy using aspirin.

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Monden, Kazuteru; Sadamori, Hiroshi; Hioki, Masayoshi; Ohno, Satoshi; Saneto, Hiromi; Ueki, Toru; Yabushita, Kazuhisa; Ono, Kazumi; Sakaguchi, Kousaku; Takakura, Norihisa

2017-07-01

Aspirin is widely used for the secondary prevention of ischemic stroke and cardiovascular disease. Perioperative aspirin may decrease thrombotic morbidity, but may also increase hemorrhagic morbidity. In particular, liver resection carries risks of bleeding, leading to higher risks of hemorrhagic morbidity. Our institution has continued aspirin therapy perioperatively in patients undergoing liver resection. This study examined the safety and feasibility of liver resection while continuing aspirin. We retrospectively evaluated 378 patients who underwent liver resection between January 2010 and January 2016. Patients were grouped according to preoperative aspirin prescription: patients with aspirin therapy (aspirin users, n = 31); and patients without use of aspirin (aspirin non-users, n = 347). Aspirin users were significantly older (P aspirin users than among aspirin non-users, no significant difference was identified. No postoperative hemorrhage was seen among aspirin users. Liver resection can be safely performed while continuing aspirin therapy without increasing hemorrhagic morbidity. Our results suggest that interruption of aspirin therapy is unnecessary for patients undergoing liver resection. © 2017 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

Enhancement of aspirin capsulation by porous particles including iron hydrous oxide

International Nuclear Information System (INIS)

Saito, Kenji; Koishi, Masumi; Hosoi, Fumio; Makuuchi, Keizo.

1986-01-01

Polymer-coated porous particles containing aspirin as a drug were prepared and the release of rate of aspirin was studied. The impregnation of aspirin was carried out by post-graft polymerization, where methyl methacrylate containing aspirin was treated with porous particles including iron oxide, pre-irradiated with γ-ray form Co-60. Release of aspirin from modified particles was examined with 50 % methanol solution. The amount of aspirin absorbed in porous particles increased by grafting of methyl methacrylate. The particles treated with iron hydrous oxide sols before irradiation led to the increment of aspirin absorption. Diffusion of aspirin through the polymer matrix and the gelled layer was the limiting process in the aspirin release from particles. The rate of aspirin released from modified particles including iron hydrous oxide wasn't affected by the grafting of methyl methacrylate. (author)

Effect of misoprostol on patients with aspirin-exacerbated respiratory disease undergoing aspirin challenge and desensitization.

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Walters, Kristen M; Simon, Ronald A; Woessner, Katharine M; Wineinger, Nathan E; White, Andrew A

2017-07-01

Prostaglandin E 2 (PGE 2 ) is an anti-inflammatory compound that inhibits 5-lipoxygenase activity. Diminished PGE 2 regulation in aspirin-exacerbated respiratory disease (AERD) leads to respiratory reactions on cyclooxygenase 1 inhibition. In vitro studies have found that exogenous PGE 2 stabilizes inflammatory mediator release. To examine whether misoprostol (oral prostaglandin E 1 analogue) use during aspirin challenge and desensitization might decrease the severity of aspirin-induced symptoms and make desensitization safer for patients with AERD. Forty-five patients undergoing aspirin challenge and/or desensitization were randomized to misoprostol (n = 30) or placebo (n = 15) and compared with a group of historical controls (n = 31). Misoprostol (200 μg) was administered at 30 minutes, 90 minutes, and 4 hours after the first dose of nasal ketorolac. Measured end points included change in forced expiratory volume in 1 second (FEV 1 ), peak nasal inspiratory flow rate (PNIF), number of treatments received for induced reactions, and adverse gastrointestinal effects. A difference in FEV 1 and PNIF reduction was detected between misoprostol and placebo (P = .03) and misoprostol and historical controls (P = .01), respectively, during nasal ketorolac challenge. No difference was detected among aspirin reactors. Among all reactors, no difference in magnitude was found for FEV 1 (P = .13) or PNIF (P = .07) reduction across all 3 groups. Total treatment requirement was similar (P = .14). Patients receiving misoprostol were more likely to report adverse gastrointestinal effects (P = .02). The addition of misoprostol to current aspirin challenge and/or desensitization protocols reveals no protective effect in reducing the intensity of nonsteroidal anti-inflammatory drug-induced symptoms and is not recommended based on the findings in this study. Copyright © 2017 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Preadmission Use of Platelet Inhibitors and Short-Term Stroke Mortality:A Population-Based Cohort Study

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Würtz, Morten; Schmidt, Morten; Grove, Erik Lerkevang

2018-01-01

Aims: The impact of preadmission antiplatelet treatment on prognosis after stroke is poorly understood. We therefore investigated whether preadmission use of aspirin and clopidogrel was associated with mortality in patients hospitalized with ischemic stroke, intracerebral hemorrhage (ICH......), or subarachnoid hemorrhage (SAH). Methods and Results: We used nationwide population-based registries to identify all first-time hospitalizations for stroke and subsequent mortality in patients treated with aspirin and clopidogrel in Denmark during 2004-2012. Based on redeemed prescriptions, we computed absolute...... 30-day mortality rates and mortality rate ratios (MRRs) for current platelet inhibitor users and non-users. We used Cox regression to control for potentially confounding factors. Among platelet inhibitor non-users, 30-day stroke mortality was 12.0% (8.8% for ischemic stroke, 29.6% for ICH, and 21...

Risk of Gastrointestinal Bleeding with Rivaroxaban: A Comparative Study with Warfarin

Directory of Open Access Journals (Sweden)

Muhammed Sherid

2016-01-01

Full Text Available Introduction. The risk of gastrointestinal (GI bleeding with rivaroxaban has not been studied extensively. The aim of our study was to assess this risk in comparison to warfarin. Methods. We examined the medical records for patients who were started on rivaroxaban or warfarin from April 2011 to April 2013. Results. We identified 300 patients (147 on rivaroxaban versus 153 on warfarin. GI bleeding occurred in 4.8% patients with rivaroxaban when compared to 9.8% patients in warfarin group (p=0.094. GI bleeding occurred in 8% with therapeutic doses of rivaroxaban (>10 mg/d compared to 9.8% with warfarin (p=0.65. Multivariate analysis showed that patients who were on rivaroxaban for ≤40 days had a higher incidence of GI bleeding than those who were on it for >40 days (OR = 2.8, p=0.023. Concomitant use of dual antiplatelet agents was associated with increased risk of GI bleeding in the rivaroxaban group (OR = 7.4, p=0.0378. Prior GI bleeding was also a risk factor for GI bleeding in rivaroxaban group (OR = 15.5. Conclusion. The incidence of GI bleeding was similar between rivaroxaban and warfarin. The risk factors for GI bleeding with rivaroxaban were the first 40 days of taking the drug, concomitant dual antiplatelet agents, and prior GI bleeding.

Oral warfarin affects peripheral blood leukocyte IL-6 and TNFα production in rats.

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Popov, Aleksandra; Belij, Sandra; Subota, Vesna; Zolotarevski, Lidija; Mirkov, Ivana; Kataranovski, Dragan; Kataranovski, Milena

2013-01-01

Warfarin is a Vitamin K (VK) antagonist that affects Vitamin K-dependent (VKD) processes, including blood coagulation, as well as processes unrelated to hemostasis such as bone growth, calcification, and growth of some cell types. In addition, warfarin exerts influence on some non-VKD-related activities, including anti-tumor and immunomodulating activity. With respect to the latter, both immune stimulating and suppressive effects have been noted in different experimental systems. To explore the in vivo immunomodulatory potential of warfarin on one type of activity (i.e., cytokine production) in two different immune cell populations (i.e., mononuclear or polymorphonuclear cells), effects of subchronic oral warfarin intake in rats on pro-inflammatory cytokine (i.e., TNFα, IL-6) production by peripheral blood mononuclear and polymorphonuclear cells (granulocytes) was examined. Differential effects of warfarin intake on TNFα and IL-6 were noted, depending on the type of peripheral blood leukocytes and on the cytokine examined. Specifically, a lack of effect on TNFα and a priming of IL-6 production by mononuclear cells along with a decrease in TNFα and a lack of effect on IL-6 in polymorphonuclear cells were seen in warfarin-exposed hosts. The cell- and cytokine-dependent effects from subchronic oral warfarin intake on peripheral blood leukocytes demonstrated in this study could, possibly, differentially affect reactions mediated by these cells. Ultimately, the observed effects in rats might have implications for those humans who are on long-term/prolonged warfarin therapy.

The future of warfarin pharmacogenetics in under-represented minority groups

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Cavallari, Larisa H; Perera, Minoli A

2012-01-01

Genotype-based dosing recommendations are provided in the US FDA-approved warfarin labeling. However, data that informed these recommendations were from predominately Caucasian populations. Studies show that variants contributing to warfarin dose requirements in Caucasians provide similar contributions to dose requirements in US Hispanics, but significantly lesser contributions in African–Americans. Further data demonstrate that variants occurring commonly in individuals of African ancestry, but rarely in other racial groups, significantly influence dose requirements in African–Americans. These data suggest that it is important to consider variants specific for African–Americans when implementing genotype-guided warfarin dosing in this population. PMID:22871196

Patterns of international normalized ratio values among new warfarin patients with nonvalvular atrial fibrillation.

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Nelson, Winnie W; Milentijevic, Dejan; Wang, Li; Baser, Onur; Damaraju, C V; Schein, Jeffrey R

2016-12-01

Limited information exists regarding the relationship between international normalized ratio (INR) control/stability and the discontinuation of warfarin therapy among patients with nonvalvular atrial fibrillation (NVAF). This study evaluated the association between INR stabilization and warfarin discontinuation and assessed INR patterns before and after INR stabilization among patients (≥18 years) with NVAF who newly initiated warfarin (Veterans Health Administration datasets; October 1, 2007 through September 30, 2012). Achievement of INR stabilization (≥3 consecutive in-range therapeutic INR measurements ≥7 days apart) was examined from warfarin initiation through the end of warfarin exposure. Proportion of time in therapeutic range during warfarin exposure was calculated (Rosendaal method) and categorized as at least 60% or less than 60%. Among 34 346 patients, 49.4% achieved INR stabilization (mean time to stabilization, 98 days). Approximately 40% of INR values were out-of-range, even after achieving stabilization. During 30 days following an INR 4.0 or higher, patients had more INR testing than the overall mean (2.51 vs. 1.67 tests). Warfarin discontinuation was 4.2 times more likely among patients without INR stabilization versus those with INR stabilization (P < 0.00001). Patients with poor INR control (time in therapeutic range <60%) were 1.76 times more likely to discontinue warfarin within 1 year (P < 0.0001). INR stabilization is a better predictor of warfarin discontinuation than poor INR control. Improved approaches are necessary to maintain appropriate anticoagulation levels among patients with NVAF.

Efficacy of Clopidogrel and Clinical Outcome When Clopidogrel Is Coadministered With Atorvastatin and Lansoprazole: A Prospective, Randomized, Controlled Trial.

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Zhang, Jian-rong; Wang, Di-qing; Du, Jun; Qu, Guang-su; Du, Jian-lin; Deng, Song-bai; Liu, Ya-jie; Cai, Jin-xi; She, Qiang

2015-12-01

This prospective, randomized, nonblind, controlled trial evaluated the effects of clopidogrel on platelet function upon coadministration with atorvastatin and lansoprazole. One hundred four adult patients with non-ST-segment elevated acute coronary syndrome (NSTE-ACS) who underwent percutaneous coronary intervention (PCI) with drug-eluting stent implantation were included. All patients were treated with standard dual antiplatelet therapy (DAPT) plus rosuvastatin 10  mg daily after the operation. On the sixth day after PCI, patients were randomly divided into 4 groups, Group A: DAPT + atorvastatin 20  mg daily (a change from rosuvastatin to atorvastatin) + lansoprazole 30  mg daily, Group B: DAPT + atorvastatin 20  mg daily (a change from rosuvastatin to atorvastatin), Group C: DAPT + lansoprazole 30  mg daily (continuing to take rosuvastatin), Group D is the control group. Additional drugs were used according to the situation of patients. Platelet function and concentrations of platelet activation markers (granular membrane protein 140 (P-selectin), thromboxane B2 (TXB2), and human soluble cluster of differentiation 40 ligand (sCD40L)) were assessed before randomization and at 15- and 30-day follow-up visits. All patients were maintained on treatment for 6 months and observed for bleeding and ischemic events. A total of 104 patients were enrolled, 27 patients in group A, 26 patients in Group B/C, 25 patients in Group D separately, and all the patients were analyzed. There were no differences in platelet function and the levels of platelet activation markers (P-selectin, TXB2, and sCD40L) among or within the 4 groups at the 3 time points of interest (P > 0.05). In the subsequent 6 months, no significant bleeding events occurred, and 12 patients experienced ischemic events, these results were also not significantly different among the groups (P > 0.05). In patients diagnosed with NSTE-ACS who have had drug-eluting stent implantation

Up-regulation of Ciliary Neurotrophic Factor in Astrocytes by Aspirin

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Modi, Khushbu K.; Sendtner, Michael; Pahan, Kalipada

2013-01-01

Ciliary neurotrophic factor (CNTF) is a promyelinating trophic factor, and the mechanisms by which CNTF expression could be increased in the brain are poorly understood. Acetylsalicylic acid (aspirin) is one of the most widely used analgesics. Interestingly, aspirin increased mRNA and protein expression of CNTF in primary mouse and human astrocytes in a dose- and time-dependent manner. Aspirin induced the activation of protein kinase A (PKA) but not protein kinase C (PKC). H-89, an inhibitor of PKA, abrogated aspirin-induced expression of CNTF. The activation of cAMP-response element-binding protein (CREB), but not NF-κB, by aspirin, the abrogation of aspirin-induced expression of CNTF by siRNA knockdown of CREB, the presence of a consensus cAMP-response element in the promoter of CNTF, and the recruitment of CREB and CREB-binding protein to the CNTF promoter by aspirin suggest that aspirin increases the expression of the Cntf gene via the activation of CREB. Furthermore, we demonstrate that aspirin-induced astroglial CNTF was also functionally active and that supernatants of aspirin-treated astrocytes of wild type, but not Cntf null, mice increased myelin-associated proteins in oligodendrocytes and protected oligodendrocytes from TNF-α insult. These results highlight a new and novel myelinogenic property of aspirin, which may be of benefit for multiple sclerosis and other demyelinating disorders. PMID:23653362

Acquired absolute vitamin K deficiency in a patient undergoing warfarin therapy.

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Takada, Hiroaki; Toru, Hifumi; Bunya, Naofumi; Kiriu, Nobuaki; Kato, Hiroshi; Koido, Yuichi; Yasuhiro, Kuroda

2014-06-01

We report a case of absolute vitamin K deficiency (VKD) diagnosed by measuring serum VK levels in an elderly woman undergoing warfarin therapy. A 78-year-old woman was admitted to our hospital because of dyspnea and sore throat diagnosed as pharyngitis 1 week before admission. On admission, the sore throat had exacerbated and dyspnea developed. She had history of atrial fibrillation, for which warfarin 1.5 mg/d was started approximately 10 years prior and her international normalized ratio (INR) had been maintained at an acceptable therapeutic level. Blood results revealed unmeasurable INR and abnormally prolonged activated partial thromboplastin time (APTT). She was diagnosed with adenoiditis and warfarin-related coagulopathy and administered intravenous VK (20 mg) and fresh frozen plasma (FFP; 4 U), which improved INR and APTT. Since the coagulopathy responded to intravenous VK administration, the patient was clinically diagnosed with warfarin-related relative VKD. Approximately 1 month later, she returned with complaints of sore throat. Blood results indicated abnormal INR (7.22) and APTT (N80.0 s). She was diagnosed with recurrent adenoiditis and VK deficient coagulopathy. The patient’s serum VK levels were low (VK1 level, 0.13 ng/mL; VK2 levels, 0.85 ng/mL). Initial treatment of VK (20 mg) and FFP followed by intravenous VK (20 mg/d) for 6 days, her symptoms dissipated. Warfarin was suspected to have caused absolute VKD. Severe coagulopathy in patients undergoing warfarin therapy is primarily caused by, relative VKD. However, the possibility of warfarin-related absolute VKD should be suspected when INRis not sufficiently improved by intravenous VK administration.

Preparation and analysis of deuterium-labeled aspirin: application to pharmacokinetic studies

International Nuclear Information System (INIS)

Pedersen, A.K.; FitzGerald, G.A.

1985-01-01

Inhibition of endogenous prostacyclin and thromboxane biosynthesis by aspirin is critically dose-dependent in humans. Gastrointestinal and hepatic hydrolysis may limit systemic availability of aspirin, especially in low doses, perhaps contributing to the biochemical selectivity of aspirin. Existing analytical methods do not permit determination of systemic bioavailability when low (less than 100 mg) doses of aspirin are administered. Deuterium-labeled aspirin (2-acetoxy[3,4,5,6- 2 H4]benzoic acid) was synthesized from salicylic acid by catalytic exchange and subsequent acetylation. Analysis of the compounds as benzyl esters by GC-MS followed extractive alkylation from plasma. Heptadeuterated compounds were used as internal standards. Simultaneous administration of tetradeuterated aspirin intravenously with native aspirin orally to anesthetized dogs permitted kinetic studies of both aspirin and salicylic acid. The sensitivity of the method is superior to published methods using HPLC and, thus, more applicable to studies of low dose aspirin. Pulse administration of stable isotope-labeled aspirin permits detailed and repeated studies of dose-related aspirin pharmacokinetics in humans

Increased mortality associated with low use of clopidogrel in patients with heart failure and acute myocardial infarction not undergoing percutaneous coronary intervention

DEFF Research Database (Denmark)

Bonde, Lisbeth; Sorensen, Rikke; Fosbøl, Emil Loldrup

2010-01-01

with patients not treated with clopidogrel. Similarly, 2 groups without HF were identified. Risks of all-cause death were obtained by the Kaplan-Meier method and Cox regression analyses. RESULTS: We identified 56,944 patients with first-time AMI. In the matched cohort with HF (n = 5,050) and a mean follow......OBJECTIVES: We studied the association of clopidogrel with mortality in acute myocardial infarction (AMI) patients with heart failure (HF) not receiving percutaneous coronary intervention (PCI). BACKGROUND: Use of clopidogrel after AMI is low in patients with HF, despite the fact that clopidogrel...... is associated with absolute mortality reduction in AMI patients. METHODS: All patients hospitalized with first-time AMI (2000 through 2005) and not undergoing PCI within 30 days from discharge were identified in national registers. Patients with HF treated with clopidogrel were matched by propensity score...

Use of an iPad to Provide Warfarin Video Education to Hospitalized Patients.

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Kim, Jenny Jane; Mohammad, Rima A; Coley, Kim C; Donihi, Amy C

2015-09-01

To evaluate the effectiveness of a warfarin educational video in the hospital setting and to determine patients' satisfaction with using an iPad to view a warfarin educational video. This prospective quality improvement project included adult (≥18 years of age) patients on warfarin in the hospital. All patients completed pre-video and post-video knowledge tests on the iPad before and after viewing the educational video on warfarin therapy. Patients also completed a patient satisfaction survey. Forty hospitalized patients were educated using the warfarin video and included for analysis. The majority of patients were new to warfarin therapy (65%). Forty-three percent of patients passed the pre-video knowledge test, and 90% passed the post-video knowledge test (P iPad and found it easy to use. Patients who were younger (iPad more than older patients (P = 0.01) and male subjects (P = 0.02), respectively. Also, younger patients found the iPad easier to use compared with patients who were older (P = 0.01). Educating hospitalized patients about warfarin by using a video on an iPad was effective. Video education on an iPad may be an alternative to traditional education in the hospital setting.

Aspirin in the Chemoprevention of Colorectal Neoplasia: An Overview

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Chan, Andrew T.; Arber, Nadir; Burn, John; Chia, John Whay-Kuang; Elwood, Peter; Hull, Mark A.; Logan, Richard F.; Rothwell, Peter M.; Schrör, Karsten; Baron, John A.

2011-01-01

Considerable evidence supports the effectiveness of aspirin for chemoprevention of colorectal cancer (CRC) in addition to its well-established benefits in the prevention of vascular disease. Epidemiologic studies have consistently observed an inverse association between aspirin use and risk of CRC. A recent pooled analysis of a long-term post-trial follow-up of nearly 14,000 patients from 4 randomized, cardiovascular disease prevention trials showed that daily aspirin treatment for about 5 years was associated with a 34% reduction in 20-year CRC mortality. A separate meta-analysis of nearly 3,000 patients with a history of colorectal adenoma or cancer in 4 randomized adenoma prevention trials demonstrated that aspirin reduced the occurrence of advanced adenomas by 28% and any adenoma by 17%. Aspirin has also been shown to be beneficial in a clinical trial of patients with Lynch syndrome, a hereditary CRC syndrome; in those treated with aspirin for at least 2 years, there was a ≥ 50% reduction in the risk of CRC commencing 5 years after randomization and after aspirin had been discontinued. A few observational studies have shown an increase in survival among patients with CRC who use aspirin. Taken together, these findings strengthen the case for consideration of long-term aspirin use in CRC prevention. Despite these compelling data, there is a lack of consensus about the balance of risks and benefits associated with long-term aspirin use, particularly in low-risk populations. The optimal dose to use for cancer prevention and the precise mechanism underlying aspirin’s anticancer effect require further investigation. PMID:22084361

Cardioversion and Risk of Adverse Events with Dabigatran versus Warfarin

DEFF Research Database (Denmark)

Pallisgaard, J. L.; Lindhardt, T. B.; Hansen, M. L.

2015-01-01

AIM: Cardioversion can rapidly and effectively restore sinus rhythm in patients with persistent atrial fibrillation. Since 2011 dabigatran has been available as an alternative to warfarin to prevent thromboembolic events in patients with non-valvular atrial fibrillation undergoing cardioversion. We......-valvular atrial fibrillation and first time cardioversion from 2011 to 2012; 37% in the dabigatran group (n = 456), and 63% in the warfarin group (n = 774). Median time to cardioversion was 4.0 (interquartile range [IQR] 2.9 to 6.5) and 6.9 (IQR 3.9 to 12.1) weeks in the dabigatran and warfarin groups...... respectively, and the adjusted odds ratio of cardioversion within the first 4 weeks was 2.3 (95% confidence interval [CI] 1.7 to 3.1) in favor of dabigatran. The cumulative incidence of composite endpoint of stroke, bleeding or death were 2.0% and 1.0% at 30 weeks in the warfarin and dabigatran groups...

Switching from rivaroxaban to warfarin: an open label pharmacodynamic study in healthy subjects

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Moore, Kenneth Todd; Byra, William; Vaidyanathan, Seema; Natarajan, Jaya; Ariyawansa, Jay; Salih, Hiba; Turner, Kenneth C

2015-01-01

Aims The primary objective was to explore the pharmacodynamic changes during transition from rivaroxaban to warfarin in healthy subjects. Safety, tolerability and pharmacokinetics were assessed as secondary objectives. Methods An open label, non-randomized, sequential two period study. In treatment period 1 (TP1), subjects received rivaroxaban 20 mg once daily (5 days), followed by co-administration with a warfarin loading dose regimen of 5 or 10 mg (for the 10 mg regimen, the dose could be uptitrated to attain target international normalized ratio [INR] ≥2.0) once daily (2–4 days). When trough INR values ≥2.0 were attained, rivaroxaban was discontinued and warfarin treatment continued as monotherapy (INR 2.0–3.0). During treatment period 2, subjects received the same warfarin regimen as in TP1, but without rivaroxaban. Results During co-administration, maximum INR and prothrombin time (PT) values were higher than with rivaroxaban or warfarin monotherapy. The mean maximum effect (Emax) for INR after co-administration was 2.79–4.15 (mean PT Emax 41.0–62.7 s), compared with 1.41–1.74 (mean PT Emax 20.1–25.2 s) for warfarin alone. However, rivaroxaban had the smallest effect on INR at trough rivaroxaban concentrations. Neither rivaroxaban nor warfarin significantly affected maximum plasma concentrations of the other drug. Conclusions The combined pharmacodynamic effects during co-administration of rivaroxaban and warfarin were greater than additive, but the pharmacokinetics of both drugs were unaffected. Co-administration was well tolerated. When transitioning from rivaroxaban to warfarin, INR monitoring during co-administration should be performed at the trough rivaroxaban concentration to minimize the effect of rivaroxaban on INR. PMID:25475601

Serious clopidogrel associated renal hematoma in a type 2 diabetic patient with primary hyperparathyroidism after extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Bahceci, Mithat; Tuzcu, Alpaslan; Agil, Cuneyt; Akay, Ferruh; Akay, Hatice

2005-01-01

Renal hematoma after extracorporeal shock wave lithotripsy SWL is a rare complication. We report a case of a large renal hematoma following SWL that resulted in nephrectomy in a type 2 diabetic patient with primary hyperparathyroidism using clopidogrel due to coronary heart disease CHD. Although it was claimed that preoperative use of clopidogrel was not associated with increased bleeding, all patients who are scheduled for SWL should be interrogated in terms of using of platelet aggregation inhibitors such as clopidogrel, and these drugs should be interrupted appropriately before undergoing SWL. (author)

[Clinical applications of dosing algorithm in the predication of warfarin maintenance dose].

