The endogenous opioid system: a common substrate in drug addiction.

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Trigo, José Manuel; Martin-García, Elena; Berrendero, Fernando; Robledo, Patricia; Maldonado, Rafael

2010-05-01

Drug addiction is a chronic brain disorder leading to complex adaptive changes within the brain reward circuits that involve several neurotransmitters. One of the neurochemical systems that plays a pivotal role in different aspects of addiction is the endogenous opioid system (EOS). Opioid receptors and endogenous opioid peptides are largely distributed in the mesolimbic system and modulate dopaminergic activity within these reward circuits. Chronic exposure to the different prototypical drugs of abuse, including opioids, alcohol, nicotine, psychostimulants and cannabinoids has been reported to produce significant alterations within the EOS, which seem to play an important role in the development of the addictive process. In this review, we will describe the adaptive changes produced by different drugs of abuse on the EOS, and the current knowledge about the contribution of each component of this neurobiological system to their addictive properties.

Discovery of endogenous opioid systems: what it has meant for the clinician's understanding of pain and its treatment.

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Ballantyne, Jane C; Sullivan, Mark D

2017-12-01

Before the discovery of the endogenous opioid system in the 1970s, opioids were understood only through the lens of opioid drug effects. Opium produced sleep, pain relief, and addiction. Once a variety of opioids had been extracted from opium, and still others synthesized chemically, it became clear that there must be endogenous receptors to explain differential drug effects. So, the search was on to identify the receptors, and subsequently their endogenous ligands. Even then, the consequential ways in which the endogenous opioid system influences the way we respond to the environment and survive took time to unravel. Today's understanding extends far beyond simply accepting pain relief and addiction as separate processes, to the realization that the endogenous opioid system achieves constant adjustments between punishment (pain) and reward in communicating areas of the brain previously thought to subserve separate functions. The system also plays a crucial role in socialization. Taken together, these 2 lines of research have led to new insights into why the endogenous opioid system is so important in terms of evolution, individual survival and day-to-day function, and how important it is to consider opioid medications within the context of these critical natural functions.

Role of endogenous opioid peptides in the pathogenesis of motion sickness

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Yasnetsov, V.V.; Il'ina, S.L.; Karsanova, S.K.; Medvedev, O.S.; Mokrousova, A.V.; Sabaev, V.V.; Shashkov, V.A.; Tigranyan, R.A.; Vakulina, O.P

1986-01-01

This paper examines the pathogenesis of motion sickness and the role of the various neurochemical systems of the body in the genesis of the condition. It has been shown that the endogenous opioid system participates in the genesis of several pathological processes; this was the motivation for the study. The plasma beta-endorphin level was determined in samples from 19 clinically healthy males. Considering the positive prophylactic and therapeutic effect of naloxone against motion sickness it can be postulated that endogenous opioid peptides participate in the genesis of the vestibulo-autonomic disorders in motion sickness

Role of endogenous opioid peptides in the pathogenesis of motion sickness

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Yasnetsov, V.V.; Il' ina, S.L.; Karsanova, S.K.; Medvedev, O.S.; Mokrousova, A.V.; Sabaev, V.V.; Shashkov, V.A.; Tigranyan, R.A.; Vakulina, O.P

1986-01-01

This paper examines the pathogenesis of motion sickness and the role of the various neurochemical systems of the body in the genesis of the condition. It has been shown that the endogenous opioid system participates in the genesis of several pathological processes; this was the motivation for the study. The plasma beta-endorphin level was determined in samples from 19 clinically healthy males. Considering the positive prophylactic and therapeutic effect of naloxone against motion sickness it can be postulated that endogenous opioid peptides participate in the genesis of the vestibulo-autonomic disorders in motion sickness.

Endogenous opioid activity in the anterior cingulate cortex is required for relief of pain.

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Navratilova, Edita; Xie, Jennifer Yanhua; Meske, Diana; Qu, Chaoling; Morimura, Kozo; Okun, Alec; Arakawa, Naohisa; Ossipov, Michael; Fields, Howard L; Porreca, Frank

2015-05-06

Pain is aversive, and its relief elicits reward mediated by dopaminergic signaling in the nucleus accumbens (NAc), a part of the mesolimbic reward motivation pathway. How the reward pathway is engaged by pain-relieving treatments is not known. Endogenous opioid signaling in the anterior cingulate cortex (ACC), an area encoding pain aversiveness, contributes to pain modulation. We examined whether endogenous ACC opioid neurotransmission is required for relief of pain and subsequent downstream activation of NAc dopamine signaling. Conditioned place preference (CPP) and in vivo microdialysis were used to assess negative reinforcement and NAc dopaminergic transmission. In rats with postsurgical or neuropathic pain, blockade of opioid signaling in the rostral ACC (rACC) inhibited CPP and NAc dopamine release resulting from non-opioid pain-relieving treatments, including peripheral nerve block or spinal clonidine, an α2-adrenergic agonist. Conversely, pharmacological activation of rACC opioid receptors of injured, but not pain-free, animals was sufficient to stimulate dopamine release in the NAc and produce CPP. In neuropathic, but not sham-operated, rats, systemic doses of morphine that did not affect withdrawal thresholds elicited CPP and NAc dopamine release, effects that were prevented by blockade of ACC opioid receptors. The data provide a neural explanation for the preferential effects of opioids on pain affect and demonstrate that engagement of NAc dopaminergic transmission by non-opioid pain-relieving treatments depends on upstream ACC opioid circuits. Endogenous opioid signaling in the ACC appears to be both necessary and sufficient for relief of pain aversiveness. Copyright © 2015 the authors 0270-6474/15/357264-08$15.00/0.

Endogenous opioid antagonism in physiological experimental pain models

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Werner, Mads U; Pereira, Manuel P; Andersen, Lars Peter H

2015-01-01

hyperalgesia models (6 studies), 'pain' models (25 studies), summation models (2 studies), nociceptive reflex models (3 studies) and miscellaneous models (2 studies). A consistent reversal of analgesia by a MOR-antagonist was demonstrated in 10 of the 25 ITP-studies, including stress-induced analgesia and r...... ratings, threshold assessments and somatosensory evoked potentials (SSEP), did not appear consistent in 28 out of 32 'pain' model studies. In conclusion, only in 2 experimental human pain models, i.e., stress-induced analgesia and rTMS, administration of MOR-antagonist demonstrated a consistent effect......Opioid antagonists are pharmacological tools applied as an indirect measure to detect activation of the endogenous opioid system (EOS) in experimental pain models. The objective of this systematic review was to examine the effect of mu-opioid-receptor (MOR) antagonists in placebo-controlled, double...

Blunted Endogenous Opioid Release Following an Oral Amphetamine Challenge in Pathological Gamblers

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Mick, Inge; Myers, Jim; Ramos, Anna C; Stokes, Paul R A; Erritzoe, David; Colasanti, Alessandro; Gunn, Roger N; Rabiner, Eugenii A; Searle, Graham E; Waldman, Adam D; Parkin, Mark C; Brailsford, Alan D; Galduróz, José C F; Bowden-Jones, Henrietta; Clark, Luke; Nutt, David J; Lingford-Hughes, Anne R

2016-01-01

Pathological gambling is a psychiatric disorder and the first recognized behavioral addiction, with similarities to substance use disorders but without the confounding effects of drug-related brain changes. Pathophysiology within the opioid receptor system is increasingly recognized in substance dependence, with higher mu-opioid receptor (MOR) availability reported in alcohol, cocaine and opiate addiction. Impulsivity, a risk factor across the addictions, has also been found to be associated with higher MOR availability. The aim of this study was to characterize baseline MOR availability and endogenous opioid release in pathological gamblers (PG) using [11C]carfentanil PET with an oral amphetamine challenge. Fourteen PG and 15 healthy volunteers (HV) underwent two [11C]carfentanil PET scans, before and after an oral administration of 0.5 mg/kg of d-amphetamine. The change in [11C]carfentanil binding between baseline and post-amphetamine scans (ΔBPND) was assessed in 10 regions of interest (ROI). MOR availability did not differ between PG and HV groups. As seen previously, oral amphetamine challenge led to significant reductions in [11C]carfentanil BPND in 8/10 ROI in HV. PG demonstrated significant blunting of opioid release compared with HV. PG also showed blunted amphetamine-induced euphoria and alertness compared with HV. Exploratory analysis revealed that impulsivity positively correlated with caudate baseline BPND in PG only. This study provides the first evidence of blunted endogenous opioid release in PG. Our findings are consistent with growing evidence that dysregulation of endogenous opioids may have an important role in the pathophysiology of addictions. PMID:26552847

Role of Endogenous Opioid System in Ischemic-Induced Late Preconditioning.

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Jan Fraessdorf

Full Text Available Opioid receptors (OR are involved in myocardial late preconditioning (LPC induced by morphine and δ1-opioid receptor (δ1-OR agonists. The role of OR in ischemic-induced LPC is unknown. We investigated whether 1 OR are involved in the trigger and/or mediation phase of LPC and 2 a time course effect on the expression of different opioid receptors and their endogenous ligands exists.Male Wistar rats were randomly allocated to four groups (each group n = 8. Awake animals were ischemic preconditioned by a 5 minutes coronary occlusion. 24 hours later, anesthetized animals underwent 25 minutes coronary occlusion followed by 2 hours of reperfusion. The role of OR was investigated by treatment with intraperitoneal naloxone (Nal 10 minutes prior to LPC (Nal-LPC; trigger phase or 10 min prior to sustained ischemia (LPC-Nal; mediation phase.LPC reduced infarct size from 61±10% in controls to 25±9% (P<0.001. Naloxone during trigger or mediation phase completely abolished LPC-induced cardioprotection (59±9% and 62±9%; P<0.001 vs. LPC. 8, 12 and 24 hours after the ischemic stimulus, expression of δ-OR in the heart was increased, whereas μ-opioid receptor (μ-OR and κ-opioid receptor (κ-OR were not. Plasma concentrations of β-endorphin and leu-enkephalin but not dynorphin were increased by LPC.Ischemic LPC is triggererd and mediated by OR. Expression of δ-OR and plasma levels of endogenous opioid peptides are increased after ischemic LPC.

Stress activates pronociceptive endogenous opioid signalling in DRG neurons during chronic colitis.

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Guerrero-Alba, Raquel; Valdez-Morales, Eduardo E; Jimenez-Vargas, Nestor N; Lopez-Lopez, Cintya; Jaramillo-Polanco, Josue; Okamoto, Takanobu; Nasser, Yasmin; Bunnett, Nigel W; Lomax, Alan E; Vanner, Stephen J

2017-12-01

Psychological stress accompanies chronic inflammatory diseases such as IBD, and stress hormones can exacerbate pain signalling. In contrast, the endogenous opioid system has an important analgesic action during chronic inflammation. This study examined the interaction of these pathways. Mouse nociceptive dorsal root ganglia (DRG) neurons were incubated with supernatants from segments of inflamed colon collected from patients with chronic UC and mice with dextran sodium sulfate (cDSS)-induced chronic colitis. Stress effects were studied by adding stress hormones (epinephrine and corticosterone) to dissociated neurons or by exposing cDSS mice to water avoidance stress. Changes in excitability of colonic DRG nociceptors were measured using patch clamp and Ca 2+ imaging techniques. Supernatants from patients with chronic UC and from colons of mice with chronic colitis caused a naloxone-sensitive inhibition of neuronal excitability and capsaicin-evoked Ca 2+ responses. Stress hormones decreased signalling induced by human and mouse supernatants. This effect resulted from stress hormones signalling directly to DRG neurons and indirectly through signalling to the immune system, leading to decreased opioid levels and increased acute inflammation. The net effect of stress was a change endogenous opioid signalling in DRG neurons from an inhibitory to an excitatory effect. This switch was associated with a change in G protein-coupled receptor excitatory signalling to a pathway sensitive to inhibitors of protein kinase A-protein, phospholipase C-protein and G protein βϒ subunits. Stress hormones block the inhibitory actions of endogenous opioids and can change the effect of opioid signalling in DRG neurons to excitation. Targeting these pathways may prevent heavy opioid use in IBD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Endogenous opioid blockade and impulsive responding in alcoholics and healthy controls.

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Mitchell, Jennifer M; Tavares, Venessa C; Fields, Howard L; D'Esposito, Mark; Boettiger, Charlotte A

2007-02-01

The opioid receptor antagonist naltrexone (NTX) is one of few approved treatments for alcoholism, yet the mechanism by which it reduces drinking remains unclear. In rats, NTX reduces morphine-induced impulsive choice bias; however, nothing is known about the drug's effect on discrete aspects of impulsive behavior in humans, such as decision-making and inhibitory control. Here, we used a modified delay discounting procedure to investigate whether NTX improves decision-making or inhibitory control in humans. We measured the effect of acute NTX (50 mg) on choice between smaller sooner (SS) and larger later monetary rewards and on response errors (motor mismatch) in a high conflict condition in a group of abstinent alcoholics (AA) and healthy control subjects (CS). We previously reported that AA selected the SS option significantly more often than did CS in this paradigm. If the choice bias of AA is due to enhanced endogenous opioid signaling in response to potential reward, NTX should reduce such bias in the AA group. We found that NTX did not reliably reduce impulsive choice in the AA group; however, NTX's effect on choice bias across individuals was robustly predictable. NTX's effect on choice bias was significantly correlated with scores on Rotter's Locus of Control (LOC) scale; increasingly internal LOC scores predicted increasing likelihood of impulsive choices on NTX. In addition, we found that NTX significantly enhanced control of motor responses, particularly within the CS group. These results suggest that endogenous opioids may impair response selection during decision-making under conflict, and that NTX's effects on explicit decision-making are personality-dependent. Determining the biological basis of this dependence could have important implications for effective alcoholism treatment.

Borderline Personality Disorder: A Dysregulation of the Endogenous Opioid System?

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Bandelow, Borwin; Schmahl, Christian; Falkai, Peter; Wedekind, Dirk

2010-01-01

The neurobiology of borderline personality disorder (BPD) remains unclear. Dysfunctions of several neurobiological systems, including serotoninergic, dopaminergic, and other neurotransmitter systems, have been discussed. Here we present a theory that alterations in the sensitivity of opioid receptors or the availability of endogenous opioids…

It still hurts: altered endogenous opioid activity in the brain during social rejection and acceptance in major depressive disorder.

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Hsu, D T; Sanford, B J; Meyers, K K; Love, T M; Hazlett, K E; Walker, S J; Mickey, B J; Koeppe, R A; Langenecker, S A; Zubieta, J-K

2015-02-01

The μ-opioid receptor (MOR) system, well known for dampening physical pain, is also hypothesized to dampen 'social pain.' We used positron emission tomography scanning with the selective MOR radioligand [(11)C]carfentanil to test the hypothesis that MOR system activation (reflecting endogenous opioid release) in response to social rejection and acceptance is altered in medication-free patients diagnosed with current major depressive disorder (MDD, n=17) compared with healthy controls (HCs, n=18). During rejection, MDD patients showed reduced endogenous opioid release in brain regions regulating stress, mood and motivation, and slower emotional recovery compared with HCs. During acceptance, only HCs showed increased social motivation, which was positively correlated with endogenous opioid release in the nucleus accumbens, a reward structure. Altered endogenous opioid activity in MDD may hinder emotional recovery from negative social interactions and decrease pleasure derived from positive interactions. Both effects may reinforce depression, trigger relapse and contribute to poor treatment outcomes.

Nicotine and endogenous opioids: neurochemical and pharmacological evidence.

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Hadjiconstantinou, Maria; Neff, Norton H

2011-06-01

Although the mesolimbic dopamine hypothesis is the most influential theory of nicotine reward and reinforcement, there has been a consensus that other neurotransmitter systems contribute to the addictive properties of nicotine as well. In this regard, the brain opioidergic system is of interest. Striatum is rich in opioid peptides and opioid receptors, and striatal opioidergic neurons are engaged in a bidirectional communication with midbrain dopaminergic neurons, closely regulating each other's activity. Enkephalins and dynorphins exert opposing actions on dopaminergic neurons, increasing and decreasing dopamine release respectively, and are components of circuits promoting positive or negative motivational and affective states. Moreover, dopamine controls the synthesis of striatal enkephalins and dynorphins. Evidence suggests that opioidergic function is altered after nicotine and endogenous opioids are involved in nicotine's behavioral effects. 1) The synthesis and release of β-endorphin, met-enkephalin and dynorphin in brain, especially nucleus accumbens (NAc), are altered after acute or chronic nicotine treatment and during nicotine withdrawal. 2) Although opioid receptor binding and mRNA do not appear to change in the striatum during nicotine withdrawal, the activity of κ-opioid (KOPr) and δ-opioid (DOPr) receptors is attenuated in NAc. 3) The nicotine withdrawal syndrome reminisces that of opiates, and naloxone precipitates some of its somatic, motivational, and affective signs. 4) Genetic and pharmacological studies indicate that μ-opioid (MOPr) receptors are mainly involved in nicotine reward, while DOPrs contribute to the emotional and KOPrs to the aversive responses of nicotine. 5) Finally, MOPrs and enkephalin, but not β-endorphin or dynorphin, are necessary for the physical manifestations of nicotine withdrawal. This article is part of a Special Issue entitled 'Trends in neuropharmacology: in memory of Erminio Costa'. Copyright © 2010 Elsevier

Functional interactions between endogenous cannabinoid and opioid systems: focus on alcohol, genetics and drug-addicted behaviors.

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López-Moreno, J A; López-Jiménez, A; Gorriti, M A; de Fonseca, F Rodríguez

2010-04-01

Although the first studies regarding the endogenous opioid system and addiction were published during the 1940s, addiction and cannabinoids were not addressed until the 1970s. Currently, the number of opioid addiction studies indexed in PubMed-Medline is 16 times greater than the number of cannabinoid addiction reports. More recently, functional interactions have been demonstrated between the endogenous cannabinoid and opioid systems. For example, the cannabinoid brain receptor type 1 (CB1) and mu opioid receptor type 1 (MOR1) co-localize in the same presynaptic nerve terminals and signal through a common receptor-mediated G-protein pathway. Here, we review a great variety of behavioral models of drug addiction and alcohol-related behaviors. We also include data providing clear evidence that activation of the cannabinoid and opioid endogenous systems via WIN 55,512-2 (0.4-10 mg/kg) and morphine (1.0-10 mg/kg), respectively, produces similar levels of relapse to alcohol in operant alcohol self-administration tasks. Finally, we discuss genetic studies that reveal significant associations between polymorphisms in MOR1 and CB1 receptors and drug addiction. For example, the SNP A118G, which changes the amino acid aspartate to asparagine in the MOR1 gene, is highly associated with altered opioid system function. The presence of a microsatellite polymorphism of an (AAT)n triplet near the CB1 gene is associated with drug addiction phenotypes. But, studies exploring haplotypes with regard to both systems, however, are lacking.

Opiate Drugs with Abuse Liability Hijack the Endogenous Opioid System to Disrupt Neuronal and Glial Maturation in the Central Nervous System

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Kurt F. Hauser

2018-01-01

Full Text Available The endogenous opioid system, comprised of multiple opioid neuropeptide and receptor gene families, is highly expressed by developing neural cells and can significantly influence neuronal and glial maturation. In many central nervous system (CNS regions, the expression of opioid peptides and receptors occurs only transiently during development, effectively disappearing with subsequent maturation only to reemerge under pathologic conditions, such as with inflammation or injury. Opiate drugs with abuse liability act to modify growth and development by mimicking the actions of endogenous opioids. Although typically mediated by μ-opioid receptors, opiate drugs can also act through δ- and κ-opioid receptors to modulate growth in a cell-type, region-specific, and developmentally regulated manner. Opioids act as biological response modifiers and their actions are highly contextual, plastic, modifiable, and influenced by other physiological processes or pathophysiological conditions, such as neuro-acquired immunodeficiency syndrome. To date, most studies have considered the acute effects of opiates on cellular maturation. For example, activating opioid receptors typically results in acute growth inhibition in both neurons and glia. However, with sustained opioid exposure, compensatory factors become operative, a concept that has been largely overlooked during CNS maturation. Accordingly, this article surveys prior studies on the effects of opiates on CNS maturation, and also suggests new directions for future research in this area. Identifying the cellular and molecular mechanisms underlying the adaptive responses to chronic opiate exposure (e.g., tolerance during maturation is crucial toward understanding the consequences of perinatal opiate exposure on the CNS.

Opiate Drugs with Abuse Liability Hijack the Endogenous Opioid System to Disrupt Neuronal and Glial Maturation in the Central Nervous System.

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Hauser, Kurt F; Knapp, Pamela E

2017-01-01

The endogenous opioid system, comprised of multiple opioid neuropeptide and receptor gene families, is highly expressed by developing neural cells and can significantly influence neuronal and glial maturation. In many central nervous system (CNS) regions, the expression of opioid peptides and receptors occurs only transiently during development, effectively disappearing with subsequent maturation only to reemerge under pathologic conditions, such as with inflammation or injury. Opiate drugs with abuse liability act to modify growth and development by mimicking the actions of endogenous opioids. Although typically mediated by μ-opioid receptors, opiate drugs can also act through δ- and κ-opioid receptors to modulate growth in a cell-type, region-specific, and developmentally regulated manner. Opioids act as biological response modifiers and their actions are highly contextual, plastic, modifiable, and influenced by other physiological processes or pathophysiological conditions, such as neuro-acquired immunodeficiency syndrome. To date, most studies have considered the acute effects of opiates on cellular maturation. For example, activating opioid receptors typically results in acute growth inhibition in both neurons and glia. However, with sustained opioid exposure, compensatory factors become operative, a concept that has been largely overlooked during CNS maturation. Accordingly, this article surveys prior studies on the effects of opiates on CNS maturation, and also suggests new directions for future research in this area. Identifying the cellular and molecular mechanisms underlying the adaptive responses to chronic opiate exposure (e.g., tolerance) during maturation is crucial toward understanding the consequences of perinatal opiate exposure on the CNS.

Plasticity of Signaling by Spinal Estrogen Receptor α, κ-Opioid Receptor, and Metabotropic Glutamate Receptors over the Rat Reproductive Cycle Regulates Spinal Endomorphin 2 Antinociception: Relevance of Endogenous-Biased Agonism.

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Liu, Nai-Jiang; Murugaiyan, Vijaya; Storman, Emiliya M; Schnell, Stephen A; Kumar, Arjun; Wessendorf, Martin W; Gintzler, Alan R

2017-11-15

We previously showed that intrathecal application of endomorphin 2 [EM2; the highly specific endogenous μ-opioid receptor (MOR) ligand] induces antinociception that varies with stage of the rat estrous cycle: minimal during diestrus and prominent during proestrus. Earlier studies, however, did not identify proestrus-activated signaling strategies that enable spinal EM2 antinociception. We now report that in female rats, increased spinal dynorphin release and κ-opioid receptor (KOR) signaling, as well as the emergence of glutamate-activated metabotropic glutamate receptor 1 (mGluR 1 ) signaling, are critical to the transition from an EM2 nonresponsive state (during diestrus) to an analgesically responsive state (during proestrus). Differential signaling by mGluR 1 , depending on its activation by membrane estrogen receptor α (mERα; during diestrus) versus glutamate (during proestrus), concomitant with the ebb and flow of spinal dynorphin/KOR signaling, functions as a switch, preventing or promoting, respectively, spinal EM2 antinociception. Importantly, EM2 and glutamate-containing varicosities appose spinal neurons that express MOR along with mGluRs and mERα, suggesting that signaling mechanisms regulating analgesic effectiveness of intrathecally applied EM2 also pertain to endogenous EM2. Regulation of spinal EM2 antinociception by both the nature of the endogenous mGluR 1 activator (i.e., endogenous biased agonism at mGluR 1 ) and changes in spinal dynorphin/KOR signaling represent a novel mechanism for modulating analgesic responsiveness to endogenous EM2 (and perhaps other opioids). This points the way for developing noncanonical pharmacological approaches to pain management by harnessing endogenous opioids for pain relief. SIGNIFICANCE STATEMENT The current prescription opioid abuse epidemic underscores the urgency to develop alternative pharmacotherapies for managing pain. We find that the magnitude of spinal endomorphin 2 (EM2) antinociception not only

Endogenous opioids: role in prostaglandin-dependent and -independent fever.

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Fraga, Daniel; Machado, Renes R; Fernandes, Luíz C; Souza, Glória E P; Zampronio, Aleksander R

2008-02-01

This study evaluated the participation of mu-opioid-receptor activation in body temperature (T(b)) during normal and febrile conditions (including activation of heat conservation mechanisms) and in different pathways of LPS-induced fever. The intracerebroventricular treatment of male Wistar rats with the selective opioid mu-receptor-antagonist cyclic d-Phe-Cys-Try-d-Trp-Arg-Thr-Pen-Thr-NH(2) (CTAP; 0.1-1.0 microg) reduced fever induced by LPS (5.0 microg/kg) but did not change T(b) at ambient temperatures of either 20 degrees C or 28 degrees C. The subcutaneous, intracerebroventricular, and intrahypothalamic injection of morphine (1.0-10.0 mg/kg, 3.0-30.0 microg, and 1-100 ng, respectively) produced a dose-dependent increase in T(b). Intracerebroventricular morphine also produced a peripheral vasoconstriction. Both effects were abolished by CTAP. CTAP (1.0 microg icv) reduced the fever induced by intracerebroventricular administration of TNF-alpha (250 ng), IL-6 (300 ng), CRF (2.5 microg), endothelin-1 (1.0 pmol), and macrophage inflammatory protein (500 pg) and the first phase of the fever induced by PGF(2alpha) (500.0 ng) but not the fever induced by IL-1beta (3.12 ng) or PGE(2) (125.0 ng) or the second phase of the fever induced by PGF(2alpha). Morphine-induced fever was not modified by the cyclooxygenase (COX) inhibitor indomethacin (2.0 mg/kg). In addition, morphine injection did not induce the expression of COX-2 in the hypothalamus, and CTAP did not modify PGE(2) levels in cerebrospinal fluid or COX-2 expression in the hypothalamus after LPS injection. In conclusion, our results suggest that LPS and endogenous pyrogens (except IL-1beta and prostaglandins) recruit the opioid system to cause a mu-receptor-mediated fever.

Endogenous opioid peptide-mediated neurotransmission in central and pericentral nuclei of the inferior colliculus recruits μ1-opioid receptor to modulate post-ictal antinociception.

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Felippotti, Tatiana Tocchini; de Freitas, Renato Leonardo; Coimbra, Norberto Cysne

2012-02-01

The aim of the present work was to investigate the involvement of the μ1-endogenous opioid peptide receptor-mediated system in post-ictal antinociception. Antinociceptive responses were determined by the tail-flick test after pre-treatment with the selective μ1-opioid receptor antagonist naloxonazine, peripherally or centrally administered at different doses. Peripheral subchronic (24 h) pre-treatment with naloxonazine antagonised the antinociception elicited by tonic-clonic seizures. Acute (10 min) pre-treatment, however, did not have the same effect. In addition, microinjections of naloxonazine into the central, dorsal cortical and external cortical nuclei of the inferior colliculus antagonised tonic-clonic seizure-induced antinociception. Neither acute (10-min) peripheral pre-treatment with naloxonazine nor subchronic intramesencephalic blockade of μ1-opioid receptors resulted in consistent statistically significant differences in the severity of tonic-clonic seizures shown by Racine's index (1972), although the intracollicular specific antagonism of μ1-opioid receptor decreased the duration of seizures. μ1-Opioid receptors and the inferior colliculus have been implicated in several endogenous opioid peptide-mediated responses such as antinociception and convulsion. The present findings suggest the involvement of μ1-opiate receptors of central and pericentral nuclei of the inferior colliculus in the modulation of tonic-clonic seizures and in the organisation of post-ictal antinociception. Copyright © 2011 Elsevier Ltd. All rights reserved.

Endogenous Opioid-Masked Latent Pain Sensitization

DEFF Research Database (Denmark)

Pereira, Manuel P; Donahue, Renee R; Dahl, Jørgen B

2015-01-01

UNLABELLED: Following the resolution of a severe inflammatory injury in rodents, administration of mu-opioid receptor inverse agonists leads to reinstatement of pain hypersensitivity. The mechanisms underlying this form of latent pain sensitization (LS) likely contribute to the development of chr...

Sensory Neuropeptides and Endogenous Opioids Expression in Human Dental Pulp with Asymptomatic Inflammation: In Vivo Study

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Daniel Chavarria-Bolaños

2015-01-01

Full Text Available Purpose. This study quantified the expression of substance P (SP, calcitonin gene-related peptide (CGRP, β-endorphins (β-End, and methionine-enkephalin (Met-Enk in human dental pulp following orthodontic intrusion. Methods. Eight patients were selected according to preestablished inclusion criteria. From each patient, two premolars (indicated for extraction due to orthodontic reasons were randomly assigned to two different groups: the asymptomatic inflammation group (EXPg, which would undergo controlled intrusive force for seven days, and the control group (CTRg, which was used to determine the basal levels of each substance. Once extracted, dental pulp tissue was prepared to determine the expression levels of both neuropeptides and endogenous opioids by radioimmunoassay (RIA. Results. All samples from the CTRg exhibited basal levels of both neuropeptides and endogenous opioids. By day seven, all patients were asymptomatic, even when all orthodontic-intrusive devices were still active. In the EXPg, the SP and CGRP exhibited statistically significant different levels. Although none of the endogenous opioids showed statistically significant differences, they all expressed increasing trends in the EXPg. Conclusions. SP and CGRP were identified in dental pulp after seven days of controlled orthodontic intrusion movement, even in the absence of pain.

Building up analgesia in humans via the endogenous μ-opioid system by combining placebo and active tDCS: a preliminary report.

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Marcos F DosSantos

Full Text Available Transcranial Direct Current Stimulation (tDCS is a method of non-invasive brain stimulation that has been frequently used in experimental and clinical pain studies. However, the molecular mechanisms underlying tDCS-mediated pain control, and most important its placebo component, are not completely established. In this pilot study, we investigated in vivo the involvement of the endogenous μ-opioid system in the global tDCS-analgesia experience. Nine healthy volunteers went through positron emission tomography (PET scans with [11C]carfentanil, a selective μ-opioid receptor (MOR radiotracer, to measure the central MOR activity during tDCS in vivo (non-displaceable binding potential, BPND--one of the main analgesic mechanisms in the brain. Placebo and real anodal primary motor cortex (M1/2mA tDCS were delivered sequentially for 20 minutes each during the PET scan. The initial placebo tDCS phase induced a decrease in MOR BPND in the periaqueductal gray matter (PAG, precuneus, and thalamus, indicating activation of endogenous μ-opioid neurotransmission, even before the active tDCS. The subsequent real tDCS also induced MOR activation in the PAG and precuneus, which were positively correlated to the changes observed with placebo tDCS. Nonetheless, real tDCS had an additional MOR activation in the left prefrontal cortex. Although significant changes in the MOR BPND occurred with both placebo and real tDCS, significant analgesic effects, measured by improvements in the heat and cold pain thresholds, were only observed after real tDCS, not the placebo tDCS. This study gives preliminary evidence that the analgesic effects reported with M1-tDCS, can be in part related to the recruitment of the same endogenous MOR mechanisms induced by placebo, and that such effects can be purposely optimized by real tDCS.

Neurotransmitters behind pain relief with transcranial magnetic stimulation - positron emission tomography evidence for release of endogenous opioids.