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Huang, Sheng-wen; Xiang, Dao-kang; An, Bang-quan; Li, Gui-fang; Huang, Ling; Wu, Hai-li

2011-12-27

To evaluate the feasibility of clinical application for genetic based dosing algorithm in the predication of warfarin maintenance dose in Chinese population. The clinical data were collected and blood samples harvested from a total of 126 patients undergoing heart valve replacement. The genotypes of VKORC1 and CYP2C9 were determined by melting curve analysis after PCR. They were divided randomly into the study and control groups. In the study group, the first three doses of warfarin were prescribed according to the predicted warfarin maintenance dose while warfarin was initiated at 2.5 mg/d in the control group. The warfarin doses were adjusted according to the measured international normalized ratio (INR) values. And all subjects were followed for 50 days after an initiation of warfarin therapy. At the end of a 50-day follow-up period, the proportions of the patients on a stable dose were 82.4% (42/51) and 62.5% (30/48) for the study and control groups respectively. The mean durations of reaching a stable dose of warfarin were (27.5 ± 1.8) and (34.7 ± 1.8) days and the median durations were (24.0 ± 1.7) and (33.0 ± 4.5) days in the study and control groups respectively. Significant differences existed in the durations of reaching a stable dose between the two groups (P = 0.012). Compared with the control group, the hazard ratio (HR) for the duration of reaching a stable dose was 1.786 in the study group (95%CI 1.088 - 2.875, P = 0.026). The predicted dosing algorithm incorporating genetic and non-genetic factors may shorten the duration of achieving efficiently a stable dose of warfarin. And the present study validates the feasibility of its clinical application.

Talk with Your Doctor about Taking Aspirin Every Day

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... t sure why this works. Can taking aspirin every day cause any side effects? Taking aspirin isn't ... read these benefits and risks of taking aspirin every day . Next section Talk with Your Doctor Previous section ...

Effect of clopidogrel premedication in off-pump cardiac surgery: are we forfeiting the benefits of reduced hemorrhagic sequelae?

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Kapetanakis, Emmanouil I; Medlam, Diego A; Petro, Kathleen R; Haile, Elizabeth; Hill, Peter C; Dullum, Mercedes K C; Bafi, Ammar S; Boyce, Steven W; Corso, Paul J

2006-04-04

Premedication with clopidogrel has reduced thrombotic complications after percutaneous coronary revascularization procedures. However, because of the enhanced and irreversible platelet inhibition by clopidogrel, patients requiring surgical revascularization have a higher risk of bleeding complications and transfusion requirements. A principal benefit of surgical coronary revascularization without cardiopulmonary bypass is its lower hemorrhagic sequelae. The purpose of this study was to evaluate the effect of preoperative clopidogrel administration in the incidence of hemostatic reexploration, blood product transfusion rates, morbidity, and mortality in patients undergoing off-pump coronary artery bypass graft surgery using a large patient sample and a risk-adjusted approach. Two hundred eighty-one patients (17.9%) did and 1291 (82.1%) did not receive clopidogrel before their surgery, for a total of 1572 patients undergoing isolated off-pump coronary artery bypass graft surgery between January 2000 and June 2002. Risk-adjusted logistic regression analyses and a matched pair analyses by propensity scores were used to assess the association between clopidogrel administration and reoperation as a result of bleeding, intraoperative and postoperative blood transfusions received, and the need for multiple transfusions. Hemorrhage-related preoperative risk factors identified in the literature and those found significant in a univariate model were used. The clopidogrel group had a higher likelihood of hemostatic reoperations (odds ratio [OR], 5.1; 95% confidence interval [CI], 2.47 to 10.47; P<0.01) and an increased need in overall packed red blood cell (OR, 2.6; 95% CI, 1.94 to 3.60; P<0.01), multiple unit (OR, 1.6; 95% CI, 1.07 to 2.48; P=0.02), and platelet (OR, 2.5; 95% CI, 1.77 to 3.66; P<0.01) transfusions. Surgical outcomes and operative mortality (1.4% versus 1.4%; P=1.00) were not statistically different. Clopidogrel administration in the cardiology suite increases

Platelet function testing to predict hyporesponsiveness to clopidogrel in patients with chest pain seen in the emergency department

Directory of Open Access Journals (Sweden)

Sharma RK

2013-05-01

Full Text Available Rakesh K Sharma,1 Stephen W Erickson,1 Rohit Sharma,2 Donald J Voelker,1 Hanumanth K Reddy,1 Harvinder Dod,2 James D Marsh1 1Division of Cardiovascular Medicine, University of Arkansas for Medical Sciences, Little Rock, 2Medical Center of South Arkansas, El Dorado, AR, USA Background: A dual antiplatelet regimen has been shown to reduce the risk of major adverse cardiovascular events after percutaneous coronary intervention. However, there is little information available on inhibition of platelet aggregation in patients with a prior coronary stent presenting with chest pain. This study evaluated the prevalence of hyporesponsiveness to clopidogrel and factors associated with this in patients presenting to our emergency department with chest pain who had previously undergone coronary stent placement and were prescribed dual antiplatelet therapy. Methods: Responsiveness to clopidogrel was evaluated in a cohort of 533 consecutive stented patients presenting to the emergency department with chest pain. P2Y12 reaction units (PRU and percent P2Y12 inhibition with clopidogrel were measured in all patients. Of 533 patients, 221 (41.6% had PRU ≥ 230. A multivariate logistic regression model was used to determine the relationship between hyporesponsiveness to clopidogrel (defined as PRU ≥ 230 and several potential risk factors, ie, gender, age, race, type 1 or type 2 diabetes, hypertension, smoking, chronic renal failure, and obesity. Results: There was a greater risk of hyporesponsiveness in African Americans than in non-African American patients (adjusted odds ratio [OR] = 2.165, in patients with type 2 diabetes than in those without (adjusted OR = 2.109, and in women than in men (adjusted OR = 1.813, as well as a greater risk of hyporesponsiveness with increasing age (adjusted OR = 1.167 per decade. Conclusion: There was a high prevalence of hyporesponsiveness to clopidogrel in patients presenting with chest pain and a prior coronary stent. Non

Effects of Ramadan fasting on platelet reactivity in diabetic patients treated with clopidogrel.

Science.gov (United States)

Bouida, W; Baccouche, H; Sassi, M; Dridi, Z; Chakroun, T; Hellara, I; Boukef, R; Hassine, M; Added, F; Razgallah, R; Khochtali, I; Nouira, S

2017-01-01

The effects of Ramadan fasting (RF) on clopidogrel antiplatelet inhibition were not previously investigated. The present study evaluated the influence of RF on platelet reactivity in patients with high cardiovascular risk (CVR) in particular those with type 2 diabetes mellitus (DM). A total of 98 stable patients with ≥2 CVR factors were recruited. All patients observed RF and were taking clopidogrel at a maintenance dose of 75 mg. Clinical findings and serum lipids data were recorded before Ramadan (Pre-R), at the last week of Ramadan (R) and 4 weeks after the end of Ramadan (Post-R). During each patient visit, nutrients intakes were calculated and platelet reactivity assessment using Verify Now P2Y12 assay was performed. In DM patients, the absolute PRU changes from baseline were +27 ( p  = 0.01) and +16 ( p  = 0.02) respectively at R and Post-R. In addition, there was a significant increase of glycemia and triglycerides levels with a significant decrease of high-density lipoprotein. In non DM patients there was no significant change in absolute PRU values and metabolic parameters. Clopidogrel resistance rate using 2 cut-off PRU values (235 and 208) did not change significantly in DM and non DM patients. RF significantly decreased platelet sensitivity to clopidogrel in DM patients during and after Ramadan. This effect is possibly related to an increase of glycemia and serum lipids levels induced by fasting. Clinical Trials.gov NCT02720133. Registered 24 July 2014.Retrospectively registered.

Aspirin resistance as cardiovascular risk after kidney transplantation

Science.gov (United States)

Sandor, Barbara; Varga, Adam; Rabai, Miklos; Toth, Andras; Papp, Judit; Toth, Kalman; Szakaly, Peter

2014-05-01

International surveys have shown that the leading cause of death after kidney transplantation has cardiovascular origin with a prevalence of 35-40%. As a preventive strategy these patients receive aspirin (ASA) therapy, even though their rate of aspirin resistance is still unknown. In our study, platelet aggregation measurements were performed between 2009 and 2012 investigating the laboratory effect of low-dose aspirin (100 mg) treatment using a CARAT TX4 optical aggregometer. ASA therapy was considered clinically effective in case of low ( i.e., below 40%) epinephrine-induced (10 μM) platelet aggregation index. Rate of aspirin resistance, morbidity and mortality data of kidney transplanted patients (n = 255, mean age: 49 ± 12 years) were compared to a patient population with cardio- and cerebrovascular diseases (n = 346, mean age: 52.6 ± 11 years). Rate of aspirin resistance was significantly higher in the renal transplantation group (RT) compared to the positive control group (PC) (35.9% vs. 25.6%, p aspirin resistance contributes to the high cardiovascular mortality after kidney transplantation.

Influence of aspirin and non-aspirin NSAID use on ovarian and endometrial cancer: Summary of epidemiologic evidence of cancer risk and prognosis.

Science.gov (United States)

Verdoodt, F; Kjaer, S K; Friis, S

2017-06-01

Increasing evidence supports a role for aspirin use in reducing the incidence and mortality of several cancer types. This has spurred a new wave of interest in this widely used drug. In this review, we present and evaluate the epidemiologic evidence of the association between the use of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) and the incidence and prognosis of ovarian and endometrial cancer. The evidence of a preventive effect of NSAID use on risk of ovarian or endometrial cancer is based primarily on results from observational studies and, consequently, is only suggestive. Overall, observational studies indicate modest reductions in risk of ovarian and endometrial cancer with aspirin use, whereas the results for non-aspirin NSAID use are equivocal. The strongest inverse associations have been reported for long-term consistent aspirin use, notably among subgroups of users (e.g., those with high body mass index). Few studies have evaluated the influence of NSAID use on the mortality of ovarian or endometrial cancer, and substantial heterogeneity of study characteristics and results preclude any conclusions. Additional studies of aspirin and non-aspirin NSAID use and ovarian or endometrial cancer risk and prognosis are warranted. In the present review, we discuss the importance of comprehensive exposure definitions (i.e., duration, timing, consistency and intensity/dose) and evaluation of potential effect modification according to user characteristics, with the aim of identifying women who may experience the largest benefit of aspirin or non-aspirin NSAID use on risk or prognosis of ovarian and endometrial cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

Quality of warfarin control in atrial fibrillation patients in South East Queensland, Australia.

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Bernaitis, N; Badrick, T; Davey, A K; Anoopkumar-Dukie, S

2016-08-01

Warfarin is widely prescribed to decrease the risk of stroke in atrial fibrillation (AF) patients. Due to patient variability in response, regular monitoring is required, and time in therapeutic range (TTR) used to indicate quality of warfarin control with a TTR>60% is recommended. Recently, an Australian Government review of anticoagulants identified the need to establish current warfarin control and determine the potential place of the newer oral anticoagulants. To determine warfarin control by a pathology practice in Queensland, Australia and identify factors influencing TTR. Retrospective data were collected from Sullivan Nicolaides Pathology, a major pathology practice offering a warfarin care programme in Australia. Patients enrolled in their programme as of September 2014 were included in the study. TTR was calculated using INR test results, and test dates using the Rosendaal method with mean patient TTR were used for analysis and comparison. Exclusions were target therapeutic range outside 2.0-3.0, less than two INR tests and programme treatment time of less than 30 days. The eligible 3692 AF patients had 73.6% of INR tests within the therapeutic range. The mean TTR was 81%, with 97% of patients above a TTR of 60%. TTR was not significantly influenced by age, gender or socioeconomic factors. The observed mean TTR of over 80% is superior to the minimum recommended threshold of 60%. The TTR achieved by the Queensland pathology practice demonstrates that dedicated warfarin programmes can produce high-quality warfarin care, ensuring the full benefit of warfarin for Australian patients. © 2016 Royal Australasian College of Physicians.

A Proteomic Approach to Analyze the Aspirin-mediated Lysine Acetylome*

Science.gov (United States)

Tatham, Michael H.; Cole, Christian; Scullion, Paul; Wilkie, Ross; Westwood, Nicholas J.; Stark, Lesley A.; Hay, Ronald T.

2017-01-01

Aspirin, or acetylsalicylic acid is widely used to control pain, inflammation and fever. Important to this function is its ability to irreversibly acetylate cyclooxygenases at active site serines. Aspirin has the potential to acetylate other amino acid side-chains, leading to the possibility that aspirin-mediated lysine acetylation could explain some of its as-yet unexplained drug actions or side-effects. Using isotopically labeled aspirin-d3, in combination with acetylated lysine purification and LC-MS/MS, we identified over 12000 sites of lysine acetylation from cultured human cells. Although aspirin amplifies endogenous acetylation signals at the majority of detectable endogenous sites, cells tolerate aspirin mediated acetylation very well unless cellular deacetylases are inhibited. Although most endogenous acetylations are amplified by orders of magnitude, lysine acetylation site occupancies remain very low even after high doses of aspirin. This work shows that while aspirin has enormous potential to alter protein function, in the majority of cases aspirin-mediated acetylations do not accumulate to levels likely to elicit biological effects. These findings are consistent with an emerging model for cellular acetylation whereby stoichiometry correlates with biological relevance, and deacetylases act to minimize the biological consequences of nonspecific chemical acetylations. PMID:27913581

Molecular displacement of warfarin from human serum albumin by flavonoid aglycones

International Nuclear Information System (INIS)

Poór, Miklós; Li, Yin; Kunsági-Máté, Sándor; Petrik, József; Vladimir-Knežević, Sanda; Kőszegi, Tamás

2013-01-01

The well-known 4-hydroxycoumarin derivative warfarin is a widespread anticoagulant drug. Besides its strong albumin binding property warfarin has a narrow therapeutic window. Therefore, a few percent of displacement from albumin can result in serious biological consequences. The flavonoid molecular group also shows very strong plasma albumin binding characteristics occupying the same binding site. It is plausible to hypothesize that flavonoid aglycones may be able to displace warfarin from human serum albumin (HSA). In our study the competing activities of different flavone (acacetin, apigenin, chrysin, luteolin), flavonol (galangin, quercetin) and flavanone (hesperetin, naringenin) aglycones were investigated using fluorescence spectroscopy. Our results represent that flavonoids are able to displace warfarin from the surface of HSA. On the other hand, when comparing flavone or flavonol groups to flavanones the latter group seems to be much weaker competitor. These observations were also supported by calculation of stability constants. Our investigations strongly suggest that we should reckon with the described molecular displacement. However, further in vivo studies are needed to support the findings of our model system. -- Highlights: • Various flavonoids are able to displace warfarin from human serum albumin. • Flavones and flavonols are much more effective competitors than flavanones. • Even 300 nM aglycone concentrations show the interaction with 3 μM warfarin. • Flavonoid pairs show quasi-additive desorbing property. • Flavones and flavonols are much stronger competitors than the examined drugs

Molecular displacement of warfarin from human serum albumin by flavonoid aglycones

Energy Technology Data Exchange (ETDEWEB)

Poór, Miklós [Institute of Laboratory Medicine, University of Pécs, Pécs H-7624 (Hungary); Li, Yin; Kunsági-Máté, Sándor [Department of General and Physical Chemistry, University of Pécs, Pécs H-7624 (Hungary); János Szentágothai Research Center, H-7624 Pécs (Hungary); Petrik, József [Department of Medical Biochemistry and Hematology, Faculty of Pharmacy and Biochemistry, University of Zagreb, HR-10000 Zagreb (Croatia); Vladimir-Knežević, Sanda [Department of Pharmacognosy, Faculty of Pharmacy and Biochemistry, University of Zagreb, HR-10000 Zagreb (Croatia); Kőszegi, Tamás, E-mail: koszegit@freemail.hu [Institute of Laboratory Medicine, University of Pécs, Pécs H-7624 (Hungary)

2013-10-15

The well-known 4-hydroxycoumarin derivative warfarin is a widespread anticoagulant drug. Besides its strong albumin binding property warfarin has a narrow therapeutic window. Therefore, a few percent of displacement from albumin can result in serious biological consequences. The flavonoid molecular group also shows very strong plasma albumin binding characteristics occupying the same binding site. It is plausible to hypothesize that flavonoid aglycones may be able to displace warfarin from human serum albumin (HSA). In our study the competing activities of different flavone (acacetin, apigenin, chrysin, luteolin), flavonol (galangin, quercetin) and flavanone (hesperetin, naringenin) aglycones were investigated using fluorescence spectroscopy. Our results represent that flavonoids are able to displace warfarin from the surface of HSA. On the other hand, when comparing flavone or flavonol groups to flavanones the latter group seems to be much weaker competitor. These observations were also supported by calculation of stability constants. Our investigations strongly suggest that we should reckon with the described molecular displacement. However, further in vivo studies are needed to support the findings of our model system. -- Highlights: • Various flavonoids are able to displace warfarin from human serum albumin. • Flavones and flavonols are much more effective competitors than flavanones. • Even 300 nM aglycone concentrations show the interaction with 3 μM warfarin. • Flavonoid pairs show quasi-additive desorbing property. • Flavones and flavonols are much stronger competitors than the examined drugs.

Comparison of hyperuricemia in type 2 diabetics on low dose aspirin and not on low dose aspirin

International Nuclear Information System (INIS)

Malik, M.I.

2013-01-01

Objective: To compare the frequency of hyperuricemia in type 2 diabetes patients who are taking low dose aspirin with those patients who are not taking low dose aspirin. Study design: Quasi experimental study. Place and duration of study: This study was carried out at Military Hospital Rawalpindi for a period of two years (June 2006-May 2008). Patients and Methods: Sixty diabetic patients were selected who were taking low dose aspirin comparing group A and sixty diabetic patients who were not taking aspirin were placed in group B. These patients were selected from the OPD through non probability convenience sampling. All these patients were being followed up in medical outpatient quite regularly on fort-nightly basis. Data had been collected through a carefully designed questionnaire. Results: In group A, 90% of the patients had uric acid less than 445 micro mol/l and 10% of the patients had uric acid more than 445micro mol/l. Whereas in group B 100% of the patients had uric acid less than 445umol/l, there was a statistically significant difference between the two groups (p< 0.05). Conclusion: Aspirin in low doses cause hyperuricemia and regular monitoring of uric acid is mandatory to prevent its adverse effects. (author)

A Review on the Relationship between Aspirin and Bone Health

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Kok-Yong Chin

2017-01-01

Full Text Available Aspirin is a cyclooxygenase inhibitor commonly used in primary prevention of cardiovascular diseases and cancers. Its users are elderly population susceptible to osteoporosis. It also inhibits the synthesis of prostaglandin E2 essential in bone remodeling. This prompts the question whether it can influence bone health among users. This review aimed to summarize the current literature on the use of aspirin on bone health. A literature search on experimental and clinical evidence on the effects of aspirin on bone health was performed using major scientific databases. In vitro studies showed that aspirin could enhance the survival of bone marrow mesenchymal stem cells, the progenitors of osteoblasts, and stimulate the differentiation of preosteoblasts. Aspirin also inhibited the nuclear factor kappa-B (NFκB pathway and decreased the expression of receptor activator of NFκB ligand, thus suppressing the formation of osteoclast. Aspirin could prevent bone loss in animal models of osteoporosis. Despite a positive effect on bone mineral density, the limited human epidemiological studies revealed that aspirin could not reduce fracture risk. A study even suggested that the use of aspirin increased fracture risk. As a conclusion, aspirin may increase bone mineral density but its effect on fracture prevention is inconclusive. More data are needed to determine the effects of aspirin and bone health in human.

Impact of warfarin discharge education program on hospital readmission and treatment costs.

Science.gov (United States)

Brunetti, Luigi; Lee, Seung-Mi; Doherty, Nancy; Suh, David; Kim, Jeong-Eun; Lee, Sun-Hong; Choi, Yong Chan; Suh, Dong-Churl

2018-03-31

Background Although warfarin is highly effective, management of patients prescribed warfarin is complex due to its narrow therapeutic window. Objective To evaluate the impact of a formal warfarin discharge education program (WDEP) on hospital readmission and treatment costs in patients who received warfarin therapy. Setting Robert Wood Johnson University Hospital Somerset in Somerville, New Jersey, USA. Method In this interventional cohort study, patients were assigned to either the WDEP group or the usual care group. The effects of the WDEP on readmission within 90 days after discharge were analyzed using Cox proportional hazards models. Factors influencing treatment cost were identified using generalized linear model with log-link function and gamma distribution. Main outcome measure Hospital readmission within 90 days and treatment costs associated with hospital readmission. Results Among 692 eligible patients, 203 in each group were matched using propensity scores and there were no statistically significant differences in the patient baseline characteristics between two groups. The risk of all-cause readmission within 90 days was significantly lower in the WDEP group compared to the usual care group (relative risk = 0.46, 95% CI 0.28-0.76). The treatment costs associated with hospital readmission in the WDEP group were 19% lower than those in the usual care group after adjusting for the study variables. Conclusion A formal, individualized WDEP provided by pharmacists resulted in significant reduction of readmission and treatment costs. The economic burden of treatment costs associated with warfarin can be controlled if well-organized warfarin education is provided to patients who received warfarin therapy.

Chondrodysplasia punctata after warfarin. Case report with 18-month follow-up

Energy Technology Data Exchange (ETDEWEB)

Tamburrini, O.; Bartolomeo-De Iuri, A.; Di Guglielmo, G.L.

1987-05-01

Administration of warfarin during pregnancy may cause a rare syndrome characterized by nasal hypoplasia, usually associated with stippled epiphyseal and extraepiphyseal calcifications ressembling chondrodysplasia punctata. A case of chondrodysplasia punctata after warfarin with 18 months follow-up is reported.

A critical appraisal of the phenomenon of aspirin resistance

DEFF Research Database (Denmark)

Svenstrup Poulsen, Tina; Risom Kristensen, Søren; Atar, Dan

2005-01-01

Aspirin is the mainstay antiplatelet treatment in patients with high risk of cardiovascular atherothrombotic events, and its beneficial effect is documented in several clinical trials. Nevertheless, the effectiveness of aspirin has been questioned by the emergence of the concept of 'aspirin...

Major Interaction between Warfarin and Na Valproate: A Case Report

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Bizhan Kouchaki

2015-10-01

Full Text Available  Abstract: Warfarin is the most commonly used oral anticoagulant drug in clinical practice with extreme inter and intra-individual variation in pharmacokinetic properties. Na Valproate, a broad spectrum anticonvulsant agent, is best known for its enzyme inhibition properties and also displacement of protein binding sites. Interaction between Warfarin and psychotropic drugs including Valproate are important and perhaps under recognized. In this report, we present a 48 year old female patient with chief complaints of abdominal pain, tea-color urine, blurred vision and headache. She had been suffering from "migraine headache" for 15 years that was relatively well controlled with Na Valproate 200mg twice daily. She was experienced a deep vein thrombosis (DVT following oral contraceptive. For management of DVT, she was received Warfarin 5mg/day which was increased to 7.5 mg /day after 2 weeks. Three days after this increment of dose, her Prothrombin Time (PT rose to 35.3 seconds (three times of normal value and evidences of bleeding including hematuria and hematemesis were observed. Based on  the history and laboratory findings, "Warfarin toxicity" was the first impression and she was treated with fresh frozen plasma and vitamin K with a well recovery. This experience emphasizes the clinical significant interaction between Warfarin and Na Valproate, which may take place even with the usual doses of each agent.  

Comparing intracerebral hemorrhages associated with direct oral anticoagulants or warfarin

Science.gov (United States)

Kurogi, Ryota; Nishimura, Kunihiro; Nakai, Michikazu; Kada, Akiko; Kamitani, Satoru; Nakagawara, Jyoji; Toyoda, Kazunori; Ogasawara, Kuniaki; Ono, Junichi; Shiokawa, Yoshiaki; Aruga, Toru; Miyachi, Shigeru; Nagata, Izumi; Matsuda, Shinya; Yoshimura, Shinichi; Okuchi, Kazuo; Suzuki, Akifumi; Nakamura, Fumiaki; Onozuka, Daisuke; Ido, Keisuke; Kurogi, Ai; Mukae, Nobutaka; Nishimura, Ataru; Arimura, Koichi; Kitazono, Takanari; Hagihara, Akihito

2018-01-01

Objectives This cross-sectional survey explored the characteristics and outcomes of direct oral anticoagulant (DOAC)–associated nontraumatic intracerebral hemorrhages (ICHs) by analyzing a large nationwide Japanese discharge database. Methods We analyzed data from 2,245 patients who experienced ICHs while taking anticoagulants (DOAC: 227; warfarin: 2,018) and were urgently hospitalized at 621 institutions in Japan between April 2010 and March 2015. We compared the DOAC- and warfarin-treated patients based on their backgrounds, ICH severities, antiplatelet therapies at admission, hematoma removal surgeries, reversal agents, mortality rates, and modified Rankin Scale scores at discharge. Results DOAC-associated ICHs were less likely to cause moderately or severely impaired consciousness (DOAC-associated ICHs: 31.3%; warfarin-associated ICHs: 39.4%; p = 0.002) or require surgical removal (DOAC-associated ICHs: 5.3%; warfarin-associated ICHs: 9.9%; p = 0.024) in the univariate analysis. Propensity score analysis revealed that patients with DOAC-associated ICHs also exhibited lower mortality rates within 1 day (odds ratio [OR] 4.96, p = 0.005), within 7 days (OR 2.29, p = 0.037), and during hospitalization (OR 1.96, p = 0.039). Conclusions This nationwide study revealed that DOAC-treated patients had less severe ICHs and lower mortality rates than did warfarin-treated patients, probably due to milder hemorrhages at admission and lower hematoma expansion frequencies. PMID:29490916

Intracellular Erythrocyte Platelet-activating Factor Acetylhydrolase I Inactivates Aspirin in Blood*

Science.gov (United States)

Zhou, Gang; Marathe, Gopal K.; Willard, Belinda; McIntyre, Thomas M.

2011-01-01

Aspirin (acetylsalicylic acid) prophylaxis suppresses major adverse cardiovascular events, but its rapid turnover limits inhibition of platelet cyclooxygenase activity and thrombosis. Despite its importance, the identity of the enzyme(s) that hydrolyzes the acetyl residue of circulating aspirin, which must be an existing enzyme, remains unknown. We find that circulating aspirin was extensively hydrolyzed within erythrocytes, and chromatography indicated these cells contained a single hydrolytic activity. Purification by over 1400-fold and sequencing identified the PAFAH1B2 and PAFAH1B3 subunits of type I platelet-activating factor (PAF) acetylhydrolase, a phospholipase A2 with selectivity for acetyl residues of PAF, as a candidate for aspirin acetylhydrolase. Western blotting showed that catalytic PAFAH1B2 and PAFAH1B3 subunits of the type I enzyme co-migrated with purified erythrocyte aspirin hydrolytic activity. Recombinant PAFAH1B2, but not its family member plasma PAF acetylhydrolase, hydrolyzed aspirin, and PAF competitively inhibited aspirin hydrolysis by purified or recombinant erythrocyte enzymes. Aspirin was hydrolyzed by HEK cells transfected with PAFAH1B2 or PAFAH1B3, and the competitive type I PAF acetylhydrolase inhibitor NaF reduced erythrocyte hydrolysis of aspirin. Exposing aspirin to erythrocytes blocked its ability to inhibit thromboxane A2 synthesis and platelet aggregation. Not all individuals or populations are equally protected by aspirin prophylaxis, the phenomenon of aspirin resistance, and erythrocyte hydrolysis of aspirin varied 3-fold among individuals, which correlated with PAFAH1B2 and not PAFAH1B3. We conclude that intracellular type I PAF acetylhydrolase is the major aspirin hydrolase of human blood. PMID:21844189

Intracellular erythrocyte platelet-activating factor acetylhydrolase I inactivates aspirin in blood.

Science.gov (United States)

Zhou, Gang; Marathe, Gopal K; Willard, Belinda; McIntyre, Thomas M

2011-10-07

Aspirin (acetylsalicylic acid) prophylaxis suppresses major adverse cardiovascular events, but its rapid turnover limits inhibition of platelet cyclooxygenase activity and thrombosis. Despite its importance, the identity of the enzyme(s) that hydrolyzes the acetyl residue of circulating aspirin, which must be an existing enzyme, remains unknown. We find that circulating aspirin was extensively hydrolyzed within erythrocytes, and chromatography indicated these cells contained a single hydrolytic activity. Purification by over 1400-fold and sequencing identified the PAFAH1B2 and PAFAH1B3 subunits of type I platelet-activating factor (PAF) acetylhydrolase, a phospholipase A(2) with selectivity for acetyl residues of PAF, as a candidate for aspirin acetylhydrolase. Western blotting showed that catalytic PAFAH1B2 and PAFAH1B3 subunits of the type I enzyme co-migrated with purified erythrocyte aspirin hydrolytic activity. Recombinant PAFAH1B2, but not its family member plasma PAF acetylhydrolase, hydrolyzed aspirin, and PAF competitively inhibited aspirin hydrolysis by purified or recombinant erythrocyte enzymes. Aspirin was hydrolyzed by HEK cells transfected with PAFAH1B2 or PAFAH1B3, and the competitive type I PAF acetylhydrolase inhibitor NaF reduced erythrocyte hydrolysis of aspirin. Exposing aspirin to erythrocytes blocked its ability to inhibit thromboxane A(2) synthesis and platelet aggregation. Not all individuals or populations are equally protected by aspirin prophylaxis, the phenomenon of aspirin resistance, and erythrocyte hydrolysis of aspirin varied 3-fold among individuals, which correlated with PAFAH1B2 and not PAFAH1B3. We conclude that intracellular type I PAF acetylhydrolase is the major aspirin hydrolase of human blood.

Warfarin skin necrosis mimicking calciphylaxis in a patient with secondary hyperparathyroidism undergoing peritoneal dialysis

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Jee Eun Park

2016-03-01

Full Text Available Warfarin skin necrosis (WSN is an infrequent complication of warfarin treatment and is characterized by painful ulcerative skin lesions that appear a few days after the start of warfarin treatment. Calciphylaxis also appears as painful skin lesions caused by tissue injury resulting from localized ischemia caused by calcification of small- to medium-sized vessels in patients with end-stage renal disease. We report on a patient who presented with painful skin ulcers on the lower extremities after the administration of warfarin after a valve operation. Calciphylaxis was considered first because of the host factors; eventually, the skin lesions were diagnosed as WSN by biopsy. The skin lesions improved after warfarin discontinuation and short-term steroid therapy. Most patients with end-stage renal disease have some form of cardiovascular disease and some require temporary or continual warfarin treatment. It is important to differentiate between WSN and calciphylaxis in patients with painful skin lesions.

Phenomenology, pathogenesis, diagnosis and treatment of aspirin-sensitive rhinosinusitis.

Science.gov (United States)

Schapowal, A G; Simon, H U; Schmitz-Schumann, M

1995-01-01

Aspirin-sensitive rhinosinusitis is a non-allergic, non-infectious perennial eosinophilic rhinitis starting in middle age and rarely seen in children. It may also been seen in atopic patients who have developed a mixed type rhinitis with recurrent airway infections. There is an intolerance to aspirin and most other NSAID. An intolerance to tartrazine, food additives, alcohol, narcotics and local anaesthetics can follow. Most aspirin-sensitive patients develop nasal polyps. Untreated, it can lead to asthma. The frequency of aspirin intolerance is 6.18% in patients with perennial rhinitis and 14.68% in patients with nasal polyps. Immunologic studies of the blood and the nasal polyps show a hyperreactive immune system with an activation of the eosinophil granulocytes due to a TH1-lymphocyte-activation. In atopic subjects with a mixed type rhinitis, we found a TH2- and B-lymphocyte-activation as well. Inhibition of eosinophil apoptosis might be a second remarkable change in the immune system of aspirin-sensitive patients. A key pathogenic event for aspirin sensitivity is the change of the leukotriene pathway for arachidonic acid metabolism releasing high amounts of leukotrienes LTC4, LTD4 and LTE4, effective chemoattractants and activators of inflammatory cells. For the diagnosis of aspirin intolerance, nasal, bronchial and oral challenge are available. The sensitivity of nasal challenge with lysine-aspirin for the diagnosis of aspirin-sensitive rhinitis is 0.93, the specificity 0.97. It is the safest test in aspirin-sensitive asthmatics causing bronchial side effects only in 0.45%. Therapy of aspirin-sensitive rhinosinusitis includes avoidance of aspirin and NSAID. A general down regulation of the immune response with glucocorticosteroids is an effective means. We prefer a maintenance dose of budesonid 400 micrograms a day. Systemic steroids for a reversibility test or in exacerbation due to viral infection are given in a dose of 50 mg a day for one week. If steroids

Aspirin desensitization for patients with aspirin-exacerbated respiratory disease: A randomized double-blind placebo-controlled trial.

Science.gov (United States)

Esmaeilzadeh, Hossein; Nabavi, Mohammad; Aryan, Zahra; Arshi, Saba; Bemanian, Mohammad Hassan; Fallahpour, Morteza; Mortazavi, Negar

2015-10-01

The effect of aspirin desensitization (AD) on immunologic profile of patients with AERD has been poorly understood. This study is aimed at investigating the effect of AD on clinical and immunological markers of patients with AERD. This randomized double-blind placebo-controlled trial comprised 34 adult patients (67.6% female) with chronic rhinosinusitis, nasal polyps, and aspirin-intolerant asthma. The active group underwent AD over a 2-day period with increasing doses of aspirin (60, 125, 325, and 625 mg), followed by receiving aspirin 625 mg twice daily for 6 months. Symptom scores and medication needs of patients with AERD who have undergone AD were significantly lower compared to the placebo group after 6 months (7.5 ± 3.5 vs. 10.6 ± 3.8 and 9.3 ± 2.0 vs. 11.0 ± 3.1, respectively, all p < 0.05). However, no significant difference was observed in serum concentration of IL-10, IFN-γ, and TGF-β between two groups neither at baseline nor at the end of study. Copyright © 2015 Elsevier Inc. All rights reserved.

Long-Term Statin Administration Does Not Affect Warfarin Time in Therapeutic Range in Australia or Singapore

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Nijole Bernaitis

2018-05-01

Full Text Available Background: Warfarin requires ongoing monitoring of the International Normalised Ratio (INR. This is because numerous factors influence the response, including drug interactions with commonly-prescribed medications, such as statins. The administration of statins with warfarin may change INR; however, there is limited information regarding the effects on warfarin control as measured by time in therapeutic range (TTR. Statins may also alter bleeds with warfarin, but there are conflicting reports demonstrating both increased and decreased bleeds, and limited data on diverse ethnic populations. Therefore, the aim of this study was to determine the effect of statin administration on warfarin control and bleeds in patients in Australia and Singapore. Methods: Retrospective data were collected for patients on warfarin between January and June 2014 in Australia and Singapore. Patient data were used to calculate TTR and bleed events. Concurrent statin therapy was assessed and comparisons of TTR and bleed incidence were made across patient subgroups. Results: Warfarin control in Australia and Singapore was not significantly affected by statins, as measured by TTR (83% and 58%, respectively, frequency of testing, and warfarin doses. In Australia, statin use did not significantly affect bleeds, whilst in Singapore the bleed incidence was significantly lower for patients on statins. Conclusions: Chronic concurrent administration of statins with warfarin does not adversely affect warfarin TTR in Australia or Singapore. In Singapore, patients on statins, compared to no statins, had a lower bleed incidence and this requires further investigation, especially given the potential genetic influences of ethnicity on both statin and warfarin metabolism.

Multidrug Resistance Protein-4 Influences Aspirin Toxicity in Human Cell Line

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Isabella Massimi

2015-01-01

Full Text Available Overexpression of efflux transporters, in human cells, is a mechanism of resistance to drug and also to chemotherapy. We found that multidrug resistance protein-4 (MRP4 overexpression has a role in reducing aspirin action in patients after bypass surgery and, very recently, we found that aspirin enhances platelet MRP4 levels through peroxisome proliferator activated receptor-α (PPARα. In the present paper, we verified whether exposure of human embryonic kidney-293 cells (Hek-293 to aspirin modifies MRP4 gene expression and its correlation with drug elimination and cell toxicity. We first investigated the effect of high-dose aspirin in Hek-293 and we showed that aspirin is able to increase cell toxicity dose-dependently. Furthermore, aspirin effects, induced at low dose, already enhance MRP4 gene expression. Based on these findings, we compared cell viability in Hek-293, after high-dose aspirin treatment, in MRP4 overexpressing cells, either after aspirin pretreatment or in MRP4 transfected cells; in both cases, a decrease of selective aspirin cell growth inhibition was observed, in comparison with the control cultures. Altogether, these data suggest that exposing cells to low nontoxic aspirin dosages can induce gene expression alterations that may lead to the efflux transporter protein overexpression, thus increasing cellular detoxification of aspirin.

Association of clopidogrel treatment with risk of mortality and cardiovascular events following myocardial infarction in patients with and without diabetes

DEFF Research Database (Denmark)

Andersson, Charlotte; Lyngbæk, Stig; Nguyen, Cu Dinh

2012-01-01

Pharmacodynamic studies have shown that persistently high platelet reactivity is common in patients with diabetes in spite of clopidogrel treatment. Clinical trials have not convincingly demonstrated that clopidogrel benefits patients with diabetes as much patients without diabetes....

Safety of atrial fibrillation ablation with novel multi-electrode array catheters on uninterrupted anticoagulation-a single-center experience.

LENUS (Irish Health Repository)

Hayes, Christopher Ruslan

2012-02-01

INTRODUCTION: A recent single-center report indicated that the performance of atrial fibrillation ablation in patients on uninterrupted warfarin using a conventional deflectable tip electrode ablation catheter may be as safe as periprocedural discontinuation of warfarin and bridging with heparin. Novel multi-electrode array catheters for atrial fibrillation ablation are currently undergoing clinical evaluation. While offering the possibility of more rapid atrial fibrillation ablation, they are stiffer and necessitate the deployment of larger deflectable transseptal sheaths, and it remains to be determined if they increase the risk of cardiac perforation and vascular injury. Such potential risks would have implications for a strategy of uninterrupted periprocedural anticoagulation. METHOD AND RESULTS: We audited the safety outcomes of our atrial fibrillation ablation procedures using multi-electrode array ablation catheters in patients on uninterrupted warfarin (CHADS2 score>or=2) and in patients not on warfarin (uninterrupted aspirin). Two bleeding complications occurred in 49 patients on uninterrupted warfarin, both of which were managed successfully without longterm sequelae, and no bleeding complication occurred in 32 patients not on warfarin (uninterrupted aspirin). There were no thromboembolic events or other complication with either anticoagulant regimen. CONCLUSION: Despite the larger diameter and increased stiffness of multi-electrode array catheters and their deflectable transseptal sheaths, their use for catheter ablation in patients with atrial fibrillation on uninterrupted warfarin in this single-center experience does not appear to be unsafe, and thus, an adequately powered multicenter prospective randomized controlled trial should be considered.

A Proteomic Approach to Analyze the Aspirin-mediated Lysine Acetylome.

Science.gov (United States)

Tatham, Michael H; Cole, Christian; Scullion, Paul; Wilkie, Ross; Westwood, Nicholas J; Stark, Lesley A; Hay, Ronald T

2017-02-01

Aspirin, or acetylsalicylic acid is widely used to control pain, inflammation and fever. Important to this function is its ability to irreversibly acetylate cyclooxygenases at active site serines. Aspirin has the potential to acetylate other amino acid side-chains, leading to the possibility that aspirin-mediated lysine acetylation could explain some of its as-yet unexplained drug actions or side-effects. Using isotopically labeled aspirin-d 3 , in combination with acetylated lysine purification and LC-MS/MS, we identified over 12000 sites of lysine acetylation from cultured human cells. Although aspirin amplifies endogenous acetylation signals at the majority of detectable endogenous sites, cells tolerate aspirin mediated acetylation very well unless cellular deacetylases are inhibited. Although most endogenous acetylations are amplified by orders of magnitude, lysine acetylation site occupancies remain very low even after high doses of aspirin. This work shows that while aspirin has enormous potential to alter protein function, in the majority of cases aspirin-mediated acetylations do not accumulate to levels likely to elicit biological effects. These findings are consistent with an emerging model for cellular acetylation whereby stoichiometry correlates with biological relevance, and deacetylases act to minimize the biological consequences of nonspecific chemical acetylations. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Comparison of Warfarin Requirements in Post-cardiac Surgery Patients: Valve Replacement Versus Non-valve Replacement.

Science.gov (United States)

Olson, Logan M; Nei, Andrea M; Joyce, David L; Ou, Narith N; Dierkhising, Ross A; Nei, Scott D

2018-01-11

Anticoagulation with warfarin affects approximately 140,000 post-cardiac surgery patients every year, yet there remains limited published data in this patient population. Dosing remains highly variable due to intrinsic risk factors that plague cardiac surgery candidates and a lack of diverse literature that can be applied to those who have undergone a cardiac surgery alternative to heart valve replacement (HVR). In the present study, our aim was to compare the warfarin requirements between HVR and non-HVR patients. This was a single-center, retrospective study of post-cardiac surgery patients initiated on warfarin at Mayo Clinic Hospital, Rochester, from January 1st, 2013 to October 31st, 2016. The primary outcome was the maintenance warfarin dose at the earliest of discharge or warfarin day 10 between patients with HVR and non-HVR cardiac surgeries. A total of 683 patients were assessed during the study period: 408 in the HVR group and 275 in the non-HVR group. The mean warfarin maintenance doses in the HVR and non-HVR groups were 2.55 mg [standard deviation (SD) 1.52] and 2.43 mg (SD 1.21), respectively (adjusted p = 0.65). A multivariable analysis was performed to adjust for gender, age, body mass index and drug interactions. This was the largest study to evaluate warfarin dose requirements in post-cardiac surgery patients and is the first to compare warfarin requirements between HVR and non-HVR patients during the immediate post-operative period. Both groups had similar warfarin requirements, which supports expanding the initial warfarin dosing recommendations of the 9th edition Chest guideline to include non-HVR patients as well as HVR patients.

Bleeding due to a probable interaction between warfarin and Gouqizi (Lycium Barbarum L.

Directory of Open Access Journals (Sweden)

Jinhua Zhang

2015-01-01

Full Text Available Unlike what is widely anticipated by the public, herbal medicines are not always safe despite being natural. We describe a 65-year-old Chinese man taking a prolonged maintenance dose of warfarin who experienced an elevated international normalized ratio (INR with associated bleeding after drinking Gouqizi (goji berry wine. This report illustrates that large doses (more than 6–12 g of Gouqizi can significantly enhance the anticoagulant action of warfarin and may cause similar adverse effects in keeping with three previous reports. Therefore, the use of herbal medicines must adhere to pharmacopoeia-recommended guidelines, including dosage regimes. Doctors should advise patients regarding possible interactions between herbs and warfarin when prescribing and should increase the frequency of INR monitoring for those patients concurrently receiving warfarin and medicinal herbs. Further study is needed to do for the mechanism of interaction between Gouqizi and warfarin.

Acute Abdomen Due to Uncontrolled Use of Warfarin: Spontaneous Intra-abdominal

Directory of Open Access Journals (Sweden)

Fatih Dal

2017-12-01

Full Text Available Warfarin is an oral anticoagulant, which is commonly used in the treatment and prophylaxis of thromboembolic conditions. Bleeding is the primary adverse effect associated with warfarin. The majority of warfarin-related bleedings are spontaneous minor hemorrhages occurring in the subcutaneous or intramuscular tissues and can be treated by decreasing the dose of oral anticoagulants. However, although rare, it is possible to encounter spontaneous major bleedings with increased risk of mortality. Conservative approach is the preferred initial therapy for hemodynamically stable patients with major intra-abdominal hemorrhages that we define as the intermediate group patients. Nevertheless, surgery is required for hemodynamically unstable patients with acute abdominal pain in cases of ongoing active hemorrhage, generalized peritonitis, obstruction, acute abdomen, intestinal ischemia, and perforation. In this article, we present a rare case of acute abdomen and spontaneous intra-abdominal hemorrhage resulting from uncontrolled use of warfarin and a new classification requirement.

Neurotoxicity and low paclitaxel clearance associated with concomitant clopidogrel therapy in a 60 year old Caucasian woman with ovarian carcinoma

DEFF Research Database (Denmark)

Bergmann, Troels K; Filppula, Anne M; Launiainen, Terhi

2015-01-01

% of the cohort geometric mean (385 L/h; range 176-726). She was hospitalised thrice, developed severe neuropathy and paclitaxel treatment was subsequently discontinued. In vitro, 30 min preincubation with 100 μM clopidogrel acyl-β-D-glucuronide inhibited the depletion rate of 0.5 μM paclitaxel by 51......AIM: The aim of this case report is to describe a novel pharmacokinetic drug-drug interaction between the antiplatelet agent clopidogrel and the antineoplastic agent paclitaxel. METHODS: The patient was identified in a previously described cohort of 93 patients with ovarian carcinoma treated...... with paclitaxel. The effect of clopidogrel acyl-β-D-glucuronide on the metabolism of paclitaxel was assessed in human liver microsomes. The analysis of clopidogrel in plasma and the quantification of paclitaxel and 6α-hydroxypaclitaxel in in vitro samples were performed by liquid chromatography tandem mass...

Inhibition of platelet aggregation by AZD6140, a reversible oral P2Y12 receptor antagonist, compared with clopidogrel in patients with acute coronary syndromes

DEFF Research Database (Denmark)

Storey, Robert F; Husted, Steen; Harrington, Robert A

2007-01-01

OBJECTIVES: In a substudy of DISPERSE (Dose confIrmation Study assessing anti-Platelet Effects of AZD6140 vs. clopidogRel in non-ST-segment Elevation myocardial infarction)-2, we compared the antiplatelet effects of AZD6140 and clopidogrel and assessed the effects of AZD6140 in clopidogrel...

Aspirin resistance: Prevalence and clinical outcome in Egypt

Directory of Open Access Journals (Sweden)

Ahmed Salah

2015-04-01

Results: Prevalence of aspirin resistance was 48% in our study group. Aspirin resistance was significantly higher in patients with family history of CAD (p = 0.044, smoking (p = 0.011, history of MI (p = 0.024, history of percutaneous coronary intervention (PCI (p = 0.001, and concomitant NSAIDs intake (p = 0.047. Moreover, aspirin resistance was more common among patients with multi-vessel CAD (p = 0.024. Aspirin-resistant patients had a significantly higher rate of UA (p = 0.001 and all major adverse cardiac events (MACE (p < 0.001.

Warfarinized Patients with Proximal Femoral Fractures: Survey of UK Clinical Practice.

Science.gov (United States)

Starks, Ian; Cooke, Stephen; Docker, Charles; Raine, Andrew

2009-06-01

In an aging population, anticoagulation in patients with musculoskeletal injuries is increasingly prevalent. The North American literature indicates an absence of consensus concerning the most appropriate management for this group. We aim to test the hypothesis that there is a lack of consensus in the UK regarding the perioperative management of patients with hip fractures on long-term warfarin therapy. A representative group of 400 consultant orthopedic surgeons was surveyed by postal questionnaire regarding their policy on the reversal of anticoagulation in warfarinized patients with hip fractures. The consultants contacted were selected to represent a geographical spread throughout the UK. There were 159 respondents (40% response rate), of which 79% (126) had a trauma commitment. 95 (75%) of these had a protocol for the reversal of anticoagulation prior to surgery. The commonest method used was to simply withhold warfarin and wait (70%). Other methods included FFP (16%), and low-dose (23%) and high-dose (14%) vitamin K. Some respondents used more than onemethod. Although nearly all respondents preferred an INR < 2.0 prior to surgery, 55% preferred an INR < 1.5. Hip fracture in the presence of long-term warfarin use is associated with significantly increased morbidity. This problem is likely to increase. Our results demonstrate variation in approach throughout the UK with regard to warfarin reversal and the acceptable INR at which to operate in this group of patients. We propose that low-dose vitamin K is considered more widely as a safe and effective method of warfarin reversal in this group.

Elevated International Normalized Ratio in a Patient Taking Warfarin and Mauby: A Case Report.

Science.gov (United States)

Sorbera, Maria; Joseph, Tina; DiGregorio, Robert V

2017-10-01

We describe a 70-year-old Haitian man who had been taking warfarin for 5 years for atrial fibrillation and pulmonary hypertension. This patient had his international normalized ratio (INR) checked in the pharmacist-run anticoagulation clinic and was followed monthly. Prior to the interaction, his INR was therapeutic for 5 months while taking warfarin 10.5 mg/d. The patient presented with an INR > 8.0. Patient held 4 days of warfarin and restarted on warfarin 8.5 mg/d. Two weeks later, his INR was 2.5. After continuing dose, patient presented 2 weeks later and INR was 4.8. Upon further questioning, the patient stated he recently began ingesting mauby. Mauby is a bitter dark liquid extracted from the bark of the mauby tree that is commonly used in the Caribbean population as a folk remedy with many health benefits. This case report illustrates that mauby may have a probable drug-herb interaction (Naranjo Algorithm Score of 6) when given with warfarin. There is a lack of published literature and unclear information on the Internet describing the interaction of mauby and warfarin. Health professionals should be cautious regarding interactions between warfarin and mauby until the interaction is fully elucidated.

Antitrombotisk behandling ved iskaemisk apopleksi og transitorisk cerebral iskaemi

DEFF Research Database (Denmark)

Overgaard, Karsten; Poulsen, Tina Svenstrup; Husted, Steen E

2007-01-01

In acute ischemic stroke and transient ischemic attack (TIA), aspirin is recommended to all patients (except immediately following thrombolysis). Heparin and anticoagulant therapy using vitamin K antagonists should be avoided in the acute phase. Secondary preventive antithrombotic treatment...... includes anticoagulation in patients with cardioembolic stroke and antiplatelet agents aspirin possibly combined with dipyridamole or clopidogrel alone in patients with non-cardioembolic stroke. Other individual risks may modify this treatment regimen. Udgivelsesdato: 2007-Oct-1...

Dichotomal effect of the coumadin derivative warfarin on inflammatory signal transduction

NARCIS (Netherlands)

Kater, Arnon P.; Peppelenbosch, Maikel P.; Brandjes, Dees P. M.; Lumbantobing, Mika

2002-01-01

Warfarin, a widely prescribed drug for preventing thrombosis, is thought to act solely through inhibition of vitamin K-dependent coagulation factors. Low concentrations of warfarin inhibit interleukin-6 production and phosphorylation Of I-kappaB but not activation of p38 mitogen-activated protein

[Advantages and disadvantages of warfarin and pradaxa therapy for venous thromboembolism].

Science.gov (United States)

Sukovatykh, B S; Belikov, L N; Savchuk, O F; Sukovatykh, M B

2014-01-01

An analysis of complex examination of 110 patients with venous thromboembolism was made. The patients were separated into 2 groups. The first group included 60 patients, who had the start heparin therapy during 7 days with the following 6-month warfarin therapy. Warfarin was substituted by pradaxa (dabigatran) for 50 patients of the second group. The efficacy of pradaxa could be compared with warfarin. However, pradaxa had a number of advantages such as the predictable anticoagulant effect, standard dosages. This medicine is more predictable and doesn't require a control of homeostasis and an adjustment of drug dosage.

The clinical dilemma of "silent desensitization" in aspirin-exacerbated respiratory disease.

Science.gov (United States)

White, Andrew A; Bosso, John V; Stevenson, Donald D

2013-01-01

Aspirin desensitization is a treatment option for patients with aspirin-exacerbated respiratory disease (AERD). Some patients with an excellent history of aspirin or nonsteroidal anti-inflammatory drug (NSAID) reactions have negative aspirin challenges/desensitization. This study discusses the clinical entity of silent desensitization in AERD and the dilemma that this presents to the practicing allergist/immunologist. We discuss a series of patients with a strong history of NSAID reactions who initially underwent a negative challenge/silent desensitization. These patients were subsequently proven to have AERD after a second positive aspirin challenge. Silent desensitization is an uncommon but important outcome to recognize in AERD. Clinicians performing aspirin desensitization should understand that this can occur and consider a second confirmatory aspirin challenge in some patients.