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Lamusuo, S; Hirvonen, J; Lindholm, P; Martikainen, I K; Hagelberg, N; Parkkola, R; Taiminen, T; Hietala, J; Helin, S; Virtanen, A; Pertovaara, A; Jääskeläinen, S K

2017-10-01

Repetitive transcranial magnetic stimulation (rTMS) at M1/S1 cortex has been shown to alleviate neuropathic pain. To investigate the possible neurobiological correlates of cortical neurostimulation for the pain relief. We studied the effects of M1/S1 rTMS on nociception, brain dopamine D2 and μ-opioid receptors using a randomized, sham-controlled, double-blinded crossover study design and 3D-positron emission tomography (PET). Ten healthy subjects underwent active and sham rTMS treatments to the right M1/S1 cortex with E-field navigated device. Dopamine D2 and μ-receptor availabilities were assessed with PET radiotracers [ 11 C]raclopride and [ 11 C]carfentanil after each rTMS treatment. Thermal quantitative sensory testing (QST), contact heat evoked potential (CHEP) and blink reflex (BR) recordings were performed between the PET scans. μ-Opioid receptor availability was lower after active than sham rTMS (P ≤ 0.0001) suggested release of endogenous opioids in the right ventral striatum, medial orbitofrontal, prefrontal and anterior cingulate cortices, and left insula, superior temporal gyrus, dorsolateral prefrontal cortex and precentral gyrus. There were no differences in striatal dopamine D2 receptor availability between active and sham rTMS, consistent with lack of long-lasting measurable dopamine release. Active rTMS potentiated the dopamine-regulated habituation of the BR compared to sham (P = 0.02). Thermal QST and CHEP remained unchanged after active rTMS. rTMS given to M1/S1 activates the endogenous opioid system in a wide brain network associated with processing of pain and other salient stimuli. Direct enhancement of top-down opioid-mediated inhibition may partly explain the clinical analgesic effects of rTMS. Neurobiological correlates of rTMS for the pain relief are unclear. rTMS on M1/S1 with 11 C-carfentanyl-PET activates endogenous opioids. Thermal and heat pain thresholds remain unchanged. rTMS induces top-down opioid-mediated inhibition

Endogenous Opioid Inhibition of Chronic Low Back Pain Influences Degree of Back Pain Relief Following Morphine Administration

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Bruehl, Stephen; Burns, John W.; Gupta, Rajnish; Buvanendran, Asokumar; Chont, Melissa; Schuster, Erik; France, Christopher R.

2014-01-01

Background and Objectives Factors underlying differential responsiveness to opioid analgesic medications used in chronic pain management are poorly understood. We tested whether individual differences in endogenous opioid inhibition of chronic low back pain were associated with magnitude of acute reductions in back pain ratings following morphine administration. Methods In randomized, counterbalanced order over three sessions, 50 chronic low back pain patients received intravenous naloxone (8mg), morphine (0.08 mg/kg), or placebo. Back pain intensity was rated pre-drug and again after peak drug activity was achieved using the McGill Pain Questionnaire-Short Form (Sensory and Affective subscales, VAS intensity measure). Opioid blockade effect measures to index degree of endogenous opioid inhibition of back pain intensity were derived as the difference between pre-to post-drug changes in pain intensity across placebo and naloxone conditions, with similar morphine responsiveness measures derived across placebo and morphine conditions. Results Morphine significantly reduced back pain compared to placebo (MPQ-Sensory, VAS; P effects of opioid blockade on back pain intensity. However, individual differences in opioid blockade effects were significantly associated with degree of acute morphine-related reductions in back pain on all measures, even after controlling for effects of age, sex, and chronic pain duration (P morphine. Conclusions Morphine appears to provide better acute relief of chronic back pain in individuals with lower natural opioidergic inhibition of chronic pain intensity. Possible implications for personalized medicine are discussed. PMID:24553304

Possible role of a dysregulation of the endogenous opioid system in antisocial personality disorder.

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Bandelow, Borwin; Wedekind, Dirk

2015-11-01

Around half the inmates in prison institutions have antisocial personality disorder (ASPD). A recent theory has proposed that a dysfunction of the endogenous opioid system (EOS) underlies the neurobiology of borderline personality disorder (BPD). In the present theoretical paper, based on a comprehensive database and hand search of the relevant literature, this hypothesis is extended to ASPD, which may be the predominant expression of EOS dysfunction in men, while the same pathology underlies BPD in women. According to evidence from human and animal studies, the problematic behaviours of persons with antisocial, callous, or psychopathic traits may be seen as desperate, unconscious attempts to stimulate their deficient EOS, which plays a key role in brain reward circuits. If the needs of this system are not being met, the affected persons experience dysphoric mood, discomfort, or irritability, and strive to increase binding of endogenous opioids to receptors by using the rewarding effects of aggression by exertion of physical or manipulative power on others, by abusing alcohol or substances that have the reward system as target, by creating an "endorphin rush" by self-harm, by increasing the frequency of their sexual contacts, or by impulsive actions and sensation seeking. Symptoms associated with ASPD can be treated with opioid antagonists like naltrexone, naloxone, or nalmefene. Copyright © 2015 John Wiley & Sons, Ltd.

Endogenous opiates and behavior: 2014.

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Bodnar, Richard J

2016-01-01

This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants). This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular

Pleiotropic opioid regulation of spinal endomorphin 2 release and its adaptations to opioid withdrawal are sexually dimorphic.

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Chakrabarti, Sumita; Liu, Nai-Jiang; Zadina, James E; Sharma, Tarak; Gintzler, Alan R

2012-01-01

We studied adaptations to acute precipitated opioid withdrawal of spinal μ-opioid receptor (MOR)-coupled regulation of the release of endomorphin 2 (EM2). The release of this highly MOR-selective endogenous opioid from opioid-naive spinal tissue of male rats is subjected to MOR-coupled positive as well as negative modulation via cholera toxin-sensitive G(s) and pertussis toxin-sensitive G(i)/G(o), respectively. The net effect of this concomitant bidirectional modulation is inhibitory. MOR-coupled pleiotropic regulation of EM2 release is retained in opioid-withdrawn spinal tissue of male rats, but the balance of MOR-coupled inhibitory and facilitatory regulation shifted such that facilitatory regulation predominates. Augmented coupling of MOR to G(s) is causally associated with this change. Strikingly, pleiotropic characteristics of MOR-coupled regulation of spinal EM2 release and adaptations thereof to opioid withdrawal are male-specific. In females, MOR-coupled regulation of EM2 release from opioid-naive and -withdrawn spinal tissue does not have a significant G(s)-coupled facilitatory component, and MOR-coupled inhibition of EM2 release persists unabated in withdrawn preparations. The male-specific adaptations to chronic morphine that shift the relative predominance of opposing dual G protein-coupled MOR pathways provides a mechanism for mitigating inhibitory MOR signaling without losing MOR-coupled feedback regulation. These adaptations enable using endogenous EM2 as a substitute for morphine that had been precipitously removed. The sexually dimorphic functionality and regulation of spinal EM2/MOR-coupled signaling suggest the clinical utility of using sex-specific treatments for addiction that harness the activity of endogenous opioids.

Sleep-waking states and the endogenous opioid system

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O.E. Ukponmwan (Otas)

1986-01-01

textabstractIn the general introductory part of this thesis (Chapters and 2) a review of some pertinent literature related to sleep-waking states and opioid peptides is offered. A global view of the neurochemical mechanisms and theories of functions of sleep, as well as the physiological and

Molecular and cellular mechanisms of the age-dependency of opioid analgesia and tolerance

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Zhao Jing

2012-05-01

Full Text Available Abstract The age-dependency of opioid analgesia and tolerance has been noticed in both clinical observation and laboratory studies. Evidence shows that many molecular and cellular events that play essential roles in opioid analgesia and tolerance are actually age-dependent. For example, the expression and functions of endogenous opioid peptides, multiple types of opioid receptors, G protein subunits that couple to opioid receptors, and regulators of G protein signaling (RGS proteins change with development and age. Other signaling systems that are critical to opioid tolerance development, such as N-methyl-D-aspartic acid (NMDA receptors, also undergo age-related changes. It is plausible that the age-dependent expression and functions of molecules within and related to the opioid signaling pathways, as well as age-dependent cellular activity such as agonist-induced opioid receptor internalization and desensitization, eventually lead to significant age-dependent changes in opioid analgesia and tolerance development.

Cholecystokinin octapeptide induces endogenous opioid-dependent anxiolytic effects in morphine-withdrawal rats.

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Wen, D; Sun, D; Zang, G; Hao, L; Liu, X; Yu, F; Ma, C; Cong, B

2014-09-26

Cholecystokinin octapeptide (CCK-8), a brain-gut peptide, plays an important role in several opioid addictive behaviors. We previously reported that CCK-8 attenuated the expression and reinstatement of morphine-induced conditioned place preference. The possible effects of CCK-8 on the negative affective components of drug abstinence are not clear. There are no studies evaluating the effect of CCK-8 on emotional symptoms, such as anxiety, in morphine-withdrawal animals. We investigated the effects of CCK-8 on the anxiety-like behavior in morphine-withdrawal rats using an elevated plus-maze. Morphine withdrawal elicited time-dependent anxiety-like behaviors with peak effects on day 10 (5 days after induction of morphine dependence). Treatment with CCK-8 (0.1 and 1 μg, i.c.v.) blocked this anxiety in a dose-dependent fashion. A CCK1 receptor antagonist (L-364,718, 10 μg, i.c.v.) blocked the effect of CCK-8. Mu-opioid receptor antagonism with CTAP (10 μg, i.c.v.) decreased the 'anxiolytic' effect. CCK-8 inhibited anxiety-like behaviors in morphine-withdrawal rats by up-regulating endogenous opioids via the CCK1 receptor in rats. This study clearly identifies a distinct function of CCK-8 and a potential medication target of central CCK1 receptors for drugs aimed at ameliorating drug addiction. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Reinforcement of wheel running in BALB/c mice: role of motor activity and endogenous opioids.

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Vargas-Pérez, Héctor; Sellings, Laurie H L; Paredes, Raúl G; Prado-Alcalá, Roberto A; Díaz, José-Luis

2008-11-01

The authors investigated the effect of the opioid antagonist naloxone on wheel-running behavior in Balb/c mice. Naloxone delayed the acquisition of wheel-running behavior, but did not reduce the expression of this behavior once acquired. Delayed acquisition was not likely a result of reduced locomotor activity, as naloxone-treated mice did not exhibit reduced wheel running after the behavior was acquired, and they performed normally on the rotarod test. However, naloxone-blocked conditioned place preference for a novel compartment paired previously with wheel running, suggesting that naloxone may delay wheel-running acquisition by blocking the rewarding or reinforcing effects of the behavior. These results suggest that the endogenous opioid system mediates the initial reinforcing effects of wheel running that are important in acquisition of the behavior.

Endogenous Opiates and Behavior: 2006

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Bodnar, Richard J.

2009-01-01

This paper is the twenty-ninth consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning thirty years of research. It summarizes papers published during 2006 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurological disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17). PMID:17949854

Endogenous opiates and behavior: 2012.

Science.gov (United States)

Bodnar, Richard J

2013-12-01

This paper is the thirty-fifth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2012 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17). Copyright © 2013 Elsevier Inc. All rights reserved.

Effect of pain chronification and chronic pain on an endogenous pain modulation circuit in rats.

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Miranda, J; Lamana, S M S; Dias, E V; Athie, M; Parada, C A; Tambeli, C H

2015-02-12

We tested the hypothesis that chronic pain development (pain chronification) and ongoing chronic pain (chronic pain) reduce the activity and induce plastic changes in an endogenous analgesia circuit, the ascending nociceptive control. An important mechanism mediating this form of endogenous analgesia, referred to as capsaicin-induced analgesia, is its dependence on nucleus accumbens μ-opioid receptor mechanisms. Therefore, we also investigated whether pain chronification and chronic pain alter the requirement for nucleus accumbens μ-opioid receptor mechanisms in capsaicin-induced analgesia. We used an animal model of pain chronification in which daily subcutaneous prostaglandin E2 (PGE2) injections into the rat's hind paw for 14 days, referred to as the induction period of persistent hyperalgesia, induce a long-lasting state of nociceptor sensitization referred to as the maintenance period of persistent hyperalgesia, that lasts for at least 30 days following the cessation of the PGE2 treatment. The nociceptor hypersensitivity was measured by the shortening of the time interval for the animal to respond to a mechanical stimulation of the hind paw. We found a significant reduction in the duration of capsaicin-induced analgesia during the induction and maintenance period of persistent mechanical hyperalgesia. Intra-accumbens injection of the μ-opioid receptor selective antagonist Cys(2),Tyr(3),Orn(5),Pen(7)amide (CTOP) 10 min before the subcutaneous injection of capsaicin into the rat's fore paw blocked capsaicin-induced analgesia. Taken together, these findings indicate that pain chronification and chronic pain reduce the duration of capsaicin-induced analgesia, without affecting its dependence on nucleus accumbens μ-opioid receptor mechanisms. The attenuation of endogenous analgesia during pain chronification and chronic pain suggests that endogenous pain circuits play an important role in the development and maintenance of chronic pain. Copyright © 2014 IBRO

Positron Emission Tomography (PET) Imaging of Opioid Receptors

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van Waarde, Aren; Absalom, Anthony; Visser, Anniek; Dierckx, Rudi; Dierckx, Rudi AJO; Otte, Andreas; De Vries, Erik FJ; Van Waarde, Aren; Luiten, Paul GM

2014-01-01

The opioid system consists of opioid receptors (which mediate the actions of opium), their endogenous ligands (the enkephalins, endorphins, endomorphins, dynorphin, and nociceptin), and the proteins involved in opioid production, transport, and degradation. PET tracers for the various opioid

Opioid system and human emotions.

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Nummenmaa, Lauri; Tuominen, Lauri

2017-04-10

Emotions are states of vigilant readiness that guide human and animal behaviour during survival-salient situations. Categorical models of emotions posit neurally and physiologically distinct basic human emotions (anger, fear, disgust, happiness, sadness and surprise) that govern different survival functions. Opioid receptors are expressed abundantly in the mammalian emotion circuit, and the opioid system modulates a variety of functions related to arousal and motivation. Yet, its specific contribution to different basic emotions has remained poorly understood. Here, we review how the endogenous opioid system and particularly the μ receptor contribute to emotional processing in humans. Activation of the endogenous opioid system is consistently associated with both pleasant and unpleasant emotions. In general, exogenous opioid agonists facilitate approach-oriented emotions (anger, pleasure) and inhibit avoidance-oriented emotions (fear, sadness). Opioids also modulate social bonding and affiliative behaviour, and prolonged opioid abuse may render both social bonding and emotion recognition circuits dysfunctional. However, there is no clear evidence that the opioid system is able to affect the emotions associated with surprise and disgust. Taken together, the opioid systems contribute to a wide array of positive and negative emotions through their general ability to modulate the approach versus avoidance motivation associated with specific emotions. Because of the protective effects of opioid system-mediated prosociality and positive mood, the opioid system may constitute an important factor contributing to psychological and psychosomatic resilience. © 2017 The British Pharmacological Society.

Endogenous opioids inhibit oxytocin release during nicotine-stimulated secretion of vasopressin in man.

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Seckl, J R; Johnson, M; Shakespear, C; Lightman, S L

1988-05-01

The effects of the opioid antagonist naloxone on the vasopressin (AVP) and oxytocin (OT) responses to nicotine were studied in male non-smokers (21-30 years old). Either saline (n = 6) or naloxone (4 mg bolus + 6 mg/h, n = 6) was infused i.v. during the study. After 60 min infusion the subjects smoked one high-nicotine content cigarette. Naloxone infusion for 60 min did not alter basal plasma AVP or OT levels. Smoking led to a significant rise in plasma vasopressin in both saline and naloxone-infused subjects (P less than 0.05). There was no significant difference in the plasma AVP response to smoking between the two groups. Saline-infused subjects did not show any change in plasma OT in response to smoking. Naloxone infusion was associated with a significant rise in OT from 1.3 +/- 0.1 pmol/l to 4.3 +/- 2.4 pmol/l 5 min after smoking (P less than 0.05). We conclude that there is endogenous opioid-mediated inhibition of OT which prevents its release when AVP is secreted in response to nicotine in man.

Opioid-Induced Glial Activation: Mechanisms of Activation and Implications for Opioid Analgesia, Dependence, and Reward

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Mark R. Hutchinson

2007-01-01

Full Text Available This review will introduce the concept of toll-like receptor (TLR–mediated glial activation as central to all of the following: neuropathic pain, compromised acute opioid analgesia, and unwanted opioid side effects (tolerance, dependence, and reward. Attenuation of glial activation has previously been demonstrated both to alleviate exaggerated pain states induced by experimental pain models and to reduce the development of opioid tolerance. Here we demonstrate that selective acute antagonism of TLR4 results in reversal of neuropathic pain as well as potentiation of opioid analgesia. Attenuating central nervous system glial activation was also found to reduce the development of opioid dependence, and opioid reward at a behavioral (conditioned place preference and neurochemical (nucleus accumbens microdialysis of morphine-induced elevations in dopamine level of analysis. Moreover, a novel antagonism of TLR4 by (+- and (˗-isomer opioid antagonists has now been characterized, and both antiallodynic and morphine analgesia potentiating activity shown. Opioid agonists were found to also possess TLR4 agonistic activity, predictive of glial activation. Targeting glial activation is a novel and as yet clinically unexploited method for treatment of neuropathic pain. Moreover, these data indicate that attenuation of glial activation, by general or selective TLR antagonistic mechanisms, may also be a clinical method for separating the beneficial (analgesia and unwanted (tolerance, dependence, and reward actions of opioids, thereby improving the safety and efficacy of their use.

FMRFamide: low affinity inhibition of opioid binding to rabbit brain membranes

International Nuclear Information System (INIS)

Zhu, X.Z.; Raffa, R.B.

1986-01-01

FMRFamide (Phe-Met-Arg-Phe-NH 2 ) was first isolated from the ganglia of molluscs by Price and Greenberg in 1977. The peptide was subsequently shown to have diverse actions on various types of molluscan and mammalian tissues. The presence of immunoreactive FMRFamide-like material (irFMRF) in multiple areas of rat brain, spinal cord, and gastrointestinal tract suggests that irFMRF may have a physiological role in mammals. Tang, Yang and Costa recently demonstrated that FMRFamide attenuates morphine antinociception in rats and postulated, based on this and several other lines of evidence, that irFMRF might be an endogenous opioid antagonist. In the present study, they tested the ability of FMRFamide to inhibit the binding of opioid receptor ligands to rabbit membrane preparations. FMRFamide inhibited the specific binding of both 3 [H]-dihydromorphine and 3 [H]-ethylketocyclazocine (IC 50 = 14 μM and 320 μM, respectively) in a dose-related manner, suggesting that FMRFamide may affect binding to at least two types of opioid receptors (mu and kappa). These data are consistent with the concept that irFMRF might act as an endogenous opioid antagonist. However, the low affinity of FMRFamide leaves open the possibility of another mechanism of opioid antagonism, such as neuromodulation

FMRFamide: low affinity inhibition of opioid binding to rabbit brain membranes

Energy Technology Data Exchange (ETDEWEB)

Zhu, X.Z.; Raffa, R.B.

1986-03-05

FMRFamide (Phe-Met-Arg-Phe-NH/sub 2/) was first isolated from the ganglia of molluscs by Price and Greenberg in 1977. The peptide was subsequently shown to have diverse actions on various types of molluscan and mammalian tissues. The presence of immunoreactive FMRFamide-like material (irFMRF) in multiple areas of rat brain, spinal cord, and gastrointestinal tract suggests that irFMRF may have a physiological role in mammals. Tang, Yang and Costa recently demonstrated that FMRFamide attenuates morphine antinociception in rats and postulated, based on this and several other lines of evidence, that irFMRF might be an endogenous opioid antagonist. In the present study, they tested the ability of FMRFamide to inhibit the binding of opioid receptor ligands to rabbit membrane preparations. FMRFamide inhibited the specific binding of both /sup 3/(H)-dihydromorphine and /sup 3/(H)-ethylketocyclazocine (IC/sub 50/ = 14 ..mu..M and 320 ..mu..M, respectively) in a dose-related manner, suggesting that FMRFamide may affect binding to at least two types of opioid receptors (mu and kappa). These data are consistent with the concept that irFMRF might act as an endogenous opioid antagonist. However, the low affinity of FMRFamide leaves open the possibility of another mechanism of opioid antagonism, such as neuromodulation.

Pain, opioids, and sleep: implications for restless legs syndrome treatment.

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Trenkwalder, Claudia; Zieglgänsberger, Walter; Ahmedzai, Sam H; Högl, Birgit

2017-03-01

Opioid receptor agonists are known to relieve restless legs syndrome (RLS) symptoms, including both sensory and motor events, as well as improving sleep. The mechanisms of action of opioids in RLS are still a matter of speculation. The mechanisms by which endogenous opioids contribute to the pathophysiology of this polygenetic disorder, in which there are a number of variants, including developmental factors, remains unknown. A summary of the cellular mode of action of morphine and its (partial) antagonist naloxone via α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors and the involvement of dendritic spine activation is described. By targeting pain and its consequences, opioids are the first-line treatment in many diseases and conditions with both acute and chronic pain and have thus been used in both acute and chronic pain conditions over the last 40 years. Addiction, dependence, and tolerability of opioids show a wide variability interindividually, as the response to opioids is influenced by a complex combination of genetic, molecular, and phenotypic factors. Although several trials have now addressed opioid treatment in RLS, hyperalgesia as a complication of long-term opioid treatment, or opioid-opioid interaction have not received much attention so far. Therapeutic opioids may act not only on opioid receptors but also via histamine or N-methyl-d-aspartate (NMDA) receptors. In patients with RLS, one of the few studies investigating opioid bindings found that possible brain regions involved in the severity of RLS symptoms are similar to those known to be involved in chronic pain, such as the medial pain system (medial thalamus, amygdala, caudate nucleus, anterior cingulate gyrus, insular cortex, and orbitofrontal cortex). The results of this diprenorphine positron emission tomography study suggested that the more severe the RLS, the greater the release of endogenous opioids. Since 1993, when the first small controlled study was performed with

Low efficacy of non-opioid drugs in opioid withdrawal symptoms.

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Hermann, Derik; Klages, Eckard; Welzel, Helga; Mann, Karl; Croissant, Bernhard

2005-06-01

Opioid withdrawal, stress or cues associated with opioid consumption can induce opioid craving. If opioids are not available, opioid-dependent patients usually search for alternative drugs. Because several non-opioid drugs stimulate the endogenous opioidergic system, this concept may explain their frequent use by opioid-dependent patients. We hypothesized that non-opioid drugs alleviate opioid withdrawal symptoms and are therefore consumed by opioid addicts. We asked 89 opioid-dependent patients participating in an out-patient opioid maintenance program to estimate the potential of several non-opioid drugs in being able to alleviate opioid withdrawal. We applied a five-point Lickert scale (1 = very good reduction of opioid withdrawal; 5 = no reduction of opioid withdrawal). Patients could also indicate a worsening of opioid withdrawal. Values (mean +/- SD) were: for benzodiazepines, 3.2 +/- 1.1; tricyclic antidepressants, 3.6 +/- 1.1; cannabis, 3.6 +/- 1.0; alcohol, 4.1 +/- 1.1; cocaine, 4.2 +/- 1.1; amphetamine, 4.4 +/- 0.9; nicotine, 4.7 +/- 0.7; and caffeine, 4.9 +/- 0.5. A worsening of opioid withdrawal was reported by 62% of the patients for cocaine, 62% for amphetamine, 50% for caffeine, 37.5% for cannabis, 27% for nicotine, 26% for alcohol, 8% for tricyclic antidepressants and 3% for benzodiazepines. Our study shows a low efficacy of non-opioid drugs in alleviating opioid withdrawal symptoms. The data basis of this study was good and the sample was suitable to be asked for estimations of drug-drug interactions. Of the patients, 26 - 62% even reported a worsening of opioid withdrawal for cannabis, alcohol, cocaine and amphetamine. Only benzodiazepines and tricyclic antidepressants were reported to have a moderate positive effect on opioid withdrawal.

Antinociceptive tolerance to NSAIDs in the agranular insular cortex is mediated by opioid mechanism

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Pirkulashvili N

2017-07-01

Full Text Available Natia Pirkulashvili,1 Nana Tsiklauri,1 Marina Nebieridze,2 Merab G Tsagareli1 1Laboratory of Pain and Analgesia, 2Laboratory of Brain Metabolism, Beritashvili Center for Experimental Biomedicine, Tbilisi, Georgia Abstract: Several lines of investigations have shown that in some brain areas, in particular, in the midbrain periaqueductal gray matter, rostral ventromedial medulla, central nucleus of amygdala, nucleus raphe magnus, and dorsal hippocampus, microinjections of nonsteroidal anti-inflammatory drugs (NSAIDs induce antinociception with distinct development of tolerance. The agranular insular cortex (AIC is a small region of the cerebral cortex located on the lateral area of the rat’s cerebral hemisphere that is involved in the perception and response to pain. In the present study, we investigated the development of tolerance to the analgesic effects of NSAIDs diclofenac, ketorolac, and xefocam microinjected into the AIC in rats. Male Wistar rats receiving NSAIDs into the AIC were tested for antinociception by tail-flick and hot plate tests. Treatment with each NSAID significantly enhanced the tail-flick and hot plate latencies on the first day, followed by a progressive decrease in the analgesic effect over a 4-day period, ie, they developed tolerance. Pretreatment with an opioid antagonist naloxone completely prevented, and posttreatment naloxone abolished, the analgesic effects of the three NSAIDs in both behavioral assays. These findings support the notion that the development of tolerance to the antinociceptive effects of NSAIDs is mediated via an endogenous opioid system possibly involving descending pain modulatory systems. Keywords: antinociception, endogenous opioids, descending modulation, nociception, non­opioid tolerance

Preference or fat? Revisiting opioid effects on food intake.

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Taha, Sharif A

2010-07-14

It is well established that opioid signaling in the central nervous system constitutes a powerful stimulus for food intake. The role of opioids in determining food preference, however, is less well defined. Opioids have been proposed to promote intake of preferred foods, or, alternatively, to preferentially increase consumption of fat. In the present manuscript, I comprehensively review results from previous studies investigating this issue. Data from these studies suggests a mechanism for opioid action that may reconcile the previously proposed hypotheses: opioid effects on food intake do appear to be largely specific for fat consumption, but individual animals' sensitivity to this effect may be dependent on baseline food preferences. In addition, I highlight the possibility that the selectivity of endogenous opioid effects may importantly differ from that of exogenous agonists in the degree to which baseline preferences, rather than macronutrient intake, are altered. The paper represents an invited review by a symposium, award winner or keynote speaker at the Society for the Study of Ingestive Behavior [SSIB] Annual Meeting in Portland, July 2009. 2010 Elsevier Inc. All rights reserved.

Chronic ethanol consumption in rats produces opioid antinociceptive tolerance through inhibition of mu opioid receptor endocytosis.

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Li He

Full Text Available It is well known that the mu-opioid receptor (MOR plays an important role in the rewarding properties of ethanol. However, it is less clear how chronic ethanol consumption affects MOR signaling. Here, we demonstrate that rats with prolonged voluntary ethanol consumption develop antinociceptive tolerance to opioids. Signaling through the MOR is controlled at many levels, including via the process of endocytosis. Importantly, agonists at the MOR that promote receptor endocytosis, such as the endogenous peptides enkephalin and β-endorphin, show a reduced propensity to promote antinociceptive tolerance than do agonists, like morphine, which do not promote receptor endocytosis. These observations led us to examine whether chronic ethanol consumption produced opioid tolerance by interfering with MOR endocytosis. Indeed, here we show that chronic ethanol consumption inhibits the endocytosis of MOR in response to opioid peptide. This loss of endocytosis was accompanied by a dramatic decrease in G protein coupled receptor kinase 2 (GRK2 protein levels after chronic drinking, suggesting that loss of this component of the trafficking machinery could be a mechanism by which endocytosis is lost. We also found that MOR coupling to G-protein was decreased in ethanol-drinking rats, providing a functional explanation for loss of opioid antinociception. Together, these results suggest that chronic ethanol drinking alters the ability of MOR to endocytose in response to opioid peptides, and consequently, promotes tolerance to the effects of opioids.

Opioid receptor desensitization: mechanisms and its link to tolerance

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Stéphane eAllouche

2014-12-01

Full Text Available Opioid receptors are part of the class A of G-protein coupled receptors and the target of the opiates, the most powerful analgesic molecules used in clinic. During a protracted use, a tolerance to analgesic effect develops resulting in a reduction of the effectiveness. So understanding mechanisms of tolerance is a great challenge and may help to find new strategies to tackle this side effect. This review will summarize receptor-related mechanisms that could underlie tolerance especially receptor desensitization. We will focus on the latest data obtained on molecular mechanisms involved in opioid receptor desensitization: phosphorylation, receptor uncoupling, internalization and post-endocytic fate of the receptor.

Opioid-induced preconditioning: recent advances and future perspectives.

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Peart, Jason N; Gross, Eric R; Gross, Garrett J

2005-01-01

Opioids, named by Acheson for compounds with morphine-like actions despite chemically distinct structures, have received much research interest, particularly for their central nervous system (CNS) actions involved in pain management, resulting in thousands of scientific papers focusing on their effects on the CNS and other organ systems. A more recent area which may have great clinical importance concerns the role of opioids, either endogenous or exogenous compounds, in limiting the pathogenesis of ischemia-reperfusion injury in heart and brain. The role of endogenous opioids in hibernation provides tantalizing evidence for the protective potential of opioids against ischemia or hypoxia. Mammalian hibernation, a distinct energy-conserving state, is associated with depletion of energy stores, intracellular acidosis and hypoxia, similar to those which occur during ischemia. However, despite the potentially detrimental cellular state induced with hibernation, the myocardium remains resilient for many months. What accounts for the hypoxia-tolerant state is of great interest. During hibernation, circulating levels of opioid peptides are increased dramatically, and indeed, are considered a "trigger" of hibernation. Furthermore, administration of opioid antagonists can effectively reverse hibernation in mammals. Therefore, it is not surprising that activation of opioid receptors has been demonstrated to preserve cellular status following a hypoxic insult, such as ischemia-reperfusion in many model systems including the intestine [Zhang, Y., Wu, Y.X., Hao, Y.B., Dun, Y. Yang, S.P., 2001. Role of endogenous opioid peptides in protection of ischemic preconditioning in rat small intestine. Life Sci. 68, 1013-1019], skeletal muscle [Addison, P.D., Neligan, P.C., Ashrafpour, H., Khan, A., Zhong, A., Moses, M., Forrest, C.R., Pang, C.Y., 2003. Noninvasive remote ischemic preconditioning for global protection of skeletal muscle against infarction. Am. J. Physiol. Heart Circ

Controlled cross-over study in normal subjects of naloxone-preceding-lactate infusions; respiratory and subjective responses: relationship to endogenous opioid system, suffocation false alarm theory and childhood parental loss.

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Preter, M; Lee, S H; Petkova, E; Vannucci, M; Kim, S; Klein, D F

2011-02-01

The expanded suffocation false alarm theory (SFA) hypothesizes that dysfunction in endogenous opioidergic regulation increases sensitivity to CO2, separation distress and panic attacks. In panic disorder (PD) patients, both spontaneous clinical panics and lactate-induced panics markedly increase tidal volume (TV), whereas normals have a lesser effect, possibly due to their intact endogenous opioid system. We hypothesized that impairing the opioidergic system by naloxone could make normal controls parallel PD patients' response when lactate challenged. Whether actual separations and losses during childhood (childhood parental loss, CPL) affected naloxone-induced respiratory contrasts was explored. Subjective panic-like symptoms were analyzed although pilot work indicated that the subjective aspect of anxious panic was not well modeled by this specific protocol. Randomized cross-over sequences of intravenous naloxone (2 mg/kg) followed by lactate (10 mg/kg), or saline followed by lactate, were given to 25 volunteers. Respiratory physiology was objectively recorded by the LifeShirt. Subjective symptomatology was also recorded. Impairment of the endogenous opioid system by naloxone accentuates TV and symptomatic response to lactate. This interaction is substantially lessened by CPL. Opioidergic dysregulation may underlie respiratory pathophysiology and suffocation sensitivity in PD. Comparing specific anti-panic medications with ineffective anti-panic agents (e.g. propranolol) can test the specificity of the naloxone+lactate model. A screen for putative anti-panic agents and a new pharmacotherapeutic approach are suggested. Heuristically, the experimental unveiling of the endogenous opioid system impairing effects of CPL and separation in normal adults opens a new experimental, investigatory area.

Controlled cross-over study in normal subjects of naloxone-preceding-lactate infusions; respiratory and subjective responses: relationship to endogenous opioid system, suffocation false alarm theory and childhood parental loss

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Preter, M.; Lee, S. H.; Petkova, E.; Vannucci, M.; Kim, S.; Klein, D. F.

2015-01-01

Background The expanded suffocation false alarm theory (SFA) hypothesizes that dysfunction in endogenous opioidergic regulation increases sensitivity to CO2, separation distress and panic attacks. In panic disorder (PD) patients, both spontaneous clinical panics and lactate-induced panics markedly increase tidal volume (TV), whereas normals have a lesser effect, possibly due to their intact endogenous opioid system. We hypothesized that impairing the opioidergic system by naloxone could make normal controls parallel PD patients' response when lactate challenged. Whether actual separations and losses during childhood (childhood parental loss, CPL) affected naloxone-induced respiratory contrasts was explored. Subjective panic-like symptoms were analyzed although pilot work indicated that the subjective aspect of anxious panic was not well modeled by this specific protocol. Method Randomized cross-over sequences of intravenous naloxone (2 mg/kg) followed by lactate (10 mg/kg), or saline followed by lactate, were given to 25 volunteers. Respiratory physiology was objectively recorded by the LifeShirt. Subjective symptomatology was also recorded. Results Impairment of the endogenous opioid system by naloxone accentuates TV and symptomatic response to lactate. This interaction is substantially lessened by CPL. Conclusions Opioidergic dysregulation may underlie respiratory pathophysiology and suffocation sensitivity in PD. Comparing specific anti-panic medications with ineffective anti-panic agents (e.g. propranolol) can test the specificity of the naloxone + lactate model. A screen for putative anti-panic agents and a new pharmacotherapeutic approach are suggested. Heuristically, the experimental unveiling of the endogenous opioid system impairing effects of CPL and separation in normal adults opens a new experimental, investigatory area. PMID:20444308

Predator-scent stress, ethanol consumption and the opioid system in an animal model of PTSD.

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Manjoch, Hadar; Vainer, Ella; Matar, Michael; Ifergane, Gal; Zohar, Joseph; Kaplan, Zeev; Cohen, Hagit

2016-06-01

Emerging literature points to stress exposure as a potential contributor to the development of alcohol abuse, but animal models have yielded inconsistent results. Converging experimental data indicate that the endogenous opioid system modulates alcohol consumption and stress regulation. The aim of the present study is to examine the interplay between stress exposure, behavioral stress responses, ethanol (EtOH) consumption and the endogenous opioid system in an animal model of posttraumatic stress disorder. Rats were exposed to stress and then tested in a two-bottle free choice (TBC) assay or in a conditioned place preference paradigm. In some experiments, the endogenous opioid system was pharmacologically manipulated prior to stress exposure. The behavioral outcomes of stress exposure were assessed in an elevated plus-maze, with the acoustic startle response, and by monitoring the freezing response to trauma reminder. Immunoreactivity of phosphorylated opioid receptors in hippocampal subregions was also measured. Stress significantly increased the consumption of EtOH in the TBC assay. The severity of the behavioral response to stress was associated with EtOH consumption, cue-triggered freezing response to a trauma reminder, and endogenous levels of phosphorylated opioid receptors in the hippocampus. Pharmacologically manipulating the endogenous opioid system prior to stress exposure attenuated trauma cue-triggered freezing responses and blocked predator scent stress-induced potentiation of EtOH consumption. These data demonstrate a stress-induced potentiation of EtOH self-administration and reveal a clear association between individual patterns of the behavioral response to stress and alcohol preference, while indicating a role for the endogenous opioid system in the neurobiological response to stress. Copyright © 2016. Published by Elsevier B.V.

Is mechanism and symptom-based analgesia an answer to opioid-Induced hyperalgesia?

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Mayank Gupta

2015-01-01

Full Text Available "Cancer Pain" and "Pain in cancer patient" are not synonymous. Opioid-induced Hyperalgesia (OIH is a paradoxical state of nociceptive sensitization caused by exposure to opioids. Neuropathic pain is only partially responsive to opioids; injudicious increase in dose of opioids in neuropathic pain may not only result in inadequate pain relief but also OIH. Majority of literature on OIH is in non-cancer pain with systemic use of opioids. We describe the development and successful treatment of OIH in a 55-year-old male patient with Small cell Carcinoma Lung. Opioid tapering, rotation, systemic desensitization helps in combatting OIH. The use of anti-neuropathic adjuvant analgesics helps not only in preventing and treating OIH but also in understanding putative mechanisms underlying neuropathic pain and OIH.

[Effect of opioid receptors on acute stress-induced changes in recognition memory].

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Liu, Ying; Wu, Yu-Wei; Qian, Zhao-Qiang; Yan, Cai-Fang; Fan, Ka-Min; Xu, Jin-Hui; Li, Xiao; Liu, Zhi-Qiang

2016-12-25

Although ample evidence has shown that acute stress impairs memory, the influences of acute stress on different phases of memory, such as acquisition, consolidation and retrieval, are different. Experimental data from both human and animals support that endogenous opioid system plays a role in stress, as endogenous opioid release is increased and opioid receptors are activated during stress experience. On the other hand, endogenous opioid system mediates learning and memory. The aim of the present study was to investigate the effect of acute forced swimming stress on recognition memory of C57 mice and the role of opioid receptors in this process by using a three-day pattern of new object recognition task. The results showed that 15-min acute forced swimming damaged the retrieval of recognition memory, but had no effect on acquisition and consolidation of recognition memory. No significant change of object recognition memory was found in mice that were given naloxone, an opioid receptor antagonist, by intraperitoneal injection. But intraperitoneal injection of naloxone before forced swimming stress could inhibit the impairment of recognition memory retrieval caused by forced swimming stress. The results of real-time PCR showed that acute forced swimming decreased the μ opioid receptor mRNA levels in whole brain and hippocampus, while the injection of naloxone before stress could reverse this change. These results suggest that acute stress may impair recognition memory retrieval via opioid receptors.

TRV0109101, a G Protein-Biased Agonist of the µ-Opioid Receptor, Does Not Promote Opioid-Induced Mechanical Allodynia following Chronic Administration.

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Koblish, Michael; Carr, Richard; Siuda, Edward R; Rominger, David H; Gowen-MacDonald, William; Cowan, Conrad L; Crombie, Aimee L; Violin, Jonathan D; Lark, Michael W

2017-08-01

Prescription opioids are a mainstay in the treatment of acute moderate to severe pain. However, chronic use leads to a host of adverse consequences including tolerance and opioid-induced hyperalgesia (OIH), leading to more complex treatment regimens and diminished patient compliance. Patients with OIH paradoxically experience exaggerated nociceptive responses instead of pain reduction after chronic opioid usage. The development of OIH and tolerance tend to occur simultaneously and, thus, present a challenge when studying the molecular mechanisms driving each phenomenon. We tested the hypothesis that a G protein-biased µ -opioid peptide receptor (MOPR) agonist would not induce symptoms of OIH, such as mechanical allodynia, following chronic administration. We observed that the development of opioid-induced mechanical allodynia (OIMA), a model of OIH, was absent in β -arrestin1 -/- and β -arrestin2 -/- mice in response to chronic administration of conventional opioids such as morphine, oxycodone and fentanyl, whereas tolerance developed independent of OIMA. In agreement with the β -arrestin knockout mouse studies, chronic administration of TRV0109101, a G protein-biased MOPR ligand and structural analog of oliceridine, did not promote the development of OIMA but did result in drug tolerance. Interestingly, following induction of OIMA by morphine or fentanyl, TRV0109101 was able to rapidly reverse allodynia. These observations establish a role for β -arrestins in the development of OIH, independent of tolerance, and suggest that the use of G protein-biased MOPR ligands, such as oliceridine and TRV0109101, may be an effective therapeutic avenue for managing chronic pain with reduced propensity for opioid-induced hyperalgesia. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Divergent short- and long-term effects of acute stress in object recognition memory are mediated by endogenous opioid system activation.

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Nava-Mesa, Mauricio O; Lamprea, Marisol R; Múnera, Alejandro

2013-11-01

Acute stress induces short-term object recognition memory impairment and elicits endogenous opioid system activation. The aim of this study was thus to evaluate whether opiate system activation mediates the acute stress-induced object recognition memory changes. Adult male Wistar rats were trained in an object recognition task designed to test both short- and long-term memory. Subjects were randomly assigned to receive an intraperitoneal injection of saline, 1 mg/kg naltrexone or 3 mg/kg naltrexone, four and a half hours before the sample trial. Five minutes after the injection, half the subjects were submitted to movement restraint during four hours while the other half remained in their home cages. Non-stressed subjects receiving saline (control) performed adequately during the short-term memory test, while stressed subjects receiving saline displayed impaired performance. Naltrexone prevented such deleterious effect, in spite of the fact that it had no intrinsic effect on short-term object recognition memory. Stressed subjects receiving saline and non-stressed subjects receiving naltrexone performed adequately during the long-term memory test; however, control subjects as well as stressed subjects receiving a high dose of naltrexone performed poorly. Control subjects' dissociated performance during both memory tests suggests that the short-term memory test induced a retroactive interference effect mediated through light opioid system activation; such effect was prevented either by low dose naltrexone administration or by strongly activating the opioid system through acute stress. Both short-term memory retrieval impairment and long-term memory improvement observed in stressed subjects may have been mediated through strong opioid system activation, since they were prevented by high dose naltrexone administration. Therefore, the activation of the opioid system plays a dual modulating role in object recognition memory. Copyright © 2013 Elsevier Inc. All rights

[Effects of chronic experimental stress and endogenous opioids on histophysiological parameters of the thyroid gland].

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Krasnoperov, R A; Glumova, V A; Riashchikov, S N; Proshutina, N E

1992-01-01

In adult rabbits stress was modelled by electrostimulation of the hypothalamus ventromedial nucleus (15-hour-long session during 30 days) and medulla's raphe big nucleus which is one of the central places of the opioid peptides synthesis was irritated. It is revealed, that under stress thyroid gland responds by serum T3 increase in comparison with control animals with statistically significant variability of the T4 profile. Chronicity of the emotional agitation involves destructive changes in the thyroid parenchyma the hurting effect of the negative emotional factor is expressed less during opioid peptides complex activation. It is suggested that there are its own stress-limiting mechanisms in thyroid gland.

South African guideline for the use of chronic opioid therapy for ...

African Journals Online (AJOL)

pain and chronic pain associated with cancer and at the end of life. Although .... Opioid drugs are agonists that bind to endogenous opioid receptors and mimic ..... interstitial cystitis/painful bladder syndrome, chronic prostate pain, and irritable ...

The opioid receptors of the rat periaqueductal gray

Energy Technology Data Exchange (ETDEWEB)

Fedynyshyn, J.P.

1989-01-01

The opioid binding characteristics of the rat (PAG) and the signal transduction mechanisms of the opioid receptors were examined with in vitro radioligand binding, GTPase, adenylyl cyclase, and inositol phosphate assays. The nonselective ligand {sup 3}H-ethylketocyclazocine (EKC), the {mu} and {delta} selective ligand {sup 3}H-(D-Ala{sup 2}, D-Leu{sup 5}) enkephalin (DADLE), the {mu} selective ligand {sup 3}H-(D-Ala{sup 2}, N-methyl Phe{sup 4}, Glyol{sup 5}) enkephalin (DAGO), and the {delta} selective ligand {sup 3}H-(D-Pen{sup 2}, D-Pen{sup 5}) enkephalin (DPDPE) were separately used as tracer ligands to label opioid binding sites in rat PAG enriched P{sub 2} membrane in competition with unlabeled DADLE, DAGO, DPDPE, or the {kappa} selective ligand trans-3,4-dichloro-N-(2-(1-pyrrolidinyl)cyclohexyl)benzeneacetamide, methane sulfonate, hydrate (U50, 488H). Only {mu} selective high affinity opioid binding was observed. No high affinity {delta} or {kappa} selective binding was detected. {sup 3}H-DAGO was used as a tracer ligand to label {mu} selective high affinity opioid binding sites in PAG enriched P{sub 2} membrane in competition with unlabeled {beta}-endorphin, dynorphin A (1-17), BAM-18, methionine enkephalin, dynorphin A (1-8), and leucine enkephalin. Of these endogenous opioid peptides only those with previously reported high affinity {mu} type opioid binding activity competed with {sup 3}H-DAGO for binding sites in rat PAG enriched P{sub 2} membrane with affinities similar to that of unlabeled DAGO.

Interactions of the opioid and cannabinoid systems in reward: Insights from knockout studies

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Katia eBefort

2015-02-01

Full Text Available The opioid system consists of three receptors, mu, delta, and kappa, which are activated by endogenous opioid peptides (enkephalins, endorphins and dynorphins. The endogenous cannabinoid system comprises lipid neuromodulators (endocannabinoids, enzymes for their synthesis and their degradation and two well-characterized receptors, cannabinoid receptors CB1 and CB2. These systems play a major role in the control of pain as well as in mood regulation, reward processing and the development of addiction. Both opioid and cannabinoid receptors are coupled to G proteins and are expressed throughout the brain reinforcement circuitry. Extending classical pharmacology, research using genetically modified mice has provided important progress in the identification of the specific contribution of each component of these endogenous systems in vivo on reward process. This review will summarize available genetic tools and our present knowledge on the consequences of gene knockout on reinforced behaviors in both systems, with a focus on their potential interactions. A better understanding of opioid-cannabinoid interactions may provide novel strategies for therapies in addicted individuals.

Effect of prenatal methadone and ethanol on opioid receptor development in rats

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Peters, M.A.; Braun, R.L. (Loma Linda Univ., CA (United States))

1991-03-11

The current literature shows that the offspring of female rats exposed to methadone or ethanol display similar neurochemical and neurobehavioral alterations, and suggests that these drugs may be operating through a common mechanism. If this hypothesis is true, their effect on the endogenous opioid systems should be qualitatively similar. In this study virgin females were treated with methadone or 10% ethanol oral solution starting prior to conception and continued throughout gestation. When the offspring had reached 15 or 30 days of age they were sacrificed, the brain was removed and prepared for opioid receptor binding studies. ({sup 3}H)DAGO and ({sup 3}H)DADLE were used as ligands for the mu and delta receptors, respectively. These studies show significant treatment-related differences in both the number of mu and delta binding sites as well as in apparent receptor affinity. Significant sex- and age-related differences between treatments were also observed. These data show that methadone and ethanol, while manifesting some similar neurochemical and behavioral effects, have unique effects on opioid receptor binding, suggesting that they may be acting by different mechanisms.

Cutaneous nociceptors lack sensitisation, but reveal μ-opioid receptor-mediated reduction in excitability to mechanical stimulation in neuropathy

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Schmidt Yvonne

2012-11-01

Full Text Available Abstract Background Peripheral nerve injuries often trigger a hypersensitivity to tactile stimulation. Behavioural studies demonstrated efficient and side effect-free analgesia mediated by opioid receptors on peripheral sensory neurons. However, mechanistic approaches addressing such opioid properties in painful neuropathies are lacking. Here we investigated whether opioids can directly inhibit primary afferent neuron transmission of mechanical stimuli in neuropathy. We analysed the mechanical thresholds, the firing rates and response latencies of sensory fibres to mechanical stimulation of their cutaneous receptive fields. Results Two weeks following a chronic constriction injury of the saphenous nerve, mice developed a profound mechanical hypersensitivity in the paw innervated by the damaged nerve. Using an in vitro skin-nerve preparation we found no changes in the mechanical thresholds and latencies of sensory fibres from injured nerves. The firing rates to mechanical stimulation were unchanged or reduced following injury. Importantly, μ-opioid receptor agonist [D-Ala2,N-Me-Phe4,Gly5]-ol-enkephalin (DAMGO significantly elevated the mechanical thresholds of nociceptive Aδ and C fibres. Furthermore, DAMGO substantially diminished the mechanically evoked discharges of C nociceptors in injured nerves. These effects were blocked by DAMGO washout and pre-treatment with the selective μ-opioid receptor antagonist Cys2-Tyr3-Orn5-Pen7-amide. DAMGO did not alter the responses of sensory fibres in uninjured nerves. Conclusions Our findings suggest that behaviourally manifested neuropathy-induced mechanosensitivity does not require a sensitised state of cutaneous nociceptors in damaged nerves. Yet, nerve injury renders nociceptors sensitive to opioids. Prevention of action potential generation or propagation in nociceptors might represent a cellular mechanism underlying peripheral opioid-mediated alleviation of mechanical hypersensitivity in neuropathy.

ENDOGENOUS ANALGESIA, DEPENDENCE, AND LATENT PAIN SENSITIZATION

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Taylor, Bradley K; Corder, Gregory

2015-01-01

Endogenous activation of μ-opioid receptors (MORs) provides relief from acute pain. Recent studies have established that tissue inflammation produces latent pain sensitization (LS) that is masked by spinal MOR signaling for months, even after complete recovery from injury and re-establishment of normal pain thresholds. Disruption with MOR inverse agonists reinstates pain and precipitates cellular, somatic and aversive signs of physical withdrawal; this phenomenon requires N-methyl-D-aspartate receptor-mediated activation of calcium-sensitive adenylyl cyclase type 1 (AC1). In this review, we present a new conceptual model of the transition from acute to chronic pain, based on the delicate balance between LS and endogenous analgesia that develops after painful tissue injury. First, injury activates pain pathways. Second, the spinal cord establishes MOR constitutive activity (MORCA) as it attempts to control pain. Third, over time, the body becomes dependent on MORCA, which paradoxically sensitizes pain pathways. Stress or injury escalates opposing inhibitory and excitatory influences on nociceptive processing as a pathological consequence of increased endogenous opioid tone. Pain begets MORCA begets pain vulnerability in a vicious cycle. The final result is a silent insidious state characterized by the escalation of two opposing excitatory and inhibitory influences on pain transmission: LS mediated by AC1 (which maintains accelerator), and pain inhibition mediated by MORCA (which maintains the brake). This raises the prospect that opposing homeostatic interactions between MORCA analgesia and latent NMDAR–AC1-mediated pain sensitization create a lasting vulnerability to develop chronic pain. Thus, chronic pain syndromes may result from a failure in constitutive signaling of spinal MORs and a loss of endogenous analgesic control. An overarching long-term therapeutic goal of future research is to alleviate chronic pain by either: a) facilitating endogenous opioid

An investigation into the receptor-regulating effects of the acute administration of opioid agonists and an antagonist on beta adrenergic receptors in the rat cerebral cortex

International Nuclear Information System (INIS)

Roper, I.

1987-01-01

Past and current research indicated that biochemical deviations which might be involved in the etiology and pathophysiology of depression, included abnormalities or imbalances in the noradrenergic, serotonergic, hormonal and possibly in the endogenous opioid, dopaminergic, histaminergic, cholinergic and trace amine systems. In order to investigate a possible link between the noradrenergic system and opioids, it was decided to test the acute effects of opioid administration on cortical beta adrenoceptor numbers and affinity. As these receptors have been most consistently downregulated by antidepressant treatment, they may be involved in the mechanism of antidepressant action of these agents. It was decided to investigate beta adrenoceptor-regulatory effects of opioid treatment. Naloxone was tested alone, with a view to suppressing any possible endogenous opioid influences upon beta receptor status and revealing an effect which would possibly be the opposite of that brought about by the administration of opioid agonists. Naloxone was administered together with morphine to demonstrate that any beta receptor up- or downregulation which might be measured, had indeed been opioid-receptor mediated. It was found that the acute administration of four different mu opioid agonists, naloxone and naloxone plus morphine, did not cause any statistically significant alterations in cortical beta adrenergic receptor numbers or affinity in the rat. A radioactive ligand, the beta adrenoceptor-labelling compound referred to as DHA (L-dihydroalprenolol HCI) was used in this study

Reward systems and food intake: role of opioids.

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Gosnell, B A; Levine, A S

2009-06-01

Humans eat for many reasons, including the rewarding qualities of foods. A host of neurotransmitters have been shown to influence eating behavior and some of these appear to be involved in reward-induced eating. Endogenous opioid peptides and their receptors were first reported more than 30 years ago, and studies suggesting a role of opioids in the regulation of food intake date back nearly as far. Opioid agonists and antagonists have corresponding stimulatory and inhibitory effects on feeding. In addition to studies aimed at identifying the relevant receptor subtypes and sites of action within the brain, there has been a continuing interest in the role of opioids on diet/taste preferences, food reward, and the overlap of food reward with others types of reward. Data exist that suggest a role for opioids in the control of appetite for specific macronutrients, but there is also evidence for their role in the stimulation of intake based on already-existing diet or taste preferences and in controlling intake motivated by hedonics rather than by energy needs. Finally, various types of studies indicate an overlap between mechanisms mediating drug reward and palatable food reward. Preference or consumption of sweet substances often parallels the self-administration of several drugs of abuse, and under certain conditions, the termination of intermittent access to sweet substances produces symptoms that resemble those observed during opiate withdrawal. The overconsumption of readily available and highly palatable foods likely contributes to the growing rates of obesity worldwide. An understanding of the role of opioids in mediating food reward and promoting the overconsumption of palatable foods may provide insights into new approaches for preventing obesity.

Electroacupuncture-Induced Dynamic Processes of Gene Expression Levels of Endogenous Opioid Peptide Precursors and Opioid Receptors in the CNS of Goats

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Li-Li Cheng

2013-01-01

Full Text Available In order to investigate the dynamic processes of mRNA levels of proenkephalin, proopiomelanocortin, prodynorphin, and opioid receptors (δ-, μ-, and κ-receptor induced by electroacupuncture (EA in the central nerve system, goats were stimulated by EA of 60 Hz for 0.5 h at a set of Baihui, Santai, Ergen, and Sanyangluo points. The pain threshold was measured using the method of potassium iontophoresis. The mRNA levels of the three opioid peptide precursors and three opioid receptors were determined with quantitative real-time PCR and the levels of Met-enkephalin with SABC immunohistochemistry at 0.5 h before and at 0, 2, 4, 6, 8, 12, and 24 h after EA. The results showed that the pain threshold correlated (P<0.01 with Met-enkephalin immunoactivities in the measured nuclei and areas of goats. The analgesic aftereffect lasted for 12 h at least. The mRNA levels of the three opioid peptide precursors and three opioid receptors began to increase at 0 h, reached the peak during the time from 4 h to 6 h or at 12 h, and remained higher at 24 h after EA was discontinued. These results suggested that the initiation of gene expression of opioid peptides and the three receptors may be associated with EA-induced analgesic aftereffect.

The role of the opioid system in binge eating disorder.

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Giuliano, Chiara; Cottone, Pietro

2015-12-01

Binge eating disorder is characterized by excessive, uncontrollable consumption of palatable food within brief periods of time. Excessive intake of palatable food is thought to be driven by hedonic, rather than energy homeostatic, mechanisms. However, reward processing does not only comprise consummatory actions; a key component is represented by the anticipatory phase directed at procuring the reward. This phase is highly influenced by environmental food-associated stimuli, which can robustly enhance the desire to eat even in the absence of physiological needs. The opioid system (endogenous peptides and their receptors) has been strongly linked to the rewarding aspects of palatable food intake, and perhaps represents the key system involved in hedonic overeating. Here we review evidence suggesting that the opioid system can also be regarded as one of the systems that regulates the anticipatory incentive processes preceding binge eating hedonic episodes.

Abnormal nociception and opiate sensitivity of STOP null mice exhibiting elevated levels of the endogenous alkaloid morphine

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Aunis Dominique

2010-12-01

Full Text Available Abstract Background- Mice deficient for the stable tubule only peptide (STOP display altered dopaminergic neurotransmission associated with severe behavioural defects including disorganized locomotor activity. Endogenous morphine, which is present in nervous tissues and synthesized from dopamine, may contribute to these behavioral alterations since it is thought to play a role in normal and pathological neurotransmission. Results- In this study, we showed that STOP null brain structures, including cortex, hippocampus, cerebellum and spinal cord, contain high endogenous morphine amounts. The presence of elevated levels of morphine was associated with the presence of a higher density of mu opioid receptor with a higher affinity for morphine in STOP null brains. Interestingly, STOP null mice exhibited significantly lower nociceptive thresholds to thermal and mechanical stimulations. They also had abnormal behavioural responses to the administration of exogenous morphine and naloxone. Low dose of morphine (1 mg/kg, i.p. produced a significant mechanical antinociception in STOP null mice whereas it has no effect on wild-type mice. High concentration of naloxone (1 mg/kg was pronociceptive for both mice strain, a lower concentration (0.1 mg/kg was found to increase the mean mechanical nociceptive threshold only in the case of STOP null mice. Conclusions- Together, our data show that STOP null mice displayed elevated levels of endogenous morphine, as well as an increase of morphine receptor affinity and density in brain. This was correlated with hypernociception and impaired pharmacological sensitivity to mu opioid receptor ligands.

Overlapping mechanisms of stress-induced relapse to opioid use disorder and chronic pain: Clinical implications

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Udi E Ghitza

2016-05-01

Full Text Available Over the past two decades, a steeply growing number of persons with chronic non-cancer pain have been using opioid analgesics chronically to treat it, accompanied by a markedly increased prevalence of individuals with opioid-related misuse, opioid use disorders, emergency department visits, hospitalizations, admissions to drug treatment programs, and drug overdose deaths. This opioid misuse and overdose epidemic calls for well-designed randomized-controlled clinical trials into more skillful and appropriate pain management and for developing effective analgesics which have lower abuse liability and are protective against stress induced by chronic non-cancer pain. However, incomplete knowledge regarding effective approaches to treat various types of pain has been worsened by an under-appreciation of overlapping neurobiological mechanisms of stress, stress-induced relapse to opioid use, and chronic non-cancer pain in patients presenting for care for these conditions. This insufficient knowledge base has unfortunately encouraged common prescription of conveniently-available opioid pain-relieving drugs with abuse liability, as opposed to treating underlying problems using team-based multidisciplinary, patient-centered, collaborative-care approaches for addressing pain and co-occurring stress and risk for opioid use disorder. This paper reviews recent neurobiological findings regarding overlapping mechanisms of stress-induced relapse to opioid misuse and chronic non-cancer pain, and then discusses these in the context of key outstanding evidence gaps and clinical-treatment research directions which may be pursued to fill these gaps. Such research directions, if conducted through well-designed randomized controlled trials, may substantively inform clinical practice in general medical settings on how to effectively care for patients presenting with pain-related distress and these common co-occurring conditions.

Interactions between opioids and anabolic androgenic steroids: implications for the development of addictive behavior.

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Nyberg, Fred; Hallberg, Mathias

2012-01-01

Over the past decades, research on doping agents, such as anabolic androgenic steroids (AAS), has revealed that these compounds are often used in combination with other drugs of abuse. It seems that misuse of AAS probably involves more than a desire to enhance appearance or sports performance and studies have revealed that steroids are commonly connected with alcohol, opioids, tobacco, and psychotropic drugs. We have observed that AAS may interact with the endogenous opioids, excitatory amino acids, and dopaminergic pathways involved in the brain reward system. Furthermore, our studies provide evidence that AAS may induce an imbalance in these signal systems leading to an increased sensitivity toward opioid narcotics and central stimulants. In fact, studies performed in various clinics have shown that individuals taking AAS are likely to get addicted to opioids like heroin. This chapter reviews current knowledge on interactions between AAS and endogenous as well as exogenous opioids based not only on research in our laboratory but also on research carried out by several other clinical and preclinical investigators. Copyright © 2012 Elsevier Inc. All rights reserved.

Opioid receptor subtypes mediating the noise-induced decreases in high-affinity choline uptake in the rat brain.

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Lai, H; Carino, M A

1992-07-01

Acute (20 min) exposure to 100-dB white noise elicits a naltrexone-sensitive decrease in sodium-dependent high-affinity choline uptake in the frontal cortex and hippocampus of the rat. In the present study, the subtypes of opioid receptors involved were investigated by pretreating rats with microinjection of specific opioid-receptor antagonists into the lateral cerebroventricle before noise exposure. We found that the noise-induced decrease in high-affinity choline uptake in the hippocampus was blocked by pretreatment with either mu-, delta-, or kappa-opioid-receptor antagonists, whereas the effect of noise on frontal cortical high-affinity choline uptake was blocked by a mu- and delta- but not by a kappa-antagonist. These data further confirm the role of endogenous opioids in mediating the effects of noise on central cholinergic activity and indicate that different neural mechanisms are involved in the effects of noise on the frontal cortical and hippocampal cholinergic systems.

Tolerance to non-opioid analgesics is opioid-sensitive in nucleus raphe magnus

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Merab G Tsagareli

2011-07-01

Full Text Available Repeated injection of opioid analgesics can lead to a progressive loss of its effect. This phenomenon is known as tolerance. Several lines of investigations have shown that systemic, intraperitoneal administration or the microinjection of non-opioid analgesics, non-steroidal anti-inflammatory drugs (NSAIDs in the midbrain periaqueductal gray matter induces antinociception with some effects of tolerance. Our recent study has revealed that microinjection of three drugs analgin, ketorolac and xefocam into the central nucleus of amygdala produce tolerance to them and cross-tolerance to morphine. Here we report that repeated administrations of these NSAIDs into the nucleus raphe magnus (NRM in the following four days result in progressively less antinociception, i.e. produce the development of tolerance to these drugs in mail rats. Special control experiments showed that post-treatment with μ-opioid antagonist naloxone in NRM significantly decreased antinociceptive effects of NSAIDs at the first day in behavioral tail flick reflex (TF and hot plate (HP latencies. At the second day, naloxone generally had trend effects in both TF and HP tests impeded the development of tolerance to the antinociceptive effect of non-opioid analgesics. These findings strongly support the suggestion on endogenous opioid involvement in NSAIDs antinociception and tolerance in the descending pain control system. Moreover, repeated injections of NSAIDs progressively lead to tolerance to them, cross-tolerance to morphine and the risk of a withdrawal syndrome. Therefore, these results are important for human medicine too.

Risk factors for endotracheal intubation and mechanical ventilation in patients with opioids intoxication

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Mirmoghtadaee, P.; Mood, N.E.; Sabzghabaee, A.M.; Yaraghi, A.

2012-01-01

Objectives: Patients poisoned with opioids sometimes need endotracheal intubation with or without the use of mechanical ventilation. This study was done to determine the prognostic risk factors for of the need for endotracheal intubation and mechanical ventilation. Methodology: In this cross-sectional study which was performed in Isfahan (Iran), one hundred (n=100) opioid poisoned patients whom their overdoses were diagnosed by their full and reliable history, physical examination and positive response to naloxone; vital signs at the hospital admission, blood biochemistry, ABG details and also the type and estimated dosage of opioid, route of consumption, and their need to mechanical ventilation were evaluated. Results: Patients were mostly aged between 20-40 years old. Seventy nine patients were male and 26 cases (21 men) required endotracheal intubation and 15 cases (14 men) needed both intubation and mechanical ventilation. The most consumed opiates among the poisoned patients were opium (35%), heroin (16%), Tramadol (15%), Methadone (9%), crack (6%), Diphenoxylate (4%) and others (15%). There was a significant difference between the mean heart rates and respiratory rate of the patients who were connected to the ventilator and others (99.8 +- 21.8 and 87.3 +- 16.3; p=0.01). The lower level of consciousness [OR: 2.2 95% Confidence Interval (CI): 1.2-4.2], and lower admission level of hemoglobin (OR: 3.6; CI:1.2-10.8) were among the factors for predicting the need for intubation and ventilation. Conclusion: Determining the risk factors with prognostic value for the need to intubation or ventilation seems to be necessary for improving the standard of therapy in opioids poisoned patients. (author)

Tolerance to Non-Opioid Analgesics is Opioid Sensitive in the Nucleus Raphe Magnus.

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Tsagareli, Merab G; Nozadze, Ivliane; Tsiklauri, Nana; Gurtskaia, Gulnaz

2011-01-01

Repeated injection of opioid analgesics can lead to a progressive loss of effect. This phenomenon is known as tolerance. Several lines of investigations have shown that systemic, intraperitoneal administration or the microinjection of non-opioid analgesics, non-steroidal anti-inflammatory drugs (NSAIDs) into the midbrain periaqueductal gray matter induces antinociception with some effects of tolerance. Our recent study has revealed that microinjection of three drugs analgin, ketorolac, and xefocam into the central nucleus of amygdala produce tolerance to them and cross-tolerance to morphine. Here we report that repeated administrations of these NSAIDs into the nucleus raphe magnus (NRM) in the following 4 days result in progressively less antinociception compare to the saline control, i.e., tolerance develops to these drugs in male rats. Special control experiments showed that post-treatment with the μ-opioid antagonist naloxone into the NRM significantly decreased antinociceptive effects of NSAIDs on the first day of testing in the tail-flick (TF) reflex and hot plate (HP) latency tests. On the second day, naloxone generally had trend effects in both TF and HP tests and impeded the development of tolerance to the antinociceptive effect of non-opioid analgesics. These findings strongly support the suggestion of endogenous opioid involvement in NSAIDs antinociception and tolerance in the descending pain-control system. Moreover, repeated injections of NSAIDs progressively lead to tolerance to them, cross-tolerance to morphine, and the risk of a withdrawal syndrome. Therefore, these results are important for human medicine too.