Van der Waals Interactions in Aspirin

Science.gov (United States)

Reilly, Anthony; Tkatchenko, Alexandre

2015-03-01

The ability of molecules to yield multiple solid forms, or polymorphs, has significance for diverse applications ranging from drug design and food chemistry to nonlinear optics and hydrogen storage. In particular, aspirin has been used and studied for over a century, but has only recently been shown to have an additional polymorphic form, known as form II. Since the two observed solid forms of aspirin are degenerate in terms of lattice energy, kinetic effects have been suggested to determine the metastability of the less abundant form II. Here, first-principles calculations provide an alternative explanation based on free-energy differences at room temperature. The explicit consideration of many-body van der Waals interactions in the free energy demonstrates that the stability of the most abundant form of aspirin is due to a subtle coupling between collective electronic fluctuations and quantized lattice vibrations. In addition, a systematic analysis of the elastic properties of the two forms of aspirin rules out mechanical instability of form II as making it metastable.

Comparing intracerebral hemorrhages associated with direct oral anticoagulants or warfarin.

Science.gov (United States)

Kurogi, Ryota; Nishimura, Kunihiro; Nakai, Michikazu; Kada, Akiko; Kamitani, Satoru; Nakagawara, Jyoji; Toyoda, Kazunori; Ogasawara, Kuniaki; Ono, Junichi; Shiokawa, Yoshiaki; Aruga, Toru; Miyachi, Shigeru; Nagata, Izumi; Matsuda, Shinya; Yoshimura, Shinichi; Okuchi, Kazuo; Suzuki, Akifumi; Nakamura, Fumiaki; Onozuka, Daisuke; Ido, Keisuke; Kurogi, Ai; Mukae, Nobutaka; Nishimura, Ataru; Arimura, Koichi; Kitazono, Takanari; Hagihara, Akihito; Iihara, Koji

2018-03-27

This cross-sectional survey explored the characteristics and outcomes of direct oral anticoagulant (DOAC)-associated nontraumatic intracerebral hemorrhages (ICHs) by analyzing a large nationwide Japanese discharge database. We analyzed data from 2,245 patients who experienced ICHs while taking anticoagulants (DOAC: 227; warfarin: 2,018) and were urgently hospitalized at 621 institutions in Japan between April 2010 and March 2015. We compared the DOAC- and warfarin-treated patients based on their backgrounds, ICH severities, antiplatelet therapies at admission, hematoma removal surgeries, reversal agents, mortality rates, and modified Rankin Scale scores at discharge. DOAC-associated ICHs were less likely to cause moderately or severely impaired consciousness (DOAC-associated ICHs: 31.3%; warfarin-associated ICHs: 39.4%; p = 0.002) or require surgical removal (DOAC-associated ICHs: 5.3%; warfarin-associated ICHs: 9.9%; p = 0.024) in the univariate analysis. Propensity score analysis revealed that patients with DOAC-associated ICHs also exhibited lower mortality rates within 1 day (odds ratio [OR] 4.96, p = 0.005), within 7 days (OR 2.29, p = 0.037), and during hospitalization (OR 1.96, p = 0.039). This nationwide study revealed that DOAC-treated patients had less severe ICHs and lower mortality rates than did warfarin-treated patients, probably due to milder hemorrhages at admission and lower hematoma expansion frequencies. Copyright © 2018 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

Pause med trombocytaggregationshaemmere hos kirurgiske patienter med kardiel stent

DEFF Research Database (Denmark)

Johansen, Mathias; Afshari, Arash; Kristensen, Billy

2010-01-01

Dual antiplatelet therapy with aspirin and clopidogrel is increasingly used for secondary prevention of cardiovascular events in patients with percutaneous coronary intervention. Anesthesiologists and surgeons are faced with the challenge of managing these patients prior to a surgical procedure...

Cost-effectiveness of pharmacogenetics-guided warfarin therapy vs. alternative anticoagulation in atrial fibrillation.

Science.gov (United States)

Pink, J; Pirmohamed, M; Lane, S; Hughes, D A

2014-02-01

Pharmacogenetics-guided warfarin dosing is an alternative to standard clinical algorithms and new oral anticoagulants for patients with nonvalvular atrial fibrillation. However, clinical evidence for pharmacogenetics-guided warfarin dosing is limited to intermediary outcomes, and consequently, there is a lack of information on the cost-effectiveness of anticoagulation treatment options. A clinical trial simulation of S-warfarin was used to predict times within therapeutic range for different dosing algorithms. Relative risks of clinical events, obtained from a meta-analysis of trials linking times within therapeutic range with outcomes, served as inputs to an economic analysis. Neither dabigatran nor rivaroxaban were cost-effective options. Along the cost-effectiveness frontier, in relation to clinically dosed warfarin, pharmacogenetics-guided warfarin and apixaban had incremental cost-effectiveness ratios of £13,226 and £20,671 per quality-adjusted life year gained, respectively. On the basis of our simulations, apixaban appears to be the most cost-effective treatment.

Aspirin and clonidine in non-cardiac surgery

DEFF Research Database (Denmark)

Garg, Amit; Kurz, Andrea; Sessler, Daniel I

2014-01-01

INTRODUCTION: Perioperative Ischaemic Evaluation-2 (POISE-2) is an international 2×2 factorial randomised controlled trial of low-dose aspirin versus placebo and low-dose clonidine versus placebo in patients who undergo non-cardiac surgery. Perioperative aspirin (and possibly clonidine) may reduce...... and preoperative chronic aspirin use. At the time of randomisation, a subpopulation agreed to a single measurement of serum creatinine between 3 and 12 months after surgery, and the authors will examine intervention effects on this outcome. ETHICS AND DISSEMINATION: The authors were competitively awarded a grant...

Duration of increased bleeding tendency after cessation of aspirin therapy.

LENUS (Irish Health Repository)

Cahill, Ronan A

2012-02-03

BACKGROUND: Aspirin has a significant effect on hemostasis, so it is often recommended that patients taking aspirin discontinue treatment before elective surgery. While off aspirin, these patients may be at risk of thrombosis. The optimum period of time that aspirin should be withheld is controversial. The aim of this study was to establish the duration of the antihemostatic effect of prolonged aspirin therapy. STUDY DESIGN: In a prospective study, 51 healthy volunteers were randomly assigned into 3 groups, each receiving an identical tablet for 14 days. One group received a placebo tablet; individuals in the other two groups received either 75 mg or 300 mg of aspirin once a day. Template bleeding times and specific platelet function testing (using the PFA-100; Dade Behring) were carried out on subjects before therapy and again after its completion until they returned to baseline. RESULTS: Thirty-eight volunteers complied sufficiently with the protocol to provide useful results. All bleeding times normalized within 96 hours and all platelet function tests within 144 hours after stopping aspirin. There was no demonstrable hemostatic defect in any volunteer persisting by or beyond the sixth day after treatment cessation. There was no apparent difference in duration of effect between those taking either 75 mg or 300 mg of aspirin. CONCLUSIONS: This study uses sensitive measures of platelet function to demonstrate the duration of increased bleeding tendency after withdrawal of aspirin therapy. It supports discontinuation of aspirin therapy 5 days before elective surgery (with the operation being performed on the sixth day).

Low dose aspirin as adjuvant treatment for venous leg ulceration: pragmatic, randomised, double blind, placebo controlled trial (Aspirin4VLU).

Science.gov (United States)

Jull, Andrew; Wadham, Angela; Bullen, Chris; Parag, Varsha; Kerse, Ngaire; Waters, Jill

2017-11-24

Objective  To determine the effect of low dose aspirin on ulcer healing in patients with venous leg ulcers. Design  Pragmatic, community based, parallel group, double blind, randomised controlled trial. Setting  Five community nursing centres in New Zealand. Participants  251 adults with venous leg ulcers who could safely be treated with aspirin or placebo: 125 were randomised to aspirin and 126 to placebo. Interventions  150 mg oral aspirin daily or matching placebo for up to 24 weeks treatment, with compression therapy as standard background treatment. Main outcome measures  The primary outcome was time to complete healing of the reference ulcer (largest ulcer if more than one ulcer was present). Secondary outcomes included proportion of participants healed, change in ulcer area, change in health related quality of life, and adverse events. Analysis was by intention to treat. Results  The median number of days to healing of the reference ulcer was 77 in the aspirin group and 69 in the placebo group (hazard ratio 0.85, 95% confidence interval 0.64 to 1.13, P=0.25). The number of participants healed at the endpoint was 88 (70%) in the aspirin group and 101 (80%) in the placebo group (risk difference -9.8%, 95% confidence interval -20.4% to 0.9%, P=0.07). Estimated change in ulcer area was 4.1 cm 2 in the aspirin group and 4.8 cm 2 in the placebo group (mean difference -0.7 cm 2 , 95% confidence interval -1.9 to 0.5 cm 2 , P=0.25). 40 adverse events occurred among 29 participants in the aspirin group and 37 adverse events among 27 participants in the placebo group (incidence rate ratio 1.1, 95% confidence interval 0.7 to 1.7, P=0.71). Conclusion  Our findings do not support the use of low dose aspirin as adjuvant treatment for venous leg ulcers. Trial registration  ClinicalTrials.gov NCT02158806. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Early aspirin use and the development of cardiac allograft vasculopathy.

Science.gov (United States)

Kim, Miae; Bergmark, Brian A; Zelniker, Thomas A; Mehra, Mandeep R; Stewart, Garrick C; Page, Deborah S; Woodcome, Erica L; Smallwood, Jennifer A; Gabardi, Steven; Givertz, Michael M

2017-12-01

Cardiac allograft vasculopathy (CAV) remains a leading cause of morbidity and mortality after orthotopic heart transplantation (OHT). Little is known about the influence of aspirin on clinical expression of CAV. We followed 120 patients with OHT at a single center for a median of 7 years and categorized them by the presence or absence of early aspirin therapy post-transplant (aspirin treatment ≥6 months in the first year). The association between aspirin use and time to the primary end-point of angiographic moderate or severe CAV (International Society for Heart and Lung Transplantation grade ≥2) was investigated. Propensity scores for aspirin treatment were estimated using boosting models and applied by inverse probability of treatment weighting (IPTW). Despite a preponderance of risk factors for CAV among patients receiving aspirin (male sex, ischemic heart disease as the etiology of heart failure, and smoking), aspirin therapy was associated with a lower rate of moderate or severe CAV at 5 years. Event-free survival was 95.9% for patients exposed to aspirin compared with 79.6% for patients without aspirin exposure (log-rank p = 0.005). IPTW-weighted Cox regression revealed a powerful inverse association between aspirin use and moderate to severe CAV (adjusted hazard ratio 0.13; 95% confidence interval 0.03-0.59), which was directionally consistent for CAV of any severity (adjusted hazard ratio 0.50; 95% confidence interval 0.23-1.08). This propensity score-based comparative observational analysis suggests that early aspirin exposure may be associated with a reduced risk of development of moderate to severe CAV. These findings warrant prospective validation in controlled investigations. Copyright © 2017 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Impact of CYP2C19 Metabolizer Status on Patients With ACS Treated With Prasugrel Versus Clopidogrel.

Science.gov (United States)

Doll, Jacob A; Neely, Megan L; Roe, Matthew T; Armstrong, Paul W; White, Harvey D; Prabhakaran, Dorairaj; Winters, Kenneth J; Duvvuru, Suman; Sundseth, Scott S; Jakubowski, Joseph A; Gurbel, Paul A; Bhatt, Deepak L; Ohman, E Magnus; Fox, Keith A A

2016-03-01

Certain alleles of the CYP2C19 gene are associated with higher platelet reactivity and increased ischemic events among patients treated with clopidogrel. However, the relationship of CYP2C19 genotype and outcomes in medically managed patients with acute coronary syndromes (ACS) is not known. This study sought to assess the effect of CYP2C19 genotype on ischemic outcomes in patients with ACS initially managed medically without revascularization who were randomized to either clopidogrel or prasugrel. We classified patients as extensive metabolizers (EM) or reduced metabolizers (RM) based on CYP2C19 genotype and evaluated ischemic outcomes and platelet reactivity. Among 9,326 patients enrolled from 2008 to 2011, 5,736 participated in the genetics cohort; of these, 2,236 had platelet function testing data. There was no association between CYP2C19 metabolizer status (EM vs. RM) and the primary composite endpoint of cardiovascular death, myocardial infarction (MI), or stroke (hazard ratio [HR]: 0.86). EM and RM patients had similar rates of the primary endpoint whether treated with prasugrel (HR: 0.82) or clopidogrel (HR: 0.91; p for interaction = 0.495). After adjusting for clinical and treatment variables, EM patients had a lower risk of MI versus RM patients (HR: 0.80), but risks of other outcomes were similar. RM patients had significantly higher mean P2Y12 reaction units versus EM patients when treated with clopidogrel (39.93), but not with prasugrel (3.87). CYP2C19 metabolizer status is not associated with the composite outcome of cardiovascular death, MI, or stroke in medically managed ACS patients treated with clopidogrel or prasugrel. Our findings do not support routine CYP2C19 genetic testing in this population. (A Comparison of Prasugrel and Clopidogrel in Acute Coronary Syndrome Subjects [TRILOGY ACS]; NCT00699998). Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

The Role of Aspirin in the Prevention of Cardiovascular Disease

Science.gov (United States)

Ittaman, Sunitha V.; VanWormer, Jeffrey J.; Rezkalla, Shereif H.

2014-01-01

Aspirin therapy is well-accepted as an agent for the secondary prevention of cardiovascular events and current guidelines also define a role for aspirin in primary prevention. In this review, we describe the seminal trials of aspirin use in the context of current guidelines, discuss factors that may influence the effectiveness of aspirin therapy for cardiovascular disease prevention, and briefly examine patterns of use. The body of evidence supports a role for aspirin in both secondary and primary prevention of cardiovascular events in selected population groups, but practice patterns may be suboptimal. As a simple and inexpensive prophylactic measure for cardiovascular disease, aspirin use should be carefully considered in all at-risk adult patients, and further measures, including patient education, are necessary to ensure its proper use. PMID:24573704

Verification of Pharmacogenetics-Based Warfarin Dosing Algorithms in Han-Chinese Patients Undertaking Mechanic Heart Valve Replacement

Science.gov (United States)

Zhao, Li; Chen, Chunxia; Li, Bei; Dong, Li; Guo, Yingqiang; Xiao, Xijun; Zhang, Eryong; Qin, Li

2014-01-01

Objective To study the performance of pharmacogenetics-based warfarin dosing algorithms in the initial and the stable warfarin treatment phases in a cohort of Han-Chinese patients undertaking mechanic heart valve replacement. Methods We searched PubMed, Chinese National Knowledge Infrastructure and Wanfang databases for selecting pharmacogenetics-based warfarin dosing models. Patients with mechanic heart valve replacement were consecutively recruited between March 2012 and July 2012. The predicted warfarin dose of each patient was calculated and compared with the observed initial and stable warfarin doses. The percentage of patients whose predicted dose fell within 20% of their actual therapeutic dose (percentage within 20%), and the mean absolute error (MAE) were utilized to evaluate the predictive accuracy of all the selected algorithms. Results A total of 8 algorithms including Du, Huang, Miao, Wei, Zhang, Lou, Gage, and International Warfarin Pharmacogenetics Consortium (IWPC) model, were tested in 181 patients. The MAE of the Gage, IWPC and 6 Han-Chinese pharmacogenetics-based warfarin dosing algorithms was less than 0.6 mg/day in accuracy and the percentage within 20% exceeded 45% in all of the selected models in both the initial and the stable treatment stages. When patients were stratified according to the warfarin dose range, all of the equations demonstrated better performance in the ideal-dose range (1.88–4.38 mg/day) than the low-dose range (warfarin dose prediction and in the low-dose and the ideal-dose ranges. Conclusions All of the selected pharmacogenetics-based warfarin dosing regimens performed similarly in our cohort. However, the algorithms of Wei, Huang, and Miao showed a better potential for warfarin prediction in the initial and the stable treatment phases in Han-Chinese patients undertaking mechanic heart valve replacement. PMID:24728385

Technetium-aspirin molecule complexes

International Nuclear Information System (INIS)

El-Shahawy, A.S.; Mahfouz, R.M.; Aly, A.A.M.; El-Zohry, M.

1993-01-01

Technetium-aspirin and technetium-aspirin-like molecule complexes were prepared. The structure of N-acetylanthranilic acid (NAA) has been decided through CNDO calculations. The ionization potential and electron affinity of the NAA molecule as well as the charge densities were calculated. The electronic absorption spectra of Tc(V)-Asp and Tc(V)-ATS complexes have two characteristic absorption bands at 450 and 600 nm, but the Tc(V)-NAA spectrum has one characteristic band at 450 nm. As a comparative study, Mo-ATS complex was prepared and its electronic absorption spectrum is comparable with the Tc-ATS complex spectrum. (author)

Pulmonary Embolism Inpatients Treated With Rivaroxaban Had Shorter Hospital Stays and Lower Costs Compared With Warfarin.

Science.gov (United States)

Margolis, Jay M; Deitelzweig, Steven; Kline, Jeffrey; Tran, Oth; Smith, David M; Crivera, Concetta; Bookhart, Brahim; Schein, Jeff

2016-11-01

Using real-world data, this study compares inpatient length of stay (LOS) and costs for patients with a primary diagnosis of pulmonary embolism (PE) initiating treatment with oral anticoagulation with rivaroxaban versus warfarin. Hospitalizations from MarketScan's Hospital Drug Database were selected from November 1, 2012, through December 31, 2013, for adults with a primary diagnosis of PE initiating treatment with rivaroxaban or warfarin. Warfarin patients were matched 1:1 to rivaroxaban patients using exact and propensity score matching. Hospital LOS, treatment patterns, and hospitalization costs were evaluated. Matched cohorts included 751 rivaroxaban-treated patients and 751 warfarin-treated patients. Adjusted mean LOS was 3.77 days for rivaroxaban patients (95% CI, 3.66-3.87 days) and 5.48 days for warfarin patients (95% CI, 5.33-5.63 days; P < .001). Mean (SD) LOS was shorter for patients taking rivaroxaban whether admission was for provoked PE (rivaroxaban: 5.2 [5.1] days; warfarin: 7.0 [6.5] days; P < .001) or unprovoked PE (rivaroxaban: 3.4 [2.3] days; warfarin: 5.1 [2.7] days; P < .001). Mean (SD) days from first dose to discharge were 2.5 (1.7) (rivaroxaban) and 4.0 (2.9) (warfarin) when initiated with parenteral anticoagulants (P < .001) and 2.7 (1.7) (rivaroxaban) and 4.0 (2.2) (warfarin) without parenteral anticoagulants (P < .001). The rivaroxaban cohort incurred significantly lower unadjusted mean (SD) hospitalization costs (rivaroxaban: $8473 [$9105]; warfarin: $10,291 [$9185]; P < .001), confirmed by covariate adjustment with generalized linear modeling estimating predicted mean hospitalization costs of $8266 for rivaroxaban patients (95% CI, $7851-$8681) and $10,511 for warfarin patients (95% CI, $10,031-$10,992; P < .001). patients with PE treated with rivaroxaban incurred significantly lower hospitalization costs by $2245 per admission compared with patients treated with warfarin, which was attributable to cost offsets from 1.71 fewer days of

Differential impairment of aspirin-dependent platelet cyclooxygenase acetylation by nonsteroidal antiinflammatory drugs

Science.gov (United States)

Li, Xuanwen; Fries, Susanne; Li, Ruizhi; Lawson, John A.; Propert, Kathleen J.; Diamond, Scott L.; Blair, Ian A.; FitzGerald, Garret A.; Grosser, Tilo

2014-01-01

The cardiovascular safety of nonsteroidal antiinflammatory drugs (NSAIDs) may be influenced by interactions with antiplatelet doses of aspirin. We sought to quantitate precisely the propensity of commonly consumed NSAIDs—ibuprofen, naproxen, and celecoxib—to cause a drug–drug interaction with aspirin in vivo by measuring the target engagement of aspirin directly by MS. We developed a novel assay of cyclooxygenase-1 (COX-1) acetylation in platelets isolated from volunteers who were administered aspirin and used conventional and microfluidic assays to evaluate platelet function. Although ibuprofen, naproxen, and celecoxib all had the potential to compete with the access of aspirin to the substrate binding channel of COX-1 in vitro, exposure of volunteers to a single therapeutic dose of each NSAID followed by 325 mg aspirin revealed a potent drug–drug interaction between ibuprofen and aspirin and between naproxen and aspirin but not between celecoxib and aspirin. The imprecision of estimates of aspirin consumption and the differential impact on the ability of aspirin to inactivate platelet COX-1 will confound head-to-head comparisons of distinct NSAIDs in ongoing clinical studies designed to measure their cardiovascular risk. PMID:25385584

Warfarin-induced calciphylaxis successfully treated with sodium thiosulphate.

Science.gov (United States)

Hafiji, Juber; Deegan, Patrick; Brais, Rebecca; Norris, Paul

2013-05-01

Calciphylaxis is a rare life-threatening form of skin necrosis. Although traditionally observed in patients with end-stage renal disease and/or hyperparathyroidism, calciphylaxis has also been reported to occur in 'non-traditional' patients with normal renal and parathyroid function. We report a case of warfarin-induced calciphylaxis treated successfully with sodium thiosulphate and discuss the role of Vitamin K2 as a potential therapeutic option in the management of warfarin-induced calciphylaxis. © 2012 The Authors. Australasian Journal of Dermatology © 2012 The Australasian College of Dermatologists.

Effects of Clopidogrel Therapy on Oxidative Stress, Inflammation, Vascular Function and Progenitor Cells in Stable Coronary Artery Disease

Science.gov (United States)

Ramadan, Ronnie; Dhawan, Saurabh S.; Syed, Hamid; Pohlel, F. Khan; Binongo, Jose Nilo G.; Ghazzal, Ziyad B.; Quyyumi, Arshed A.

2014-01-01

Background Traditional cardiovascular risk factors lead to endothelial injury and activation of leucocytes and platelets that initiate and propagate atherosclerosis. We proposed that clopidogrel therapy in patients with stable CAD imparts a pleiotropic effect that extends beyond anti-platelet aggregation to other athero-protective processes. Methods Forty-one subjects were randomized in a double-blind, placebo-controlled crossover study to either clopidogrel 75 mg daily or placebo for 6-weeks, and then transitioned immediately to the other treatment for an additional 6 weeks. We assessed 1) endothelial function as flow-mediated dilation of the brachial artery, 2) arterial stiffness and central augmentation index using applanation tonometry, 3) vascular function as fingertip reactive hyperemia index, 4) inflammation by measuring plasma CD40 ligand and serum high-sensitivity c-reactive protein levels, 5) oxidative stress by measuring plasma aminothiols, and 6) circulating progenitor cells, at baseline and at the end of each 6-week treatment period. Results Clopidogrel therapy resulted in a significant reduction in soluble CD40 ligand (p=0.03), a pro-thrombotic and pro-inflammatory molecule derived mainly from activated platelets. However, clopidogrel therapy had no effect on endothelial function, arterial stiffness, inflammatory and oxidative stress markers, or progenitor cells. Conclusions Our findings suggest a solitary anti-platelet effect of clopidogrel therapy in patients with stable CAD, with no effect on other sub-clinical markers of cardiovascular disease risk. PMID:24336012

THERAPEUTIC EQUIVALENCE OF ORIGINAL CLOPIDOGREL (PLAVIX AND ITS GENERIC (EGITROMB. RESULTS OF COMPARATIVE RANDOMIZED CROSS-OVER BLIND STUDY

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V. V. Yakusevich

2011-01-01

Full Text Available Aim. To study therapeutic equivalence (efficacy, safety and tolerability of original clopidogrel (Plavix and its generic (Egitromb in patients of high cardiovascular risk. Material and methods. Thirty one patients with coronary heart disease and indications for clopidogrel therapy were involved into the randomized cross-over blind study. Half of the patients received original clopidogrel (75 mg daily during the first 2 weeks and then they received generic clopidogrel in the same dose during next 2 weeks. Another half of the patients received the drugs in reverse order. Antiplatelet activity of Plavix and Egitromb was estimated by effects on ADP-induced platelet aggregation initially and after 2 weeks of treatment with each drug. Study blinding was provided by the following approach: doctors of cardiology clinic performed clinical monitoring and drug distribution; coded blood samples for platelet aggregation assessment were studied in independent laboratory of thrombosis; statistical data analysis was performed by biostatistics expert in other research center. Results. 2-week therapy with each drug led to a significant decrease of ADP-induced platelet aggregation which remained low after switching from original drug to generic and vice versa. Aggregation dynamics did not depend on the first administered drug. There were no significant differences between aggregation changes as a result of treatment with original or generic drug. No one adverse event was observed in association with both drugs therapy. Conclusion. Generic drug Egitromb (Egis, Hungary and original clopidogrel Plavix (Sanofi-Aventis, France have equivalent antiplatelet effect.

Regular Use of Aspirin or Non-Aspirin Nonsteroidal Anti-Inflammatory Drugs Is Not Associated With Risk of Incident Pancreatic Cancer in Two Large Cohort Studies.

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Khalaf, Natalia; Yuan, Chen; Hamada, Tsuyoshi; Cao, Yin; Babic, Ana; Morales-Oyarvide, Vicente; Kraft, Peter; Ng, Kimmie; Giovannucci, Edward; Ogino, Shuji; Stampfer, Meir; Cochrane, Barbara B; Manson, JoAnn E; Clish, Clary B; Chan, Andrew T; Fuchs, Charles S; Wolpin, Brian M

2018-04-01

Use of aspirin and/or non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs) reduces the risk of several cancers, but it is not clear if use of these drugs is associated with risk of pancreatic cancer. We evaluated aspirin and non-aspirin NSAID use and risk of pancreatic adenocarcinoma in 141,940 participants from the Health Professionals Follow-up Study and Nurses' Health Study using multivariable-adjusted Cox proportional hazards regression. We considered several exposure classifications to model differing lag times between NSAID exposure and cancer development. We also conducted a nested case-control study of participants from 3 prospective cohorts using conditional logistic regression to evaluate pre-diagnosis levels of plasma salicylurate, a major metabolite of aspirin, in 396 pancreatic cancer cases and 784 matched individuals without pancreatic cancer (controls). In the prospective cohort study, 1122 participants developed pancreatic adenocarcinoma over 4.2 million person-years. Use of aspirin or non-aspirin NSAIDs was not associated with pancreatic cancer risk, even after considering several latency exposure classifications. In a pre-planned subgroup analysis, regular aspirin use was associated with reduced pancreatic cancer risk among participants with diabetes (relative risk, 0.71; 95% CI, 0.54-0.94). In the nested case-control study, pre-diagnosis levels of salicylurate were not associated with pancreatic cancer risk (odds ratio, 1.08; 95% CI, 0.72-1.61; P trend 0.81; comparing participants in the highest quintile with those in the lowest quintile of plasma salicylurate). Regular aspirin or non-aspirin NSAID use was not associated with future risk of pancreatic cancer in participants from several large prospective cohort studies. A possible reduction in risk for pancreatic cancer among people with diabetes who regularly use aspirin should be further examined in preclinical and human studies. Copyright © 2018 AGA Institute. Published by Elsevier

Aspirin responsiveness changes in obese patients following bariatric surgery.

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Norgard, Nicholas B; Monte, Scott V; Fernandez, Stanley F; Ma, Qing

2017-08-01

Bariatric surgery has emerged as a promising treatment option for weight loss and to counter the metabolic consequences of obesity. Obesity has been linked to a hyperaggregable state, as well as a blunted response to aspirin. This pilot study assessed the hypothesis that bariatric surgery would lead to an improvement in aspirin-induced platelet inhibition and a reduction in platelet aggregability. Fifteen patients scheduled to undergo bariatric surgery were administered two 7-day courses of aspirin 81 mg: the first course administered before surgery and the second was 3 months following surgery. Platelet aggregation was measured before and after each aspirin course using VerifyNow-Aspirin. The primary endpoint was the change in on-treatment aspirin reactive units (ARU) pre- and postsurgery. Data from bariatric surgery study patients were compared to data of normal weighted subjects gathered in a previous study. Roux-en-Y gastric bypass was performed in 80%, and 20% underwent sleeve gastrectomy. The mean starting body mass index (BMI) was 46.9 kg/m 2 . Patients lost on average 24.5 kg, resulting in a postsurgical BMI of 38.5 kg/m 2 . Postbariatric surgery, off-treatment ARU was significantly reduced from presurgery levels (602±59 vs 531±78; P=.035). On-aspirin platelet reactivity was also significantly reduced following surgery (469±60 vs 432±143, P=.03). There was a significant correlation between the extent of weight loss and the degree of improvement in on-aspirin platelet reactivity (r 2 =.49, P=.024). Presurgery on-aspirin platelet reactivity was significantly higher in obese patients compared to normal weighted subjects (469±60 vs 419±52; P=.016) and reduced to the baseline after the surgery (432±63 vs 419±52; P=.54). Aspirin-induced platelet inhibition may be more potent following bariatric surgery. The mechanisms behind this improvement require further investigation. © 2017 John Wiley & Sons Ltd.

Contemporary medical therapies of atherosclerotic carotid artery disease.

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Cheng, Suk F; Brown, Martin M

2017-03-01

Contemporary medical therapy consists of identification and treatment of all patient-modifiable vascular risk factors. Specific atherosclerotic disease therapies are designed to reduce the risk of thrombosis, and the disease progression in order to reduce the risk of future cardiovascular events. Contemporary medical management emphasizes the need to support the patient in achieving lifestyle modifications and to adjust medication to achieve individualized target values for specific quantifiable risk factors. Antiplatelet therapy in the form of aspirin or clopidogrel is routinely used for the prevention of ischemic stroke in patients who have had a transient ischemic attack or stroke. There is evidence from a recent trial that the use of combination antiplatelet therapy with aspirin and clopidogrel started within 24 hours of minor stroke or transient ischemic attack reduces the risk of recurrent stroke compared to the use of aspirin alone, and therefore we use aspirin plus clopidogrel in recently symptomatic patients with carotid stenosis pending carotid revascularization. Anticoagulation with heparins or vitamin K antagonist is not recommended except in patients at risk for cardio-embolic events. Lowering blood pressure to target levels has been shown to slow down the progression of carotid artery stenosis and reduces the intima-media thickness of the carotid plaque, while lowering lipid levels with statins has become an essential element in the medical therapy of carotid artery stenosis. Diabetes management should be optimized. Lifestyle choices, including tobacco smoking, physical inactivity, unhealthy diet, obesity, and excessive alcohol intake, are all important modifiable vascular risk factors. The combination of dietary modification, physical exercise, and use of aspirin, a statin, and an antihypertensive agent can be expected to give a cumulative relative stroke risk reduction of 80%. The evidence suggests that intensive medical therapy is so effective that

SPECIAL CONSIDERATIONS REGARDING WARFARIN DOSE TITRATION IN PATIENTS WITH ATRIAL FIBRILLATION DEPENDING ON CLINICAL FACTORS

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E. L. Artanova

2011-01-01

Full Text Available Aim. To study the relations of clinical characteristics and individual warfarin dose titration in patients with atrial fibrillation. Material and methods. Period of warfarin dose titration was analyzed in 68 patients with atrial fibrillation due to ischemic heart disease. Adjusted warfarin dose in milligram, duration of dose titration in days and maximal international normalized ratio (INR were taken into account. Sex, age, history of myocardial infarction and stroke, concomitant diseases, amiodarone therapy were considered among clinical characteristics. Results. Adjusted warfarin dose was significantly higher in obesity , and it was lower in case of experienced myocardial infarction. The INR highest levels and maximal amplitudes of its fluctuations were observed in patients with thyroid gland nodes and smokers. Period of warfarin dose titration was longer in patients treated with amiodarone. Conclusion. Warfarin dose titration in patients with atrial fibrillation depends on the presence of myocardial infarction, obesity , thyroid nodular changes, smoking and amiodarone treatment.

Clopidogrel in infants with systemic-to-pulmonary-artery shunts

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Wessel, David L; Berger, Felix; Li, Jennifer S

2013-01-01

BACKGROUND: Infants with cyanotic congenital heart disease palliated with placement of a systemic-to-pulmonary-artery shunt are at risk for shunt thrombosis and death. We investigated whether the addition of clopidogrel to conventional therapy reduces mortality from any cause and morbidity relate......-related morbidity. (Funded by Sanofi-Aventis and Bristol-Myers Squibb; ClinicalTrials.gov number, NCT00396877.)....

Initiation and persistence with warfarin therapy in atrial fibrillation according to ethnicity

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Hansen, Carolina Malta; Olesen, Jonas Bjerring; Hansen, Morten Lock

2012-01-01

The aim of this study was to investigate initiation of and persistence with warfarin treatment in patients with atrial fibrillation (AF) according to ethnicity. Patients hospitalized with first-time AF from 1997 to 2009, prescription claims of warfarin and country of birth were identified...... by individual-level linkage of nationwide administrative agencies. Cox proportional hazards models were used to estimate the relationship between covariates affecting initiation and non-persistence with warfarin treatment. A total of 151,537 patients were included in the study and 5,061(3.3%) were of non......-Danish origin. CHADS2 score distribution varied substantially according to ethnicity, the proportion of patients with CHADS2 score ≥1 being 79.2, 78.1, 65.9, and 46.0% for patients of Danish, Western, Eastern, and African origin, respectively. 79,239(52.4%) of all patients initiated treatment with warfarin...

Monkey liver cytochrome P450 2C19 is involved in R- and S-warfarin 7-hydroxylation.

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Hosoi, Yoshio; Uno, Yasuhiro; Murayama, Norie; Fujino, Hideki; Shukuya, Mitsunori; Iwasaki, Kazuhide; Shimizu, Makiko; Utoh, Masahiro; Yamazaki, Hiroshi

2012-12-15

Cynomolgus monkeys are widely used as primate models in preclinical studies. However, some differences are occasionally seen between monkeys and humans in the activities of cytochrome P450 enzymes. R- and S-warfarin are model substrates for stereoselective oxidation in humans. In this current research, the activities of monkey liver microsomes and 14 recombinantly expressed monkey cytochrome P450 enzymes were analyzed with respect to R- and S-warfarin 6- and 7-hydroxylation. Monkey liver microsomes efficiently mediated both R- and S-warfarin 7-hydroxylation, in contrast to human liver microsomes, which preferentially catalyzed S-warfarin 7-hydroxylation. R-Warfarin 7-hydroxylation activities in monkey liver microsomes were not inhibited by α-naphthoflavone or ketoconazole, and were roughly correlated with P450 2C19 levels and flurbiprofen 4-hydroxylation activities in microsomes from 20 monkey livers. In contrast, S-warfarin 7-hydroxylation activities were not correlated with the four marker drug oxidation activities used. Among the 14 recombinantly expressed monkey P450 enzymes tested, P450 2C19 had the highest activities for R- and S-warfarin 7-hydroxylations. Monkey P450 3A4 and 3A5 slowly mediated R- and S-warfarin 6-hydroxylations. Kinetic analysis revealed that monkey P450 2C19 had high V(max) and low K(m) values for R-warfarin 7-hydroxylation, comparable to those for monkey liver microsomes. Monkey P450 2C19 also mediated S-warfarin 7-hydroxylation with V(max) and V(max)/K(m) values comparable to those for recombinant human P450 2C9. R-warfarin could dock favorably into monkey P450 2C19 modeled. These results collectively suggest high activities for monkey liver P450 2C19 toward R- and S-warfarin 6- and 7-hydroxylation in contrast to the saturation kinetics of human P450 2C9-mediated S-warfarin 7-hydroxylation. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of aspirin on tumour cell colony formation and evolution.

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Wodarz, Dominik; Goel, Ajay; Boland, C Richard; Komarova, Natalia L

2017-09-01

Aspirin is known to reduce the risk of colorectal cancer (CRC) incidence, but the underlying mechanisms are not fully understood. In a previous study, we quantified the in vitro growth kinetics of different CRC tumour cell lines treated with varying doses of aspirin, measuring the rate of cell division and cell death. Here, we use these measured parameters to calculate the chances of successful clonal expansion and to determine the evolutionary potential of the tumour cell lines in the presence and absence of aspirin. The calculations indicate that aspirin increases the probability that a single tumour cell fails to clonally expand. Further, calculations suggest that aspirin increases the evolutionary potential of an expanding tumour cell colony. An aspirin-treated tumour cell population is predicted to result in the accumulation of more mutations (and is thus more virulent and more difficult to treat) than a cell population of the same size that grew without aspirin. This indicates a potential trade-off between delaying the onset of cancer and increasing its evolutionary potential through chemoprevention. Further work needs to investigate to what extent these findings apply to in vivo settings, and to what degree they contribute to the epidemiologically documented aspirin-mediated protection. © 2017 The Author(s).

Clopidogrel administration prior to coronary artery bypass grafting surgery: the cardiologist's panacea or the surgeon's headache?

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Kapetanakis, Emmanouil I; Medlam, Diego A; Boyce, Steven W; Haile, Elizabeth; Hill, Peter C; Dullum, Mercedes K C; Bafi, Ammar S; Petro, Kathleen R; Corso, Paul J

2005-03-01

Thrombotic complications after percutaneous coronary intervention procedures have decreased in past years mainly due to the use of clopidogrel antiplatelet therapy. However, the risk of bleeding due to enhanced and irreversible platelet inhibition in patients who will require surgical coronary revascularization instead has not been adequately addressed in the literature. The purpose of this study was to evaluate the effect of pre-operative clopidrogel exposure in haemorrhage-related re-exploration rates, peri-operative transfusion requirements, morbidity, and mortality in patients undergoing coronary artery bypass grafting (CABG) surgery. A study population of 2359 patients undergoing isolated CABG between January 2000 and June 2002 was reviewed. Of these, 415 (17.6%) received clopidogrel prior to CABG surgery, and 1944 (82.4%) did not. A risk-adjusted logistic regression analysis was used to assess the association between clopidogrel pre-medication (vs. no) and haemostatic re-operation, intraoperative and post-operative blood transfusion rates, and multiple transfusions received. Haemorrhage-related pre-operative risk factors identified from the literature and those found significant in a univariate model were used. Furthermore, a sub-cohort, matched-pair by propensity scores analysis, was also conducted. The clopidogrel group had a higher likelihood of haemostatic re-operation [OR = 4.9, (95% CI, 2.63-8.97), P < 0.01], an increase in total packed red blood cell transfusions [OR = 2.2, (95% CI, 1.70-2.84), P < 0.01], multiple unit blood transfusions [OR = 1.9, (95% CI, 1.33-2.75), P < 0.01] and platelet transfusions [OR = 2.6, (95% CI, 1.95-3.56), P < 0.01]. Surgical outcomes and operative mortality [OR = 1.5, (95% CI, 0.36-6.51), P = 0.56] were not significantly different. Pre-operative clopidogrel exposure increases the risk of haemostatic re-operation and the requirements for blood and blood product transfusion during, and after, CABG surgery.

Valsartan combined with clopidogrel and/or leflunomide for the treatment of progressive immunoglobulin A nephropathy.

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Cheng, Genyang; Liu, Dongwei; Margetts, Peter; Liu, Limin; Zhao, Zhanzheng; Liu, Zhangsuo; Tang, Lin; Fang, Yudong; Li, Haijian; Guo, Yuanyuan; Chen, Fengmei; Liu, Fengxun

2015-02-01

The current standard treatment for IgA nephropathy relies on steroid and/or immunosuppressive therapy and angiotensin converting enzyme inhibitors (ACEI) or angiotensin receptor blocker (ARB). This study examines the benefits and safety of combining valsartan with clopidogrel and leflunomide as a treatment for progressive IgA nephropathy. Patients with primary IgA nephropathy, confirmed by renal biopsy, were recruited for this study. Patients were separated into four groups (n = 42 each) after 2 months of run-in period of valsartan treatment. All patients were treated with valsartan alone (Group 1) or valsartan and either clopidogrel (Group 2) or leflunomide (Group 3) or both clopidogrel and leflunomide (Group 4). Each group was followed up for their next 24 months for 24 h urinary protein excretion, serum creatinine and estimated glomerular filtration rate (eGFR) to assess the effect of the treatment. Adverse effects were recorded concurrently to evaluate the safety of the treatment. Of all 168 patients, 107 were males and 61 were females, with an average age of 33.8 ± 8.79 years. Baseline characteristics were comparable among the four groups (P > 0.05) prior to the experimental treatment. There was a significant (P Valsartan combined with Clopidogrel and Leflunomide can reduce the urinary proteins loss and renal function deterioration for IgA nephropathy patients and cause minimal adverse reactions. Our study suggests a new clinical treatment option for IgA nephropathy. © 2014 Asian Pacific Society of Nephrology.

The role of clopidogrel in early and sustained arterial patency after fibrinolysis for ST-segment elevation myocardial infarction: the ECG CLARITY-TIMI 28 Study.

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Scirica, Benjamin M; Sabatine, Marc S; Morrow, David A; Gibson, C Michael; Murphy, Sabina A; Wiviott, Stephen D; Giugliano, Robert P; McCabe, Carolyn H; Cannon, Christopher P; Braunwald, Eugene

2006-07-04

This study was designed to determine the relationship between clopidogrel and early ST-segment resolution (STRes) and the interaction of the two with clinical outcomes after fibrinolysis. ST-segment resolution is an early noninvasive marker of coronary reperfusion. The CLARITY-TIMI 28 (Clopidogrel as Adjunctive Reperfusion Therapy-Thrombolysis in Myocardial Infarction 28) trial randomized 3,491 patients with ST-segment elevation myocardial infarction (STEMI) undergoing fibrinolysis to clopidogrel versus placebo. ST-segment resolution was defined as complete (>70%), partial (30% to 70%), or none (STRes between the clopidogrel and placebo groups at 90 min (38.4% vs. 36.6% at 90 min). When patients were stratified by STRes category, treatment with clopidogrel resulted in greater benefit among those with evidence of early STRes, with greater odds of an open artery at late angiography in patients with partial (odds ratio [OR] 1.4, p = 0.04) or complete (OR 2.0, p STRes, but no improvement in those with no STRes at 90 min (OR 0.89, p = 0.48) (p for interaction = 0.003). Clopidogrel was also associated with a significant reduction in the odds of an in-hospital death or myocardial infarction in patients who achieved partial (OR 0.30, p = 0.003) or complete STRes at 90 min (OR 0.49, p = 0.056), whereas clinical benefit was not apparent in patients who had no STRes (OR 0.98, p = 0.95) (p for interaction = 0.027). By 30 days, the clinical benefit of clopidogrel was predominately seen in patients with complete STRes. Clopidogrel appears to improve late coronary patency and clinical outcomes by preventing reocclusion of open arteries rather than by facilitating early reperfusion.

Effect of Ankaferd Blood Stopper on Skin Superoxide Dismutase and Catalase Activities in Warfarin-Treated Rats.

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Aktop, Sertaç; Emekli-Alturfan, Ebru; Gönül, Onur; Göçmen, Gökhan; Garip, Hasan; Yarat, Ayşen; Göker, Kamil

2017-03-01

Ankaferd Blood Stopper (ABS) is a new promising local hemostatic agent, and its mechanism on hemostasis has been shown by many studies. However, the effects of ABS on skin superoxide dismutase (SOD) and catalase (CAT) activities have not been investigated before. The aim of this study was to evaluate the effects of this new generation local hemostatic agent on warfarin-treated rats focusing on its the antioxidant potential in short-term soft tissue healing. Twelve systemically warfarin treated (warfarin group) and 12 none treated Wistar Albino rats (control group) were selected for the trial. Rats in the warfarin group were treated intraperitonally with 0.1 mg/kg warfarin, and rats in the control group were given 1 mL/kg saline 3 days earlier to surgical procedure and continued until killing. All rats had incisions on dorsal dermal tissue, which was applied ABS or no hemostatic agent before suturing. Six of each group were killed on day 4, and the other 6 were killed on day 8. Blood and skin samples were taken. Prothrombin time (PT) in blood samples, CAT, and SOD activities in skin samples were determined. Warfarin treatment dose was found to be convenient and warfarin treatment increased the PT levels as expected. Warfarin treatment decreased CAT activity significantly compared to the control group. The ABS treatment significantly increased SOD activities in the warfarin group at the end of the eighth day. Ankaferd Blood Stopper acted positively in short-term tissue healing by increasing SOD activity in warfarin-treated rats. Therefore, ABS may be suggeted as a promoting factor in tissue healing.

Verification of pharmacogenetics-based warfarin dosing algorithms in Han-Chinese patients undertaking mechanic heart valve replacement.

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Zhao, Li; Chen, Chunxia; Li, Bei; Dong, Li; Guo, Yingqiang; Xiao, Xijun; Zhang, Eryong; Qin, Li

2014-01-01

To study the performance of pharmacogenetics-based warfarin dosing algorithms in the initial and the stable warfarin treatment phases in a cohort of Han-Chinese patients undertaking mechanic heart valve replacement. We searched PubMed, Chinese National Knowledge Infrastructure and Wanfang databases for selecting pharmacogenetics-based warfarin dosing models. Patients with mechanic heart valve replacement were consecutively recruited between March 2012 and July 2012. The predicted warfarin dose of each patient was calculated and compared with the observed initial and stable warfarin doses. The percentage of patients whose predicted dose fell within 20% of their actual therapeutic dose (percentage within 20%), and the mean absolute error (MAE) were utilized to evaluate the predictive accuracy of all the selected algorithms. A total of 8 algorithms including Du, Huang, Miao, Wei, Zhang, Lou, Gage, and International Warfarin Pharmacogenetics Consortium (IWPC) model, were tested in 181 patients. The MAE of the Gage, IWPC and 6 Han-Chinese pharmacogenetics-based warfarin dosing algorithms was less than 0.6 mg/day in accuracy and the percentage within 20% exceeded 45% in all of the selected models in both the initial and the stable treatment stages. When patients were stratified according to the warfarin dose range, all of the equations demonstrated better performance in the ideal-dose range (1.88-4.38 mg/day) than the low-dose range (pharmacogenetics-based warfarin dosing regimens performed similarly in our cohort. However, the algorithms of Wei, Huang, and Miao showed a better potential for warfarin prediction in the initial and the stable treatment phases in Han-Chinese patients undertaking mechanic heart valve replacement.

Once- versus twice-daily aspirin treatment in patients with essential thrombocytosis

DEFF Research Database (Denmark)

Larsen, Mads Lamm; Pedersen, Oliver Heidmann; Hvas, Anne-Mette

2018-01-01

Insufficient platelet inhibition has been reported in up to 40% of aspirin-treated patients, including patients with essential thrombocytosis. To maintain sufficient platelet inhibition, a shorter dosing interval with aspirin has been suggested. We aimed to investigate the antiplatelet effect...... of low-dose aspirin given twice-daily compared to standard once-daily dosing in patients with essential thrombocytosis. We included 22 patients, who were treated for 7 days with standard once-daily aspirin (75 mg once-daily) followed by 7 days treatment of twice-daily aspirin (37.5 mg twice......-daily). The two regimens were separated by 14 days aspirin washout. Blood samples were obtained 1h and 24h/12h after the last pill intake in each regimen. The effect of aspirin was evaluated by: (1) platelet aggregation measured by whole blood impedance aggregometry (Multiplate® Analyser) using arachidonic acid...

Fluconazole-Warfarin Interaction: A case report with deadly consequences

Directory of Open Access Journals (Sweden)

Elliot V Hersh

2017-06-01

Full Text Available Adverse drug-drug interactions are more common in the elderly because of the commonality of polypharmacy. When one of the interacting drugs has a low therapeutic index, the consequences can be life-threatening or fatal. This case describes a fatal cerebral haemorrhage in an 80-year old male on stable doses of warfarin prescribed by his cardiologist, who was prescribed fluconazole 200mg, once daily, for 14 days by an oral and maxillofacial surgeon to treat an intraoral fungal infection. The oral surgeon was aware that the patient was on warfarin and his INR two days prior to the appointment was 2.4. While a drug interaction alert was sent to the patient’s primary care family physician regarding fluconazole and the simvastatin she had been prescribing, the interaction was not reviewed by her for another 9- days. She then informed the patient that “it was fine” to finish the fluconazole. However, this phone conversation prompted the patient to discontinue the fluconazole after 8 doses. Two days later, the patient was confused and driving his car erratically. His son rushed him to the hospital where a CAT scan revealed a large frontal intraparenchymal haemorrhage. His INR was a 9.6. This event illustrates that this well-documented adverse drug interaction needs to be better highlighted in dental and medical training. Warfarin’s primary metabolic pathway involves the cytochrome P-450 2C9 isoform and fluconazole is a strong inhibitor of this enzyme, with the potential outcome being excessive warfarin blood levels. Frequent INR monitoring with potential warfarin dosage adjustments downward if fluconazole is prescribed, or the complete avoidance of fluconazole is recommended in patients taking warfarin. The importance of communication and coordinated care between different health care providers cannot be overstated.

Impact on survival of warfarin in patients with pulmonary arterial hypertension receiving subcutaneous treprostinil.

Science.gov (United States)

Ascha, Mona; Zhou, Xuan; Rao, Youlan; Minai, Omar A; Tonelli, Adriano R

2017-10-01

Anticoagulation is a common treatment modality in patients with pulmonary arterial hypertension (PAH). Further studies are needed to appropriately assess the risk/benefit ratio of anticoagulation, particularly in PAH patients receiving PAH-specific therapies. We use observational long-term data on PAH patients treated with subcutaneous (SQ) treprostinil from a large open-label study. Patients were followed for up to 4 years. The use of warfarin and bleeding events were recorded. At total of 860 patients (age [mean±SD] 46±15 years, 76% female, 83% Caucasian, 49% idiopathic PAH, and 76% New York Heart Association [NYHA] functional class III) were included. All patients received SQ treprostinil (15% also other pulmonary hypertension [PH]-therapies) and 590 (69%) received warfarin during the study. The proportions of women, African American, and idiopathic pulmonary hypertension (IPAH) patients were higher in the group receiving warfarin. A higher proportion of patients with congenital heart disease and portopulmonary hypertension did not receive warfarin. There were no differences in unadjusted long-term survival between PAH patients receiving warfarin or not (log-rank test, P value=.69), even when only considering idiopathic PAH (P=.32). In addition, no difference was found in adjusted long-term survival both in PAH (P=.84) and idiopathic PAH patients (P=.44) based on the use of warfarin. Furthermore, no survival difference based on the use of warfarin were noted between propensity score-matched PAH patients (P=.37). Long-term anticoagulation with warfarin was not associated with any significant effect on survival in PAH or idiopathic PAH patients treated with SQ treprostinil. © 2017 John Wiley & Sons Ltd.

Efficacy of protocol-based pharmacotherapy management on anticoagulation with warfarin for patients with cardiovascular surgery.