Stress-evoked opioid release inhibits pain in major depressive disorder.

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Frew, Ashley K; Drummond, Peter D

2008-10-15

To determine whether stress-evoked release of endogenous opioids might account for hypoalgesia in major depressive disorder (MDD), the mu-opioid antagonist naltrexone (50mg) or placebo was administered double-blind to 24 participants with MDD and to 31 non-depressed controls. Eighty minutes later participants completed a painful foot cold pressor test and, after a 5-min interval, began a 25-min arithmetic task interspersed with painful electric shocks. Ten minutes later participants completed a second cold pressor test. Negative affect was greater in participants with MDD than in non-depressed controls throughout the experiment, and increased significantly in both groups during mental arithmetic. Before the math task, naltrexone unmasked direct linear relationships between severity of depression, negative affect while resting quietly, and cold-induced pain in participants with MDD. In contrast, facilitatory effects of naltrexone on cold- and shock-induced pain were greatest in controls with the lowest depression scores. Naltrexone strengthened the relationship between negative affect and shock-induced pain during the math task, particularly in the depressed group, and heightened anxiety in both groups toward the end of the task. Thus, mu-opioid activity apparently masked a positive association between negative affect and pain in the most distressed participants. These findings suggest that psychological distress inhibits pain via stress-evoked release of opioid peptides in severe cases of MDD. In addition, tonic endogenous opioid neurotransmission could inhibit depressive symptoms and pain in people with low depression scores.

Mycobacteria attenuate nociceptive responses by formyl peptide receptor triggered opioid peptide release from neutrophils.

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Heike L Rittner

2009-04-01

Full Text Available In inflammation, pain is regulated by a balance of pro- and analgesic mediators. Analgesic mediators include opioid peptides which are secreted by neutrophils at the site of inflammation, leading to activation of opioid receptors on peripheral sensory neurons. In humans, local opioids and opioid peptides significantly downregulate postoperative as well as arthritic pain. In rats, inflammatory pain is induced by intraplantar injection of heat inactivated Mycobacterium butyricum, a component of complete Freund's adjuvant. We hypothesized that mycobacterially derived formyl peptide receptor (FPR and/or toll like receptor (TLR agonists could activate neutrophils, leading to opioid peptide release and inhibition of inflammatory pain. In complete Freund's adjuvant-induced inflammation, thermal and mechanical nociceptive thresholds of the paw were quantified (Hargreaves and Randall-Selitto methods, respectively. Withdrawal time to heat was decreased following systemic neutrophil depletion as well as local injection of opioid receptor antagonists or anti-opioid peptide (i.e. Met-enkephalin, beta-endorphin antibodies indicating an increase in pain. In vitro, opioid peptide release from human and rat neutrophils was measured by radioimmunoassay. Met-enkephalin release was triggered by Mycobacterium butyricum and formyl peptides but not by TLR-2 or TLR-4 agonists. Mycobacterium butyricum induced a rise in intracellular calcium as determined by FURA loading and calcium imaging. Opioid peptide release was blocked by intracellular calcium chelation as well as phosphoinositol-3-kinase inhibition. The FPR antagonists Boc-FLFLF and cyclosporine H reduced opioid peptide release in vitro and increased inflammatory pain in vivo while TLR 2/4 did not appear to be involved. In summary, mycobacteria activate FPR on neutrophils, resulting in tonic secretion of opioid peptides from neutrophils and in a decrease in inflammatory pain. Future therapeutic strategies may aim

Sex versus sweet: opposite effects of opioid drugs on the reward of sucrose and sexual pheromones.

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Agustín-Pavón, Carmen; Martínez-Ricós, Joana; Martínez-García, Fernando; Lanuza, Enrique

2008-04-01

Endogenous opioids mediate some reward processes involving both natural (food, sweet taste) and artificial (morphine, heroin) rewards. In contrast, sexual behavior (which is also reinforcing) is generally inhibited by opioids. To establish the role of endogenous opioids for a newly described natural reinforcer, namely male sexual pheromones for female mice, we checked the effects of systemic injections of the general opioid antagonist naloxone (1-10 mg/kg) and the agonist fentanyl (0.1- 0.5 mg/kg) in a number of behavioral tests. Naloxone affected neither the innate preference for male-soiled bedding (vs. female-soiled bedding) in 2-choice tests nor the induction of place conditioning using male pheromones as rewarding stimuli, although it effectively blocked the preference for consuming a sucrose solution. In contrast, fentanyl inhibited the preference for male chemosignals without altering sucrose preference. These results suggest that, in macrosmatic animals such as rodents, opioidergic inhibition of sexual behavior might be due, at least partially, to an impaired processing of pheromonal cues and that the hedonic value of sweet-tasting solutions and sexual pheromones are under different opioid modulation.

Mechanism(s) involved in opioid drug abuse modulation of HAND.

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Dutta, Raini; Roy, Sabita

2012-07-01

Drug abuse and HIV infection are interlinked. From the onset of the HIV/AIDS epidemic, the impact of illicit drug use on HIV disease progression has been a focus of many investigations. Both laboratory-based and epidemiological studies strongly indicate that drug abuse may exacerbate HIV disease progression and increase mortality and morbidity in these patients. Increase susceptibility to opportunistic infection has been implicated as one of the major causes for this detriment. Furthermore, opioids are known to elicit prevalence of neurodegenerative disorders in HIV-infected patients. Numerous authors have delineated various molecular as well as cellular mechanisms associated with neurological complications in these patients. This review gives an overview of these findings. Understanding the mechanisms will allow for the development of targeted therapies aimed at reducing the progression of neurocognitive decline in the drug abusing HIV infected individuals.

Introduction to the College on Problems of Drug Dependence special issue: contemporary advances in opioid neuropharmacology.

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Walsh, Sharon L; Unterwald, Ellen M; Izenwasser, Sari

2010-05-01

Opioid receptors are critical therapeutic targets for medications development relevant to the treatment of drug dependence and pain. With recent advances in molecular neurobiology, it has become evident that the functional activity of opioid receptors, as ligand-regulated protein complexes, is modulated by multifarious intracellular and extracellular events, that there is genetic variation in coding for receptors, and that the activity of endogenous opioid systems may underlie actions common to other addictive disorders. This supplemental issue of Drug and Alcohol Dependence, arising from an invited symposium at the 71st Annual Meeting of the College on Problems of Drug Dependence, provides a series of contemporary reviews focused on recent advances in opioid neuropharmacology. Each speaker provides herein an invited comprehensive review of the state of knowledge on a specific topic in opioid neuropharmacology. Evans and colleagues describe the multi-faceted control of the opioid G-protein coupled receptor as a dynamic "sensor" complex and identify novel targets for drug development. von Zastrow focuses on opioid receptor-mediated events regulated by endocytosis and membrane trafficking through the endocytic pathway and differential responses to opioid agonists. Blendy and colleague provide a review of human association studies on the functional relevance of the mu opioid receptor variant, A118G, and presents data from the A112G knock-in model, an analogous mouse variant to A118G. Finally, Maldonado and colleagues provide a broader systems review from genetic, pharmacologic and behavioral studies implicating the endogenous opioid systems as a substrate for the mediation of substance use disorders spanning pharmacological classes.

Sex differences in opioid analgesia and addiction: interactions among opioid receptors and estrogen receptors

Science.gov (United States)

2013-01-01

Opioids are widely used as the pain reliever and also notorious for being addictive drugs. Sex differences in the opioid analgesia and addiction have been reported and investigated in human subjects and animal models. Yet, the molecular mechanism underlying the differences between males and females is still unclear. Here, we reviewed the literature describing the sex differences in analgesic responses and addiction liabilities to clinically relevant opioids. The reported interactions among opioids, estrogens, opioid receptors, and estrogen receptors are also evaluated. We postulate that the sex differences partly originated from the crosstalk among the estrogen and opioid receptors when stimulated by the exogenous opioids, possibly through common secondary messengers and the downstream gene transcriptional regulators. PMID:24010861

Toll-like receptor 9 is required for opioid-induced microglia apoptosis.

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Lei He

2011-04-01

Full Text Available Opioids have been widely applied in clinics as one of the most potent pain relievers for centuries, but their abuse has deleterious physiological effects beyond addiction. However, the underlying mechanism by which microglia in response to opioids remains largely unknown. Here we show that morphine induces the expression of Toll-like receptor 9 (TLR9, a key mediator of innate immunity and inflammation. Interestingly, TLR9 deficiency significantly inhibited morphine-induced apoptosis in microglia. Similar results were obtained when endogenous TLR9 expression was suppressed by the TLR9 inhibitor CpGODN. Inhibition of p38 MAPK by its specific inhibitor SB203580 attenuated morphine-induced microglia apoptosis in wild type microglia. Morphine caused a dramatic decrease in Bcl-2 level but increase in Bax level in wild type microglia, but not in TLR9 deficient microglia. In addition, morphine treatment failed to induce an increased levels of phosphorylated p38 MAPK and MAP kinase kinase 3/6 (MKK3/6, the upstream MAPK kinase of p38 MAPK, in either TLR9 deficient or µ-opioid receptor (µOR deficient primary microglia, suggesting an involvement of MAPK and µOR in morphine-mediated TLR9 signaling. Moreover, morphine-induced TLR9 expression and microglia apoptosis appears to require μOR. Collectively, these results reveal that opioids prime microglia to undergo apoptosis through TLR9 and µOR as well. Taken together, our data suggest that inhibition of TLR9 and/or blockage of µOR is capable of preventing opioid-induced brain damage.

MDR1 P-glycoprotein transports endogenous opioid peptides

NARCIS (Netherlands)

Oude Elferink, R. P.; Zadina, J.

2001-01-01

MDR1 P-glycoprotein is generally regarded as an efflux pump for amphipathic toxic compounds. The question remains, however, whether certain endogenous compounds are also substrates for this transporter. Certain peptides have been shown to interact with MDR1 Pgp as well and we have therefore

Opioid transport by ATP-binding cassette transporters at the blood-brain barrier: implications for neuropsychopharmacology.

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Tournier, Nicolas; Declèves, Xavier; Saubaméa, Bruno; Scherrmann, Jean-Michel; Cisternino, Salvatore

2011-01-01

Some of the ATP-binding cassette (ABC) transporters like P-glycoprotein (P-gp; ABCB1, MDR1), BCRP (ABCG2) and MRPs (ABCCs) that are present at the blood-brain barrier (BBB) influence the brain pharmacokinetics (PK) of their substrates by restricting their uptake or enhancing their clearance from the brain into the blood, which has consequences for their CNS pharmacodynamics (PD). Opioid drugs have been invaluable tools for understanding the PK-PD relationships of these ABC-transporters. The effects of morphine, methadone and loperamide on the CNS are modulated by P-gp. This review examines the ways in which other opioid drugs and some of their active metabolites interact with ABC transporters and suggests new mechanisms that may be involved in the variability of the response of the CNS to these drugs like carrier-mediated system belonging to the solute carrier (SLC) superfamily. Exposure to opioids may also alter the expression of ABC transporters. P-gp can be overproduced during morphine treatment, suggesting that the drug has a direct or, more likely, an indirect action. Variations in cerebral neurotransmitters during exposure to opioids and the release of cytokines during pain could be new endogenous stimuli affecting transporter synthesis. This review concludes with an analysis of the pharmacotherapeutic and clinical impacts of the interactions between ABC transporters and opioids.

Adoptive transfer of M2 macrophages reduces neuropathic pain via opioid peptides.

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Pannell, Maria; Labuz, Dominika; Celik, Melih Ö; Keye, Jacqueline; Batra, Arvind; Siegmund, Britta; Machelska, Halina

2016-10-07

During the inflammation which occurs following nerve damage, macrophages are recruited to the site of injury. Phenotypic diversity is a hallmark of the macrophage lineage and includes pro-inflammatory M1 and anti-inflammatory M2 populations. Our aim in this study was to investigate the ability of polarized M0, M1, and M2 macrophages to secrete opioid peptides and to examine their relative contribution to the modulation of neuropathic pain. Mouse bone marrow-derived cells were cultured as unstimulated M0 macrophages or were stimulated into an M1 phenotype using lipopolysaccharide and interferon-γ or into an M2 phenotype using interleukin-4. The macrophage phenotypes were verified using flow cytometry for surface marker analysis and cytokine bead array for cytokine profile assessment. Opioid peptide levels were measured by radioimmunoassay and enzyme immunoassay. As a model of neuropathic pain, a chronic constriction injury (CCI) of the sciatic nerve was employed. Polarized M0, M1, and M2 macrophages (5 × 10 5 cells) were injected perineurally twice, on days 14 and 15 following CCI or sham surgery. Mechanical and heat sensitivity were measured using the von Frey and Hargreaves tests, respectively. To track the injected macrophages, we also transferred fluorescently stained polarized cells and analyzed the surface marker profile of endogenous and injected cells in the nerves ex vivo. Compared to M0 and M1 cells, M2 macrophages contained and released higher amounts of opioid peptides, including Met-enkephalin, dynorphin A (1-17), and β-endorphin. M2 cells transferred perineurally at the nerve injury site reduced mechanical, but not heat hypersensitivity following the second injection. The analgesic effect was reversed by the perineurally applied opioid receptor antagonist naloxone methiodide. M2 cells did not affect sensitivity following sham surgery. Neither M0 nor M1 cells altered mechanical and heat sensitivity in CCI or sham-operated animals. Tracing the

Structure of the [delta]-opioid receptor bound to naltrindole

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Granier, Sébastien; Manglik, Aashish; Kruse, Andrew C.; Kobilka, Tong Sun; Thian, Foon Sun; Weis, William I.; Kobilka, Brian K. (Stanford-MED)

2012-07-11

The opioid receptor family comprises three members, the {mu}-, {delta}- and {kappa}-opioid receptors, which respond to classical opioid alkaloids such as morphine and heroin as well as to endogenous peptide ligands like endorphins. They belong to the G-protein-coupled receptor (GPCR) superfamily, and are excellent therapeutic targets for pain control. The {delta}-opioid receptor ({delta}-OR) has a role in analgesia, as well as in other neurological functions that remain poorly understood. The structures of the {mu}-OR and {kappa}-OR have recently been solved. Here we report the crystal structure of the mouse {delta}-OR, bound to the subtype-selective antagonist naltrindole. Together with the structures of the {mu}-OR and {kappa}-OR, the {delta}-OR structure provides insights into conserved elements of opioid ligand recognition while also revealing structural features associated with ligand-subtype selectivity. The binding pocket of opioid receptors can be divided into two distinct regions. Whereas the lower part of this pocket is highly conserved among opioid receptors, the upper part contains divergent residues that confer subtype selectivity. This provides a structural explanation and validation for the 'message-address' model of opioid receptor pharmacology, in which distinct 'message' (efficacy) and 'address' (selectivity) determinants are contained within a single ligand. Comparison of the address region of the {delta}-OR with other GPCRs reveals that this structural organization may be a more general phenomenon, extending to other GPCR families as well.

Illicit Opioid Intoxication: Diagnosis and Treatment

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A. Fareed

2011-01-01

Full Text Available Opioid intoxications and overdose are associated with high rates of morbidity and mortality. Opioid overdose may occur in the setting of intravenous or intranasal heroin use, illicit use of diverted opioid medications, intentional or accidental misuse of prescription pain medications, or iatrogenic overdose. In this review, we focused on the epidemiology of illict opioid use in the United States and on the mechanism of action of opioid drugs. We also described the signs and symptoms, and diagnoses of intoxication and overdose. Lastly, we updated the reader about the most recent recommendations for treatment and prevention of opioid intoxications and overdose.

Tolerance and withdrawal from prolonged opioid use in critically ill children.

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Anand, Kanwaljeet J S; Willson, Douglas F; Berger, John; Harrison, Rick; Meert, Kathleen L; Zimmerman, Jerry; Carcillo, Joseph; Newth, Christopher J L; Prodhan, Parthak; Dean, J Michael; Nicholson, Carol

2010-05-01

After prolonged opioid exposure, children develop opioid-induced hyperalgesia, tolerance, and withdrawal. Strategies for prevention and management should be based on the mechanisms of opioid tolerance and withdrawal. Relevant manuscripts published in the English language were searched in Medline by using search terms "opioid," "opiate," "sedation," "analgesia," "child," "infant-newborn," "tolerance," "dependency," "withdrawal," "analgesic," "receptor," and "individual opioid drugs." Clinical and preclinical studies were reviewed for data synthesis. Mechanisms of opioid-induced hyperalgesia and tolerance suggest important drug- and patient-related risk factors that lead to tolerance and withdrawal. Opioid tolerance occurs earlier in the younger age groups, develops commonly during critical illness, and results more frequently from prolonged intravenous infusions of short-acting opioids. Treatment options include slowly tapering opioid doses, switching to longer-acting opioids, or specifically treating the symptoms of opioid withdrawal. Novel therapies may also include blocking the mechanisms of opioid tolerance, which would enhance the safety and effectiveness of opioid analgesia. Opioid tolerance and withdrawal occur frequently in critically ill children. Novel insights into opioid receptor physiology and cellular biochemical changes will inform scientific approaches for the use of opioid analgesia and the prevention of opioid tolerance and withdrawal.

Is tapentadol different from classical opioids? A review of the evidence.

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Langford, Richard M; Knaggs, Roger; Farquhar-Smith, Paul; Dickenson, Anthony H

2016-11-01

Tapentadol is a single molecule able to deliver analgesia by two distinct mechanisms, a feature which differentiates it from many other analgesics. Pre-clinical data demonstrate two mechanisms of action: mu-opioid receptor agonist activity and noradrenaline re-uptake inhibition. From these, one may predict that tapentadol would be applicable across a broad spectrum of pain from nociceptive to neuropathic. The evidence in animal models suggests that norepinephrine re-uptake inhibition (NRI) is a key mechanism and may even predominate over opioid actions in chronic (and especially neuropathic) pain states, reinforcing that tapentadol is different to classical opioids and may, therefore, be an a priori choice for the treatment of neuropathic and mixed pain. The clinical studies and subsequent practice experience and surveillance support the concept of opioid and non-opioid mechanisms of action. The reduced incidence of some of the typical opioid-induced side effects, compared to equianalgesic doses of classical opioids, supports the hypothesis that tapentadol analgesia is only partially mediated by opioid agonist mechanisms. Both the pre-clinical and clinical profiles appear to be differentiated from those of classical opioids.

The gut-brain interaction in opioid tolerance.

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Akbarali, Hamid I; Dewey, William L

2017-12-01

The prevailing opioid crisis has necessitated the need to understand mechanisms leading to addiction and tolerance, the major contributors to overdose and death and to develop strategies for developing drugs for pain treatment that lack abuse liability and side-effects. Opioids are commonly used for treatment of pain and symptoms of inflammatory bowel disease. The significant effect of opioids in the gut, both acute and chronic, includes persistent constipation and paradoxically may also worsen pain symptoms. Recent work has suggested a significant role of the gastrointestinal microbiome in behavioral responses to opioids, including the development of tolerance to its pain-relieving effects. In this review, we present current concepts of gut-brain interaction in analgesic tolerance to opioids and suggest that peripheral mechanisms emanating from the gut can profoundly affect central control of opioid function. Copyright © 2017 Elsevier Ltd. All rights reserved.

Functional μ-Opioid-Galanin Receptor Heteromers in the Ventral Tegmental Area.

Science.gov (United States)

Moreno, Estefanía; Quiroz, César; Rea, William; Cai, Ning-Sheng; Mallol, Josefa; Cortés, Antoni; Lluís, Carme; Canela, Enric I; Casadó, Vicent; Ferré, Sergi

2017-02-01

The neuropeptide galanin has been shown to interact with the opioid system. More specifically, galanin counteracts the behavioral effects of the systemic administration of μ-opioid receptor (MOR) agonists. Yet the mechanism responsible for this galanin-opioid interaction has remained elusive. Using biophysical techniques in mammalian transfected cells, we found evidence for selective heteromerization of MOR and the galanin receptor subtype Gal1 (Gal1R). Also in transfected cells, a synthetic peptide selectively disrupted MOR-Gal1R heteromerization as well as specific interactions between MOR and Gal1R ligands: a negative cross talk, by which galanin counteracted MAPK activation induced by the endogenous MOR agonist endomorphin-1, and a cross-antagonism, by which a MOR antagonist counteracted MAPK activation induced by galanin. These specific interactions, which represented biochemical properties of the MOR-Gal1R heteromer, could then be identified in situ in slices of rat ventral tegmental area (VTA) with MAPK activation and two additional cell signaling pathways, AKT and CREB phosphorylation. Furthermore, in vivo microdialysis experiments showed that the disruptive peptide selectively counteracted the ability of galanin to block the dendritic dopamine release in the rat VTA induced by local infusion of endomorphin-1, demonstrating a key role of MOR-Gal1R heteromers localized in the VTA in the direct control of dopamine cell function and their ability to mediate antagonistic interactions between MOR and Gal1R ligands. The results also indicate that MOR-Gal1R heteromers should be viewed as targets for the treatment of opioid use disorders. The μ-opioid receptor (MOR) localized in the ventral tegmental area (VTA) plays a key role in the reinforcing and addictive properties of opioids. With parallel in vitro experiments in mammalian transfected cells and in situ and in vivo experiments in rat VTA, we demonstrate that a significant population of these MORs form

Human Mu Opioid Receptor (OPRM1A118G) polymorphism is associated with brain mu- opioid receptor binding potential in smokers

International Nuclear Information System (INIS)

Ray, R.; Logan, J.; Ruparel, K.; Newberg, A.; Wileyto, E.P.; Loughead, J.W.; Divgi, C.; Blendy, J.A.; Logan, J.; Zubieta, J.-K.; Lerman, C.

2011-01-01

Evidence points to the endogenous opioid system, and the mu-opioid receptor (MOR) in particular, in mediating the rewarding effects of drugs of abuse, including nicotine. A single nucleotide polymorphism (SNP) in the human MOR gene (OPRM1 A118G) has been shown to alter receptor protein level in preclinical models and smoking behavior in humans. To clarify the underlying mechanisms for these associations, we conducted an in vivo investigation of the effects of OPRM1 A118G genotype on MOR binding potential (BP ND or receptor availability). Twenty-two smokers prescreened for genotype (12 A/A, 10 */G) completed two [ 11 C] carfentanil positron emission tomography (PET) imaging sessions following overnight abstinence and exposure to a nicotine-containing cigarette and a denicotinized cigarette. Independent of session, smokers homozygous for the wild-type OPRM1 A allele exhibited significantly higher levels of MOR BP ND than smokers carrying the G allele in bilateral amygdala, left thalamus, and left anterior cingulate cortex. Among G allele carriers, the extent of subjective reward difference (denicotinized versus nicotine cigarette) was associated significantly with MOR BP ND difference in right amygdala, caudate, anterior cingulate cortex, and thalamus. Future translational investigations can elucidate the role of MORs in nicotine addiction, which may lead to development of novel therapeutics.

New perspective on the pathophysiology of panic: merging serotonin and opioids in the periaqueductal gray

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F.G. Graeff

2012-04-01

Full Text Available Panic disorder patients are vulnerable to recurrent panic attacks. Two neurochemical hypotheses have been proposed to explain this susceptibility. The first assumes that panic patients have deficient serotonergic inhibition of neurons localized in the dorsal periaqueductal gray matter of the midbrain that organize defensive reactions to cope with proximal threats and of sympathomotor control areas of the rostral ventrolateral medulla that generate most of the neurovegetative symptoms of the panic attack. The second suggests that endogenous opioids buffer normal subjects from the behavioral and physiological manifestations of the panic attack, and their deficit brings about heightened suffocation sensitivity and separation anxiety in panic patients, making them more vulnerable to panic attacks. Experimental results obtained in rats performing one-way escape in the elevated T-maze, an animal model of panic, indicate that the inhibitory action of serotonin on defense is connected with activation of endogenous opioids in the periaqueductal gray. This allows reconciliation of the serotonergic and opioidergic hypotheses of panic pathophysiology, the periaqueductal gray being the fulcrum of serotonin-opioid interaction.

Neuraxial opioid-induced pruritus: a review.

LENUS (Irish Health Repository)

Szarvas, Szilvia

2012-02-03

When intrathecal and epidural opioids are administered, pruritus occurs as an unwanted and troublesome side effect. The reported incidence varies between 30% and 100%. The exact mechanisms of neuraxial opioid-induced pruritus remain unclear. Postulated mechanisms include the presence of an "itch center" in the central nervous system, medullary dorsal horn activation, and antagonism of inhibitory transmitters. The treatment of intrathecal opioid-induced pruritus remains a challenge. Many pharmacological therapies, including antihistamines, 5-HT(3)-receptor antagonists, opiate-antagonists, propofol, nonsteroid antiinflammatory drugs, and droperidol, have been studied. In this review, we will summarize pathophysiological and pharmacological advances that will improve understanding and ultimately the management of this troublesome problem.

Rhodotorula Endogenous Endophthalmitis: A Novel Harbinger of the Injection Drug Epidemic in the United States

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Preston M. Luong

2017-01-01

Full Text Available Endogenous endophthalmitis is a rare but feared infectious ocular complication of injection drug use (IDU. The recent opioid epidemic in the United States threatens to increase the incidence of this disease. We report the first case of endogenous endophthalmitis in the United States caused by the emerging fungal pathogen Rhodotorula in an injection drug user which led to no light perception vision (NLP. Worldwide experience with Rhodotorula endogenous endophthalmitis is limited, but existing cases suggest infection by this particular fungal genus has a grim prognosis.

Mechanism Governing Human Kappa-Opioid Receptor Expression under Desferrioxamine-Induced Hypoxic Mimic Condition in Neuronal NMB Cells

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Jennifer Babcock

2017-01-01

Full Text Available Cellular adaptation to hypoxia is a protective mechanism for neurons and relevant to cancer. Treatment with desferrioxamine (DFO to induce hypoxia reduced the viability of human neuronal NMB cells. Surviving/attached cells exhibited profound increases of expression of the human kappa-opioid receptor (hKOR and hypoxia inducible factor-1α (HIF-1α. The functional relationship between hKOR and HIF-1α was investigated using RT-PCR, Western blot, luciferase reporter, mutagenesis, siRNA and receptor-ligand binding assays. In surviving neurons, DFO increased HIF-1α expression and its amount in the nucleus. DFO also dramatically increased hKOR expression. Two (designated as HIFC and D out of four potential HIF response elements of the hKOR gene (HIFA–D synergistically mediated the DFO response. Mutation of both elements completely abolished the DFO-induced effect. The CD11 plasmid (containing HIFC and D with an 11 bp spacing produced greater augmentation than that of the CD17 plasmid (HIFC and D with a 17 bp-spacing, suggesting that a proper topological interaction of these elements synergistically enhanced the promoter activity. HIF-1α siRNA knocked down the increase of endogenous HIF-1α messages and diminished the DFO-induced increase of hKOR expression. Increased hKOR expression resulted in the up-regulation of hKOR protein. In conclusion, the adaptation of neuronal hKOR under hypoxia was governed by HIF-1, revealing a new mechanism of hKOR regulation.

Human Mu Opioid Receptor (OPRM1A118G) polymorphism is associated with brain mu- opioid receptor binding potential in smokers

Energy Technology Data Exchange (ETDEWEB)

Ray, R.; Logan, J.; Ray, R.; Ruparel, K.; Newberg, A.; Wileyto, E.P.; Loughead, J.W.; Divgi, C.; Blendy, J.A.; Logan, J.; Zubieta, J.-K.; Lerman, C.

2011-04-15

Evidence points to the endogenous opioid system, and the mu-opioid receptor (MOR) in particular, in mediating the rewarding effects of drugs of abuse, including nicotine. A single nucleotide polymorphism (SNP) in the human MOR gene (OPRM1 A118G) has been shown to alter receptor protein level in preclinical models and smoking behavior in humans. To clarify the underlying mechanisms for these associations, we conducted an in vivo investigation of the effects of OPRM1 A118G genotype on MOR binding potential (BP{sub ND} or receptor availability). Twenty-two smokers prescreened for genotype (12 A/A, 10 */G) completed two [{sup 11}C] carfentanil positron emission tomography (PET) imaging sessions following overnight abstinence and exposure to a nicotine-containing cigarette and a denicotinized cigarette. Independent of session, smokers homozygous for the wild-type OPRM1 A allele exhibited significantly higher levels of MOR BP{sub ND} than smokers carrying the G allele in bilateral amygdala, left thalamus, and left anterior cingulate cortex. Among G allele carriers, the extent of subjective reward difference (denicotinized versus nicotine cigarette) was associated significantly with MOR BP{sub ND} difference in right amygdala, caudate, anterior cingulate cortex, and thalamus. Future translational investigations can elucidate the role of MORs in nicotine addiction, which may lead to development of novel therapeutics.

The effect of opioid receptor blockade on the neural processing of thermal stimuli.

Directory of Open Access Journals (Sweden)

Eszter D Schoell

Full Text Available The endogenous opioid system represents one of the principal systems in the modulation of pain. This has been demonstrated in studies of placebo analgesia and stress-induced analgesia, where anti-nociceptive activity triggered by pain itself or by cognitive states is blocked by opioid antagonists. The aim of this study was to characterize the effect of opioid receptor blockade on the physiological processing of painful thermal stimulation in the absence of cognitive manipulation. We therefore measured BOLD (blood oxygen level dependent signal responses and intensity ratings to non-painful and painful thermal stimuli in a double-blind, cross-over design using the opioid receptor antagonist naloxone. On the behavioral level, we observed an increase in intensity ratings under naloxone due mainly to a difference in the non-painful stimuli. On the neural level, painful thermal stimulation was associated with a negative BOLD signal within the pregenual anterior cingulate cortex, and this deactivation was abolished by naloxone.

Atypical Opioid Mechanisms of Control of Injury-Induced Cutaneous Pain by Delta Receptors

Science.gov (United States)

2016-07-01

treat, and current opioids (i.e. mu opioid receptor agonists such as morphine) cause unacceptable side effects including addiction . Injuries suffered...treat, and current opioids that act on mu opioid receptors such as morphine generate significant side effects including addiction . War-related...al., J Neurosci Methods, 1994), starting with 0.1 g and ending with 2.0 g filament as cutoff value. As shown in Figure 2, our preliminary experiments

Endogenous Opiates in the Nucleus Tractus Solitarius Mediate Electroacupuncture-Induced Sleep Activities in Rats

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Chiung-Hsiang Cheng

2011-01-01

Full Text Available Electroacupuncture (EA possesses various therapeutic effects, including alleviation of pain, reduction of inflammation and improvement of sleep disturbance. The mechanisms of EA on sleep improvement, however, remain to be determined. It has been stated in ancient Chinese literature that the Anmian (EX17 acupoint is one of the trigger points that alleviates insomnia. We previously demonstrated that EA stimulation of Anmian acupoints in rats during the dark period enhances non-rapid eye movement (NREM sleep, which involves the induction of cholinergic activity in the nucleus tractus solitarius (NTS. In addition to cholinergic activation of the NTS, activation of the endogenous opioidergic system may also be a mechanism by which acupuncture affects sleep. Therefore, this study was designed to investigate the involvement of the NTS opioidergic system in EA-induced alterations in sleep. Our present results indicate that EA of Anmian acupoints increased NREM sleep, but not rapid eye movement sleep, during the dark period in rats. This enhancement in NREM sleep was dose-dependently blocked by microinjection of opioid receptor antagonist, naloxone, and the μ-opioid receptor antagonist, naloxonazine, into the NTS; administrations of δ-receptor antagonist, natrindole, and the κ-receptor antagonist, nor-binaltrophimine, however, did not affect EA-induced alterations in sleep. Furthermore, β-endorphin was significantly increased in both the brainstem and hippocampus after the EA stimuli, an effect blocked by administration of the muscarinic antagonist scopolamine into the NTS. Our findings suggest that mechanisms of EA-induced NREM sleep enhancement may be mediated, in part, by cholinergic activation, stimulation of the opiodergic neurons to increase the concentrations of β-endorphin and the involvement of the μ-opioid receptors.

Opioid adjuvant strategy: improving opioid effectiveness.

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Bihel, Frédéric

2016-01-01

Opioid analgesics continue to be the mainstay of pharmacologic treatment of moderate to severe pain. Many patients, particularly those suffering from chronic pain, require chronic high-dose analgesic therapy. Achieving clinical efficacy and tolerability of such treatment regimens is hampered by the appearance of opioid-induced side effects such as tolerance, hyperalgesia and withdrawal syndrome. Among the therapeutic options to improve the opioid effectiveness, this current review focuses on strategies combining opioids to other drugs that can modulate opioid-mediated effects. We will discuss about experimental evidences reported for several potential opioid adjuvants, including N-methyl-D-aspartate receptor antagonists, 5-HT7 agonists, sigma-1 antagonists, I2-R ligands, cholecystokinin antagonists, neuropeptide FF-R antagonists and toll-like receptor 4 antagonists.

Nitrous oxide as an opioid agonist: some experimental and clinical applications

International Nuclear Information System (INIS)

Gillman, M.A.

1984-01-01

The interactions of nitrous oxide at analgesic concentrations with the endogenous opioid system is investigated, both in vitro and in vivo, with particular emphasis on the possibility that nitrous oxide is a possible tool both experimentally, diagnostically and therapeutically. In vitro findings show that nitrous oxide displaces ( 3 H) - naloxone from its binding sites in a definite and measurable manner, indicating a direct action of nitrous oxide at opioid receptors, in this case the mu site. An additional finding is that nitrous oxide unmasks a heretofore undiscovered super high affinity sites which may be an opioid auto-receptor. Naloxone was demonstrated to reverse acute alcoholic intoxication in some cases. The investigative as well as therapeutic role of nitrous oxide was investigated. It is concluded that nitrous oxide at analgesic concentrations (ie. low concentrations of nitrous oxide diluted with high concentrations of oxygen) is a safe and effective therapeutic agent

The potent opioid agonist, (+)-cis-3-methylfentanyl binds pseudoirreversibly to the opioid receptor complex in vitro and in vivo: Evidence for a novel mechanism of action

Energy Technology Data Exchange (ETDEWEB)

Band, L.; Xu, Heng; Bykov, V.; Rothman, R.B.; Kim, Chongho; Newman, A.; Jacobson, A.E.; Rice, K.C. (NIDDK, Bethesda, MD (USA)); Greig, N. (NIA, Bethesda, MD (USA))

1990-01-01

The present study demonstrates that pretreatment of rat brain membranes with (+)-cis-3-methylfentanyl ((+)-cis-MF), followed by extensive washing of the membranes, produces a wash-resistant decreasing in the binding of ({sup 3}H)-(D-ala{sup 2}, D-leu{sup 5})enkephalin to the d binding site of the opioid receptor complex ({delta}{sub cx} binding site). Intravenous administration of (+)-cis-MF (50 {mu}g/kg) to rats produced a pronounced catalepsy and also produced a wash-resistant masking of {delta}{sub cx} and {mu} binding sites in membranes prepared 120 min post-injection. Administration of 1 mg/kg i.v. of the opioid antagonist, 6-desoxy-6{beta}-fluoronaltrexone (cycloFOXY), 100 min after the injection of (+)-cis-MF (20 min prior to the preparation of membranes) completely reversed the catatonia and restored masked {delta}{sub cx} binding sites to control levels. This was not observed with (+)-cycloFOXY. The implications of these and other findings for the mechanism of action of (+)-cis-MF and models of the opioid receptors are discussed.

Chronic nicotine-induced changes in gene expression of delta and kappa-opioid receptors and their endogenous ligands in the mesocorticolimbic system of the rat.

Science.gov (United States)

Ugur, Muzeyyen; Kaya, Egemen; Gozen, Oguz; Koylu, Ersin O; Kanit, Lutfiye; Keser, Aysegul; Balkan, Burcu

2017-09-01

Delta and kappa opioid receptors (DOR and KOR, respectively) and their endogenous ligands, proenkephalin (PENK) and prodynorphin (PDYN)-derived opioid peptides are proposed as important mediators of nicotine reward. This study investigated the regulatory effect of chronic nicotine treatment on the gene expression of DOR, KOR, PENK and PDYN in the mesocorticolimbic system. Three groups of rats were injected subcutaneously with nicotine at doses of 0.2, 0.4, or 0.6 mg/kg/day for 6 days. Rats were decapitated 1 hr after the last dose on day six, as this timing coincides with increased dopamine release in the mesocorticolimbic system. mRNA levels in the ventral tegmental area (VTA), lateral hypothalamic area (LHA), amygdala (AMG), dorsal striatum (DST), nucleus accumbens, and medial prefrontal cortex were measured by quantitative real-time PCR. Our results showed that nicotine upregulated DOR mRNA in the VTA at all of the doses employed, in the AMG at the 0.4 and 0.6 mg/kg doses, and in the DST at the 0.4 mg/kg dose. Conversely, PDYN mRNA was reduced in the LHA with 0.6 mg/kg nicotine and in the AMG with 0.4 mg/kg nicotine. KOR mRNA was also decreased in the DST with 0.6 mg/kg nicotine. Nicotine did not regulate PENK mRNA in any brain region studied. © 2017 Wiley Periodicals, Inc.

Opioid rotation with extended-release opioids: where should we begin?

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Nalamachu S

2011-12-01

Full Text Available Srinivas NalamachuInternational Clinical Research Institute and Pain Management Institute, Overland Park, KS, USAAbstract: Opioid rotation is a common and necessary clinical practice in the management of chronic non-cancer pain to improve therapeutic efficacy with the lowest opioid dose. When dose escalations fail to achieve adequate analgesia or are associated with intolerable side effects, a trial of a new opioid should be considered. Much of the scientific rationale of opioid rotation is based on the wide interindividual variability in sensitivity to opioid analgesics and the novel patient response observed when introducing an opioid-tolerant patient to a new opioid. This article discusses patient indicators for opioid rotation, the conversion process between opioid medications, and additional practical considerations for increasing the effectiveness of opioid therapy during a trial of a new opioid. A Patient vignette that demonstrates a step-wise approach to opioid rotation is also presented.Keywords: extended-release opioids, chronic pain, opioid rotation

Opioid-induced delay in gastric emptying: a peripheral mechanism in humans.

LENUS (Irish Health Repository)

Murphy, D B

2012-02-03

BACKGROUND: Opioids delay gastric emptying, which in turn may increase the risk of vomiting and pulmonary aspiration. Naloxone reverses this opiate action on gastric emptying, but it is not known whether this effect in humans is mediated by central or peripheral opiate antagonism. The importance of peripheral opioid receptor antagonism in modulating opioid-induced delay in gastric emptying was evaluated using methylnaltrexone, a quaternary derivative of the opiate antagonist naltrexone, which does not cross the blood-brain barrier. METHODS: In a randomized, double-blind, crossover placebo-controlled study, 11 healthy volunteers were given either placebo (saline), 0.09 mg\\/kg morphine, or 0.09 mg\\/kg morphine plus 0.3 mg\\/kg methylnaltrexone on three separate occasions before ingesting 500 ml deionized water. The rate of gastric emptying was measured by two methods: a noninvasive epigastric bioimpedance technique and the acetaminophen absorption test. RESULTS: The epigastric bioimpedance technique was sufficiently sensitive to detect opioid-induced changes in the rate of gastric emptying. The mean +\\/- SD time taken for the gastric volume to decrease to 50% (t0.5) after placebo was 5.5 +\\/- 2.1 min. Morphine prolonged gastric emptying to (t0.5) of 21 +\\/- 9.0 min (P < 0.03). Methylnaltrexone given concomitantly with morphine reversed the morphine-induced delay in gastric emptying to a t0.5 of 7.4 +\\/- 3.0 (P < 0.04). Maximum concentrations and area under the concentration curve from 0 to 90 min of serum acetaminophen concentrations after morphine were significantly different from placebo and morphine administered concomitantly with methylnaltrexone (P < 0.05). No difference in maximum concentration or area under the concentration curve from 0 to 90 min was noted between placebo and methylnaltrexone coadministered with morphine. CONCLUSIONS: The attenuation of morphine-induced delay in gastric emptying by methylnaltrexone suggests that the opioid effect is

Disruption of gut homeostasis by opioids accelerates HIV disease progression

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Jingjing eMeng

2015-06-01

Full Text Available Cumulative studies during the past 30 years have established the correlation between opioid abuse and human immunodeficiency virus (HIV infection. Further studies also demonstrate that opioid addiction is associated with faster progression to AIDS in patients. Recently, it was revealed that disruption of gut homeostasis and subsequent microbial translocation play important roles in pathological activation of the immune system during HIV infection and contributes to accelerated disease progression. Similarly, opioids have been shown to modulate gut immunity and induce gut bacterial translocation. This review will explore the mechanisms by which opioids accelerate HIV disease progression by disrupting gut homeostasis. Better understanding of these mechanisms will facilitate the search for new therapeutic interventions to treat HIV infection especially in opioid abusing population.

Dextromethorphan differentially affects opioid antinociception in rats

Science.gov (United States)

Chen, Shiou-Lan; Huang, Eagle Yi-Kung; Chow, Lok-Hi; Tao, Pao-Luh

2005-01-01

Opioid drugs such as morphine and meperidine are widely used in clinical pain management, although they can cause some adverse effects. A number of studies indicate that N-methyl-D-aspartate (NMDA) receptors may play a role in the mechanism of morphine analgesia, tolerance and dependence. Being an antitussive with NMDA antagonist properties, dextromethorphan (DM) may have some therapeutic benefits when coadministered with morphine. In the present study, we investigated the effects of DM on the antinociceptive effects of different opioids. We also investigated the possible pharmacokinetic mechanisms involved. The antinociceptive effects of the μ-opioid receptor agonists morphine (5 mg kg−1, s.c.), meperidine (25 mg kg−1, s.c.) and codeine (25 mg kg−1, s.c.), and the κ-opioid agonists nalbuphine (8 mg kg−1, s.c.) and U-50,488H (20 mg kg−1, s.c.) were studied using the tail-flick test in male Sprague–Dawley rats. Coadministration of DM (20 mg kg−1, i.p.) with these opioids was also performed and investigated. The pharmacokinetic effects of DM on morphine and codeine were examined, and the free concentration of morphine or codeine in serum was determined by HPLC. It was found that DM potentiated the antinociceptive effects of some μ-opioid agonists but not codeine or κ-opioid agonists in rats. DM potentiated morphine's antinociceptive effect, and acutely increased the serum concentration of morphine. In contrast, DM attenuated the antinociceptive effect of codeine and decreased the serum concentration of its active metabolite (morphine). The pharmacokinetic interactions between DM and opioids may partially explain the differential effects of DM on the antinociception caused by opioids. PMID:15655510

Development of concepts on the interaction of drugs with opioid receptors

Energy Technology Data Exchange (ETDEWEB)

Kuzmina, N E; Kuzmin, V S

2011-02-28

The development of concepts on the molecular mechanisms of the action of medicinal drugs on the opioid receptors is briefly surveyed. The modern point of view on the mechanism of activation of opioid receptors is given based on the data from chimeric and site-directed mutagenesis of the cloned opioid receptors and the computer-aided simulations of the reception zone and ligand-receptor complexes. Three-dimensional models of the opioid pharmacophore derived by both conventional methods and a comparative analysis of molecular fields are described in detail.

Non-analgesic effects of opioids: opioids and the endocrine system.

Science.gov (United States)

Elliott, Jennifer A; Opper, Susan E; Agarwal, Sonali; Fibuch, Eugene E

2012-01-01

Opioids are among the oldest known and most widely used analgesics. The application of opioids has expanded over the last few decades, especially in the treatment of chronic non-malignant pain. This upsurge in opioid use has been accompanied by the increasingly recognized occurrence of opioid-associated endocrinopathy. This may arise after exposure to enteral, parenteral, or neuraxial opioids. Opioid-associated endocrinopathy consists primarily of hypothalamic-pituitary-gonadal axis or hypothalamic-pituitary-adrenal axis dysfunction and may manifest with symptoms of hypogonadism, adrenal dysfunction, and other hormonal disturbances. Additionally, opioid related endocrine dysfunction may be coupled with such disorders as osteoporosis and mood disturbances including depression. Undesirable changes in pain sensitivity such as opioid-induced hyperalgesia, and reduced potency of opioid analgesia may also be potential consequences of chronic opioid consumption. Few studies to date have been able to establish what degree of opioid exposure, in terms of dose or duration of therapy, may predispose patients to opioid-associated endocrinopathy. This article will review the currently available literature concerning opioid-associated endocrinopathy and will provide recommendations for the evaluation, monitoring, and management of opioid-associated endocrinopathy and its other accompanying undesired effects.

Combining Semi-Endogenous and Fully Endogenous Growth: a Generalization.

OpenAIRE

Cozzi, Guido

2017-01-01

This paper shows that combining the semi-endogenous and the fully endogenous growth mechanisms with a general CES aggregator, either growth process can prevail in the balanced growth path depending on their degree of complementarity/substitutability. Policy-induced long-run economic switches to the fully endogenous steady state as the R&D employment ratio surpasses a positive threshold are possible if the two growth engines are gross substitutes.

Response of the μ-opioid system to social rejection and acceptance.

Science.gov (United States)

Hsu, D T; Sanford, B J; Meyers, K K; Love, T M; Hazlett, K E; Wang, H; Ni, L; Walker, S J; Mickey, B J; Korycinski, S T; Koeppe, R A; Crocker, J K; Langenecker, S A; Zubieta, J-K

2013-11-01

The endogenous opioid system, which alleviates physical pain, is also known to regulate social distress and reward in animal models. To test this hypothesis in humans (n=18), we used an μ-opioid receptor (MOR) radiotracer to measure changes in MOR availability in vivo with positron emission tomography during social rejection (not being liked by others) and acceptance (being liked by others). Social rejection significantly activated the MOR system (i.e., reduced receptor availability relative to baseline) in the ventral striatum, amygdala, midline thalamus and periaqueductal gray (PAG). This pattern of activation is consistent with the hypothesis that the endogenous opioids have a role in reducing the experience of social pain. Greater trait resiliency was positively correlated with MOR activation during rejection in the amygdala, PAG and subgenual anterior cingulate cortex (sgACC), suggesting that MOR activation in these areas is protective or adaptive. In addition, MOR activation in the pregenual ACC was correlated with reduced negative affect during rejection. In contrast, social acceptance resulted in MOR activation in the amygdala and anterior insula, and MOR deactivation in the midline thalamus and sgACC. In the left ventral striatum, MOR activation during acceptance predicted a greater desire for social interaction, suggesting a role for the MOR system in social reward. The ventral striatum, amygdala, midline thalamus, PAG, anterior insula and ACC are rich in MORs and comprise a pathway by which social cues may influence mood and motivation. MOR regulation of this pathway may preserve and promote emotional well being in the social environment.

Are Prescription Opioids Driving the Opioid Crisis? Assumptions vs Facts.

Science.gov (United States)

Rose, Mark Edmund

2018-04-01

Sharp increases in opioid prescriptions, and associated increases in overdose deaths in the 2000s, evoked widespread calls to change perceptions of opioid analgesics. Medical literature discussions of opioid analgesics began emphasizing patient and public health hazards. Repetitive exposure to this information may influence physician assumptions. While highly consequential to patients with pain whose function and quality of life may benefit from opioid analgesics, current assumptions about prescription opioid analgesics, including their role in the ongoing opioid overdose epidemic, have not been scrutinized. Information was obtained by searching PubMed, governmental agency websites, and conference proceedings. Opioid analgesic prescribing and associated overdose deaths both peaked around 2011 and are in long-term decline; the sharp overdose increase recorded in 2014 was driven by illicit fentanyl and heroin. Nonmethadone prescription opioid analgesic deaths, in the absence of co-ingested benzodiazepines, alcohol, or other central nervous system/respiratory depressants, are infrequent. Within five years of initial prescription opioid misuse, 3.6% initiate heroin use. The United States consumes 80% of the world opioid supply, but opioid access is nonexistent for 80% and severely restricted for 4.1% of the global population. Many current assumptions about opioid analgesics are ill-founded. Illicit fentanyl and heroin, not opioid prescribing, now fuel the current opioid overdose epidemic. National discussion has often neglected the potentially devastating effects of uncontrolled chronic pain. Opioid analgesic prescribing and related overdoses are in decline, at great cost to patients with pain who have benefited or may benefit from, but cannot access, opioid analgesic therapy.

Safety and efficacy of an oxycodone vaccine: Addressing some of the unique considerations posed by opioid abuse.

Directory of Open Access Journals (Sweden)

M D Raleigh

Full Text Available Among vaccines aimed at treating substance use disorders, those targeting opioids present several unique medication development challenges. 1 Opioid overdose is a common complication of abuse, so it is desirable for an opioid vaccine to block the toxic as well as the addictive effects of opioids. 2 It is important that an opioid vaccine not interfere with the action of opioid antagonists used to reverse opioid overdose or treat addiction. 3 Some opioids are immunosuppressive and chronic ongoing opioid use could interfere with vaccine immunogenicity. 4 Although antibody-bound oxycodone is unable to enter the brain because of its size, it might still be able to activate peripheral opioid receptors. To assess vaccine impact on opioid toxicity, rats vaccinated with oxycodone conjugated to keyhole limpet hemocyanin subunit dimer (OXY-dKLH adsorbed to alum or controls vaccinated with dKLH were compared with regard to oxycodone-induced hotplate analgesia and oxycodone-induced respiratory depression and bradycardia. Vaccination shifted the dose-response curves to the right, representing protection, for each of these endpoints. Naloxone was equally effective in both OXY-dKLH and control groups, providing complete and rapid reversal of respiratory depression. The administration of a long-acting naltrexone formulation during vaccination did not impair vaccine immunogenicity in mice. Similarly, serum anti-oxycodone antibody titers were not altered by continuous morphine infusion during vaccination compared to opioid-naïve controls. Competitive ELISA assay showed negligible or low affinity of immune antiserum for endogenous opioids or opioid antagonists. In vitro receptor binding assays showed that antibody-bound oxycodone does not activate mu opioid receptors. These data support further study of OXY-dKLH as a potential treatment for oxycodone abuse and suggest that vaccination might also reduce the severity of oxycodone overdose.

Brain catalase activity inhibition as well as opioid receptor antagonism increases ethanol-induced HPA axis activation.

Science.gov (United States)

Pastor, Raúl; Sanchis-Segura, Carles; Aragon, Carlos M G

2004-12-01

Growing evidence indicates that brain catalase activity is involved in the psychopharmacological actions of ethanol. Recent data suggest that participation of this enzymatic system in some ethanol effects could be mediated by the endogenous opioid system. The present study assessed whether brain catalase has a role in ethanol-induced activation of the HPA axis, a neuroendocrine system modulated by the endogenous opioid neurotransmission. Swiss male mice received an intraperitoneal injection of the catalase inhibitor 3-amino-1,2,4-triazole (AT; 0-1 g/kg), and 0 to 20 hr after this administration, animals received an ethanol (0-4 g/kg; intraperitoneally) challenge. Thirty, 60, or 120 min after ethanol administration, plasma corticosterone levels were determined immunoenzymatically. In addition, we tested the effects of 45 mg/kg of cyanamide (another catalase inhibitor) and 0 to 2 mg/kg of naltrexone (nonselective opioid receptor antagonist) on ethanol-induced enhancement in plasma corticosterone values. The present study revealed that AT boosts ethanol-induced increase in plasma corticosterone levels in a dose- and time-dependent manner. However, it did not affect corticosterone values when measured after administration of saline, cocaine (4 mg/kg, intraperitoneally), or morphine (30 mg/kg, intraperitoneally). The catalase inhibitor cyanamide (45 mg/kg, intraperitoneally) also increased ethanol-related plasma corticosterone levels. These effects of AT and cyanamide on ethanol-induced corticosterone values were observed under treatment conditions that decreased significantly brain catalase activity. Indeed, a significant correlation between effects of catalase manipulations on both variables was found. Finally, we found that the administration of naltrexone enhanced the levels of plasma corticosterone after the administration of saline or ethanol. This study shows that the inhibition of brain catalase increases ethanol-induced plasma corticosterone levels. Results are

Are peripheral opioid antagonists the solution to opioid side effects?

LENUS (Irish Health Repository)

Bates, John J

2012-02-03

Opioid medication is the mainstay of therapy for severe acute and chronic pain. Unfortunately, the side effects of these medications can affect patient comfort and safety, thus limiting their proven therapeutic potential. Whereas the main analgesic effects of opioids are centrally mediated, many of the common side effects are mediated via peripheral receptors. Novel peripheral opioid antagonists have been recently introduced that can block the peripheral actions of opioids without affecting centrally mediated analgesia. We review the clinical and experimental evidence of their efficacy in ameliorating opioid side effects and consider what further information might be useful in defining their role. IMPLICATIONS: The major analgesic effects of opioid medication are mediated within the brain and spinal cord. Many of the side effects of opioids are caused by activation of receptors outside these areas. Recently developed peripherally restricted opioid antagonists have the ability to block many opioid side effects without affecting analgesia.

Cell-Autonomous Regulation of Mu-Opioid Receptor Recycling by Substance P

Directory of Open Access Journals (Sweden)

Shanna L. Bowman

2015-03-01

Full Text Available How neurons coordinate and reprogram multiple neurotransmitter signals is an area of broad interest. Here, we show that substance P (SP, a neuropeptide associated with inflammatory pain, reprograms opioid receptor recycling and signaling. SP, through activation of the neurokinin 1 (NK1R receptor, increases the post-endocytic recycling of the mu-opioid receptor (MOR in trigeminal ganglion (TG neurons in an agonist-selective manner. SP-mediated protein kinase C (PKC activation is both required and sufficient for increasing recycling of exogenous and endogenous MOR in TG neurons. The target of this cross-regulation is MOR itself, given that mutation of either of two PKC phosphorylation sites on MOR abolishes the SP-induced increase in recycling and resensitization. Furthermore, SP enhances the resensitization of fentanyl-induced, but not morphine-induced, antinociception in mice. Our results define a physiological pathway that cross-regulates opioid receptor recycling via direct modification of MOR and suggest a mode of homeostatic interaction between the pain and analgesic systems.

Effect of the opioid methionine enkephalinamide on signal transduction in human T-lymphocytes

DEFF Research Database (Denmark)

Sørensen, A N; Claesson, Mogens Helweg

1998-01-01

T cell receptor (TCR/CD3) induced fluctuations in intracellular free ionizied calcium, [Ca2+]i, was analysed in the human T leukemia cell clone, Jurkat, cultured in the presence of the opioid methionine enkephalinamide (Met-Enk) in titrated concentrations (10[-7] to 10[-15] M) or saline (PBS....... Moreover, the levels of [Ca2+]i in this particular fraction were lower than control levels prior to ligation of the TCR/CD3 complex. The data support the idea that signal transduction in T cells can be influenced by endogenous opioid. The data therefore give credit to the evolving hypothesis...... of a functional relationship between the neuroendocrine system and the immune system....

Kappa-Opioid Antagonists for Psychiatric Disorders: From Bench to Clinical Trials.

Science.gov (United States)

Carlezon, William A; Krystal, Andrew D

2016-10-01

Kappa-opioid receptor (KOR) antagonists are currently being considered for the treatment of a variety of neuropsychiatric conditions, including depressive, anxiety, and substance abuse disorders. A general ability to mitigate the effects of stress, which can trigger or exacerbate these conditions, may explain their putative efficacy across such a broad array of conditions. The discovery of their potentially therapeutic effects evolved from preclinical research designed to characterize the molecular mechanisms by which experience causes neuroadaptations in the nucleus accumbens (NAc), a key element of brain reward circuitry. This research established that exposure to drugs of abuse or stress increases the activity of the transcription factor CREB (cAMP response element binding protein) in the NAc, which leads to elevated expression of the opioid peptide dynorphin that in turn causes core signs of depressive- and anxiety-related disorders. Disruption of KORs-the endogenous receptors for dynorphin-produces antidepressant- and anxiolytic-like actions in screening procedures that identify standard drugs of these classes, and reduces stress effects in tests used to study addiction and stress-related disorders. Although interest in this target is high, prototypical KOR antagonists have extraordinarily persistent pharmacodynamic effects that complicate clinical trials. The development of shorter acting KOR antagonists together with more rapid designs for clinical trials may soon provide insight on whether these drugs are efficacious as would be predicted by preclinical work. If successful, KOR antagonists would represent a unique example in psychiatry where the therapeutic mechanism of a drug class is understood before it is shown to be efficacious in humans. © 2016 Wiley Periodicals, Inc.

Endogenous molecular network reveals two mechanisms of heterogeneity within gastric cancer

Science.gov (United States)

Li, Site; Zhu, Xiaomei; Liu, Bingya; Wang, Gaowei; Ao, Ping

2015-01-01

Intratumor heterogeneity is a common phenomenon and impedes cancer therapy and research. Gastric cancer (GC) cells have generally been classified into two heterogeneous cellular phenotypes, the gastric and intestinal types, yet the mechanisms of maintaining two phenotypes and controlling phenotypic transition are largely unknown. A qualitative systematic framework, the endogenous molecular network hypothesis, has recently been proposed to understand cancer genesis and progression. Here, a minimal network corresponding to such framework was found for GC and was quantified via a stochastic nonlinear dynamical system. We then further extended the framework to address the important question of intratumor heterogeneity quantitatively. The working network characterized main known features of normal gastric epithelial and GC cell phenotypes. Our results demonstrated that four positive feedback loops in the network are critical for GC cell phenotypes. Moreover, two mechanisms that contribute to GC cell heterogeneity were identified: particular positive feedback loops are responsible for the maintenance of intestinal and gastric phenotypes; GC cell progression routes that were revealed by the dynamical behaviors of individual key components are heterogeneous. In this work, we constructed an endogenous molecular network of GC that can be expanded in the future and would broaden the known mechanisms of intratumor heterogeneity. PMID:25962957

Molecular mechanism of action of opioids in human neuroblastoma cells

International Nuclear Information System (INIS)

Yu, V.C.K.

1987-01-01

A series of human neuroblastoma cell lines was screened for the presence of opioid receptor sites. Of these cell lines, SK-N-SH was found to express approximately 50,000 μ and 10,000 δ opioid receptor sites/cell. In vitro characterization revealed that the binding properties of these receptor sites closely resembled those of human and rodent brain. Phosphatidylinositol turnover as a potential second messenger system for the μ receptor was examined in SK-N-SH cells. Neurotransmitter receptor systems were determined in the three sub-clones of SK-N-SH cells. Cells of the SH-SY5Y line, a phenotypically stable subclone of SK-N-SH cells, were induced to differentiate by treatment with various inducing agents, and changes of several neurotransmitter receptor systems were determined. Nerve growth factor (NGF) and retinoic acid (RA) up-regulated, while dBcAMP down-regulated opioid receptor sites. [ 3 H]Dopamine uptake was slightly enhanced only in RA-treated cells. Strikingly, the efficacy of PGE 1 -stimulated accumulation of cAMP was enhanced by 15- to 30-fold upon RA treatment

Effects of stress and. beta. -funal trexamine pretreatment on morphine analgesia and opioid binding in rats

Energy Technology Data Exchange (ETDEWEB)

Adams, J.U.; Andrews, J.S.; Hiller, J.M.; Simon, E.J.; Holtzman, S.G.

1987-12-28

This study was essentially an in vivo protection experiment designed to test further the hypothesis that stress induces release of endogenous opiods which then act at opioid receptors. Rats that were either subjected to restraint stress for 1 yr or unstressed were injected ICV with either saline or 2.5 ..mu..g of ..beta..-funaltrexamine (..beta..-FNA), an irreversible opioid antagonist that alkylates the mu-opioid receptor. Twenty-four hours later, subjects were tested unstressed for morphine analgesia or were sacrificed and opioid binding in brain was determined. (/sup 3/H)D-Ala/sup 2/NMePhe/sup 4/-Gly/sup 5/(ol)enkephalin (DAGO) served as a specific ligand for mu-opioid receptors, and (/sup 3/H)-bremazocine as a general ligand for all opioid receptors. Rats injected with saline while stressed were significantly less sensitive to the analgesic action of morphine 24 hr later than were their unstressed counterparts. ..beta..-FNA pretreatment attenuated morphine analgesia in an insurmountable manner. Animals pretreated with ..beta..-FNA while stressed were significantly more sensitive to the analgesic effect of morphine than were animals that received ..beta..-FNA while unstressed. ..beta..-FNA caused small and similar decreases in (/sup 3/H)-DAGO binding in brain of both stressed and unstressed animals. 35 references, 2 figures, 2 tables.

Is there a role for opioids in the treatment of fibromyalgia?

Science.gov (United States)

Littlejohn, Geoffrey O; Guymer, Emma K; Ngian, Gene-Siew

2016-05-01

The use of opioids for chronic pain has increased significantly due to a combination of the high patient burden of pain and the more widespread availability of a range of long-acting opioid preparations. This increased opioid use has translated into the care of many patients with fibromyalgia. The pain mechanism in fibromyalgia is complex but does not seem to involve disturbance of opioid analgesic functions. Hence, there is general concern about the harms in the absence of benefits of opioids in this setting. There is no evidence that pure opioids are effective in fibromyalgia but there is some evidence that opioids with additional actions on the norepinephrine-related pain modulatory pathways, such as tramadol, can be clinically useful in some patients. Novel actions of low-dose opioid antagonists may lead to better understanding of the role of opioid function in fibromyalgia.

Endogenous reward mechanisms and their importance in stress reduction, exercise and the brain.

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Esch, Tobias; Stefano, George B

2010-06-30

Stress can facilitate disease processes and causes strain on the health care budgets. It is responsible or involved in many human ailments of our time, such as cardiovascular illnesses, particularly related to the psychosocial stressors of daily life, including work. Besides pharmacological or clinical medical treatment options, behavioral stress reduction is much-needed. These latter approaches rely on an endogenous healing potential via life-style modification. Hence, research has suggested different ways and approaches to self-treat stress or buffer against stressors and their impacts. These self-care-centred approaches are sometimes referred to as mind-body medicine or multi-factorial stress management strategies. They consist of various cognitive behavioral techniques, as well as relaxation exercises and nutritional counselling. However, a critical and consistent element of modern effective stress reduction strategies are exercise practices. With regard to underlying neurobiological mechanisms of stress relief, reward and motivation circuitries that are imbedded in the limbic regions of the brain are responsible for the autoregulatory and endogenous processing of stress. Exercise techniques clearly have an impact upon these systems. Thereby, physical activities have a potential to increase mood, i.e., decrease psychological distress by pleasure induction. For doing so, neurobiological signalling molecules such as endogenous morphine and coupled nitric oxide pathways get activated and finely tuned. Evolutionarily, the various activities and autoregulatory pathways are linked together, which can also be demonstrated by the fact that dopamine is endogenously converted into morphine which itself leads to enhanced nitric oxide release by activation of constitutive nitric oxide synthase enzymes. These molecules and mechanisms are clearly stress-reducing.

Opioid intoxication

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... easily result in intoxication. The provider prescribes a sleep medicine (sedative) in addition to the opioid. The provider ... an opioid with certain other drugs, such as sleep medicines or alcohol Taking the opioid in ways not ...

The role of opioid antagonist efficacy and constitutive opioid receptor activity in the opioid withdrawal syndrome in mice

OpenAIRE

Navani, Dipesh M.; Sirohi, Sunil; Madia, Priyanka A.; Yoburn, Byron C.

2011-01-01

On the basis of efficacy, opioid antagonists are classified as inverse opioid agonists (e.g. naltrexone) or neutral opioid antagonists (e.g. 6β-naltrexol). This study examined the interaction between naltrexone and 6β-naltrexol in the precipitated opioid withdrawal syndrome in morphine dependent mice. Furthermore, the possible contribution of constitutive opioid receptor activity to precipitated withdrawal was evaluated using increasing levels of morphine dependence. In the first experiment, ...

Neurobiological mechanisms of placebo responses.

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Zubieta, Jon-Kar; Stohler, Christian S

2009-03-01

Expectations, positive or negative, are modulating factors influencing behavior. They are also thought to underlie placebo effects, potentially impacting perceptions and biological processes. We used sustained pain as a model to determine the neural mechanisms underlying placebo-induced analgesia and affective changes in healthy humans. Subjects were informed that they could receive either an active agent or an inactive compound, similar to routine clinical trials. Using PET and the mu-opioid selective radiotracer [(11)C]carfentanil we demonstrate placebo-induced activation of opioid neurotransmission in a number of brain regions. These include the rostral anterior cingulate, orbitofrontal and dorsolateral prefrontal cortex, anterior and posterior insula, nucleus accumbens, amygdala, thalamus, hypothalamus, and periaqueductal grey. Some of these regions overlap with those involved in pain and affective regulation but also motivated behavior. The activation of endogenous opioid neurotransmission was further associated with reductions in pain report and negative affective state. Additional studies with the radiotracer [(11)C]raclopride, studies labeling dopamine D2/3 receptors, also demonstrate the activation of nucleus accumbens dopamine during placebo administration under expectation of analgesia. Both dopamine and opioid neurotransmission were related to expectations of analgesia and deviations from those initial expectations. When the activity of the nucleus accumbens was probed with fMRI using a monetary reward expectation paradigm, its activation was correlated with both dopamine, opioid responses to placebo in this region and the formation of placebo analgesia. These data confirm that specific neural circuits and neurotransmitter systems respond to the expectation of benefit during placebo administration, inducing measurable physiological changes.