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Katada, Y; Nakagawa, S; Minakata, K; Odaka, M; Taue, H; Sato, Y; Yonezawa, A; Kayano, Y; Yano, I; Nakatsu, T; Sakamoto, K; Uehara, K; Sakaguchi, H; Yamazaki, K; Minatoya, K; Sakata, R; Matsubara, K

2017-10-01

Anticoagulation therapy with warfarin requires periodic monitoring of prothrombin time-international normalized ratio (PT-INR) and adequate dose adjustments based on the data to minimize the risk of bleeding and thromboembolic events. In our hospital, we have developed protocol-based pharmaceutical care, which we called protocol-based pharmacotherapy management (PBPM), for warfarin therapy. The protocol requires pharmacists to manage timing of blood sampling for measuring PT-INR and warfarin dosage determination based on an algorithm. This study evaluated the efficacy of PBPM in warfarin therapy by comparing to conventional pharmaceutical care. From October 2013 to June 2015, a total of 134 hospitalized patients who underwent cardiovascular surgeries received post-operative warfarin therapy. The early series of patients received warfarin therapy as the conventional care (control group, n=77), whereas the latter received warfarin therapy based on the PBPM (PBPM group, n=68). These patients formed the cohort of the present study and were retrospectively analysed. The indications for warfarin included aortic valve replacement (n=56), mitral valve replacement (n=4), mitral valve plasty (n=22) and atrial fibrillation (n=29). There were no differences in patients' characteristics between both groups. The percentage time in therapeutic range in the first 10 days was significantly higher in the PBPM group (47.1%) than that in the control group (34.4%, PWarfarin therapy based on our novel PBPM was clinically safe and resulted in significantly better anticoagulation control compared to conventional care. © 2017 John Wiley & Sons Ltd.

Pharmacogenetics of clopidogrel: comparison between a standard and a rapid genetic testing.

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Saracini, Claudia; Vestrini, Anna; Galora, Silvia; Armillis, Alessandra; Abbate, Rosanna; Giusti, Betti

2012-06-01

CYP2C19 variant alleles are independent predictors of clopidogrel response variability and occurrence of major adverse cardiovascular events in high-risk vascular patients on clopidogrel therapy. Increasing evidence suggests a combination of platelet function testing with CYP2C19 genetic testing may be more effective in identifying high-risk individuals for alternative antiplatelet therapeutic strategies. A crucial point in evaluating the use of these polymorphisms in clinical practice, besides test accuracy, is the cost of the genetic test and rapid availability of the results. One hundred acute coronary syndrome patients were genotyped for CYP2C19*2,*3,*4,*5, and *17 polymorphisms with two platforms: Verigene(®) and the TaqMan(®) system. Genotyping results obtained by the classical TaqMan approach and the rapid Verigene approach showed a 100% concordance for all the five polymorphisms investigated. The Verigene system had shorter turnaround time with respect to TaqMan. The cost of reagents for TaqMan genotyping was lower than that for the Verigene system, but the effective manual staff involvement and the relative cost resulted in higher cost for TaqMan than for Verigene. The Verigene system demonstrated good performance in terms of turnaround time and cost for the evaluation of the clopidogrel poor metabolizer status, giving genetic information in suitable time (206 min) for a therapeutic strategy decision.

Monitoring aspirin therapy with the Platelet Function Analyzer-100

DEFF Research Database (Denmark)

Mortensen, Jette; Poulsen, Tina Svenstrup; Grove, Erik Lerkevang

2008-01-01

OBJECTIVE: Low platelet response to aspirin has been reported to be associated with a high incidence of vascular events. The reported prevalence of aspirin low-responsiveness varies, which may be explained by poor reproducibility of the methods used to evaluate aspirin response and low compliance....... The Platelet Function Analyzer-100 (PFA-100) is a commonly used platelet function test. We aimed to assess the reproducibility of the PFA-100 and the agreement with optical platelet aggregometry (OPA) in healthy volunteers and in patients with coronary artery disease (CAD) treated with low-dose aspirin....... MATERIAL AND METHODS: Twenty-one healthy volunteers and 43 patients with CAD took part in the study. During treatment with aspirin 75 mg daily, all participants had platelet function assessed in duplicate with the PFA-100 and OPA on 4 consecutive days. Additionally, platelet function was assessed before...

Warfarin resistance associated with genetic polymorphism of VKORC1: linking clinical response to molecular mechanism using computational modeling.

Science.gov (United States)

Lewis, Benjamin C; Nair, Pramod C; Heran, Subash S; Somogyi, Andrew A; Bowden, Jeffrey J; Doogue, Matthew P; Miners, John O

2016-01-01

The variable response to warfarin treatment often has a genetic basis. A protein homology model of human vitamin K epoxide reductase, subunit 1 (VKORC1), was generated to elucidate the mechanism of warfarin resistance observed in a patient with the Val66Met mutation. The VKORC1 homology model comprises four transmembrane (TM) helical domains and a half helical lid domain. Cys132 and Cys135, located in the N-terminal end of TM-4, are linked through a disulfide bond. Two distinct binding sites for warfarin were identified. Site-1, which binds vitamin K epoxide (KO) in a catalytically favorable orientation, shows higher affinity for S-warfarin compared with R-warfarin. Site-2, positioned in the domain occupied by the hydrophobic tail of KO, binds both warfarin enantiomers with similar affinity. Displacement of Arg37 occurs in the Val66Met mutant, blocking access of warfarin (but not KO) to Site-1, consistent with clinical observation of warfarin resistance.

Thromboembolic and Major Bleeding Events With Rivaroxaban Versus Warfarin Use in a Real-World Setting.

Science.gov (United States)

Russo-Alvarez, Giavanna; Martinez, Kathryn A; Valente, Megan; Bena, James; Hu, Bo; Luxenburg, Jennifer; Chaitoff, Alexander; Ituarte, Catherine; Brateanu, Andrei; Rothberg, Michael B

2018-01-01

Although randomized trials demonstrate the noninferiority of rivaroxaban compared with warfarin in the context of nonvalvular atrial fibrillation (AF), little is known about how these drugs compare in practice. To assess the relative effectiveness and safety of rivaroxaban versus warfarin in a large health system and to evaluate this association by time in therapeutic range (TTR). We conducted a retrospective cohort study with propensity matching in the Cleveland Clinic Health System. The study included patients initiated on warfarin or rivaroxaban for thromboembolic prevention in nonvalvular AF between January 2012 and July 2016. The main outcomes were thromboembolic events and major bleeds. Analyses were stratified by warfarin patients' TTR. The cohort consisted of 472 propensity-matched pairs. The mean age was 73.6 years (SD = 11.7), and the mean CHADS 2 score was 1.8. The median TTR for warfarin patients was 64%. In the propensity-matched analysis, there was no significant difference in thromboembolic or major bleeding events between groups. Among warfarin patients with a TTR warfarin and rivaroxaban were associated with similar safety and effectiveness, even among those with suboptimal therapeutic control. Individualized decision making, taking into account the nontherapeutic tradeoffs associated with these medications (eg, monitoring, half-life, cost) is warranted.

Aspirin for Evidence-Based Preeclampsia Prevention trial: influence of compliance on beneficial effect of aspirin in prevention of preterm preeclampsia.

Science.gov (United States)

Wright, David; Poon, Liona C; Rolnik, Daniel L; Syngelaki, Argyro; Delgado, Juan Luis; Vojtassakova, Denisa; de Alvarado, Mercedes; Kapeti, Evgenia; Rehal, Anoop; Pazos, Andrea; Carbone, Ilma Floriana; Dutemeyer, Vivien; Plasencia, Walter; Papantoniou, Nikos; Nicolaides, Kypros H

2017-12-01

The Aspirin for Evidence-Based Preeclampsia Prevention trial was a multicenter study in women with singleton pregnancies. Screening was carried out at 11-13 weeks' gestation with an algorithm that combines maternal factors and biomarkers (mean arterial pressure, uterine artery pulsatility index, and maternal serum pregnancy-associated plasma protein A and placental growth factor). Those with an estimated risk for preterm preeclampsia of >1 in 100 were invited to participate in a double-blind trial of aspirin (150 mg/d) vs placebo from 11-14 until 36 weeks' gestation. Preterm preeclampsia with delivery at preeclampsia in the Aspirin for Evidence-Based Preeclampsia Prevention trial. This was a secondary analysis of data from the trial. The proportion of prescribed tablets taken was used as an overall measure of compliance. Logistic regression analysis was used to estimate the effect of aspirin on the incidence of preterm preeclampsia according to compliance of preeclampsia at screening and the participating center. The choice of cut-off of 90% was based on an exploratory analysis of the treatment effect. Logistic regression analysis was used to investigate predictors of compliance ≥90% among maternal characteristics and medical history. Preterm preeclampsia occurred in 5/555 (0.9%) participants in the aspirin group with compliance ≥90%, in 8/243 (3.3%) of participants in the aspirin group with compliance preeclampsia was 0.24 (95% confidence interval, 0.09-0.65) for compliance ≥90% and 0.59 (95% confidence interval, 0.23-1.53) for compliance preeclampsia and negatively associated with smoking, maternal age preeclampsia in a previous pregnancy. The beneficial effect of aspirin in the prevention of preterm preeclampsia appears to depend on compliance. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of Ticagrelor Plus Aspirin, Ticagrelor Alone, or Aspirin Alone on Saphenous Vein Graft Patency 1 Year After Coronary Artery Bypass Grafting: A Randomized Clinical Trial.

Science.gov (United States)

Zhao, Qiang; Zhu, Yunpeng; Xu, Zhiyun; Cheng, Zhaoyun; Mei, Ju; Chen, Xin; Wang, Xiaowei

2018-04-24

The effect of ticagrelor with or without aspirin on saphenous vein graft patency in patients undergoing coronary artery bypass grafting (CABG) is unknown. To compare the effect of ticagrelor + aspirin or ticagrelor alone vs aspirin alone on saphenous vein graft patency 1 year after CABG. Randomized, multicenter, open-label, clinical trial among 6 tertiary hospitals in China. Eligible patients were aged 18 to 80 years with indications for elective CABG. Patients requiring urgent revascularization, concomitant cardiac surgery, dual antiplatelet or vitamin K antagonist therapy post-CABG, and who were at risk of serious bleeding were excluded. From July 2014 until November 2015, 1256 patients were identified and 500 were enrolled. Follow-up was completed in January 2017. Patients were randomized (1:1:1) to start ticagrelor (90 mg twice daily) + aspirin (100 mg once daily) (n = 168), ticagrelor (90 mg twice daily) (n = 166), or aspirin (100 mg once daily) (n = 166) within 24 hours post-CABG. Neither patients nor treating physicians were blinded to allocation. Primary outcome was saphenous vein graft patency 1 year after CABG (FitzGibbon grade A) adjudicated independently by a committee blinded to allocation. Saphenous vein graft patency was assessed by multislice computed tomographic angiography or coronary angiography. Among 500 randomized patients (mean age, 63.6 years; women, 91 [18.2%]), 461 (92.2%) completed the trial. Saphenous vein graft patency rates 1 year post-CABG were 88.7% (432 of 487 vein grafts) with ticagrelor + aspirin; 82.8% (404 of 488 vein grafts) with ticagrelor alone; and 76.5% (371 of 485 vein grafts) with aspirin alone. The difference between ticagrelor + aspirin vs aspirin alone was statistically significant (12.2% [95% CI, 5.2% to 19.2%]; P aspirin alone was not statistically significant (6.3% [95% CI, -1.1% to 13.7%]; P = .10). Five major bleeding episodes occurred during 1 year of follow-up (3 with

Preemptive warfarin dose reduction after initiation of sulfamethoxazole-trimethoprim or metronidazole.

Science.gov (United States)

Powers, Anna; Loesch, Erin B; Weiland, Anthony; Fioravanti, Nicole; Lucius, David

2017-07-01

To evaluate the utility of a preemptive warfarin dose reduction at the time of initiation of either sulfamethoxazole-trimethoprim or metronidazole, a retrospective chart review of patients who received an outpatient prescription for warfarin and either sulfamethoxazole-trimethoprim and/or metronidazole from July 1, 2011 to July 1, 2015 was conducted. Clinical outcomes compared Veterans who had a warfarin dose reduction and those who did not within 120 h (5 days) of antibiotic initiation. The primary outcome compared the pre-and post-antibiotic International Normalized Ratio (INR) of patients in the intervention group (warfarin dose reduction) with those in the control group (no intervention). Secondary outcomes assessed incidence of thromboembolic and major bleeding events within 30 days of antibiotic completion. Fifty patients were assessed. Forty-nine patients had at least one follow-up appointment; 126 follow-up visits were evaluated. There was a statistically significant difference for the change in therapeutic INR at the first follow-up appointment (p = 0.029) for those patients in the control group. On average, the patients in the intervention group required fewer follow-up visits (p = 0.019). There were no statistically significant differences for the overall rate of therapeutic INR values between groups, as well as no instances of a thromboembolic or major bleeding events during the follow-up period. Clinically significant differences were observed for patients who received a preemptive warfarin dose reduction upon initiation of sulfamethoxazole-trimethoprim or metronidazole. Patients in the intervention group required fewer follow-up appointments and were more likely maintain a therapeutic INR within the 30 days following the antibiotic course. Results of this study will be presented the at Pharmacy and Therapeutics committee in an effort to seek approval for policy development to initiate a local preemptive warfarin dose adjustment as a standard

Survey of the use of warfarin and the newer anticoagulant dabigatran in patients with atrial fibrillation

Directory of Open Access Journals (Sweden)

Choi JC

2014-02-01

Full Text Available Jiyoon C Choi,1 Marco d DiBonaventura,2 Lewis Kopenhafer,2 Winnie W Nelson31LifeScan, Inc, West Chester, PA, 2Health Sciences Practice, Kantar Health, New York, NY, 3Janssen Scientific Affairs LLC, Raritan, NJ, USABackground: Oral dabigatran was recently approved as an alternative to warfarin for prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation. Unlike warfarin, dabigatran has a fixed dosage and few drug interactions, and does not require anticoagulation monitoring or dietary restrictions.Methods: This study aimed to describe and compare characteristics of patients with atrial fibrillation who used dabigatran or only warfarin. Patients with a self-reported diagnosis of atrial fibrillation aged ≥18 years who were receiving (or had received warfarin or dabigatran completed an online survey. Differences in characteristics of dabigatran and warfarin users were tested using chi-squared tests and analysis of variance for categorical and continuous variables, respectively.Results: Overall, 364 patients were surveyed (204 warfarin users, 160 dabigatran users. The mean age was 65.1 years, and 68.7% were male. Dabigatran users were more likely than warfarin users to be female (36.9% versus 27.0% and to have experienced adverse events, including gastrointestinal bleeding, in the 3 months before the survey (21.9% versus 6.9%; P<0.05. Both groups reported high medication adherence (dabigatran users 0.65 versus warfarin users 0.63 missed doses/month. Dabigatran users were more likely than warfarin users to discuss treatment options with their physician before beginning therapy (36.9% versus 24.5%; P<0.05 and less likely to switch anticoagulant medication (10.7% versus 31.9%; P<0.05. Although dabigatran users were more likely to experience adverse events, they reported greater satisfaction with anticoagulation treatment than warfarin users.Conclusion: The efficacy and convenience reported by dabigatran users

Warfarin Initiation, Atrial Fibrillation, and Kidney Function: Comparative Effectiveness and Safety of Warfarin in Older Adults With Newly Diagnosed Atrial Fibrillation.

Science.gov (United States)

Jun, Min; James, Matthew T; Ma, Zhihai; Zhang, Jianguo; Tonelli, Marcello; McAlister, Finlay A; Manns, Braden J; Ravani, Pietro; Quinn, Robert R; Wiebe, Natasha; Perkovic, Vlado; Wilton, Stephen B; Winkelmayer, Wolfgang C; Hemmelgarn, Brenda R

2017-06-01

The effectiveness and safety of warfarin use among patients with atrial fibrillation (AF) and reduced kidney function are uncertain. Community-based retrospective cohort study (May 1, 2003, to March 31, 2012) using province-wide laboratory and administrative data in Alberta, Canada. 14,892 adults 66 years or older with new AF and a measurement of kidney function. Long-term dialysis patients or kidney transplant recipients were excluded. Propensity scores were used to construct a matched-pairs cohort of patients with AF who did and did not have a warfarin prescription within a 60-day period surrounding their AF diagnosis. Within 1 year of initiating warfarin therapy (or the matched date for nonusers): (1) the composite of all-cause death, ischemic stroke, or transient ischemic attack (also assessed as separate end points) and (2) first hospitalization or emergency department visit for a major bleeding episode defined as an intracranial, upper or lower gastrointestinal, or other bleeding. Baseline glomerular filtration rate (GFR) was estimated using the CKD-EPI creatinine equation. Patients were matched within estimated GFR (eGFR) categories: ≥90, 60 to 89, 45 to 59, 30 to 44, and warfarin therapy initiation was associated with lower risk for the composite outcome compared to nonuse (adjusted HRs [95% CI] for eGFR categories ≥ 90, 60-89, 45-59, 30-44, and warfarin therapy was not associated with higher risk for major bleeding except for those with eGFRs of 60 to 89mL/min/1.73m 2 (HR, 1.36; 95% CI, 1.13-1.64). Selection bias. Among older adults with AF, warfarin therapy initiation was associated with a significantly lower 1-year risk for the composite outcome across all strata of kidney function. The risk for major bleeding associated with warfarin use was increased only among those with eGFRs of 60 to 89mL/min/1.73m 2 . Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Comparison of 3-Factor Prothrombin Complex Concentrate and Low-Dose Recombinant Factor VIIa for Warfarin Reversal

OpenAIRE

Chapman, Scott A; Irwin, Eric D; Abou-Karam, Nada M; Rupnow, Nichole M; Hutson, Katherine E; Vespa, Jeffrey; Roach, Robert M

2014-01-01

Introduction Prothrombin complex concentrate (PCC) and recombinant Factor VIIa (rFVIIa) have been used for emergent reversal of warfarin anticoagulation. Few clinical studies have compared these agents in warfarin reversal. We compared warfarin reversal in patients who received either 3 factor PCC (PCC3) or low-dose rFVIIa (LDrFVIIa) for reversal of warfarin anticoagulation. Methods Data were collected from medical charts of patients who received at least one dose of PCC3 (20 units/kg) or LDr...

Impact of triple antithrombotic therapy in patients with acute coronary syndrome undergoing percutaneous coronary intervention in real-world practice

NARCIS (Netherlands)

Yan, Yan; Wang, Xiao; Fan, Jing-Yao; Nie, Shao-Ping; Raposeiras-Roubín, Sergio; Abu-Assi, Emad; Henriques, Jose P. Simao; D'Ascenzo, Fabrizio; Saucedo, Jorge; González-Juanatey, José R.; Wilton, Stephen B.; Kikkert, Wouter J.; Nuñez-Gil, Iván; Ariza-Sole, Albert; Song, Xian-Tao; Alexopoulos, Dimitrios; Liebetrau, Christoph; Kawaji, Tetsuma; Moretti, Claudio; Huczek, Zenon; Fujii, Toshiharu; Correia, Luis Cl; Kawashiri, Masa-Aki; Kedev, Sasko

2017-01-01

The optimal antithrombotic regimen for patients on oral anticoagulation (OAC) after acute coronary syndrome (ACS) and percutaneous coronary intervention (PCI) remains debated. This study sought to evaluate the efficacy and safety of OAC plus clopidogrel with or without aspirin in a real-world

Outcomes With Edoxaban Versus Warfarin in Patients With Previous Cerebrovascular Events

DEFF Research Database (Denmark)

Rost, Natalia S; Giugliano, Robert P; Ruff, Christian T

2016-01-01

BACKGROUND AND PURPOSE: Patients with atrial fibrillation and previous ischemic stroke (IS)/transient ischemic attack (TIA) are at high risk of recurrent cerebrovascular events despite anticoagulation. In this prespecified subgroup analysis, we compared warfarin with edoxaban in patients with ver......BACKGROUND AND PURPOSE: Patients with atrial fibrillation and previous ischemic stroke (IS)/transient ischemic attack (TIA) are at high risk of recurrent cerebrovascular events despite anticoagulation. In this prespecified subgroup analysis, we compared warfarin with edoxaban in patients...... with versus without previous IS/TIA. METHODS: ENGAGE AF-TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) was a double-blind trial of 21 105 patients with atrial fibrillation randomized to warfarin (international normalized ratio......). Because only HDER is approved, we focused on the comparison of HDER versus warfarin. RESULTS: Of 5973 (28.3%) patients with previous IS/TIA, 67% had CHADS2 (congestive heart failure, hypertension, age, diabetes, prior stroke/transient ischemic attack) >3 and 36% were ≥75 years. Compared with 15 132...

Critical appraisal of ticagrelor in the management of acute coronary syndrome

Directory of Open Access Journals (Sweden)

Nawarskas JJ

2011-12-01

Full Text Available James J Nawarskas, Stanley S SnowdenUniversity of New Mexico College of Pharmacy, Albuquerque, NM, USAAbstract: Ticagrelor is a novel P2Y12 receptor antagonist which, like clopidogrel and prasugrel, functions by blocking adenosine diphosphate-mediated platelet aggregation. However, unlike the aforementioned agents, the binding of ticagrelor to this receptor is reversible. Ticagrelor is also believed to mediate some of its beneficial effects by augmenting the effects of adenosine, which is another unique pharmacologic property of this drug. In terms of antiplatelet effect, ticagrelor is more potent than clopidogrel and produces a faster and stronger inhibition of platelet aggregation. This may also be an advantage of ticagrelor over prasugrel, but this has not been adequately studied. Due to the reversible nature of the binding of ticagrelor to the platelet receptor, ticagrelor has a relatively fast offset of effect, with platelet aggregation approaching pretreatment levels about 3 days after discontinuation of therapy. This has advantages in patients requiring invasive procedures, but also makes medication adherence very important in order to be able to maintain an effective antiplatelet effect. Ticagrelor has been shown to be clinically superior to clopidogrel when given to patients with an acute coronary syndrome, resulting in significantly lower rates of myocardial infarction and vascular death. However, ticagrelor is indicated to be administered with aspirin, and the clinical benefits of ticagrelor may be less when daily dosages of aspirin exceed 100 mg. As expected, bleeding is the most common adverse effect with ticagrelor, although it occurs at rates comparable with those seen for clopidogrel with the exception of noncoronary artery bypass graft-related major bleeding and fatal intracranial bleeds, the latter of which occurs only rarely. Dyspnea is another common adverse effect with ticagrelor, although this is usually not severe and

A Cost-Effectiveness Analysis of Clopidogrel for Patients with Non-ST-Segment Elevation Acute Coronary Syndrome in China.

Science.gov (United States)

Cui, Ming; Tu, Chen Chen; Chen, Er Zhen; Wang, Xiao Li; Tan, Seng Chuen; Chen, Can

2016-09-01

There are a number of economic evaluation studies of clopidogrel for patients with non-ST-segment elevation acute coronary syndrome (NSTEACS) published from the perspective of multiple countries in recent years. However, relevant research is quite limited in China. We aimed to estimate the long-term cost effectiveness for up to 1-year treatment with clopidogrel plus acetylsalicylic acid (ASA) versus ASA alone for NSTEACS from the public payer perspective in China. This analysis used a Markov model to simulate a cohort of patients for quality-adjusted life years (QALYs) gained and incremental cost for lifetime horizon. Based on the primary event rates, adherence rate, and mortality derived from the CURE trial, hazard functions obtained from published literature were used to extrapolate the overall survival to lifetime horizon. Resource utilization, hospitalization, medication costs, and utility values were estimated from official reports, published literature, and analysis of the patient-level insurance data in China. To assess the impact of parameters' uncertainty on cost-effectiveness results, one-way sensitivity analyses were undertaken for key parameters, and probabilistic sensitivity analysis (PSA) was conducted using the Monte Carlo simulation. The therapy of clopidogrel plus ASA is a cost-effective option in comparison with ASA alone for the treatment of NSTEACS in China, leading to 0.0548 life years (LYs) and 0.0518 QALYs gained per patient. From the public payer perspective in China, clopidogrel plus ASA is associated with an incremental cost of 43,340 China Yuan (CNY) per QALY gained and 41,030 CNY per LY gained (discounting at 3.5% per year). PSA results demonstrated that 88% of simulations were lower than the cost-effectiveness threshold of 150,721 CYN per QALY gained. Based on the one-way sensitivity analysis, results are most sensitive to price of clopidogrel, but remain well below this threshold. This analysis suggests that treatment with

Warfarin and vitamin K intake in the era of pharmacogenetics

OpenAIRE

Lurie, Yael; Loebstein, Ronen; Kurnik, Daniel; Almog, Shlomo; Halkin, Hillel

2010-01-01

The considerable variability in the warfarin dose–response relationship between individuals, is explained mainly by genetic variation in its major metabolic (CYP2C9) and target (VKORC1) enzymes. Despite the predominance of pharmacogenetics, environmental factors also affect the pharmacokinetics and pharmacodynamics of warfarin, and are often overlooked. Among these factors, dietary and supplemental vitamin K consumption is a controllable contributor to within-, and between-patient variability...

Aspirin effects on lymphocyte cyclic AMP levels in normal human subjects.

Science.gov (United States)

Snider, D E; Parker, C W

1976-01-01

In purified lymphocytes from the peripheral blood of healthy human subjects who had ingested therapeutic doses of aspirin, there was a significant decrease in resting cyclic AMP levels as well as a partial inhibition of the rise in cyclic AMP with isoproterenol or prostaglandin E1. These changes were seen as early as 30 min after aspirin ingestion and did not appear to result from aspirin effects on lymphocyte recovery, purity, viability, or relative number of thymus- or bone marrow-derived lymphocytes. In contrast, the direct addition of aspirin to suspensions of purified peripheral lymphocytes did not significantly alter their cyclic AMP levels. However, an effect of aspirin could be obtained in vitro if aspirin was added to unprocessed whole blood during the dextran sedimentation phase of the cell purification. Thus the effect of aspirin on lymphocyte cyclic AMP metabolism, may be indirect, through other cells present in the peripheral blood. PMID:182720

Hepatic uptake and storage of warfarin. The relation with the target enzyme vitamin K 2,3-epoxide reductase

International Nuclear Information System (INIS)

Thijssen, H.H.; Baars, L.G.

1987-01-01

The mechanisms of the reported dose-dependent warfarin pharmacokinetics were investigated using [ 14 C]warfarin. When administered in microdoses (9 micrograms i.v.) to rats (male Wistars, 270-300 g), a steep distribution phase (T1/2 = 0.25 hr) was followed by a relatively slow beta-phase (T1/2 = 40 hr). The observed volume of distribution was 390 ml. This pharmacokinetic behavior contrasted highly with the one seen for higher (greater than 0.2 mg/kg) doses (unlabeled) warfarin; volume of distribution = 45 ml, T1/2 = 12.5 hr. If a macrodose (0.2 mg/kg) preceded (16 hr) the microdose, normal pharmacokinetics were observed for the latter, suggesting a saturable deep compartment. The administration of 4-hydroxycoumarins (i.e., acenocoumarol, phenprocoumon and warfarin) after the microdose of [ 14 C]warfarin was in its beta-phase caused a rapid rise of plasma [ 14 C]warfarin indicating [ 14 C]warfarin to be displaced from the deep compartment. The rate of appearance of [ 14 C]warfarin was 0.3 hr-1 irrespective the 4-hydroxycoumarin used. The hepatic distribution of [ 14 C]warfarin was investigated and the effect of a displacer thereupon. Fifty-three hours after the [ 14 C]warfarin administration, the liver contained about 40% of the dose; 45% of it was bound to microsomes. The administration of acenocoumarol (0.2 mg/kg) at 48 hr, halved the liver content. [ 14 C]warfarin was redistributed from microsomes (-65%) and from the 10,000 X g pellet (-65%) into the cytosol (+260%) and the plasma (+320%). Microsomal bound [ 14 C]warfarin in vitro could not be washed out or be displaced unless dithiothreitol (50 mM) was included in the washing buffers

Effect of Aspirin in Postoperative Management of Adult Ischemic Moyamoya Disease.

Science.gov (United States)

Zhao, Yahui; Zhang, Qian; Zhang, Dong; Zhao, Yuanli

2017-09-01

Aspirin has been implicated in the postoperative management of moyamoya disease (MMD) in order to avoid bypass failure and decrease the incidence of subsequent stroke. However, its effect has not been completely determined yet. In this study, we retrospectively reviewed data of 184 adult patients (197 hemispheres) presented with ischemic-onset MMD who had undergone direct or combined revascularization in our hospital, to clarify the effect of postoperative aspirin therapy in the management of moyamoya disease. Fifty-nine hemispheres that had been administered with aspirin (100 mg/day) after bypass surgery were defined as the "aspirin group," whereas 138 that hadn't been given aspirin postoperatively were defined as the "control group". Among 197 hemispheres, the mortality rate was 0. The incidence of postoperative newly developed infarction, transient ischemic attack, and hemorrhage were not significantly different between the aspirin and control groups. The patency rate of bypass graft was not significantly different between the groups, either. Notably, more patients experienced major stroke in the control group (9/138) than the aspirin group (1/59), but no statistical difference was found (P > 0.05). In the aspirin group, more patients had improved outcome than the control group (P = 0.04). Our findings showed that aspirin might not decrease the incidence of postoperative ischemic stroke or increase patency rate of bypass graft, but it does not increase the risk of hemorrhages, either. Also, postoperative aspirin therapy might improve outcome. More studies are needed to provide evidence for postoperative antiplatelet therapy in MMD management. Copyright © 2017 Elsevier Inc. All rights reserved.

Warfarin and Rivaroxaban Duplication: A Case Report and Medication Error Analysis.

Science.gov (United States)

Fusco, Julie A; Paulus, Eric J; Shubat, Alexandra R; Miah, Sharminara

2015-12-01

A 62-year-old African American man received unintentional duplicate anticoagulation therapy with warfarin 5 mg and rivaroxaban 20 mg daily for the treatment of recurrent pulmonary embolism. The patient presented to the anticoagulation clinic 6 days after hospital discharge with an International Normalized Ratio (INR) of 2.3 and he was instructed to continue warfarin 5 mg daily. Seven days later, he returned to the clinic with an INR >8.0 using a point-of-care device. He denied any signs or symptoms of bleeding. During the interview, he reported starting a new medication for neuropathy 5 days earlier. The clinical pharmacist contacted the dispensing pharmacy and determined rivaroxaban 20 mg was the new medication. The patient denied receiving new prescription counseling at the dispensing pharmacy. Because rivaroxaban can falsely elevate INR results, the actual INR value was unknown. To minimize the risk for recurrent venous thromboembolism, vitamin K was not administered and no warfarin doses were held. Rather, the patient was instructed to stop rivaroxaban and reduce the warfarin dose. Five days later, the patient returned with an INR of 4.3. He still had not experienced any signs or symptoms of bleeding. The patient was quickly stabilized on a warfarin maintenance dose of 22.5 mg weekly. The anticoagulation clinic pharmacist notified management at the clinic and at the dispensing pharmacy in an effort to identify process errors and prevent additional incidents.

A computational prospect to aspirin side effects: aspirin and COX-1 interaction analysis based on non-synonymous SNPs.

Science.gov (United States)

Marjan, Mojtabavi Naeini; Hamzeh, Mesrian Tanha; Rahman, Emamzadeh; Sadeq, Vallian

2014-08-01

Aspirin (ASA) is a commonly used nonsteroidal anti-inflammatory drug (NSAID), which exerts its therapeutic effects through inhibition of cyclooxygenase (COX) isoform 2 (COX-2), while the inhibition of COX-1 by ASA leads to apparent side effects. In the present study, the relationship between COX-1 non-synonymous single nucleotide polymorphisms (nsSNPs) and aspirin related side effects was investigated. The functional impacts of 37 nsSNPs on aspirin inhibition potency of COX-1 with COX-1/aspirin molecular docking were computationally analyzed, and each SNP was scored based on DOCK Amber score. The data predicted that 22 nsSNPs could reduce COX-1 inhibition, while 15 nsSNPs showed increasing inhibition level in comparison to the regular COX-1 protein. In order to perform a comparing state, the Amber scores for two Arg119 mutants (R119A and R119Q) were also calculated. Moreover, among nsSNP variants, rs117122585 represented the closest Amber score to R119A mutant. A separate docking computation validated the score and represented a new binding position for ASA that acetyl group was located within the distance of 3.86Å from Ser529 OH group. This could predict an associated loss of activity of ASA through this nsSNP variant. Our data represent a computational sub-population pattern for aspirin COX-1 related side effects, and provide basis for further research on COX-1/ASA interaction. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of continuous administration of clopidogrel before off-pump coronary artery bypass grafting in patients with acute coronary syndrome. A propensity score analysis

International Nuclear Information System (INIS)

Song, Suk-Won; Youn, Young-Nam; Yi, Gijong; Lee, Sak; Yoo, Kyung-Jong

2008-01-01

Clopidogrel has become standard treatment after urgent percutaneous coronary revascularization. Due to its enhanced and irreversible platelet inhibition, patients undergoing urgent surgical revascularization have a higher risk of bleeding complications and transfusions. Therefore, the effect of preoperative continuous administration of clopidogrel on the incidence of hemorrhagic complications in patients undergoing off-pump coronary artery bypass surgery with acute coronary syndrome was evaluated. From March 2004 to September 2006, 172 patients with acute coronary syndrome underwent isolated off-pump coronary artery bypass surgery; 70 (40.7%) and 102 (59.3%) of these patients did or did not take clopidogrel before surgery respectively. Seventy patients in each group were matched using propensity scores and associations between preoperative continuous administration of clopidogrel and postoperative bleeding, hemostatic reoperation, blood products received, the need for multiple transfusions and early graft patency by coronary computed tomography were assessed. Univariate analysis showed the continuous clopidogrel group had similar levels of postoperative bleeding for 24 h (601.4±312.6 ml vs 637.2±452.4 ml, p=0.616) and rates of reexploration (1.4% vs 1.4%), perioperative blood transfusion (33.3% vs 34.3%, p>0.05) and platelet transfusion (2.9% vs 7.1%, p=0.44) compared with the non-continuous group. Preoperative continuous administration of clopidogrel did not increase the risk of hemorrhagic complications in patients with acute coronary syndrome undergoing isolated off-pump coronary artery bypass surgery. These findings indicate that surgery after clopidogrel treatment in patients with acute coronary syndrome should not be delayed until platelet function returns to normal because they may have a higher risk of recurrent myocardial ischemic events. (author)

Effects of simvastatin/ezetimibe on microparticles, endothelial progenitor cells and platelet aggregation in subjects with coronary heart disease under antiplatelet therapy

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Camargo, L.M.; França, C.N.; Izar, M.C.; Bianco, H.T.; Lins, L.S.; Barbosa, S.P.; Pinheiro, L.F.; Fonseca, F.A.H. [Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Medicina, São Paulo, SP, Brasil, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil)

2014-04-15

It is not known whether the addition of ezetimibe to statins adds cardiovascular protection beyond the expected changes in lipid levels. Subjects with coronary heart disease were treated with four consecutive 1-week courses of therapy (T) and evaluations. The courses were: T1, 100 mg aspirin alone; T2, 100 mg aspirin and 40 mg simvastatin/10 mg ezetimibe; T3, 40 mg simvastatin/10 mg ezetimibe, and 75 mg clopidogrel (300 mg initial loading dose); T4, 75 mg clopidogrel alone. Platelet aggregation was examined in whole blood. Endothelial microparticles (CD51), platelet microparticles (CD42/CD31), and endothelial progenitor cells (CD34/CD133; CDKDR/CD133, or CD34/KDR) were quantified by flow cytometry. Endothelial function was examined by flow-mediated dilation. Comparisons between therapies revealed differences in lipids (T2 and T3T1 and T4, P=0.001). Decreased platelet aggregation was observed after aspirin (arachidonic acid, T1clopidogrel (adenosine, T3 and T4

Effects of simvastatin/ezetimibe on microparticles, endothelial progenitor cells and platelet aggregation in subjects with coronary heart disease under antiplatelet therapy

International Nuclear Information System (INIS)

Camargo, L.M.; França, C.N.; Izar, M.C.; Bianco, H.T.; Lins, L.S.; Barbosa, S.P.; Pinheiro, L.F.; Fonseca, F.A.H.

2014-01-01

It is not known whether the addition of ezetimibe to statins adds cardiovascular protection beyond the expected changes in lipid levels. Subjects with coronary heart disease were treated with four consecutive 1-week courses of therapy (T) and evaluations. The courses were: T1, 100 mg aspirin alone; T2, 100 mg aspirin and 40 mg simvastatin/10 mg ezetimibe; T3, 40 mg simvastatin/10 mg ezetimibe, and 75 mg clopidogrel (300 mg initial loading dose); T4, 75 mg clopidogrel alone. Platelet aggregation was examined in whole blood. Endothelial microparticles (CD51), platelet microparticles (CD42/CD31), and endothelial progenitor cells (CD34/CD133; CDKDR/CD133, or CD34/KDR) were quantified by flow cytometry. Endothelial function was examined by flow-mediated dilation. Comparisons between therapies revealed differences in lipids (T2 and T3T1 and T4, P=0.001). Decreased platelet aggregation was observed after aspirin (arachidonic acid, T1clopidogrel (adenosine, T3 and T4

Interaction between polymorphisms in aspirin metabolic pathways, regular aspirin use and colorectal cancer risk: A case-control study in unselected white European populations.

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Sheth, Harsh; Northwood, Emma; Ulrich, Cornelia M; Scherer, Dominique; Elliott, Faye; Barrett, Jennifer H; Forman, David; Wolf, C Roland; Smith, Gillian; Jackson, Michael S; Santibanez-Koref, Mauro; Haile, Robert; Casey, Graham; Jenkins, Mark; Win, Aung Ko; Hopper, John L; Marchand, Loic Le; Lindor, Noralane M; Thibodeau, Stephen N; Potter, John D; Burn, John; Bishop, D Timothy

2018-01-01

Regular aspirin use is associated with reduced risk of colorectal cancer (CRC). Variation in aspirin's chemoprevention efficacy has been attributed to the presence of single nucleotide polymorphisms (SNPs). We conducted a meta-analysis using two large population-based case-control datasets, the UK-Leeds Colorectal Cancer Study Group and the NIH-Colon Cancer Family Registry, having a combined total of 3325 cases and 2262 controls. The aim was to assess 42 candidate SNPs in 15 genes whose association with colorectal cancer risk was putatively modified by aspirin use, in the literature. Log odds ratios (ORs) and standard errors were estimated for each dataset separately using logistic regression adjusting for age, sex and study site, and dataset-specific results were combined using random effects meta-analysis. Meta-analysis showed association between SNPs rs6983267, rs11694911 and rs2302615 with CRC risk reduction (All Paspirin use and CRC risk (Pinteraction = 0.01 and 0.02, respectively); stratification by aspirin use showed an association for decreased CRC risk for aspirin users having a wild-type genotype (rs2070959 OR = 0.77, 95% CI = 0.68-0.86; rs1105879 OR = 0.77 95% CI = 0.69-0.86) compared to variant allele cariers. The direction of the interaction however is in contrast to that published in studies on colorectal adenomas. Both SNPs showed potential site-specific interaction with aspirin use and colon cancer risk only (Pinteraction = 0.006 and 0.008, respectively), with the direction of association similar to that observed for CRC. Additionally, they showed interaction between any non-steroidal anti-inflammatory drugs (including aspirin) use and CRC risk (Pinteraction = 0.01 for both). All gene x environment (GxE) interactions however were not significant after multiple test correction. Candidate gene investigation indicated no evidence of GxE interaction between genetic variants in genes involved in aspirin pathways, regular aspirin use and colorectal cancer

VKORC1 polymorphisms and warfarin maintenance dose in population of Sakha (Yakuts).

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Chertovskikh, Y V; Malova, E U; Maksimova, N R; Popova, N V; Sychev, D A

2015-01-01

Vitamin K antagonists are effective in the prevention and treatment of thromboembolic disorders. Warfarin is one of the most widely prescribed vitamin K antagonists in the world [1, 2]. It has a narrow therapeutic range and a given dose may result in a large inter-individual variation of response. Insufficient dose may fail to prevent thromboembolism, while an overdose increases the risk of bleeding. Patient-specific factors (e.g., age, body size, race, concurrent diseases, and medications) explain some of the variability in warfarin dosage, but genetic factors influencing warfarin response explain a significantly higher proportion of this variability [3]. Molecular analysis of the gene that encodes the target enzyme vitamin K epoxide reductase complex 1 (VKORC1) strongly suggests that its genetic variations greatly affect the individual response to oral anticoagulants [4-7]. To evaluate effects of VKORC1 polymorphisms on warfarin dose excess anticoagulation (INR >4.0) in the population of Sakha (S) patients. 53 patients (29-women, 24-men) with atrial fibrillation (68%), congestive heart failure (60%), hypertension (49%) and cardiac valve replacement (26%) were recruited. The age range was 26-80 years, with a mean age of 62.87 ± 12.57 years.International normalized ratio and plasma warfarin concentrations were determined. Genotyping was carried out by RT-PCR (real-time PCR). The three genetic polymorphisms of the gene VKORC1 G3673A (rs9923231) were studied: normal (GG), heterozygous (GA) and homozygous (AA). Fisher exact probability test and chi-square test (with Yates correction) were applied to compare data among the AA and GG + GA groups; also Mann-Whitney test was used. The median maintenance daily dose of warfarin among AA carriers was 3.0 mg/day [1.25-7.5 mg], while in GG and GA patients it was 3.13 mg/day [1.88-7.92 mg]. The mean daily warfarin dosage was higher in GG and GA genotype carriers 4.05 mg/day (SD ± 1.7) than in patients with AA genotype 3

Aspirin as a chemoprevention agent for colorectal cancer.

LENUS (Irish Health Repository)

Lee, Chun Seng

2012-11-01

Colorectal cancer (CRC) is one of the leading causes of mortality in the western world. It is widely accepted that neoplasms such as colonic polyps are precursors to CRC formation; with the polyp-adenoma-carcinoma sequences well described in medical literature [1, 2]. It has been shown that Aspirin and other non-steroid anti-inflammatory drugs (NSAID) have a negative effect on polyp and cancer formation. This review aims to describe some of the mechanism behind the chemoprotective properties of aspirin; COX 2 inhibition, regulation of proliferation and apoptosis and effects on the immune system and also the current evidence that supports its use as a chemoprevention agent against CRC. We will also aim to explore the side effects with the use of aspirin and the pitfalls of using aspirin routinely for primary prophylaxis against CRC.

Measurement of warfarin in the oral fluid of patients undergoing anticoagulant oral therapy.

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Silvia Ghimenti

Full Text Available BACKGROUND: Patients on warfarin therapy undergo invasive and expensive checks for the coagulability of their blood. No information on coagulation levels is currently available between two controls. METHODOLOGY: A method was developed to determine warfarin in oral fluid by HPLC and fluorimetric detection. The chromatographic separation was performed at room temperature on a C-18 reversed-phase column, 65% PBS and 35% methanol mobile phase, flow rate 0.7 mL/min, injection volume 25 µL, excitation wavelength 310 nm, emission wavelength 400 nm. FINDINGS: The method was free from interference and matrix effect, linear in the range 0.2-100 ng/mL, with a detection limit of 0.2 ng/mL. Its coefficient of variation was <3% for intra-day measurements and <5% for inter-day measurements. The average concentration of warfarin in the oral fluid of 50 patients was 2.5±1.6 ng/mL (range 0.8-7.6 ng/mL. Dosage was not correlated to INR (r = -0.03, p = 0.85 but positively correlated to warfarin concentration in the oral fluid (r = 0.39, p = 0.006. The correlation between warfarin concentration and pH in the oral fluid (r = 0.37, p = 0.009 confirmed the importance of pH in regulating the drug transfer from blood. A correlation between warfarin concentration in the oral fluid and INR was only found in samples with pH values ≥7.2 (r = 0.84, p = 0.004. CONCLUSIONS: Warfarin diffuses from blood to oral fluid. The method allows to measure its concentration in this matrix and to analyze correlations with INR and other parameters.

Safety Outcomes of Apixaban Compared With Warfarin in Patients With End-Stage Renal Disease.

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Sarratt, Stefanie C; Nesbit, Ross; Moye, Robert

2017-06-01

Current guidelines make no specific recommendations on the selection of direct oral anticoagulants for the prevention and treatment of venous thromboembolism in patients with end-stage renal disease (ESRD) receiving hemodialysis. Based on these guidelines, warfarin remains the anticoagulant of choice in these patients. To compare bleeding rates in patients receiving apixaban or warfarin with ESRD undergoing chronic hemodialysis. This was a single-center, retrospective, institutional review board-approved cohort analysis. Patients with ESRD undergoing chronic hemodialysis and receiving anticoagulation therapy with either apixaban or warfarin were included in this study. All data were collected from paper charts and electronic medical records and included documentation of bleeding events and related interventions. The primary outcome of this study was clinically relevant major bleeding events. Secondary outcomes included clinically relevant nonmajor bleeding events and minor bleeding events. A total of 160 patients were included in this study (warfarin group, n = 120; apixaban group, n = 40). There were 7 major bleeding events in the warfarin group compared with zero in the apixaban group ( P = 0.34). There were similar rates of clinically relevant nonmajor bleeding events (12.5% vs 5.8%, P = 0.17) and minor bleeding (2.5% vs 2.5%, P = 0.74) events in patients receiving apixaban and warfarin. There were no observed differences in bleeding rates in patients receiving apixaban compared with those receiving warfarin. Apixaban may be a cautious consideration in hemodialysis patients until there is further insight into the effect of subsequent, multiple doses on drug accumulation and clinical outcomes.

Warfarin monitoring in nursing homes assessed by case histories. Do recommendations and electronic alerts affect judgements?

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Teruel, Reyes Serrano; Thue, Geir; Fylkesnes, Svein Ivar; Sandberg, Sverre; Kristoffersen, Ann Helen

2017-09-01

Older adults treated with warfarin are prone to complications, and high-quality monitoring is essential. The aim of this case history based study was to assess the quality of warfarin monitoring in a routine situation, and in a situation with an antibiotic-warfarin interaction, before and after receiving an electronic alert. In April 2014, a national web-based survey with two case histories was distributed among Norwegian nursing home physicians and general practitioners working part-time in nursing homes. Case A represented a patient on stable warfarin treatment, but with a substantial INR increase within the therapeutic interval. Case B represented a more challenging patient with trimethoprim sulfamethoxazole (TMS) treatment due to pyelonephritis. In both cases, the physicians were asked to state the next warfarin dose and the INR recall interval. In case B, the physicians could change their suggestions after receiving an electronic alert on the TMS-warfarin interaction. Three hundred and ninety eight physicians in 292 nursing homes responded. Suggested INR recall intervals and warfarin doses varied substantially in both cases. In case A, 61% gave acceptable answers according to published recommendations, while only 9% did so for case B. Regarding the TMS-warfarin interaction in case history B, the electronic alert increased the percentage of respondents correctly suggesting a dose reduction from 29% to 53%. Having an INR instrument in the nursing home was associated with shortened INR recall times. Practical advice on handling of warfarin treatment and drug interactions is needed. Electronic alerts as presented in electronic medical records seem insufficient to change practice. Availability of INR instruments may be important regarding recall time.

Treatments for Reversing Warfarin Anticoagulation in Patients with Acute Intracranial Hemorrhage: A Structured Literature Review

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2011-07-08

available soon. Treatments for reversing warfarin anticoagulation in patients with acute intracranial hemorrhage: a structured literature review...DATE 08 JUL 2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE Treatments For Reversing Warfarin ...distribution unlimited 13. SUPPLEMENTARY NOTES International Journal of Emergency Medicine 2011 14. ABSTRACT The acute management of patients on warfarin

Vitamin K2 for the reversal of warfarin-related coagulopathy.

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Hifumi, Toru; Takada, Hiroaki; Ogawa, Daisuke; Suzuki, Kenta; Hamaya, Hideyuki; Shinohara, Natsuyo; Abe, Yuko; Takano, Koshiro; Kawakita, Kenya; Hagiike, Masanobu; Koido, Yuichi; Kuroda, Yasuhiro

2015-08-01

The American Heart Association/American College of Cardiology Foundation recommends vitamin K1 for warfarin-related coagulopathy. In Japan, vitamin K2 is used more commonly for such purpose. The difference between vitamins K1 and K2 in reversing warfarin-related coagulopathy has not been discussed. Herein, we report a case that was reversed with vitamin K2; alterations in vitamins K1 and K2 levels and coagulation markers are also presented.

Use and Safety of Non-Steroidal Inflammatory Drugs and Aspirin

NARCIS (Netherlands)

V.E. Valkhoff (Vera)

2012-01-01

textabstractThe use of acetylsalicylic acid, better known as aspirin, dates back to the Egyptians in 1534 BC. Aspirin-like compounds are naturally derived from willow tree bark and myr-tle. At the end of the 19th century aspirin was patented by Bayer as the world’s first syn-thetic drug. The

Ticlopidine-, clopidogrel-, and prasugrel-associated thrombotic thrombocytopenic purpura: a 20-year review from the Southern Network on Adverse Reactions (SONAR).

Science.gov (United States)

Jacob, Sony; Dunn, Brianne L; Qureshi, Zaina P; Bandarenko, Nicholas; Kwaan, Hau C; Pandey, Dilip K; McKoy, June M; Barnato, Sara E; Winters, Jeffrey L; Cursio, John F; Weiss, Ivy; Raife, Thomas J; Carey, Patricia M; Sarode, Ravindra; Kiss, Joseph E; Danielson, Constance; Ortel, Thomas L; Clark, William F; Rock, Gail; Matsumoto, Masanori; Fujimura, Yoshihiro; Zheng, X Long; Chen, Hao; Chen, Fei; Armstrong, John M; Raisch, Dennis W; Bennett, Charles L

2012-11-01

Thienopyridine-derivatives (ticlopidine, clopidogrel, and prasugrel) are the primary antiplatelet agents. Thrombotic thrombocytopenic purpura (TTP) is a rare drug-associated syndrome, with the thienopyridines being the most common drugs implicated in this syndrome. We reviewed 20 years of information on clinical, epidemiologic, and laboratory findings for thienopyridine-associated TTP. Four, 11, and 11 cases of thienopyridine-associated TTP were reported in the first year of marketing of ticlopidine (1989), clopidogrel (1998), and prasugrel (2010), respectively. As of 2011, the FDA received reports of 97 ticlopidine-, 197 clopidogrel-, and 14 prasugrel-associated TTP cases. Severe deficiency of ADAMTS-13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) was present in 80% and antibodies to 100% of these TTP patients on ticlopidine, 0% of the patients with clopidogrel-associated TTP (p < 0.05), and an unknown percentage of patients with prasugrel-associated TTP. TTP is associated with use of each of the three thienopyridines, although the mechanistic pathways may differ. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Vitamin K for improved anticoagulation control in patients receiving warfarin.