γ-endorphin and Nα-acetyl-γ-endorphin interfere with distinct dopaminergic systems in the nucleus accumbens via opioid and non-opioid mechanisms

NARCIS (Netherlands)

Ree, J.M. van; Gaffori, O.; Kiraly, I.

1984-01-01

Low doses (10 ng) of the dopamine agonist apomorphine induced hypolocomotion when injected into the nucleus accumbens of rats. This behavioral response was antagonized by local treatment with either the opioid peptide γ-endorphin (γE) or the non-opioid peptide Nα-acetyl-γ-endorphin (AcγE) in a dose

Radioreceptor opioid assay

International Nuclear Information System (INIS)

Miller, R.J.; Chang, K.-J.

1981-01-01

A radioreceptor assay is described for assaying opioid drugs in biological fluids. The method enables the assay of total opioid activity, being specific for opioids as a class but lacking specificity within the class. A radio-iodinated opioid and the liquid test sample are incubated with an opiate receptor material. The percentage inhibition of the binding of the radio-iodinated compound to the opiate receptor is calculated and the opioid activity of the test liquid determined from a standard curve. Examples of preparing radio-iodinated opioids and assaying opioid activity are given. A test kit for the assay is described. Compared to other methods, this assay is cheap, easy and rapid. (U.K.)

Comorbid Post-Traumatic Stress Disorder and Opioid Dependence.

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Patel, Rikinkumar S; Elmaadawi, Ahmed; Nasr, Suhayl; Haskin, John

2017-09-03

Post-traumatic stress disorder (PTSD) is predominant amongst individuals addicted to opioids and obscures the course of illness and the treatment outcome. We report the case of a patient with major depressive disorder and opioid dependence, who experienced post-traumatic stress disorder symptoms during a recent visit to the inpatient unit. The similarity of symptoms between post-traumatic stress disorder and opioid dependence is so high that, sometimes, it is a challenge to differentiate between these conditions. Since opioid withdrawal symptoms mimic hyper vigilance, this results in an exaggeration of the response of patients with post-traumatic stress disorder. This comorbidity is associated with worse health outcomes, as its pathophysiology involves a common neurobiological circuit. Opioid substitution therapy and psychotherapeutic medications in combination with evidence-based cognitive behavioral therapy devised for individuals with comorbid post-traumatic stress disorder and opioid dependence may improve treatment outcomes in this population. Therefore, we conclude that the screening for post-traumatic stress disorder in the opioid-abusing population is crucial. To understand the underlying mechanisms for this comorbidity and to improve the treatment response, further research should be encouraged.

Mechanism of the Interaction of Cannabinoid System in Central Amygdale with Opioid System

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S. Sarahroodi

2008-01-01

Full Text Available Background and objectivesCannabinoids which are active compounds of marijuana show some pharmacological effects similar to the opioids. There are also functional interactions between both cannabinoid and opioid systems. In this study we investigated the role of cannabinoid receptors in central amygdala and its interaction with opioid system.MethodsIn the present study, we investigated the effects of intraperitoneal injection of opioid drugs on response-induced by intra-amygdala (intra-Amyg microinjection of cannabinoid agents in rats, using elevated plus-maze test of anxiety. ResultsIntraperitoneal injection of morphine (3, 6 and 9 mg/kg increased %OAT and %OAE, but not locomotor activity, showing an anxiolytic response. However, some doses of the opioid receptor antagonist, naloxone reduced %OAT and locomotor activity as well. Intra-Amyg administration of CB1 cannabinoid receptor agonist, ACPA (at the dose of 1.25 and 5 ng/rat increased %OAT and %OAE but not locomotor activity, thus showing an anxiolytic response, which was increased by morphine (6 mg/kg, i.p. without any interaction. Naloxone also reduced ACPA effects. Intra-Amyg administration of CB1 cannabinoid receptor antagonist, AM251 (2.5, 25 and 100 ng/rat did not alter %OAT and %OAE but higher doses of drug (25 and 100 ng/rat reduced locomotor activity. However, the drug in combination of morphine anxiolytic response and with naloxone decreased anxiety.ConclusionThe results may indicate an anxiolytic for CB1 cannabinoid. Our results also showed that opioid system may have interaction with cannabinoid receptor in the amygdale. Keywords: Cannabinoids, Morphine; Naloxone, Anxiety, Elevated Plus-Maze

Using behavioral economics to predict opioid use during prescription opioid dependence treatment.

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Worley, Matthew J; Shoptaw, Steven J; Bickel, Warren K; Ling, Walter

2015-03-01

Research grounded in behavioral economics has previously linked addictive behavior to disrupted decision-making and reward-processing, but these principles have not been examined in prescription opioid addiction, which is currently a major public health problem. This study examined whether pre-treatment drug reinforcement value predicted opioid use during outpatient treatment of prescription opioid addiction. Secondary analyses examined participants with prescription opioid dependence who received 12 weeks of buprenorphine-naloxone and counseling in a multi-site clinical trial (N=353). Baseline measures assessed opioid source and indices of drug reinforcement value, including the total amount and proportion of income spent on drugs. Weekly urine drug screens measured opioid use. Obtaining opioids from doctors was associated with lower pre-treatment drug spending, while obtaining opioids from dealers/patients was associated with greater spending. Controlling for demographics, opioid use history, and opioid source frequency, patients who spent a greater total amount (OR=1.30, peconomic resources to drugs, reflects propensity for continued opioid use during treatment among individuals with prescription opioid addiction. Future studies should examine disrupted decision-making and reward-processing in prescription opioid users more directly and test whether reinforcer pathology can be remediated in this population. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Reduced basal ganglia μ-opioid receptor availability in trigeminal neuropathic pain: A pilot study

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DosSantos Marcos

2012-09-01

Full Text Available Abstract Background Although neuroimaging techniques have provided insights into the function of brain regions involved in Trigeminal Neuropathic Pain (TNP in humans, there is little understanding of the molecular mechanisms affected during the course of this disorder. Understanding these processes is crucial to determine the systems involved in the development and persistence of TNP. Findings In this study, we examined the regional μ-opioid receptor (μOR availability in vivo (non-displaceable binding potential BPND of TNP patients with positron emission tomography (PET using the μOR selective radioligand [11C]carfentanil. Four TNP patients and eight gender and age-matched healthy controls were examined with PET. Patients with TNP showed reduced μOR BPND in the left nucleus accumbens (NAc, an area known to be involved in pain modulation and reward/aversive behaviors. In addition, the μOR BPND in the NAc was negatively correlated with the McGill sensory and total pain ratings in the TNP patients. Conclusions Our findings give preliminary evidence that the clinical pain in TNP patients can be related to alterations in the endogenous μ-opioid system, rather than only to the peripheral pathology. The decreased availability of μORs found in TNP patients, and its inverse relationship to clinical pain levels, provide insights into the central mechanisms related to this condition. The results also expand our understanding about the impact of chronic pain on the limbic system.

Opioid withdrawal syndrome: emerging concepts and novel therapeutic targets.

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Rehni, Ashish K; Jaggi, Amteshwar S; Singh, Nirmal

2013-02-01

Opioid withdrawal syndrome is a debilitating manifestation of opioid dependence and responds poorly to the available clinical therapies. Studies from various in vivo and in vitro animal models of opioid withdrawal syndrome have led to understanding of its pathobiology which includes complex interrelated pathways leading to adenylyl cyclase superactivation based central excitation. Advancements in the elucidation of opioid withdrawal syndrome mechanisms have revealed a number of key targets that have been hypothesized to modulate clinical status. The present review discusses the neurobiology of opioid withdrawal syndrome and its therapeutic target recptors like calcitonin gene related peptide receptors (CGRP), N-methyl-D-aspartate (NMDA) receptors, gamma aminobutyric acid receptors (GABA), G-proteingated inwardly rectifying potassium (GIRK) channels and calcium channels. The present review further details the potential role of second messengers like calcium (Ca2+) / calmodulin-dependent protein kinase (CaMKII), nitric oxide synthase, cytokines, arachidonic acid metabolites, corticotropin releasing factor, fos and src kinases in causing opioid withdrawal syndrome. The exploitation of these targets may provide effective therapeutic agents for the management of opioid dependence-induced abstinence syndrome.

Reduction of opioid withdrawal and potentiation of acute opioid analgesia by systemic AV411 (ibudilast).

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Hutchinson, Mark R; Lewis, Susannah S; Coats, Benjamen D; Skyba, David A; Crysdale, Nicole Y; Berkelhammer, Debra L; Brzeski, Anita; Northcutt, Alexis; Vietz, Christine M; Judd, Charles M; Maier, Steven F; Watkins, Linda R; Johnson, Kirk W

2009-02-01

Morphine-induced glial proinflammatory responses have been documented to contribute to tolerance to opioid analgesia. Here, we examined whether drugs previously shown to suppress glial proinflammatory responses can alter other clinically relevant opioid effects; namely, withdrawal or acute analgesia. AV411 (ibudilast) and minocycline, drugs with distinct mechanisms of action that result in attenuation of glial proinflammatory responses, each reduced naloxone-precipitated withdrawal. Analysis of brain nuclei associated with opioid withdrawal revealed that morphine altered expression of glial activation markers, cytokines, chemokines, and a neurotrophic factor. AV411 attenuated many of these morphine-induced effects. AV411 also protected against spontaneous withdrawal-induced hyperactivity and weight loss recorded across a 12-day timecourse. Notably, in the spontaneous withdrawal study, AV411 treatment was delayed relative to the start of the morphine regimen so to also test whether AV411 could still be effective in the face of established morphine dependence, which it was. AV411 did not simply attenuate all opioid effects, as co-administering AV411 with morphine or oxycodone caused three-to-five-fold increases in acute analgesic potency, as revealed by leftward shifts in the analgesic dose response curves. Timecourse analyses revealed that plasma morphine levels were not altered by AV411, suggestive that potentiated analgesia was not simply due to prolongation of morphine exposure or increased plasma concentrations. These data support and extend similar potentiation of acute opioid analgesia by minocycline, again providing converging lines of evidence of glial involvement. Hence, suppression of glial proinflammatory responses can significantly reduce opioid withdrawal, while improving analgesia.

Neurobiology of opioid withdrawal: Role of the endothelin system.

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Bhalla, Shaifali; Andurkar, Shridhar V; Gulati, Anil

2016-08-15

Morphine and oxycodone are potent opioid analgesics most commonly used for the management of moderate to severe acute and chronic pain. Their clinical utility is limited by undesired side effects like analgesic tolerance, dependence, and withdrawal. We have previously demonstrated that endothelin-A (ETA) receptor antagonists potentiate opioid analgesia and eliminate analgesic tolerance. Mechanistically, G proteins and regulatory proteins such as β-arrestins have shown to play an important role in mediating opioid tolerance, dependence, and withdrawal. Recently, the involvement of central ET mechanisms in opioid withdrawal was investigated. ETA receptor antagonist was shown to block majority of the signs and symptoms associated with opioid withdrawal. This review focuses on ET as one of the potential novel strategies to manage the challenge of opioid withdrawal. An overview of additional players in this process (G proteins and β-arrestin2), and the possible therapeutic implications of these findings are presented. Copyright © 2016 Elsevier Inc. All rights reserved.

Opioid antagonists with minimal sedation for opioid withdrawal.

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Gowing, Linda; Ali, Robert; White, Jason M

2017-05-29

Managed withdrawal is a necessary step prior to drug-free treatment or as the endpoint of long-term substitution treatment. To assess the effects of opioid antagonists plus minimal sedation for opioid withdrawal. Comparators were placebo as well as more established approaches to detoxification, such as tapered doses of methadone, adrenergic agonists, buprenorphine and symptomatic medications. We updated our searches of the following databases to December 2016: CENTRAL, MEDLINE, Embase, PsycINFO and Web of Science. We also searched two trials registers and checked the reference lists of included studies for further references to relevant studies. We included randomised and quasi-randomised controlled clinical trials along with prospective controlled cohort studies comparing opioid antagonists plus minimal sedation versus other approaches or different opioid antagonist regimens for withdrawal in opioid-dependent participants. We used standard methodological procedures expected by Cochrane. Ten studies (6 randomised controlled trials and 4 prospective cohort studies, involving 955 participants) met the inclusion criteria for the review. We considered 7 of the 10 studies to be at high risk of bias in at least one of the domains we assessed.Nine studies compared an opioid antagonist-adrenergic agonist combination versus a treatment regimen based primarily on an alpha 2 -adrenergic agonist (clonidine or lofexidine). Other comparisons (placebo, tapered doses of methadone, buprenorphine) made by included studies were too diverse for any meaningful analysis. This review therefore focuses on the nine studies comparing an opioid antagonist (naltrexone or naloxone) plus clonidine or lofexidine versus treatment primarily based on clonidine or lofexidine.Five studies took place in an inpatient setting, two studies were in outpatients with day care, two used day care only for the first day of opioid antagonist administration, and one study described the setting as outpatient

Opioid Mechanism Involvement in the Synergism Produced by the Combination of Diclofenac and Caffeine in the Formalin Model

OpenAIRE

Flores-Ramos, Jos? Mar?a; D?az-Reval, M. Irene

2013-01-01

Analgesics can be administered in combination with caffeine for improved analgesic effectiveness in a process known as synergism. The mechanisms by which these combinations produce synergism are not yet fully understood. The aim of this study was to analyze whether the administration of diclofenac combined with caffeine produced antinociceptive synergism and whether opioid mechanisms played a role in this event. The formalin model was used to evaluate the antinociception produced by the oral ...

Mu Opioid Receptor Gene: New Point Mutations in Opioid Addicts

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Amin Dinarvand

2014-02-01

Full Text Available Introduction: Association between single-nucleotide polymorphisms (SNPs in mu opioid receptor gene and drug addiction has been shown in various studies. Here, we have evaluated the existence of polymorphisms in exon 3 of this gene in Iranian population and investigated the possible association between these mutations and opioid addiction.  Methods: 79 opioid-dependent subjects (55 males, 24 females and 134 non-addict or control individuals (74 males, 60 females participated in the study. Genomic DNA was extracted from volunteers’ peripheral blood and exon 3 of the mu opioid receptor gene was amplified by polymerase chain reaction (PCR whose products were then sequenced.  Results: Three different heterozygote polymorphisms were observed in 3 male individuals: 759T>C and 877G>A mutations were found in 2 control volunteers and 1043G>C substitution was observed in an opioid-addicted subject. Association between genotype and opioid addiction for each mutation was not statistically significant.  Discussion: It seems that the sample size used in our study is not enough to confirm or reject any association between 759T>C, 877G>A and 1043G>C substitutions in exon 3 of the mu opioid receptor gene and opioid addiction susceptibility in Iranian population.

Chimeric opioid peptides: Tools for identifying opioid receptor types

International Nuclear Information System (INIS)

Xie, G.; Miyajima, A.; Yokota, T.; Arai, K.; Goldstein, A.

1990-01-01

The authors synthesized several chimeric [125J-labelled] peptides in which the N-terminal nine residues of dynorphin-32, a peptide selective for the κ opioid receptor, were replaced by opioid peptides selective for other opioid receptor types. Each chimeric peptide retained the high affinity and type selectivity characteristic of its N-terminal sequence. The common C-terminal two-thirds of the chimeric peptides served as an epitope recognized by the same monoclonal antibody. When bound to receptors on a cell surface or membrane preparation, these peptides could still bind specifically to the monoclonal antibody. These chimeric peptides should be useful for isolating μ, δ, and κ opioid receptors and for identifying opioid receptors on transfected cells in expression cloning procedures. The general approach using chimeric peptides should be applicable to other peptide receptors

A Trigger for Opioid Misuse: Chronic Pain and Stress Dysregulate the Mesolimbic Pathway and Kappa Opioid System.

Science.gov (United States)

Massaly, Nicolas; Morón, Jose A; Al-Hasani, Ream

2016-01-01

Pain and stress are protective mechanisms essential in avoiding harmful or threatening stimuli and ensuring survival. Despite these beneficial roles, chronic exposure to either pain or stress can lead to maladaptive hormonal and neuronal modulations that can result in chronic pain and a wide spectrum of stress-related disorders including anxiety and depression. By inducing allostatic changes in the mesolimbic dopaminergic pathway, both chronic pain and stress disorders affect the rewarding values of both natural reinforcers, such as food or social interaction, and drugs of abuse. Despite opioids representing the best therapeutic strategy in pain conditions, they are often misused as a result of these allostatic changes induced by chronic pain and stress. The kappa opioid receptor (KOR) system is critically involved in these neuronal adaptations in part through its control of dopamine release in the nucleus accumbens. Therefore, it is likely that changes in the kappa opioid system following chronic exposure to pain and stress play a key role in increasing the misuse liability observed in pain patients treated with opioids. In this review, we will discuss how chronic pain and stress-induced pathologies can affect mesolimbic dopaminergic transmission, leading to increased abuse liability. We will also assess how the kappa opioid system may underlie these pathological changes.

A trigger for opioid misuse: Chronic pain and stress dysregulate the mesolimbic pathway and kappa opioid system

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Nicolas Massaly

2016-11-01

Full Text Available Pain and stress are protective mechanisms essential in avoiding harmful or threatening stimuli and ensuring survival. Despite these beneficial roles, chronic exposure to either pain or stress can lead to maladaptive hormonal and neuronal modulations that can result in chronic pain and a wide spectrum of stress-related disorders including anxiety and depression. By inducing allostatic changes in the mesolimbic dopaminergic pathway, both chronic pain and stress disorders affect the rewarding values of both natural reinforcers, such as food or social interaction, and drugs of abuse. Despite opioids representing the best therapeutic strategy in acute pain conditions, they are often misused as a result of these allostatic changes induced by chronic pain and stress. The kappa opioid receptor system is critically involved in these neuronal adaptations in part through its control of dopamine release in the nucleus accumbens. Therefore, it is likely that changes in the kappa opioid system following chronic exposure to pain and stress play a key role in increasing the misuse liability observed in pain patients treated with opioids. In this review, we will discuss how chronic pain and stress-induced pathologies can affect mesolimbic dopaminergic transmission, leading to increased abuse liability. We will also assess how the kappa opioid system may underlie these pathological changes.

The role of endogenous and exogenous mechanisms in the formation of R&D networks

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Tomasello, Mario V.; Perra, Nicola; Tessone, Claudio J.; Karsai, Márton; Schweitzer, Frank

2014-01-01

We develop an agent-based model of strategic link formation in Research and Development (R&D) networks. Empirical evidence has shown that the growth of these networks is driven by mechanisms which are both endogenous to the system (that is, depending on existing alliances patterns) and exogenous (that is, driven by an exploratory search for newcomer firms). Extant research to date has not investigated both mechanisms simultaneously in a comparative manner. To overcome this limitation, we develop a general modeling framework to shed light on the relative importance of these two mechanisms. We test our model against a comprehensive dataset, listing cross-country and cross-sectoral R&D alliances from 1984 to 2009. Our results show that by fitting only three macroscopic properties of the network topology, this framework is able to reproduce a number of micro-level measures, including the distributions of degree, local clustering, path length and component size, and the emergence of network clusters. Furthermore, by estimating the link probabilities towards newcomers and established firms from the data, we find that endogenous mechanisms are predominant over the exogenous ones in the network formation, thus quantifying the importance of existing structures in selecting partner firms. PMID:25022561

The role of endogenous and exogenous mechanisms in the formation of R&D networks

Science.gov (United States)

Tomasello, Mario V.; Perra, Nicola; Tessone, Claudio J.; Karsai, Márton; Schweitzer, Frank

2014-07-01

We develop an agent-based model of strategic link formation in Research and Development (R&D) networks. Empirical evidence has shown that the growth of these networks is driven by mechanisms which are both endogenous to the system (that is, depending on existing alliances patterns) and exogenous (that is, driven by an exploratory search for newcomer firms). Extant research to date has not investigated both mechanisms simultaneously in a comparative manner. To overcome this limitation, we develop a general modeling framework to shed light on the relative importance of these two mechanisms. We test our model against a comprehensive dataset, listing cross-country and cross-sectoral R&D alliances from 1984 to 2009. Our results show that by fitting only three macroscopic properties of the network topology, this framework is able to reproduce a number of micro-level measures, including the distributions of degree, local clustering, path length and component size, and the emergence of network clusters. Furthermore, by estimating the link probabilities towards newcomers and established firms from the data, we find that endogenous mechanisms are predominant over the exogenous ones in the network formation, thus quantifying the importance of existing structures in selecting partner firms.

Participation of endogenous opioids in the antinociception induced by resistance exercise in rats

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G.S. Galdino

2010-09-01

Full Text Available Exercise is a low-cost intervention that promotes health and contributes to the maintenance of the quality of life. The present study was designed to investigate the influence of different resistance exercise protocols on the nociceptive threshold of rats. Female Wistar rats were used to perform exercises in a weight-lifting exercise model. The following groups were examined (N = 6 per group: untrained rats (control group; an acute protocol group consisting of rats submitted to 15 sets of 15 repetitions of resistance exercise (acute group; rats exercised with 3 sets of 10 repetitions, three times per week for 12 weeks (trained group, and a group consisting of trained rats that were further submitted to the acute protocol (trained-acute group. The nociceptive threshold was measured by the paw-withdrawal test, in which the withdrawal threshold (escape reaction was measured by an apparatus applying force to the plantar surface of the animal paw. The opioid antagonist naloxone (2 mg/kg was administered subcutaneously 10 min before the exercise protocols. The trained group demonstrated antinociception only up to day 45 of the 12-week training period. A significant increase (37%, P < 0.05 in the nociceptive threshold was produced immediately after exercise, decreasing to 15% after 15 min, when the acute exercise protocol was used. Naloxone reversed this effect. These data show that the acute resistance exercise protocol was effective in producing antinociception for 15 min. This antinociceptive effect is mediated by the activation of opioid receptors.

High-Dose Opioid Prescribing and Opioid-Related Hospitalization: A Population-Based Study.

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Kimberly Fernandes

Full Text Available To examine the impact of national clinical practice guidelines and provincial drug policy interventions on prevalence of high-dose opioid prescribing and rates of hospitalization for opioid toxicity.Interventional time-series analysis.Ontario, Canada, from 2003 to 2014.Ontario Drug Benefit (ODB beneficiaries aged 15 to 64 years from 2003 to 2014.Publication of Canadian clinical practice guidelines for use of opioids in chronic non-cancer pain (May 2010 and implementation of Ontario's Narcotics Safety and Awareness Act (NSAA; November 2011.Three outcomes were explored: the rate of opioid use among ODB beneficiaries, the prevalence of opioid prescriptions exceeding 200 mg and 400 mg morphine equivalents per day, and rates of opioid-related emergency department visits and hospital admissions.Over the 12 year study period, the rate of opioid use declined 15.2%, from 2764 to 2342 users per 10,000 ODB eligible persons. The rate of opioid use was significantly impacted by the Canadian clinical practice guidelines (p-value = .03 which led to a decline in use, but no impact was observed by the enactment of the NSAA (p-value = .43. Among opioid users, the prevalence of high-dose prescribing doubled (from 4.2% to 8.7% over the study period. By 2014, 40.9% of recipients of long-acting opioids exceeded daily doses of 200 mg morphine or equivalent, including 55.8% of long-acting oxycodone users and 76.3% of transdermal fentanyl users. Moreover, in the last period, 18.7% of long-acting opioid users exceeded daily doses of 400 mg morphine or equivalent. Rates of opioid-related emergency department visits and hospital admissions increased 55.0% over the study period from 9.0 to 14.0 per 10,000 ODB beneficiaries from 2003 to 2013. This rate was not significantly impacted by the Canadian clinical practice guidelines (p-value = .68 or enactment of the NSAA (p-value = .59.Although the Canadian clinical practice guidelines for use of opioids in chronic non

Sex Differences in Kappa Opioid Receptor Function and Their Potential Impact on Addiction

OpenAIRE

Chartoff, Elena H.; Mavrikaki, Maria

2015-01-01

Behavioral, biological, and social sequelae that lead to drug addiction differ between men and women. Our efforts to understand addiction on a mechanistic level must include studies in both males and females. Stress, anxiety, and depression are tightly linked to addiction, and whether they precede or result from compulsive drug use depends on many factors, including biological sex. The neuropeptide dynorphin (DYN), an endogenous ligand at kappa opioid receptors (KORs), is necessary for stress...

Opioid tapering in patients with prescription opioid use disorder : A retrospective study

NARCIS (Netherlands)

Zhou, Kehua; Jia, Peng; Bhargava, Swati; Zhang, Yong; Reza, Taslima; Peng, Yuan Bo; Wang, Gary G.

2017-01-01

Background and aims: Opioid use disorder (OUD) refers to a maladaptive pattern of opioid use leading to clinically significant impairment or distress. OUD causes, and vice versa, misuses and abuse of opioid medications. Clinicians face daily challenges to treat patients with prescription opioid use

Past-year Prescription Drug Monitoring Program Opioid Prescriptions and Self-reported Opioid Use in an Emergency Department Population With Opioid Use Disorder.

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Hawk, Kathryn; D'Onofrio, Gail; Fiellin, David A; Chawarski, Marek C; O'Connor, Patrick G; Owens, Patricia H; Pantalon, Michael V; Bernstein, Steven L

2017-11-22

Despite increasing reliance on prescription drug monitoring programs (PDMPs) as a response to the opioid epidemic, the relationship between aberrant drug-related behaviors captured by the PDMP and opioid use disorder is incompletely understood. How PDMP data should guide emergency department (ED) assessment has not been studied. The objective was to evaluate a relationship between PDMP opioid prescription records and self-reported nonmedical opioid use of prescription opioids in a cohort of opioid-dependent ED patients enrolled in a treatment trial. PDMP opioid prescription records during 1 year prior to study enrollment on 329 adults meeting Diagnostic and Statistical Manual IV criteria for opioid dependence entering a randomized clinical trial in a large, urban ED were cross-tabulated with data on 30-day nonmedical prescription opioid use self-report. The association among these two types of data was assessed by the Goodman and Kruskal's gamma; a logistic regression was used to explore characteristics of participants who had PDMP record of opioid prescriptions. During 1 year prior to study enrollment, 118 of 329 (36%) patients had at least one opioid prescription (range = 1-51) in our states' PDMP. Patients who reported ≥15 of 30 days of nonmedical prescription opioid use were more likely to have at least four PDMP opioid prescriptions (20/38; 53%) than patients reporting 1 to 14 days (14/38, 37%) or zero days of nonmedical prescription opioid use (4/38, 11%; p = 0.002). Female sex and having health insurance were significantly more represented in the PDMP (p Medicine.

[Mechanisms of leukocyte formation of endogenous pyrogen].

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Rybakina, E G; Sorokin, A V

1982-06-01

A study was made of the kinetics of endogenous pyrogen production by rabbit blood and exudate leukocytes and possible role played by the products of activated leukocytes in autoregulation of the process. It was established that accumulation of endogenous pyrogen in the cell precedes its release by stimulated cells. Then the processes of active pyrogen formation and release gel interdependent: pyrogen formed releases from the cell; the lowering of pyrogen concentration in the cell is accompanied by the decrease of its content in the medium. No stimulating effect of the products activated during leukocyte inflammation on pyrogen formation by blood leukocytes was discovered.

Role and psychological dependenci arrangement of opioid by type of reseptor opioid

OpenAIRE

Arif Nurrochmad, Arif Nurrochmad

2015-01-01

Opioid receptor can be classified as p., 8, and K-opioid receptor that widely expressed in the CNS. The development of selective receptor agonist and cloning of each receptor have contributed greatly to our increasing knowledge of the neuropharmacological profile of each opioid receptor type. This review focuses on the functional interaction among these opioid receptor types that contribute to opioid dependence especially in psychological dependence. Several lines of evidence provide argument...

Methylnaltrexone in the treatment of opioid-induced constipation

Directory of Open Access Journals (Sweden)

Beverley Greenwood-Van Meerveld

2008-12-01

Full Text Available Beverley Greenwood-Van Meerveld1, Kelly M Standifer21Veterans Affairs Medical Center, Oklahoma Center for Neuroscience, Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; 2Department of Pharmaceutical Sciences, Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USAAbstract: Constipation is a significant problem related to opioid medications used to manage pain. This review attempts to outline the latest findings related to the therapeutic usefulness of a μ opioid receptor antagonist, methylnaltrexone in the treatment of opioid-induced constipation. The review highlights methylnaltrexone bromide (RelistorTM; Progenics/Wyeth a quaternary derivative of naltrexone, which was recently approved in the United States, Europe and Canada. The Food and Drug Administration in the United States approved a subcutaneous injection for the treatment of opioid bowel dysfunction in patients with advanced illness who are receiving palliative care and when laxative therapy has been insufficient. Methylnaltrexone is a peripherally restricted, μ opioid receptor antagonist that accelerates oral–cecal transit in patients with opioidinduced constipation without reversing the analgesic effects of morphine or inducing symptoms of opioid withdrawal. An analysis of the mechanism of action and the potential benefits of using methylnaltrexone is based on data from published basic research and recent clinical studies.Keywords: methylnaltrexone, constipation, opioid

Hyperthermic responses to central injections of some peptide and non-peptide opioids in the guinea-pig

Science.gov (United States)

Kandasamy, S. B.; Williams, B. A.

1983-01-01

The intracerebroventricular administration of prototype nonpeptide opioid receptor (mu, kappa, and sigma) agonists, morphine, ketocyclazocine, and N-allyl normetazocine and an agonist at both kappa and sigma receptors, pentazocine, was found to induce hyperthermia in guinea pigs. The similar administration of peptide opioids like beta endorphin, methionine endkephalin, leucine endkephaline, and several of their synthetic analogues was also found to cause hyperthermia. Only the liver-like transport system of the three anion transport systems (iodide, hippurate, and liver-like) present in the choroid plexus was determined to be important to the central inactivation of beta-endorphin and two synthetic analogues. Prostaglandins and norepinephrine (NE) as well as cAMP were not involved in peptide and nonpeptide opioid-induced hyperthermia. Naloxone-sensitive receptors were found to be involved in the induction of hyperthermia by morphine and beta-endorphin, while hyperthermic responses to ketocyclazocine, N-allyl normetazocine, pentazocine, Met-enkephalin, Leu-enkephalin, and two of the synthetic analogues were not antagonized by nalozone. The lack of antagonism of naloxone on pyrogen, arachidonic acid, PGE2, dibutyryl cAMP, and NE-induced hyperthermia shows that endogenous opioid peptides are not likely to be central mediators of the hyperthermia induced by these agents.

β-Arrestin-2 knockout prevents development of cellular μ-opioid receptor tolerance but does not affect opioid-withdrawal-related adaptations in single PAG neurons.

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Connor, M; Bagley, E E; Chieng, B C; Christie, M J

2015-01-01

Tolerance to the behavioural effects of morphine is blunted in β-arrestin-2 knockout mice, but opioid withdrawal is largely unaffected. The cellular mechanisms of tolerance have been studied in some neurons from β-arrestin-2 knockouts, but tolerance and withdrawal mechanisms have not been examined at the cellular level in periaqueductal grey (PAG) neurons, which are crucial for central tolerance and withdrawal phenomena. μ-Opioid receptor (MOPr) inhibition of voltage-gated calcium channel currents (ICa ) was examined by patch-clamp recordings from acutely dissociated PAG neurons from wild-type and β-arrestin-2 knockout mice treated chronically with morphine (CMT) or vehicle. Opioid withdrawal-induced activation of GABA transporter type 1 (GAT-1) currents was determined using perforated patch recordings from PAG neurons in brain slices. MOPr inhibition of ICa in PAG neurons was unaffected by β-arrestin-2 deletion. CMT impaired coupling of MOPrs to ICa in PAG neurons from wild-type mice, but this cellular tolerance was not observed in neurons from CMT β-arrestin-2 knockouts. However, β-arrestin-2 knockouts displayed similar opioid-withdrawal-induced activation of GAT-1 currents as wild-type PAG neurons. In β-arrestin-2 knockout mice, the central neurons involved in the anti-nociceptive actions of opioids also fail to develop cellular tolerance to opioids following chronic morphine. The results also provide the first cellular physiological evidence that opioid withdrawal is not disrupted by β-arrestin-2 deletion. However, the unaffected basal sensitivity to opioids in PAG neurons provides further evidence that changes in basal MOPr sensitivity cannot account for the enhanced acute nociceptive response to morphine reported in β-arrestin-2 knockouts. This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2. © 2014 The British

Studies on the pathogenesis of fever. IX. Characteristics of endogenous serum pyrogen and mechanisms governing its release.

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PETERSDORF, R G; KEENE, W R; BENNETT, I L

1957-12-01

The "endogenous serum pyrogen" that appears in the circulating blood after a single intravenous injection of endotoxin does not produce leukopenia in normal animals, fails to provoke the local Shwartzman reaction, and elicits no "tolerance" when injected daily. Suppression of the febrile response to endotoxin by prednisone does not prevent the appearance of pyrogen in the blood. Animals given large amounts of endotoxin daily continue to respond with high fevers despite failure of endogenous serum pyrogen to appear in detectable amounts after the first two or three injections. Analysis of the response to daily injections shows clearly that the fever during the first 2 hours after administration of endotoxin is unrelated to levels of endogenous serum pyrogen; in contrast, the magnitude of the fever after the 2nd hour correlates well with endogenous pyrogen in some instances. The leukopenic response to endotoxin could not be correlated with the appearance of endogenous serum pyrogen. The differences between endotoxin and endogenous pyrogen and the similarities between leukocyte extracts (sterile exudates) and endogenous pyrogen are summarized and discussed. Dissociation of the febrile response to bacterial endotoxin and levels of endogenous serum pyrogen are discussed and it is concluded that a mechanism involving both direct and indirect action of endotoxins offers the best explanation for the pyrogenic action of these bacterial products.

Co-morbid pain and opioid addiction: long term effect of opioid maintenance on acute pain.

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Wachholtz, Amy; Gonzalez, Gerardo

2014-12-01

Medication assisted treatment for opioid dependence alters the pain experience. This study will evaluate changes pain sensitivity and tolerance with opioid treatments; and duration of this effect after treatment cessation. 120 Individuals with chronic pain were recruited in 4 groups (N = 30): 1-methadone for opioid addiction; 2-buprenorphine for opioid addiction; 3-history of opioid maintenance treatment for opioid addiction but with prolonged abstinence (M = 121 weeks; SD = 23.3); and 4-opioid naïve controls. Participants completed a psychological assessment and a cold water task including, time to first pain (sensitivity) and time to stopping the pain task (tolerance). Data analysis used survival analyses. A Kaplan-Meier-Cox survival analysis showed group differences for both pain sensitivity (log rank = 15.50; p opioid maintenance resulted in differing pain sensitivity compared to opioid naïve (p's opioid maintenance compared to active methadone patients (p opioid naïve control group participants (p's opioid abstinence increased (R = .37; p opioid maintenance, there appears to be long-term differences in pain sensitivity that do not resolve with discontinuation of opioid maintenance. Although pain sensitivity does not change, pain tolerance does improve after opioid maintenance cessation. Implications for treating co-morbid opioid addiction and pain (acute and chronic) are discussed. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Cell-Autonomous Regulation of Mu-Opioid Receptor Recycling by Substance P

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Bowman, Shanna L.; Soohoo, Amanda L.; Shiwarski, Daniel J.; Schulz, Stefan; Pradhan, Amynah A.; Puthenveedu, Manojkumar A.

2015-01-01

SUMMARY How neurons coordinate and reprogram multiple neurotransmitter signals is an area of broad interest. Here, we show that substance P (SP), a neuropep-tide associated with inflammatory pain, reprograms opioid receptor recycling and signaling. SP, through activation of the neurokinin 1 (NK1R) receptor, increases the post-endocytic recycling of the muopioid receptor (MOR) in trigeminal ganglion (TG) neurons in an agonist-selective manner. SP-mediated protein kinase C (PKC) activation is both required and sufficient for increasing recycling of exogenous and endogenous MOR in TG neurons. The target of this cross-regulation is MOR itself, given that mutation of either of two PKC phosphorylation sites on MOR abolishes the SP-induced increase in recycling and resensitization. Furthermore, SP enhances the resensitization of fentanyl-induced, but not morphine-induced, antinociception in mice. Our results define a physiological pathway that cross-regulates opioid receptor recycling via direct modification of MOR and suggest a mode of homeo-static interaction between the pain and analgesic systems. PMID:25801029

Distance traveled and frequency of interstate opioid dispensing in opioid shoppers and nonshoppers.

Science.gov (United States)

Cepeda, M Soledad; Fife, Daniel; Yuan, Yingli; Mastrogiovanni, Greg

2013-10-01

Little is known about how far opioid shoppers travel or how often they cross state lines to fill their opioid prescriptions. This retrospective cohort study evaluated these measures for opioid shoppers and nonshoppers using a large U.S. prescription database. Patients with ≥3 opioid dispensings were followed for 18 months. A subject was considered a shopper when he or she filled overlapping opioid prescriptions written by >1 prescriber at ≥3 pharmacies. A heavy shopper had ≥5 shopping episodes. Outcomes assessed were distance traveled among pharmacies and number of states visited to fill opioid prescriptions. A total of 10,910,451 subjects were included; .7% developed any shopping behavior and their prescriptions accounted for 8.6% of all opioid dispensings. Shoppers and heavy shoppers were younger than the nonshoppers. Shoppers traveled a median of 83.8 miles, heavy shoppers 199.5 miles, and nonshoppers 0 miles. Almost 20% of shoppers or heavy shoppers, but only 4% of nonshoppers, visited >1 state. Shoppers traveled greater distances and more often crossed state borders to fill opioid prescriptions than nonshoppers, and their dispensings accounted for a disproportionate number of opioid dispensings. Sharing of data among prescription-monitoring programs will likely strengthen those programs and may decrease shopping behavior. This study shows that opioid shoppers travel greater distances and more often cross state borders to fill opioid prescriptions than nonshoppers, and their dispensings accounted for a disproportionate number of opioid dispensings. The findings support the need for data sharing among prescription-monitoring programs to deter opioid shopping behavior. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

Anhedonia to music and mu-opioids: Evidence from the administration of naltrexone

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Mallik, Adiel; Chanda, Mona Lisa; Levitin, Daniel J.

2017-01-01

Music’s universality and its ability to deeply affect emotions suggest an evolutionary origin. Previous investigators have found that naltrexone (NTX), a μ-opioid antagonist, may induce reversible anhedonia, attenuating both positive and negative emotions. The neurochemical basis of musical experience is not well-understood, and the NTX-induced anhedonia hypothesis has not been tested with music. Accordingly, we administered NTX or placebo on two different days in a double-blind crossover study, and assessed participants’ responses to music using both psychophysiological (objective) and behavioral (subjective) measures. We found that both positive and negative emotions were attenuated. We conclude that endogenous opioids are critical to experiencing both positive and negative emotions in music, and that music uses the same reward pathways as food, drug and sexual pleasure. Our findings add to the growing body of evidence for the evolutionary biological substrates of music. PMID:28176798

Analgesic synergy between opioid and α2 -adrenoceptors.

Science.gov (United States)

Chabot-Doré, A-J; Schuster, D J; Stone, L S; Wilcox, G L

2015-01-01

Opioid and α2 -adrenoceptor agonists are potent analgesic drugs and their analgesic effects can synergize when co-administered. These supra-additive interactions are potentially beneficial clinically; by increasing efficacy and/or reducing the total drug required to produce sufficient pain relief, undesired side effects can be minimized. However, combination therapies of opioids and α2 -adrenoceptor agonists remain underutilized clinically, in spite of a large body of preclinical evidence describing their synergistic interaction. One possible obstacle to the translation of preclinical findings to clinical applications is a lack of understanding of the mechanisms underlying the synergistic interactions between these two drug classes. In this review, we provide a detailed overview of the interactions between different opioid and α2 -adrenoceptor agonist combinations in preclinical studies. These studies have identified the spinal cord as an important site of action of synergistic interactions, provided insights into which receptors mediate these interactions and explored downstream signalling events enabling synergy. It is now well documented that the activation of both μ and δ opioid receptors can produce synergy with α2 -adrenoceptor agonists and that α2 -adrenoceptor agonists can mediate synergy through either the α2A or the α2C adrenoceptor subtypes. Current hypotheses surrounding the cellular mechanisms mediating opioid-adrenoceptor synergy, including PKC signalling and receptor oligomerization, and the evidence supporting them are presented. Finally, the implications of these findings for clinical applications and drug discovery are discussed. This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2. © 2014 The British Pharmacological Society.

Nonopioid substance use disorders and opioid dose predict therapeutic opioid addiction.

Science.gov (United States)

Huffman, Kelly L; Shella, Elizabeth R; Sweis, Giries; Griffith, Sandra D; Scheman, Judith; Covington, Edward C

2015-02-01

Limited research examines the risk of therapeutic opioid addiction (TOA) in patients with chronic noncancer pain. This study examined TOA among 199 patients undergoing long-term opioid therapy at the time of admission to a pain rehabilitation program. It was hypothesized that nonopioid substance use disorders and opioid dosage would predict TOA. Daily mean opioid dose was 132.85 mg ± 175.39. Patients with nonopioid substance use disorders had 28 times the odds (odds ratio [OR] = 28.58; 95% confidence interval [CI] = 10.86, 75.27) of having TOA. Each 50-mg increase in opioid dose nearly doubled the odds of TOA (OR = 1.73; 95% CI = 1.29, 2.32). A 100-mg increase was associated with a 3-fold increase in odds (OR = 3.00; 95% CI = 1.67, 5.41). Receiver operating characteristic analysis revealed that opioid dose was a moderately accurate predictor (area under the curve = .75; 95% CI = .68, .82) of TOA. The sensitivity (.70) and specificity (.68) of opioid dose in predicting TOA was maximized at 76.10 mg; in addition, 46.00 mg yielded 80% sensitivity in identifying TOA. These results underscore the importance of obtaining a substance use history prior to prescribing and suggest a low screening threshold for TOA in patients who use opioids in the absence of improvement in pain or functional impairment. This article examines TOA in patients with chronic noncancer pain undergoing long-term opioid therapy. Results suggest that patients should be screened for nonopioid substance use disorders prior to prescribing. In the absence of improvement in pain or function, there is a low threshold (∼50 mg daily opioid dose) for addiction screening. Copyright © 2015 American Pain Society. Published by Elsevier Inc. All rights reserved.

Does the kappa opioid receptor system contribute to pain aversion?

Directory of Open Access Journals (Sweden)

Catherine M Cahill

2014-11-01

Full Text Available The kappa opioid receptor (KOR and the endogenous peptide-ligand dynorphin have received significant attention due the involvement in mediating a variety of behavioral and neurophysiological responses, including opposing the rewarding properties of drugs of abuse including opioids. Accumulating evidence indicates this system is involved in regulating states of motivation and emotion. Acute activation of the KOR produces an increase in motivational behavior to escape a threat, however, KOR activation associated with chronic stress leads to the expression of symptoms indicative of mood disorders. It is well accepted that KOR can produce analgesia and is engaged in chronic pain states including neuropathic pain. Spinal studies have revealed KOR-induced analgesia in reversing pain hypersensitivities associated with peripheral nerve injury. While systemic administration of KOR agonists attenuates nociceptive sensory transmission, this effect appears to be a stress-induced effect as anxiolytic agents, including delta opioid receptor agonists, mitigate KOR agonist-induced analgesia. Additionally, while the role of KOR and dynorphin in driving the dysphoric and aversive components of stress and drug withdrawal has been well characterized, how this system mediates the negative emotional states associated with chronic pain is relatively unexplored. This review provides evidence that dynorphin and the KOR system contribute to the negative affective component of pain and that this receptor system likely contributes to the high comorbidity of mood disorders associated with chronic neuropathic pain.

Neonatal opioid withdrawal syndrome.

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Sutter, Mary Beth; Leeman, Lawrence; Hsi, Andrew

2014-06-01

Neonatal opioid withdrawal syndrome is common due to the current opioid addiction epidemic. Infants born to women covertly abusing prescription opioids may not be identified as at risk until withdrawal signs present. Buprenorphine is a newer treatment for maternal opioid addiction and appears to result in a milder withdrawal syndrome than methadone. Initial treatment is with nonpharmacological measures including decreasing stimuli, however pharmacological treatment is commonly required. Opioid monotherapy is preferred, with phenobarbital or clonidine uncommonly needed as adjunctive therapy. Rooming-in and breastfeeding may decease the severity of withdrawal. Limited evidence is available regarding long-term effects of perinatal opioid exposure. Copyright © 2014 Elsevier Inc. All rights reserved.

Pavlovian conditioning of multiple opioid-like responses in mice.

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Bryant, Camron D; Roberts, Kristofer W; Culbertson, Christopher S; Le, Alan; Evans, Christopher J; Fanselow, Michael S

2009-07-01

Conditional responses in rodents such as locomotion have been reported for drugs of abuse and similar to the placebo response in humans, may be associated with the expectation of reward. We examined several conditional opioid-like responses and the influence of drug expectation on conditioned place preference and concomitant conditional locomotion. Male C57BL/6J mice were conditioned with the selective mu opioid receptor agonist fentanyl (0.2mg/kg, i.p.) in a novel context and subsequently given a vehicle injection. In separate experiments, locomotor activity, Straub tail, hot plate sensitivity, and conditioned place preference (CPP) were measured. Mice exhibited multiple conditional opioid-like responses including conditional hyperlocomotion, a conditional pattern of opioid-like locomotion, Straub tail, analgesia, and place preference. Modulating drug expectation via administration of fentanyl to "demonstrator" mice in the home cage did not affect the expression of conditioned place preference or the concomitant locomotor activity in "observer" mice. In summary, Pavlovian conditioning of an opioid in a novel context induced multiple conditional opioid-like behaviors and provides a model for studying the neurobiological mechanisms of the placebo response in mice.

Physician Introduction to Opioids for Pain Among Patients with Opioid Dependence and Depressive Symptoms

Science.gov (United States)

Tsui, Judith I.; Herman, Debra S.; Kettavong, Malyna; Alford, Daniel; Anderson, Bradley J.; Stein, Michael D.

2011-01-01

This study determined the frequency of reporting being introduced to opioids by a physician among opioid dependent patients. Cross-sectional analyses were performed using baseline data from a cohort of opioid addicts seeking treatment with buprenorphine. The primary outcome was response to the question: “Who introduced you to opiates?” Covariates included sociodemographics, depression, pain, current and prior substance use. Of 140 participants, 29% reported that they had been introduced to opioids by a physician. Of those who were introduced to opioids by a physician, all indicated that they had initially used opioids for pain, versus only 11% of those who did not report being introduced to opioids by a physician (p<0.01). There was no difference in current pain (78% vs. 85%, p=0.29), however participants who were introduced to opioids by a physician were more likely to have chronic pain (63% vs. 43%, p=0.04). A substantial proportion of individuals with opioid dependence seeking treatment may have been introduced to opioids by a physician. PMID:20727704

CXCL10 Controls Inflammatory Pain via Opioid Peptide-Containing Macrophages in Electroacupuncture

Science.gov (United States)

Wang, Ying; Gehringer, Rebekka; Mousa, Shaaban A.; Hackel, Dagmar; Brack, Alexander; Rittner, Heike L.

2014-01-01

Acupuncture is widely used for pain treatment in patients with osteoarthritis or low back pain, but molecular mechanisms remain largely enigmatic. In the early phase of inflammation neutrophilic chemokines direct opioid-containing neutrophils in the inflamed tissue and stimulate opioid peptide release and antinociception. In this study the molecular pathway and neuroimmune connections in complete Freund's adjuvant (CFA)-induced hind paw inflammation and electroacupuncture for peripheral pain control were analyzed. Free moving Wistar rats with hind paw inflammation were treated twice with electroacupuncture at GB30 (Huan Tiao - gall bladder meridian) (day 0 and 1) and analyzed for mechanical and thermal nociceptive thresholds. The cytokine profiles as well as the expression of opioid peptides were quantified in the inflamed paw. Electroacupuncture elicited long-term antinociception blocked by local injection of anti-opioid peptide antibodies (beta-endorphin, met-enkephalin, dynorphin A). The treatment altered the cytokine profile towards an anti-inflammatory pattern but augmented interferon (IFN)-gamma and the chemokine CXCL10 (IP-10: interferon gamma-inducible protein) protein and mRNA expression with concomitant increased numbers of opioid peptide-containing CXCR3+ macrophages. In rats with CFA hind paw inflammation without acupuncture repeated injection of CXCL10 triggered opioid-mediated antinociception and increase opioid-containing macrophages. Conversely, neutralization of CXCL10 time-dependently decreased electroacupuncture-induced antinociception and the number of infiltrating opioid peptide-expressing CXCR3+ macrophages. In summary, we describe a novel function of the chemokine CXCL10 - as a regulator for an increase of opioid-containing macrophages and antinociceptive mediator in inflammatory pain and as a key chemokine regulated by electroacupuncture. PMID:24732949

Medications Development for Opioid Abuse

Science.gov (United States)

Negus, S. Stevens; Banks, Matthew L.

2013-01-01

Here we describe methods for preclinical evaluation of candidate medications to treat opioid abuse and dependence. Our perspective is founded on the propositions that (1) drug self-administration procedures provide the most direct method for assessment of medication effects, (2) procedures that assess choice between opioid and nondrug reinforcers are especially useful, and (3) the states of opioid dependence and withdrawal profoundly influence both opioid reinforcement and the effects of candidate medications. Effects of opioid medications on opioid choice in nondependent and opioid-dependent subjects are reviewed. Various nonopioid medications have also been examined, but none yet have been identified that safely and reliably reduce opioid choice. Future research will focus on (1) strategies for increasing safety and/or effectiveness of opioid medications, and (2) continued development of nonopioids such as inhibitors of endocannabinoid catabolic enzymes or inhibitors of opioid-induced glial activation. PMID:23125072

delta-Opioid-induced pharmacologic myocardial hibernation during cardiopulmonary resuscitation.

Science.gov (United States)

Fang, Xiangshao; Tang, Wanchun; Sun, Shijie; Weil, Max Harry

2006-12-01

Cardiac arrest and cardiopulmonary resuscitation is an event of global myocardial ischemia and reperfusion, which is associated with severe postresuscitation myocardial dysfunction and fatal outcome. Evidence has demonstrated that mammalian hibernation is triggered by cyclic variation of a delta-opiate-like compound in endogenous serum, during which the myocardial metabolism is dramatically reduced and the myocardium tolerates the stress of ischemia and reperfusion without overt ischemic and reperfusion injury. Previous investigations also proved that the delta-opioid agonist elicited the cardioprotection in a model of regional ischemic intact heart or myocyte. Accordingly, we were prompted to search for an alternative intervention of pharmacologically induced myocardial hibernation that would result in rapid reductions of myocardial metabolism and therefore minimize the myocardial ischemic and reperfusion injury during cardiac arrest and cardiopulmonary resuscitation. Prospective, controlled laboratory study. University-affiliated research laboratory. In the series of studies performed in the established rat and pig model of cardiac arrest and cardiopulmonary resuscitation, the delta-opioid receptor agonist, pentazocine, was administered during ventricular fibrillation. : The myocardial metabolism reflected by the concentration of lactate, or myocardial tissue PCO2 and PO2, is dramatically reduced during cardiac arrest and cardiopulmonary resuscitation. These are associated with less severe postresuscitation myocardial dysfunction and longer duration of postresuscitation survival. delta-Opioid-induced pharmacologic myocardial hibernation is an option to minimize the myocardial ischemia and reperfusion injury during cardiac arrest and cardiopulmonary resuscitation.

Opioid tapering in patients with prescription opioid use disorder: A retrospective study.

Science.gov (United States)

Zhou, Kehua; Jia, Peng; Bhargava, Swati; Zhang, Yong; Reza, Taslima; Peng, Yuan Bo; Wang, Gary G

2017-10-01

Opioid use disorder (OUD) refers to a maladaptive pattern of opioid use leading to clinically significant impairment or distress. OUD causes, and vice versa, misuses and abuse of opioid medications. Clinicians face daily challenges to treat patients with prescription opioid use disorder. An evidence-based management for people who are already addicted to opioids has been identified as the national priority in the US; however, options are limited in clinical practices. In this study, we aimed to explore the success rate and important adjuvant medications in the medication assisted treatment with temporary use of methadone for opioid discontinuation in patients with prescription OUD. This is a retrospective chart review performed at a private physician office for physical medicine and rehabilitation. We reviewed all medical records dated between December 1st, 2011 and August 30th, 2016. The initial evaluation of the included patients (N=140) was completed between December 1st, 2011 and December 31st, 2014. They all have concumittant prescription OUD and chronic non-cancer pain. The patients (87 female and 53 male) were 46.7±12.7 years old, and had a history of opioid use of 7.7±6.1 years. All patients received the comprehensive opioid taper treatments (including interventional pain management techniques, psychotherapy, acupuncture, physical modalities and exercises, and adjuvant medications) on top of the medication assisted treatment using methadone (transient use). Opioid tapering was considered successful when no opioid medication was used in the last patient visit. The 140 patients had pain of 9.6±8.4 years with 8/10 intensity before treatment which decreased after treatment in all comparisons (pOUD. For patients with OUD, indefinite opioid maintenance treatment may not be necessary. Considering the ethical values of autonomy, nonmaleficence, and beneficence, clinicians should provide patients with OUD the option of opioid tapering. Copyright © 2017

Chimeric opioid peptides: tools for identifying opioid receptor types.

OpenAIRE

Xie, G X; Miyajima, A; Yokota, T; Arai, K; Goldstein, A

1990-01-01

We synthesized several chimeric peptides in which the N-terminal nine residues of dynorphin-32, a peptide selective for the kappa opioid receptor, were replaced by opioid peptides selective for other opioid receptor types. Each chimeric peptide retained the high affinity and type selectivity characteristic of its N-terminal sequence. The common C-terminal two-thirds of the chimeric peptides served as an epitope recognized by the same monoclonal antibody. When bound to receptors on a cell surf...

Opioid withdrawal suppression efficacy of oral dronabinol in opioid dependent humans.

Science.gov (United States)

Lofwall, Michelle R; Babalonis, Shanna; Nuzzo, Paul A; Elayi, Samy Claude; Walsh, Sharon L

2016-07-01

The cannabinoid (CB) system is a rational novel target for treating opioid dependence, a significant public health problem around the world. This proof-of-concept study examined the potential efficacy of a CB1 receptor partial agonist, dronabinol, in relieving signs and symptoms of opioid withdrawal. Twelve opioid dependent adults participated in this 5-week, inpatient, double-blind, randomized, placebo-controlled study. Volunteers were maintained on double-blind oxycodone (30mg oral, four times/day) and participated in a training session followed by 7 experimental sessions, each testing a single oral test dose (placebo, oxycodone 30 and 60mg, dronabinol 5, 10, 20, and 30mg [decreased from 40mg]). Placebo was substituted for oxycodone maintenance doses for 21h before each session in order to produce measurable opioid withdrawal. Outcomes included observer- and participant-ratings of opioid agonist, opioid withdrawal and psychomotor/cognitive performance. Oxycodone produced prototypic opioid agonist effects (i.e. suppressing withdrawal and increasing subjective effects indicative of abuse liability). Dronabinol 5 and 10mg produced effects most similar to placebo, while the 20 and 30mg doses produced modest signals of withdrawal suppression that were accompanied by dose-related increases in high, sedation, bad effects, feelings of heart racing, and tachycardia. Dronabinol was not liked more than placebo, showed some impairment in cognitive performance, and was identified as marijuana with increasing dose. CB1 receptor activation is a reasonable strategy to pursue for the treatment of opioid withdrawal; however, dronabinol is not a likely candidate given its modest withdrawal suppression effects of limited duration and previously reported tachycardia during opioid withdrawal. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Craving and subsequent opioid use among opioid dependent patients who initiate treatment with buprenorphine

Science.gov (United States)

Tsui, Judith I.; Anderson, Bradley J.; Strong, David R.; Stein, Michael D.

2016-01-01

Background Few studies have directly assessed associations between craving and subsequent opioid use among treated patients. Our objective was to prospectively evaluate the relative utility of two craving questionnaires to predict opioid use among opioid dependent patients in treatment. Method Opioid dependent patients (n=147) initiating buprenorphine treatment were assessed for three months. Craving was measured using: 1) the Desires for Drug Questionnaire (DDQ) and 2) the Penn Alcohol-Craving Scale adapted for opioid craving (PCS) for this study. Multi-level logistic regression models estimated the effects of craving on the likelihood of opioid use after adjusting for gender, age, ethnicity, education, opioid of choice, frequency of use, pain and depression. In these analyses craving assessed at time t was entered as a time-varying predictor of opioid use at time t+1. Results In adjusted regression models, a 1-point increase in PCS scores (on a 7-point scale) was associated with a significant increase in the odds of opioid use at the subsequent assessment (OR = 1.27, 95% CI 1.08; 1.49, p .05) or DDQ control (OR = 0.97, 95%CI 0.85; 1.11, p > .05) scores. Conclusion Self-reported craving for opioids was associated with subsequent lapse to opioid use among a cohort of patients treated with buprenorphine. PMID:24521036

Differences between opioids

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Drewes, Asbjørn; Jensen, Rasmus D.; Nielsen, Lecia M.

2013-01-01

to morphine. Although this approach is recognized as cost-effective in most cases there is solid evidence that, on an individual patient basis, opioids are not all equal. Therefore it is important to have an armamentarium of strong analgesics in clinical practice to ensure a personalized approach in patients...... who do not respond to standard treatment. In this review we highlight differences between opioids in human studies from a pharmacological, experimental, clinical and health economics point of view. We provide evidence that individuals respond differently to opioids, and that general differences......Clinical studies comparing the response and side effects of various opioids have not been able to show robust differences between drugs. Hence, recommendations of the regulatory authorities have been driven by costs with a general tendency in many countries to restrict physician's use of opioids...

Prescription Opioids

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... therapy in a primary care setting struggles with opioid addiction. 4,5,6 Once addicted, it can be ... of drug overdose deaths involving methadone and other opioid analgesics in West Virginia. Addiction 2009;104(9):1541-8. Dunn KM, Saunders ...

The Opioid System in Temporal Lobe Epilepsy: Functional Role and Therapeutic Potential

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Johannes Burtscher

2017-08-01

Full Text Available Temporal lobe epilepsy is considered to be one of the most common and severe forms of focal epilepsies. Patients often develop cognitive deficits and emotional blunting along the progression of the disease. The high incidence of resistance to antiepileptic drugs and a frequent lack of admissibility to surgery poses an unmet medical challenge. In the urgent quest of novel treatment strategies, neuropeptides are interesting candidates, however, their therapeutic potential has not yet been exploited. This review focuses on the functional role of the endogenous opioid system with respect to temporal lobe epilepsy, specifically in the hippocampus. The role of dynorphins and kappa opioid receptors (KOPr as modulators of neuronal excitability is well understood: both the reduced release of glutamate as well of postsynaptic hyperpolarization were shown in glutamatergic neurons. In line with this, low levels of dynorphin in humans and mice increase the risk of epilepsy development. The role of enkephalins is not understood so well. On one hand, some agonists of the delta opioid receptors (DOPr display pro-convulsant properties probably through inhibition of GABAergic interneurons. On the other hand, enkephalins play a neuro-protective role under hypoxic or anoxic conditions, most probably through positive effects on mitochondrial function. Despite the supposed absence of endorphins in the hippocampus, exogenous activation of the mu opioid receptors (MOPr induces pro-convulsant effects. Recently-expanded knowledge of the complex ways opioid receptors ligands elicit their effects (including biased agonism, mixed binding, and opioid receptor heteromers, opens up exciting new therapeutic potentials with regards to seizures and epilepsy. Potential adverse side effects of KOPr agonists may be minimized through functional selectivity. Preclinical data suggest a high potential of such compounds to control seizures, with a strong predictive validity toward human

Successful Treatment of Opioid-Refractory Cancer Pain with Short-Course, Low-Dose Ketamine.

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Waldfogel, Julie M; Nesbit, Suzanne; Cohen, Steven P; Dy, Sydney M

2016-12-01

Opioids remain the mainstay of treatment for severe cancer pain, but up to 20% of patients have persistent or refractory pain despite rapid and aggressive opioid titration, or develop refractory pain after long-term opioid use. In these scenarios, alternative agents and mechanisms for analgesia should be considered. This case report describes a 28-year-old man with metastatic pancreatic neuroendocrine cancer with severe, intractable pain despite high-dose opioids including methadone and a hydromorphone patient-controlled analgesia (PCA). After treatment with short-course, low-dose ketamine, his opioid requirements decreased by 99% and pain ratings by 50%, with the majority of this decrease occurring in the first 48 hours. As this patient's pain and opioid regimen escalated, he likely experienced some component of central sensitization and hyperalgesia. Administration of ketamine reduced opioid consumption by 99% and potentially "reset" neuronal hyperexcitability and reduced pain signaling, allowing for improved pain control.

Repair of endogenous and ionizing radiation-induced DNA damages: mechanisms and biological functions

International Nuclear Information System (INIS)

Boiteux, S.

2002-01-01

The cellular DNA is continuously exposed to endogenous and exogenous stress. Oxidative stress due to cellular metabolism is the major cause of endogenous DNA damage. On the other hand, ionizing radiation (IR) is an important exogenous stress. Both induce similar DNA damages: damaged bases, abasic sites and strand breakage. Most of these lesions are lethal and/or mutagenic. The survival of the cell is managed by efficient and accurate DNA repair mechanisms that remove lesions before their replication or transcription. DNA repair pathways involved in the removal of IR-induced lesions are briefly described. Base excision repair (BER) is mostly involved in the removal of base damage, abasic sites and single strand breaks. In contrast, DNA double strand breaks are mostly repaired by non-homologous end joining (NHEJ) or homologous recombination (HR). How DNA repair pathways prevent cancer process is also discussed. (author)

Production of endogenous pyrogen.

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Dinarello, C A

1979-01-01

The production and release of endogenous pyrogen by the host is the first step in the pathogenesis of fever. Endogenous pyrogen is a low-molecular-weight protein released from phagocytic leukocytes in response to several substances of diverse nature. Some of these agents stimulate production of endogenous pyrogen because they are toxic; others act as antigens and interact with either antibody or sensitized lymphocytes in order to induce its production. Some tumors of macrophage origin produce the molecule spontaneously. Whatever the mechanism involved, endogenous pyrogen is synthesized following transcription of new DNA and translation of mRNA into new protein. Once synthesis is completed, the molecule is released without significant intracellular storage. Recent evidence suggests that following release, molecular aggregates form which are biologically active. In its monomer form, endogenous pyrogen is a potent fever-producing substance and mediates fever by its action on the thermoregulatory center.

Opioid dependence - management in general practice.

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Frei, Matthew

2010-08-01

Addiction to opioids, or opioid dependence, encompasses the biopsychosocial dysfunction seen in illicit heroin injectors, as well as aberrant behaviours in patients prescribed opioids for chronic nonmalignant pain. To outline the management of opioid dependence using opioid pharmacotherapy as part of a comprehensive chronic illness management strategy. The same principles and skills general practitioners employ in chronic illness management underpin the care of patients with opioid dependence. Opioid pharmacotherapy, with the substitution medications methadone and buprenorphine, is an effective management of opioid dependence. Training and regulatory requirements for prescribing opioid pharmacotherapies vary between jurisdictions, but this treatment should be within the scope of most Australian GPs.

Opioid and GABAB receptors differentially couple to an adenylyl cyclase/protein kinase A downstream effector after chronic morphine treatment.