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Mahtani, Kamal R; Heneghan, Carl J; Nunan, David; Roberts, Nia W

2014-05-15

Effective use of warfarin involves keeping the international normalised ratio (INR) within a relatively narrow therapeutic range. However, patients respond widely to their dose of warfarin. Overcoagulation can lead to an increased risk of excessive bleeding, while undercoagulation can lead to increased clot formation. There is some evidence that patients with a variable response to warfarin may benefit from a concomitant low dose of vitamin K. To assess the effects of concomitant supplementation of low-dose oral vitamin K for anticoagulation control in patients being initiated on or taking a maintenance dose of warfarin. To identify previous reviews, we searched the Database of Abstracts of Reviews of Effects (DARE via The Cochrane Library, Wiley) (Issue 2, 2011). To identify primary studies, we searched the Cochrane Central Register of Controlled Trials (CENTRAL via The Cochrane Library, Wiley) (Issue 2, 2014), Ovid MEDLINE (R) In-Process & Other Non-Indexed Citations database and Ovid MEDLINE (R) (OvidSP) (1946 to 25 February 2014), Embase (OvidSP) (1974 to week 8 of 2014), Science Citation Index Expanded™ & Conference Proceedings Citation Index - Science (Web of Science™) (1945 to 27 February 2014), and the NHS Economics Evaluations Database (NHS EED) (via The Cochrane Library, Wiley) (Issue 2, 2014). We did not apply any language or date restrictions. We used additional methods to identify grey literature and ongoing studies. Randomised controlled trials comparing the addition of vitamin K versus placebo in patients initiating warfarin or already taking warfarin. Two review authors independently selected and extracted data from included studies. When disagreement arose, a third author helped reached a consensus. We also assessed risk of bias. We identified two studies with a total of 100 participants for inclusion in the review. We found the overall risk of bias to be unclear in a number of domains. Neither study reported the time taken to the first INR in

Aspirin and Risk of Subarachnoid Hemorrhage: Systematic Review and Meta-Analysis.

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Phan, Kevin; Moore, Justin M; Griessenauer, Christoph J; Ogilvy, Christopher S; Thomas, Ajith J

2017-05-01

Recent studies have suggested that the use of low-dose aspirin may reduce the risk of aneurysmal subarachnoid hemorrhage (aSAH). We aimed to evaluate any association between aspirin use and risk of aSAH based on the literature, and whether this is influenced by duration or frequency of aspirin use. A search of electronic databases was done from inception to September 2016. For each study, data on risk of aSAH in aspirin versus nonaspirin users were used to generate odds ratios and 95% confidence intervals, and combined using inverse variance-weighted averages of logarithmic odds ratios in a random-effects models. From 7 included studies, no significant difference was noted between aspirin use of any duration or frequency and nonaspirin users (odds ratio, 1.00; 95% confidence interval, 0.81-1.24; P =0.99). We found a significant association between short-term use of aspirin (3 years of durations of use. No significant association was found between infrequent aspirin use (≤2× per week) or frequent use (≥3× per week) with risk of aSAH. Current evidence suggests that short-term (aspirin is associated with increased risk of aSAH. Limitations include substantial heterogenity of the included studies. The role of long-term aspirin in reducing risk of aSAH remains unclear and ideally should be addressed by an appropriately designed randomized controlled trial. © 2017 American Heart Association, Inc.

Educating patients about warfarin therapy using information technology: A survey on healthcare professionals’ perspectives

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Mullan J

2012-06-01

Full Text Available Objective: To explore healthcare professionals’ views about the benefits and challenges of using information technology (IT resources for educating patients about their warfarin therapy.Methods: A cross-sectional survey of both community and hospital-based healthcare professionals (e.g., doctors, pharmacists and nurses involved using a purpose-designed questionnaire. The questionnaires were distributed using a multi-modal approach to maximise response rates.Results: Of the total 300 questionnaires distributed, 109 completed surveys were received (43.3% response rate. Over half (53.2% of the healthcare participants were aged between 40-59 years, the majority (59.5% of whom were female. Fifty nine (54.1% participants reported having had no access to warfarin-specific IT-based patient education resources, and a further 19 (38.0% of the participants who had IT-access reported that they never used such resources. According to the healthcare participants, the main challenges associated with educating their patients about warfarin therapy included: patient-related factors, such as older age, language barriers, cognitive impairments and/or ethnic backgrounds or healthcare professional factors, such as time constraints. The healthcare professionals reported that there were several aspects about warfarin therapy which they found difficult to educate their patients about which is why they identified computers and interactive touch screen kiosks as preferred IT devices to deliver warfarin education resources in general practices, hospital-based clinics and community pharmacies. At the same time, the healthcare professionals also identified a number of facilitators (e.g., to reinforce warfarin education, to offer reliable and easily comprehensible information and barriers (e.g., time and costs of using IT resources, difficulty in operating the resources that could impact on the effective implementation of these devices in educating patients about their

Anaesthesia in aspirin-induced asthma.

Science.gov (United States)

Celiker, V; Basgül, E

2003-01-01

The triad of bronchial asthma, nasal polyposis, and intolerance to aspirin and aspirin-like chemicals are designated aspirin-induced asthma (AIA) or Samter's syndrome. The exact mechanism of the disease is unknown but it is thought to be a disorder of arachidonic acid metabolism. These patients are frequently referred to allergy clinics for preoperative evaluation for possible anesthetic agent sensitivity, requiring anesthesia for nasal polypectomy or several other reasons. Anesthetists must be aware of their pulmonary dysfunction, because the anesthetic management of asthma requires a specific approach. Marked cross-sensitivity with NSAIDs, which may also precipitate severe bronchospasm and adverse reactions, is the main problem faced by anesthetists in postoperative pain management. This article discusses the relationship between AIA and anesthesia. We also present our experience with 47 patients diagnosed with AIA between 1991 and 2003 in the department of chest diseases and adult allergy unit who underwent surgery requiring general anesthesia. In conclusion, preoperative evaluation of these patients and collaboration between the allergists and anesthesiologists is essential to prevent preoperative, perioperative and postoperative complications.

Predictors of warfarin use in atrial fibrillation in the United States: a systematic review and meta-analysis

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2012-01-01

Background Despite warfarin's marked efficacy, not all eligible patients receive it for stroke prevention in AF. The aim of this meta-analysis was to evaluate the association between prescriber and/or patient characteristics and subsequent prescription of warfarin for stroke prevention in patients with atrial fibrillation (AF). Methods Observational studies conducted in the US using multivariate analysis to determine the relationship between characteristics and the odds of receiving warfarin for stroke prevention were identified in MEDLINE, EMBASE and a manual review of references. Effect estimates of prescriber and/or patient characteristics from individual studies were pooled to calculate odds ratios (ORs) with 95% confidence intervals. Results Twenty-eight studies reporting results of 33 unique multivariate analyses were identified. Warfarin use across studies ranged from 9.1%-79.8% (median = 49.1%). There was a moderately-strong correlation between warfarin use and year of study (r = 0.60, p = 0.002). Upon meta-analysis, characteristics associated with a statistically significant increase in the odds of warfarin use included history of cerebrovascular accident (OR = 1.59), heart failure (OR = 1.36), and male gender (OR = 1.12). Those associated with a significant reduction in the odds of warfarin use included alcohol/drug abuse (OR = 0.62), perceived barriers to compliance (OR = 0.87), contraindication(s) to warfarin (OR = 0.81), dementia (OR = 0.32), falls (OR = 0.60), gastrointestinal hemorrhage (OR = 0.47), intracranial hemorrhage (OR = 0.39), hepatic (OR = 0.59), and renal impairment (OR = 0.69). While age per 10-year increase (OR = 0.78) and advancing age as a dichotomized variable (cut-off varied by study) (OR = 0.57) were associated with significant reductions in warfarin use; qualitative review of results of studies evaluating age as a categorical variable did not confirm this relationship. Conclusions Warfarin use has increased somewhat over time. The

[Comparison of quality and hemorragic risk of oral anticoagulant therapy using acenocoumarol versus warfarin].

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Oliva Berini, Elvira; Galán Alvarez, Pilar; Pacheco Onrubia, Ana María

2008-06-21

Long half life oral anticoagulants have shown a higher anticoagulation stability and a lower hemorragic risk than those of a short half life. We have compared therapeutic stability and hemorragic risk of acenocoumarol versus warfarin in 2 groups of patients on preventive anticoagulation because of atrial fibrilation (international normalised ratio [INR]: 2-3). Data on 120 patients treated with acenocoumarol and 120 on warfarin treatment who had started and continued treatment in our hospital for a minimum of a year was collected. The percentage of visits within the intended range of INR (2 to 3) was 65.5% with warfarin and 63.4% with acenocoumarol. Thirty percent of patients on warfarin had 75% or more of their controls within range, while for those treated with acenocoumarol this percentage was 22.5%. In the acenocoumarol group, 0.3 visits/patient/year presented an INR > or = 6 versus 0.07 in the warfarin group (p = 0.003). Patients treated with acenocoumarol show a higher risk of presenting with an INR > or = 6, but no statistically significant differences are observed in therapeutic stability.

Association of Proton Pump Inhibitors with Reduced Risk of Warfarin-related Serious Upper Gastrointestinal Bleeding

Science.gov (United States)

Ray, Wayne A.; Chung, Cecilia P.; Murray, Katherine T.; Smalley, Walter E.; Daugherty, James R.; Dupont, William D.; Stein, C. Michael

2016-01-01

Background & Aims Proton-pump inhibitors (PPIs) might reduce the risk of serious warfarin-related upper gastrointestinal bleeding, but the evidence of their efficacy for this indication is limited. A gastroprotective effect of PPIs would be particularly important for patients who take warfarin with antiplatelet drugs or nonselective non-steroidal anti-inflammatory drugs (NSAIDs), which further increase the risk of gastrointestinal bleeding. Methods This retrospective cohort study of patients beginning warfarin treatment in Tennessee Medicaid and the 5% National Medicare Sample identified 97,430 new episodes of warfarin treatment with 75,720 person-years of follow up. The study endpoints were hospitalizations for upper gastrointestinal bleeding potentially preventable by PPIs and for bleeding at other sites. Results Patients who took warfarin without PPI co-therapy had 119 hospitalizations for upper gastrointestinal bleeding per 10,000 person-years of treatment. The risk decreased by 24% among patients who received PPI co-therapy (adjusted hazard ratio [HR], 0.76; 95% CI, 0.63–0.91). There was no significant reduction in the risk of other gastrointestinal bleeding hospitalizations (HR, 1.07; 95% CI, 0.94–1.22) or non-gastrointestinal bleeding hospitalizations (HR, 0.98; 95% CI, 0.84–1.15) in this group. Among patients concurrently using antiplatelet drugs or NSAIDs, those without PPI co-therapy had 284 upper gastrointestinal bleeding hospitalizations per 10,000 person-years of warfarin treatment. The risk decreased by 45% (HR, 0.55; 95% CI, 0.39–0.77) with PPI co-therapy. PPI co-therapy had no significant protective effect for warfarin patients not using antiplatelet drugs or NSAIDs (HR, 0.86; 95% CI, 0.70-1.06). Findings were similar in both study populations. Conclusions In an analysis of patients beginning warfarin treatment in Tennessee Medicaid and the 5% National Medicare Sample, PPI co-therapy was associated with reduced risk of warfarin-related upper

Interaction between polymorphisms in aspirin metabolic pathways, regular aspirin use and colorectal cancer risk: A case-control study in unselected white European populations.

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Harsh Sheth

Full Text Available Regular aspirin use is associated with reduced risk of colorectal cancer (CRC. Variation in aspirin's chemoprevention efficacy has been attributed to the presence of single nucleotide polymorphisms (SNPs. We conducted a meta-analysis using two large population-based case-control datasets, the UK-Leeds Colorectal Cancer Study Group and the NIH-Colon Cancer Family Registry, having a combined total of 3325 cases and 2262 controls. The aim was to assess 42 candidate SNPs in 15 genes whose association with colorectal cancer risk was putatively modified by aspirin use, in the literature. Log odds ratios (ORs and standard errors were estimated for each dataset separately using logistic regression adjusting for age, sex and study site, and dataset-specific results were combined using random effects meta-analysis. Meta-analysis showed association between SNPs rs6983267, rs11694911 and rs2302615 with CRC risk reduction (All P<0.05. Association for SNP rs6983267 in the CCAT2 gene only was noteworthy after multiple test correction (P = 0.001. Site-specific analysis showed association between SNPs rs1799853 and rs2302615 with reduced colon cancer risk only (P = 0.01 and P = 0.004, respectively, however neither reached significance threshold following multiple test correction. Meta-analysis of SNPs rs2070959 and rs1105879 in UGT1A6 gene showed interaction between aspirin use and CRC risk (Pinteraction = 0.01 and 0.02, respectively; stratification by aspirin use showed an association for decreased CRC risk for aspirin users having a wild-type genotype (rs2070959 OR = 0.77, 95% CI = 0.68-0.86; rs1105879 OR = 0.77 95% CI = 0.69-0.86 compared to variant allele cariers. The direction of the interaction however is in contrast to that published in studies on colorectal adenomas. Both SNPs showed potential site-specific interaction with aspirin use and colon cancer risk only (Pinteraction = 0.006 and 0.008, respectively, with the direction of association similar to

Clopidogrel in a combined therapy with anticancer drugs-effect on tumor growth, metastasis, and treatment toxicity: Studies in animal models.

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Agnieszka Denslow

Full Text Available Clopidogrel, a thienopyridine derivative with antiplatelet activity, is widely prescribed for patients with cardiovascular diseases. In addition to antiplatelet activity, antiplatelet agents possess anticancer and antimetastatic properties. Contrary to this, results of some studies have suggested that the use of clopidogrel and other thienopyridines accelerates the progression of breast, colorectal, and prostate cancer. Therefore, in this study, we aimed to evaluate the efficacy of clopidogrel and various anticancer agents as a combined treatment using mouse models of breast, colorectal, and prostate cancer. Metastatic dissemination, selected parameters of platelet morphology and biochemistry, as well as angiogenesis were assessed. In addition, body weight, blood morphology, and biochemistry were evaluated to test toxicity of the studied compounds. According to the results, clopidogrel increased antitumor and/or antimetastatic activity of chemotherapeutics such as 5-fluorouracil, cyclophosphamide, and mitoxantrone, whereas it decreased the anticancer activity of doxorubicin, cisplatin, and tamoxifen. The mechanisms of such divergent activities may be based on the modulation of tumor vasculature via factors, such as transforming growth factor β1 released from platelets. Moreover, clopidogrel increased the toxicity of docetaxel and protected against mitoxantrone-induced toxicity, which may be due to the modulation of hepatic enzymes and protection of the vasculature, respectively. These results demonstrate that antiplatelet agents can be useful but also dangerous in anticancer treatment and therefore use of thienopyridines in patients undergoing chemotherapy should be carefully evaluated.

Regular use of aspirin and pancreatic cancer risk

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Mahoney Martin C

2002-09-01

Full Text Available Abstract Background Regular use of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs has been consistently associated with reduced risk of colorectal cancer and adenoma, and there is some evidence for a protective effect for other types of cancer. As experimental studies reveal a possible role for NSAIDs is reducing the risk of pancreatic cancer, epidemiological studies examining similar associations in human populations become more important. Methods In this hospital-based case-control study, 194 patients with pancreatic cancer were compared to 582 age and sex-matched patients with non-neoplastic conditions to examine the association between aspirin use and risk of pancreatic cancer. All participants received medical services at the Roswell Park Cancer Institute in Buffalo, NY and completed a comprehensive epidemiologic questionnaire that included information on demographics, lifestyle factors and medical history as well as frequency and duration of aspirin use. Patients using at least one tablet per week for at least six months were classified as regular aspirin users. Unconditional logistic regression was used to compute crude and adjusted odds ratios (ORs with 95% confidence intervals (CIs. Results Pancreatic cancer risk in aspirin users was not changed relative to non-users (adjusted OR = 1.00; 95% CI 0.72–1.39. No significant change in risk was found in relation to greater frequency or prolonged duration of use, in the total sample or in either gender. Conclusions These data suggest that regular aspirin use may not be associated with lower risk of pancreatic cancer.

Use and Misuse of Aspirin in Primary Cardiovascular Prevention

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Sergio Coccheri

2017-04-01

Full Text Available The use of low-dose aspirin in primary prevention of cardiovascular (CV events in healthy or apparently healthy people is a widely debated topic. Many arguments indicate that “primary prevention” is only a conventional definition and that the transition from primary to secondary prevention represents a continuum of increasing levels of CV risk. Although there are no direct proofs of a different efficacy of aspirin at different CV risk levels, in low-risk populations aspirin will appear to be less efficient. In fact, the lower number of events occurring in patients at low risk yields lower absolute numbers of events prevented. As many as 6 meta-analyses of trials of primary CV prevention with aspirin versus placebo, performed between 2009 and 2016, confirmed the above concepts and showed a concordant, significant reduction in nonfatal myocardial infarction, with no significant effects on stroke, as well as on CV and all-cause mortality. The recent demonstration of a moderate protective effect of aspirin on cancer (especially colorectal confers, however, additional value to the use of aspirin, although unusually long durations of treatment and optimal daily compliance seem to be necessary. Because aspirin increases the bleeding risk, the evaluation of its net clinical benefit is an important point of debate. Thus, it is justified to search for a cutoff level of global CV risk above which the net clinical benefit of aspirin becomes evident. Such a threshold value has been calculated considering the data of 9 primary prevention trials, by the Thrombosis Group of the European Society of Cardiology, and has been indicated as a risk value of 2 or more major CV events per 100 persons per year. Also, in the recent 2016 US Guidelines, the main criterion adopted for the indication of aspirin is the level of global CV risk (suggested cutoff is 1 or more major CV events per 100 persons per year. Beyond the different values selected, it is seems very

Rivaroxaban for Preventing Atherothrombotic Events in People with Acute Coronary Syndrome and Elevated Cardiac Biomarkers: An Evidence Review Group Perspective of a NICE Single Technology Appraisal.

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Pandor, Abdullah; Pollard, Daniel; Chico, Tim; Henderson, Robert; Stevenson, Matt

2016-05-01

As part of its Single Technology Appraisal process, the National Institute for Health and Care Excellence (NICE) invited the company that manufactures rivaroxaban (Xarelto, Bayer) to submit evidence of the clinical and cost effectiveness of rivaroxaban for the prevention of adverse outcomes in patients after the acute management of acute coronary syndrome (ACS). The School of Health and Related Research Technology Appraisal Group at the University of Sheffield was commissioned to act as the independent Evidence Review Group (ERG). The ERG produced a critical review of the evidence for the clinical and cost effectiveness of the technology, based upon the company's submission to NICE. The evidence was derived mainly from a randomised, double-blind, phase III, placebo-controlled trial of rivaroxaban (either 2.5 or 5 mg twice daily) in patients with recent ACS [unstable angina, non-ST segment elevation myocardial infarction (NSTEMI) or ST segment elevation myocardial infarction (STEMI)]. In addition, all patients received antiplatelet therapy [aspirin alone or aspirin and a thienopyridine either as clopidogrel (approximately 99 %) or ticlopidine (approximately 1 %) according to national or local guidelines]. The higher dose of rivaroxaban (5 mg twice daily) did not form part of the marketing authorisation. A post hoc subgroup analysis of the licensed patients who had ACS with elevated cardiac biomarkers (that is, patients with STEMI and NSTEMI) without prior stroke or transient ischaemic stroke showed that compared with standard care, the addition of rivaroxaban (2.5 mg twice daily) to existing antiplatelet therapy reduced the composite endpoint of cardiovascular mortality, myocardial infarction or stroke, but increased the risk of major bleeding and intracranial haemorrhage. However, there were a number of limitations in the evidence base that warrant caution in its interpretation. In particular, the evidence may be confounded because of the post hoc subgroup

Aspirin reduces lipopolysaccharide-induced pulmonary inflammation in human models of ARDS.

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Hamid, U; Krasnodembskaya, A; Fitzgerald, M; Shyamsundar, M; Kissenpfennig, A; Scott, C; Lefrancais, E; Looney, M R; Verghis, R; Scott, J; Simpson, A J; McNamee, J; McAuley, D F; O'Kane, C M

2017-11-01

Platelets play an active role in the pathogenesis of acute respiratory distress syndrome (ARDS). Animal and observational studies have shown aspirin's antiplatelet and immunomodulatory effects may be beneficial in ARDS. To test the hypothesis that aspirin reduces inflammation in clinically relevant human models that recapitulate pathophysiological mechanisms implicated in the development of ARDS. Healthy volunteers were randomised to receive placebo or aspirin 75  or 1200 mg (1:1:1) for seven days prior to lipopolysaccharide (LPS) inhalation, in a double-blind, placebo-controlled, allocation-concealed study. Bronchoalveolar lavage (BAL) was performed 6 hours after inhaling 50 µg of LPS. The primary outcome measure was BAL IL-8. Secondary outcome measures included markers of alveolar inflammation (BAL neutrophils, cytokines, neutrophil proteases), alveolar epithelial cell injury, systemic inflammation (neutrophils and plasma C-reactive protein (CRP)) and platelet activation (thromboxane B2, TXB2). Human lungs, perfused and ventilated ex vivo (EVLP) were randomised to placebo or 24 mg aspirin and injured with LPS. BAL was carried out 4 hours later. Inflammation was assessed by BAL differential cell counts and histological changes. In the healthy volunteer (n=33) model, data for the aspirin groups were combined. Aspirin did not reduce BAL IL-8. However, aspirin reduced pulmonary neutrophilia and tissue damaging neutrophil proteases (Matrix Metalloproteinase (MMP)-8/-9), reduced BAL concentrations of tumour necrosis factor α and reduced systemic and pulmonary TXB2. There was no difference between high-dose and low-dose aspirin. In the EVLP model, aspirin reduced BAL neutrophilia and alveolar injury as measured by histological damage. These are the first prospective human data indicating that aspirin inhibits pulmonary neutrophilic inflammation, at both low and high doses. Further clinical studies are indicated to assess the role of aspirin in the

Aspirin decreases platelet uptake on Dacron vascular grafts in baboons

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Mackey, W.C.; Connolly, R.J.; Callow, A.D.

1984-01-01

The influence of a single dose of aspirin (5.4-7.4 mg/kg) on platelet uptake on 4-mm Dacron interposition grafts was studied in a baboon model using gamma camera scanning for 111-Indium labeled platelets. In vitro assessment of platelet function after aspirin administration revealed that in the baboon, as in the human, aspirin abolished arachidonic acid-induced platelet aggregation, prolonged the lag time between exposure to collagen and aggregation, and decreased plasma thromboxane B2 levels. Aspirin also prolonged the template bleeding time. Scans for 111-Indium labeled platelets revealed that pretreatment with a single dose of aspirin decreased platelet uptake on 4-mm Dacron carotid interposition grafts. This decrease in platelet uptake was associated with a significant improvement in 2-hour graft patency and with a trend toward improved 2-week patency

Cardioversion and Risk of Adverse Events with Dabigatran versus Warfarin-A Nationwide Cohort Study.

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Jannik Langtved Pallisgaard

Full Text Available Cardioversion can rapidly and effectively restore sinus rhythm in patients with persistent atrial fibrillation. Since 2011 dabigatran has been available as an alternative to warfarin to prevent thromboembolic events in patients with non-valvular atrial fibrillation undergoing cardioversion. We studied time to cardioversion, risk of adverse events, and risk of readmission with atrial fibrillation after cardioversion according to anticoagulation therapy.Through the nationwide Danish registries we included 1,230 oral anticoagulation naïve patients with first time non-valvular atrial fibrillation and first time cardioversion from 2011 to 2012; 37% in the dabigatran group (n = 456, and 63% in the warfarin group (n = 774. Median time to cardioversion was 4.0 (interquartile range [IQR] 2.9 to 6.5 and 6.9 (IQR 3.9 to 12.1 weeks in the dabigatran and warfarin groups respectively, and the adjusted odds ratio of cardioversion within the first 4 weeks was 2.3 (95% confidence interval [CI] 1.7 to 3.1 in favor of dabigatran. The cumulative incidence of composite endpoint of stroke, bleeding or death were 2.0% and 1.0% at 30 weeks in the warfarin and dabigatran groups respectively, with an adjusted hazard ratio of 1.33 (95% CI 0.33 to 5.42. Cumulative incidence of readmission with atrial fibrillation after 30 weeks were 9% and 11% in the warfarin and dabigatran groups, respectively, and an adjusted hazard ratio of 0.66 (95% CI 0.41 to 1.08.Anticoagulation treatment with dabigatran allows shorter time to cardioversion for atrial fibrillation than warfarin, and appears to be an effective and safe alternative treatment strategy to warfarin.

Cardioprotective aspirin users and their excess risk of upper gastrointestinal complications.

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Hernández-Díaz, Sonia; García Rodríguez, Luis A

2006-09-20

To balance the cardiovascular benefits from low-dose aspirin against the gastrointestinal harm caused, studies have considered the coronary heart disease risk for each individual but not their gastrointestinal risk profile. We characterized the gastrointestinal risk profile of low-dose aspirin users in real clinical practice, and estimated the excess risk of upper gastrointestinal complications attributable to aspirin among patients with different gastrointestinal risk profiles. To characterize aspirin users in terms of major gastrointestinal risk factors (i.e., advanced age, male sex, prior ulcer history and use of non-steroidal anti-inflammatory drugs), we used The General Practice Research Database in the United Kingdom and the Base de Datos para la Investigación Farmacoepidemiológica en Atención Primaria in Spain. To estimate the baseline risk of upper gastrointestinal complications according to major gastrointestinal risk factors and the excess risk attributable to aspirin within levels of these factors, we used previously published meta-analyses on both absolute and relative risks of upper gastrointestinal complications. Over 60% of aspirin users are above 60 years of age, 4 to 6% have a recent history of peptic ulcers and over 13% use other non-steroidal anti-inflammatory drugs. The estimated average excess risk of upper gastrointestinal complications attributable to aspirin is around 5 extra cases per 1,000 aspirin users per year. However, the excess risk varies in parallel to the underlying gastrointestinal risk and might be above 10 extra cases per 1,000 person-years in over 10% of aspirin users. In addition to the cardiovascular risk, the underlying gastrointestinal risk factors have to be considered when balancing harms and benefits of aspirin use for an individual patient. The gastrointestinal harms may offset the cardiovascular benefits in certain groups of patients where the gastrointestinal risk is high and the cardiovascular risk is low.