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Elena Elizabeth Bagley

2014-06-01

Full Text Available Opioids are intensely addictive, and cessation of their chronic use is associated with a highly aversive withdrawal syndrome. A cellular hallmark of withdrawal is an opioid sensitive protein kinase A-dependent increase in GABA transporter-1 (GAT-1 currents in periaqueductal gray (PAG neurons. Elevated GAT-1 activity directly increases GABAergic neuronal excitability and synaptic GABA release, which will enhance GABAergic inhibition of PAG output neurons. This reduced activity of PAG output neurons to several brain regions, including the hypothalamus and medulla, contributes to many of the PAG-mediated signs of opioid withdrawal. The GABAB receptor agonist baclofen reduces some of the PAG mediated signs of opioid withdrawal. Like the opioid receptors the GABAB receptor is a Gi/Go coupled G-protein coupled receptor. This suggests it could be modulating GAT-1 activity in PAG neurons through its inhibition of the adenylyl cyclase/protein kinase A pathway. Opioid modulation of the GAT-1 activity can be detected by changes in the reversal potential of opioid membrane currents. We found that when opioids are reducing the GAT-1 cation conductance and increasing the GIRK conductance the opioid agonist reversal potential is much more negative than Ek. Using this approach for GABAB receptors we show that the GABAB receptor agonist, baclofen, does not couple to inhibition of GAT-1 currents during opioid withdrawal. It is possible this differential signaling of the two Gi/Go coupled G-protein coupled receptors is due to the strong compartmentalization of the GABAB receptor that does not favor signaling to the adenylyl cyclase/protein kinase A/GAT-1 pathway. This highlights the importance of studying the effects of G-protein coupled receptors in native tissue with endogenous G-protein coupled receptors and the full complement of relevant proteins and signaling molecules. This study suggests that baclofen reduces opioid withdrawal symptoms through a non-GAT-1

Salvinorin A, a kappa-opioid receptor (KOP-r agonist hallucinogen: Pharmacology and potential template for novel pharmacotherapeutic agents in neuropsychiatric disorders

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Eduardo eButelman

2015-09-01

Full Text Available Salvinorin A is a potent hallucinogen, isolated from the ethnomedical plant Salvia divinorum. Salvinorin A is a selective high efficacy kappa-opioid receptor (KOPr agonist, and thus implicates the KOPr system and its endogenous agonist ligands (the dynorphins in higher functions, including cognition, and perceptual effects. Salvinorin A is the only selective KOPr ligand to be widely available outside research or medical settings, and salvinorin A- containing products have undergone frequent non-medical use. KOPr/dynorphin systems in the brain are known to be powerful counter-modulatory mechanisms to dopaminergic function, which is important in mood and reward engendered by natural and drug reinforcers (including drugs of abuse. KOPr activation (including by salvinorin A can thus cause aversion and anhedonia in preclinical models. Salvinorin A is also a completely new scaffold for medicinal chemistry approaches, since it is a non-nitrogenous neoclerodane, unlike all other known opioid ligands. Ongoing efforts have the goal of discovering novel semi-synthetic salvinorin analogs with potential KOPr-mediated pharmacotherapeutic effects (including partial agonist or biased agonist effects, with a reduced burden of undesirable effects associated with salvinorin A.

Oral opioid administration and hyperalgesia in patients with cancer or chronic nonmalignant pain.

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Reznikov, Igor; Pud, Dorit; Eisenberg, Elon

2005-09-01

Previous research has reported on reduced paw withdrawal latencies to heat and mechanical stimuli after parenteral administration of opioids in animals and on increased pain sensitivity in humans subsequent to postoperative infusions of short-acting opioids or in drug addicts. The aim of the present study was to explore the possibility that oral opioid treated patients with cancer-related or chronic nonmalignant pain differ in their pain sensitivity from patients treated with non-opioid analgesics. The study population consisted of 224 patients, including 142 in the opioid-treated group and 82 in the non-opioid-treated group. Pain thresholds for punctuate measured by von Frey filaments (g), mechanical pressure measured by pressure algometer (mmHg), heat stimuli measured by quantitative sensory testing (degrees C), as well as suprathreshold tonic heat pain intensity (46.5 degrees C for 1 min) measured by 0-10 numerical pain scale (NPS) were obtained at a nonpainful site (thenar eminence) in all patients. No differences between the groups were found for gender, age, duration of pain, or duration of treatment (independent variables). No significant differences between the groups were found in punctuate (difference = 17.0 g (95% CI -8.8, 42.8), P = 0.19), pressure (2.2 mmHg (-28.7, 33.2), P = 0.89) and heat (-0.3 degrees C (-1.5, 0.9), P = 0.70) pain thresholds, or in suprathreshold heat pain intensity (difference between maximal pain intensities -0.4 NPS units (95% CI -1.2, 0.4), P = 0.31). Pearson correlations within the opioid-treated group failed to show significant relationships between any of the independent variables and the outcome measures. A further comparison of the outcomes between the 'weak' opioid-treated subgroup and the 'strong' opioid-treated subgroup again revealed insignificant results. These results suggest that the administration of 'commonly used' dosages of oral opioids does not result in abnormal pain sensitivity beyond that of patients

Recent advances in acute pain management: understanding the mechanisms of acute pain, the prescription of opioids, and the role of multimodal pain therapy [version 1; referees: 3 approved

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Richa Wardhan

2017-11-01

Full Text Available In this review, we discuss advances in acute pain management, including the recent report of the joint American Pain Society and American Academy of Pain Medicine task force on the classification of acute pain, the role of psychosocial factors, multimodal pain management, new non-opioid therapy, and the effect of the “opioid epidemic”. In this regard, we propose that a fundamental principle in acute pain management is identifying patients who are most at risk and providing an “opioid free anesthesia and postoperative analgesia”. This can be achieved by using a multimodal approach that includes regional anesthesia and minimizing the dose and the duration of opioid prescription. This allows prescribing medications that work through different mechanisms. We shall also look at the recent pharmacologic and treatment advances made in acute pain and regional anesthesia.

Non-analgesic effects of opioids: management of opioid-induced constipation by peripheral opioid receptor antagonists: prevention or withdrawal?

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Holzer, Peter

2012-01-01

The therapeutic action of opioid analgesics is compromised by peripheral adverse effects among which opioid-induced constipation (OIC) is the most disabling, with a prevalence reported to vary between 15 and 90 %. Although OIC is usually treated with laxatives, there is insufficient clinical evidence that laxatives are efficacious in this indication. In contrast, there is ample evidence from double- blind, randomized and placebo-controlled trials that peripheral opioid receptor antagonists (PORAs) counteract OIC. This specific treatment modality is currently based on subcutaneous methylnaltrexone for the interruption of OIC in patients with advanced illness, and a fixed combination of oral prolonged-release naloxone with prolonged-release oxycodone for the prevention of OIC in the treatment of non-cancer and cancer pain. Both drugs counteract OIC while the analgesic effect of opioids remains unabated. The clinical studies show that more than 50 % of the patients with constipation under opioid therapy may benefit from the use of PORAs, while PORA-resistant patients are likely to suffer from non-opioid-induced constipation, the prevalence of which increases with age. While the addition of naloxone to oxycodone seems to act by preventing OIC, the intermittent dosing of methylnaltrexone every other day seems to stimulate defaecation by provoking an intestinal withdrawal response. The availability of PORAs provides a novel opportunity to specifically control OIC and other peripheral adverse effects of opioid analgesics (e.g., urinary retention and pruritus). The continuous dosing of a PORA has the advantage of few adverse effects, while intermittent dosing of a PORA can be associated with abdominal cramp-like pain.

Effects of opioid drugs on dopamine mediated locomotor activity in rats

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Leathern, L L

1986-01-01

Opioid drugs influence various behavioural parameters including locomotor activity in experimental animals. The interaction between the opioid and dopaminergic systems is one possible explanation for the effect of opioid drugs on locomotor activity. In this study behavioural and biochemical assays were done to investigate the interaction between the opioid and dopaminergic systems. Behavioural studies were done by measurement of locomotor activity (LA) of rats after acute or chronic pretreatment with opioid andor dopaminergic drugs. Biochemical studies were in the form of radioligand binding assays, the effect on the number (Bmax) and affinity (K/sub D/) of receptors was measured after chronic pretreatment with opioid andor dopaminergic drugs. The opioid drugs used are morphine, nalbuphine and naloxone. Dopaminergic drugs used included: agonists-apomorphine and piribedil; antagonists-pimozide, haloperidol, chlorpromazine. In the acute situation increased LA was obtained with morphine and the DA agonists. A correlation between the behavioural and biochemical assays was found. Chronic pretreatment with morphine enhanced apomorphine induced LA, this supersensitivity was also measured as an increased receptor density (Bmax) of D2 receptors in the striatum. Chronic morphine pretreatment caused a decrease in morphine induced LA, while this subsensitivity was not apparent in the ligand binding assays - where no change in receptor number was observed. Chronic naloxone pretreatment enhanced morphine induced LA, as well as increased the Bmax of opioid receptors in the whole brain. It is concluded that an interaction between the opioid and dopaminergic systems does exist, and may account for the mechanism of action of the opioids.

Ancient and recent positive selection transformed opioid cis-regulation in humans.

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Matthew V Rockman

2005-12-01

Full Text Available Changes in the cis-regulation of neural genes likely contributed to the evolution of our species' unique attributes, but evidence of a role for natural selection has been lacking. We found that positive natural selection altered the cis-regulation of human prodynorphin, the precursor molecule for a suite of endogenous opioids and neuropeptides with critical roles in regulating perception, behavior, and memory. Independent lines of phylogenetic and population genetic evidence support a history of selective sweeps driving the evolution of the human prodynorphin promoter. In experimental assays of chimpanzee-human hybrid promoters, the selected sequence increases transcriptional inducibility. The evidence for a change in the response of the brain's natural opioids to inductive stimuli points to potential human-specific characteristics favored during evolution. In addition, the pattern of linked nucleotide and microsatellite variation among and within modern human populations suggests that recent selection, subsequent to the fixation of the human-specific mutations and the peopling of the globe, has favored different prodynorphin cis-regulatory alleles in different parts of the world.

Social stress engages opioid regulation of locus coeruleus norepinephrine neurons and induces a state of cellular and physical opiate dependence.

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Chaijale, Nayla N; Curtis, Andre L; Wood, Susan K; Zhang, Xiao-Yan; Bhatnagar, Seema; Reyes, Beverly As; Van Bockstaele, Elisabeth J; Valentino, Rita J

2013-09-01

Stress is implicated in diverse psychiatric disorders including substance abuse. The locus coeruleus-norepinephrine (LC-NE) system is a major stress response system that is also a point of intersection between stress neuromediators and endogenous opioids and so may be a site at which stress can influence drug-taking behaviors. As social stress is a common stressor for humans, this study characterized the enduring impact of repeated social stress on LC neuronal activity. Rats were exposed to five daily consecutive sessions of social stress using the resident-intruder model or control manipulation. LC discharge rate recorded 2 days after the last manipulation was decreased in stressed rats compared with controls. By 10 days after the last manipulation, LC rates were comparable between groups. Systemic administration of the opiate antagonist, naloxone, robustly increased LC discharge rate in a manner suggestive of opiate withdrawal, selectively in stressed rats when administered 2 or 10 days after the last manipulation. This was accompanied by behavioral signs of mild opiate withdrawal. Western blot and electron microscopic studies indicated that repeated social stress decreased corticotropin-releasing factor type 1 receptor and increased μ-opioid receptor levels in the LC. Together, the results suggest that repeated social stress engages endogenous opioid modulation of LC activity and induces signs of cellular and physical opiate dependence that endure after the stress. These cellular effects may predispose individuals with a history of repeated social stress to substance abuse behaviors.

Differential regulation of morphine antinociceptive effects by endogenous enkephalinergic system in the forebrain of mice

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Sun Wei-Zen

2008-09-01

Full Text Available Abstract Background Mice lacking the preproenkephalin (ppENK gene are hyperalgesic and show more anxiety and aggression than wild-type (WT mice. The marked behavioral changes in ppENK knock-out (KO mice appeared to occur in supraspinal response to painful stimuli. However the functional role of enkephalins in the supraspinal nociceptive processing and their underlying mechanism is not clear. The aim of present study was to compare supraspinal nociceptive and morphine antinociceptive responses between WT and ppENK KO mice. Results The genotypes of bred KO mice were confirmed by PCR. Met-enkephalin immunoreactive neurons were labeled in the caudate-putamen, intermediated part of lateral septum, lateral globus pallidus, intermediated part of lateral septum, hypothalamus, and amygdala of WT mice. Met-enkephalin immunoreactive neurons were not found in the same brain areas in KO mice. Tail withdrawal and von Frey test results did not differ between WT and KO mice. KO mice had shorter latency to start paw licking than WT mice in the hot plate test. The maximal percent effect of morphine treatments (5 mg/kg and 10 mg/kg, i.p. differed between WT and KO mice in hot plate test. The current source density (CSD profiles evoked by peripheral noxious stimuli in the primary somatosenstory cortex (S1 and anterior cingulate cortex (ACC were similar in WT and KO mice. After morphine injection, the amplitude of the laser-evoked sink currents was decreased in S1 while the amplitude of electrical-evoked sink currents was increased in the ACC. These differential morphine effects in S1 and ACC were enhanced in KO mice. Facilitation of synaptic currents in the ACC is mediated by GABA inhibitory interneurons in the local circuitry. Percent increases in opioid receptor binding in S1 and ACC were 5.1% and 5.8%, respectively. Conclusion The present results indicate that the endogenous enkephalin system is not involved in acute nociceptive transmission in the spinal cord

Mu and delta opioid receptors oppositely regulate motor impulsivity in the signaled nose poke task.

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Mary C Olmstead

Full Text Available Impulsivity is a primary feature of many psychiatric disorders, most notably attention deficit hyperactivity disorder and drug addiction. Impulsivity includes a number of processes such as the inability to delay gratification, the inability to withhold a motor response, or acting before all of the relevant information is available. These processes are mediated by neural systems that include dopamine, serotonin, norepinephrine, glutamate and cannabinoids. We examine, for the first time, the role of opioid systems in impulsivity by testing whether inactivation of the mu- (Oprm1 or delta- (Oprd1 opioid receptor gene alters motor impulsivity in mice. Wild-type and knockout mice were examined on either a pure C57BL6/J (BL6 or a hybrid 50% C57Bl/6J-50% 129Sv/pas (HYB background. Mice were trained to respond for sucrose in a signaled nose poke task that provides independent measures of associative learning (responses to the reward-paired cue and motor impulsivity (premature responses. Oprm1 knockout mice displayed a remarkable decrease in motor impulsivity. This was observed on the two genetic backgrounds and did not result from impaired associative learning, as responses to the cue signaling reward did not differ across genotypes. Furthermore, mutant mice were insensitive to the effects of ethanol, which increased disinhibition and decreased conditioned responding in wild-type mice. In sharp contrast, mice lacking the Oprd1 gene were more impulsive than controls. Again, mutant animals showed no deficit in associative learning. Ethanol completely disrupted performance in these animals. Together, our results suggest that mu-opioid receptors enhance, whereas delta-opioid receptors inhibit, motor impulsivity. This reveals an unanticipated contribution of endogenous opioid receptor activity to disinhibition. In a broader context, these data suggest that alterations in mu- or delta-opioid receptor function may contribute to impulse control disorders.

Opioid modulation of immunocompetence: Receptor characterization and second messenger involvement

International Nuclear Information System (INIS)

Hemmick, L.M.

1989-01-01

The purpose of this thesis was to examine the effects of opioids on several indices of immunocompetence, determined the receptor specificity of these effects, and ascertain whether the actions of opioids on lymphocytes could be correlated with activation of second messenger systems. By measuring 45 Ca 2+ uptake into lymphocytes, it was demonstrated that β-endorphin 1-31 (β-END 1-31) enhanced rat thymocyte Ca 2+ uptake in response to concanavalin A (Con A) but not phytohemagglutinin (PHA). Related opioid peptides and alkaloids were unable to mimic the effect, and naloxone did not block it, suggesting that β-END 1-31 acted by binding to specific, non-opioid receptors on the thymocytes. Rat splenocyte Con A-stimulated Ca 2+ uptake was not affected by β-END 1-31. β-END 1-31 did not affect basal Ca 2+ uptake by either cell type. Using [ 3 H]thymidine uptake as an index of lymphocyte proliferation, β-END 1-31 and several related opioid peptides reversed prostaglandin E 1 (PGE 1 ) suppression of rat lymph node cell Con A- and PHA-stimulated proliferation. Naloxone did not block the reversal. β-END 1-31 was unable to reverse forskolin and cholera toxin suppression of proliferation, indicating that the lowering of cyclic AMP levels was not the mechanism involved. Verapamil inhibition of proliferation was also not reversed by β-END 1-31, suggesting that promotion of Ca 2+ influx was not a major mechanism involved

Pain management of opioid-treated cancer patients in hospital settings in Denmark

DEFF Research Database (Denmark)

Lundorff, L.; Peuckmann, V.; Sjøgren, Per

2008-01-01

AIM: To evaluate the performance and quality of cancer pain management in hospital settings. METHODS: Anaesthesiologists specialised in pain and palliative medicine studied pain management in departments of oncology and surgery. Study days were randomly chosen and patients treated with oral opioids......-treated patients in hospital settings: however, focussing on average pain intensity, the outcome seems favourable compared with other countries. Pain mechanisms were seldom examined and adjuvant drugs were not specifically used for neuropathic pain. Opioid dosing intervals and supplemental opioid doses were most...

Deltorphins: a family of naturally occurring peptides with high affinity and selectivity for delta opioid binding sites.

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Erspamer, V; Melchiorri, P; Falconieri-Erspamer, G; Negri, L; Corsi, R; Severini, C; Barra, D; Simmaco, M; Kreil, G

1989-07-01

Deltorphins are endogenous linear heptapeptides, isolated from skin extracts of frogs belonging to the genus Phyllomedusa, that have a higher affinity and selectivity for delta opioid binding sites than any other natural compound known. Two deltorphins with the sequence Tyr-Ala-Phe-Asp(or Glu)-Val-Val-Gly-NH2 have been isolated from skin extracts of Phyllomedusa bicolor. The alanine in position 2 is in the D configuration. These peptides, [D-Ala2]deltorphins I and II, show an even higher affinity for delta receptors than the previously characterized deltorphin, which contains D-methionine as the second amino acid. These peptides show some similarity to another constituent of Phyllomedusa skin, dermorphin, which is highly selective for mu-opioid receptors. These peptides all have the N-terminal sequence Tyr-D-Xaa-Phe, where D-Xaa is either D-alanine or D-methionine. While this structure seems to be capable of activating both mu and delta opioid receptors, differences in the C-terminal regions of these peptides are probably responsible for the observed high receptor selectivity of dermorphin and deltorphin.

Endogenous pyrogen-like substance produced by reptiles.

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Bernheim, H A; Kluger, M J

1977-06-01

1. Injection of lizards (Dipsosaurus dorsalis) with rabbit endogenous pyrogen led to a fever. Injections with denatured endogenous pyrogen did not affect body temperature. 2. Injection of lizards with lizard endogenous pyrogen led to a fever of short duration, while injection of denatured lizard endogenous pyrogen produced no change in body temperature. 3. These data support the hypothesis that the febrile mechanism observed in the higher vertebrates has its origins in some primitive vertebrate.

Changing patterns in opioid addiction

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Sproule, Beth; Brands, Bruna; Li, Selina; Catz-Biro, Laura

2009-01-01

ABSTRACT OBJECTIVE To evaluate the clinical observation that the number of individuals seeking opioid detoxification from oxycodone was increasing at the Centre for Addiction and Mental Health (CAMH) in Toronto, Ont; and to identify the characteristics of individuals seeking opioid detoxification at CAMH. DESIGN Retrospective analysis of patient health records. SETTING Medical Withdrawal Management Service at CAMH. PARTICIPANTS All patients admitted for opioid detoxification between January 2000 and December 2004. MAIN OUTCOME MEASURES Number of opioid detoxification admissions each year; type, dose, and source of opioids; comorbid problems and symptoms. RESULTS There were 571 opioid detoxification admissions during the 5-year study period. The number of admissions increased steadily over the 5 years; in particular, the number of admissions related to controlled-release oxycodone increased substantially (3.8%, 8.3%, 20.8%, 30.6%, and 55.4% of the total opioid admissions in 2000 to 2004, respectively; χ42= 105.5, P < .001). The rates of admissions involving heroin remained low and stable. Use of controlled-release oxycodone was associated with considerably higher doses than use of other prescription opioids was. Physician prescriptions were the source of the prescription opioids for a large percentage of patients, particularly for older patients. Prescription opioid users reported considerable comorbid substance use problems, pain, and psychiatric symptoms. CONCLUSION This study has demonstrated a significant rise in the number of individuals seeking treatment at CAMH for controlled-release oxycodone addiction. The substantial comorbid pain, psychiatric symptoms, and other psychoactive substance use problems in these patients, coupled with the finding that prescriptions were an important source of opioids, highlight the clinical complexities encountered in the treatment of these individuals. Further research examining these complexities and the many possible

Effect of Iboga alkaloids on µ-opioid receptor-coupled G protein activation.

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Tamara Antonio

Full Text Available The iboga alkaloids are a class of small molecules defined structurally on the basis of a common ibogamine skeleton, some of which modify opioid withdrawal and drug self-administration in humans and preclinical models. These compounds may represent an innovative approach to neurobiological investigation and development of addiction pharmacotherapy. In particular, the use of the prototypic iboga alkaloid ibogaine for opioid detoxification in humans raises the question of whether its effect is mediated by an opioid agonist action, or if it represents alternative and possibly novel mechanism of action. The aim of this study was to independently replicate and extend evidence regarding the activation of μ-opioid receptor (MOR-related G proteins by iboga alkaloids.Ibogaine, its major metabolite noribogaine, and 18-methoxycoronaridine (18-MC, a synthetic congener, were evaluated by agonist-stimulated guanosine-5´-O-(γ-thio-triphosphate ([(35S]GTPγS binding in cells overexpressing the recombinant MOR, in rat thalamic membranes, and autoradiography in rat brain slices.In rat thalamic membranes ibogaine, noribogaine and 18-MC were MOR antagonists with functional Ke values ranging from 3 uM (ibogaine to 13 uM (noribogaine and 18MC. Noribogaine and 18-MC did not stimulate [(35S]GTPγS binding in Chinese hamster ovary cells expressing human or rat MORs, and had only limited partial agonist effects in human embryonic kidney cells expressing mouse MORs. Ibogaine did not did not stimulate [(35S]GTPγS binding in any MOR expressing cells. Noribogaine did not stimulate [(35S]GTPγS binding in brain slices using autoradiography. An MOR agonist action does not appear to account for the effect of these iboga alkaloids on opioid withdrawal. Taken together with existing evidence that their mechanism of action also differs from that of other non-opioids with clinical effects on opioid tolerance and withdrawal, these findings suggest a novel mechanism of action, and

Endogenous Pyrogen Physiology.

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Beisel, William R.

1980-01-01

Discusses the physiology of endogenous pyrogen (EP), the fever-producing factor of cellular origin. Included are: its hormone-like role, its molecular nature, bioassay procedures, cellular production and mechanisms of EP action. (SA)

Mechanism of the Interaction of Cannabinoid System in Central Amygdale with Opioid System

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S Sarahroodi

2012-05-01

Full Text Available

Background and objectives

Cannabinoids which are active compounds of marijuana show some pharmacological effects similar to the opioids. There are also functional interactions between both cannabinoid and opioid systems. In this study we investigated the role of cannabinoid receptors in central amygdala and its interaction with opioid system.

Methods

In the present study, we investigated the effects of intraperitoneal injection of opioid drugs on response-induced by intra-amygdala (intra-Amyg microinjection of cannabinoid agents in rats, using elevated plus-maze test of anxiety.

Results

Intraperitoneal injection of morphine (3, 6 and 9 mg/kg increased %OAT and %OAE, but not locomotor activity, showing an anxiolytic response. However, some doses of the opioid receptor antagonist, naloxone reduced %OAT and locomotor activity as well. Intra-Amyg administration of CB1 cannabinoid receptor agonist, ACPA (at the dose of 1.25 and 5 ng/rat increased %OAT and %OAE but not locomotor activity, thus showing an anxiolytic response, which was increased by morphine (6 mg/kg, i.p. without any interaction. Naloxone also reduced ACPA effects.  

Intra-Amyg administration of CB1 cannabinoid receptor antagonist, AM251 (2.5, 25 and 100 ng/rat did not alter %OAT and %OAE but higher doses of drug (25 and 100 ng/rat reduced locomotor activity. However, the drug in combination of morphine anxiolytic response and with naloxone decreased anxiety.

Conclusion

The results may indicate an anxiolytic for CB1 cannabinoid. Our results also showed that opioid

Opioid Abuse and Addiction - Multiple Languages

Science.gov (United States)

... Spanish) PDF The basics - Opioids, part 1 - English MP3 The basics - Opioids, part 1 - español (Spanish) MP3 The basics - Opioids, part 1 - English MP4 The ... español (Spanish) PDF Pain - Opioids, part 2 - English MP3 Pain - Opioids, part 2 - español (Spanish) MP3 Pain - ...

Neurogenetics of acute and chronic opiate/opioid abstinence: treating symptoms and the cause.

Science.gov (United States)

Blum, Kenneth; Gold, Mark S; Jacobs, William; McCall, William Vaughn; Febo, Marcelo; Baron, David; Dushaj, Kristina; Demetrovics, Zsolt; Badgaiyan, Rajendra D

2017-03-01

This review begins with a comprehensive history of opioid dependence and treatment in the United States. The focus is an evidence-based treatment model for opioid/opiate dependent individuals. The role of reward genetic polymorphisms and the epigenetic modifications that lead to vulnerability to use and misuse of opiates/opioid to treat pain are reviewed. The neurochemical mechanisms of acute opiate withdrawal and opiate/opioid reward mechanisms are explored with a goal of identifying specific treatment targets. Alterations in functional brain connectivity based on neurobiological mechanisms in heroin dependence and abstinence are also reviewed. A new clinical model an alternative to merely blocking acute withdrawal symptoms as identified in the DSM -5 is proposed. Genetic diagnosis at the onset of detoxification, to determine risk stratification, and identify polymorphic gene targets for pharmaceutical and nutraceutical interventions, followed by the simultaneous initiation of Medication Assisted Therapy (MAT), to enable psychological extinction, and steady pro-dopaminergic therapy with the goal of developing "dopamine homeostasis" is recommended. The objective of these interventions is to prevent future relapse by treating all "Reward Deficiency Syndrome" (RDS) behaviors and eventually make an addiction-free life possible .

Opioid-induced hyponatremia in a patient with central diabetes insipidus: independence from ADH.

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Bhat, Nandini; Balliu, Erjola; Osipoff, Jennifer; Lane, Andrew; Wilson, Thomas

2017-05-24

Hyponatremia can be a complication of opioid therapy, which has been postulated to occur secondary to inappropriate antidiuretic hormone secretion (syndrome of inappropriate antidiuretic hormone secretion [SIADH]). We report severe hyponatremia following wisdom teeth extraction with opioid analgesia in a 19-year-old female with diabetes insipidus (DI) and acquired panhypopituitarism that challenges this theory. As this patient has DI, we believe opioid treatment caused severe hyponatremia by the following mechanisms: (1) Opioids have a direct antidiuretic effect independent of changes in ADH, as demonstrated in Brattleboro rats with central DI. (2) Hydrocodone may have stimulated this patient's thirst center contributing to hyponatremia, as demonstrated in animal studies. Opioid use can cause hyponatremia in patients independent of ADH. It is important for clinicians to be aware of this so that patients can be appropriately counseled.

Is this ?complicated? opioid withdrawal?

OpenAIRE

Parkar, S.R.; Seethalakshmi, R; Adarkar, S; Kharawala, S

2006-01-01

Seven patients with opioid dependence admitted in the de-addiction centre for detoxification developed convulsions and delirium during the withdrawal phase. After ruling out all other possible causes of these complications, opioid withdrawal seemed to emerge as the most likely explanation. The unpredictability of the course of opioid dependence and withdrawal needs to be considered when treating patients with opioid dependence.

An Emerging New Paradigm in Opioid Withdrawal: A Critical Role for Glia-Neuron Signaling in the Periaqueductal Gray

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Handong Ouyang

2012-01-01

Full Text Available The chronic use of opiates (i.e., narcotics such as the natural derivatives of opium including morphine or codeine or opioids (i.e., semisynthetic derivatives of opium and other molecules that activate opioid receptors induces dependence, which is associated with various specific behavioral and somatic signs after their withdrawal or after the administration of an opioid antagonist. Among the brain regions implicated in opiate dependence and withdrawal, the periaqueductal gray area (PAG appears to be critical in regulating the complex signs and symptoms of opioid withdrawal. Numerous neurochemical mechanisms in the PAG have been identified that may contribute to the opioid withdrawal syndrome. Accumulating evidence suggests that glial activation leading to the release of proinflammatory molecules acting on neurons is important in the complex syndrome of opioid dependence and withdrawal. This paper focuses on the recent advances in our understanding of the vital role that glia-neuron interactions play in opioid dependence and withdrawal within the PAG. We summarize those neurochemical mechanisms associated with opioid withdrawal including the recently defined importance of TNFα release from activated glial cells that communicate with TNF receptors on PAG neurons.

Management of opioid addiction with buprenorphine: French history and current management

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Poloméni P

2014-03-01

Full Text Available Pierre Poloméni,1 Raymund Schwan2,3 1Department of Addictology, Paris Seine Saint Denis University Hospital, AP-HP, Site René Muret Sevran, France; 2Care Center for the Treatment and Prevention of Addictions (CSAPA, Nancy University Hospital, 3General Psychiatric Division for the Greater Nancy Urban Community, Psychotherapeutic Center of Nancy, Laxou, France Abstract: The way in which opioid addiction is managed in France is unique, as it is based on the prescription of buprenorphine by general practitioners and is dispensed by retail pharmacies. This policy has had a direct, positive impact on the number of deaths caused by heroin overdose, which was reduced by four-fifths between 1994 and 2002. In addition, certain associated comorbidities, such as infection with the human immunodeficiency virus, have also been reduced; the incidence of acquired immune deficiency syndrome in intravenous drug users fell from 25% in the mid-1990s to 6% in 2010. Since the implementation of this French model of opioid management, major scientific progress has been made, leading to a better understanding of the pathophysiologic mechanisms of addiction and of the management modalities required for its treatment. However, despite notable advances in scientific knowledge and in the implementation of devices, opioid addiction remains a major public health care issue in France, with 275,000–360,000 "problem drug users" being reported in 2011. The situation is still particularly worrying due to psychoactive substance use and misuse of opioid substitution treatments. Since 2003, there has been a persistent increase in the number of deaths and comorbidities related to opioid addiction, principally hepatitis C virus infection, which affects up to 40% of intravenous drug users. In France, the direct involvement of general practitioners in the management of opioid addiction is indisputable. Nevertheless, management could be optimized through better understanding of the

Gabapentin, opioids, and the risk of opioid-related death: A population-based nested case-control study.

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Tara Gomes

2017-10-01

Full Text Available Prescription opioid use is highly associated with risk of opioid-related death, with 1 of every 550 chronic opioid users dying within approximately 2.5 years of their first opioid prescription. Although gabapentin is widely perceived as safe, drug-induced respiratory depression has been described when gabapentin is used alone or in combination with other medications. Because gabapentin and opioids are both commonly prescribed for pain, the likelihood of co-prescription is high. However, no published studies have examined whether concomitant gabapentin therapy is associated with an increased risk of accidental opioid-related death in patients receiving opioids. The objective of this study was to investigate whether co-prescription of opioids and gabapentin is associated with an increased risk of accidental opioid-related mortality.We conducted a population-based nested case-control study among opioid users who were residents of Ontario, Canada, between August 1, 1997, and December 31, 2013, using administrative databases. Cases, defined as opioid users who died of an opioid-related cause, were matched with up to 4 controls who also used opioids on age, sex, year of index date, history of chronic kidney disease, and a disease risk index. After matching, we included 1,256 cases and 4,619 controls. The primary exposure was concomitant gabapentin use in the 120 days preceding the index date. A secondary analysis characterized gabapentin dose as low (<900 mg daily, moderate (900 to 1,799 mg daily, or high (≥1,800 mg daily. A sensitivity analysis examined the effect of concomitant nonsteroidal anti-inflammatory drug (NSAID use in the preceding 120 days. Overall, 12.3% of cases (155 of 1,256 and 6.8% of controls (313 of 4,619 were prescribed gabapentin in the prior 120 days. After multivariable adjustment, co-prescription of opioids and gabapentin was associated with a significantly increased odds of opioid-related death (odds ratio [OR] 1.99, 95% CI

Reasons for opioid use among patients with dependence on prescription opioids: the role of chronic pain.

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Weiss, Roger D; Potter, Jennifer Sharpe; Griffin, Margaret L; McHugh, R Kathryn; Haller, Deborah; Jacobs, Petra; Gardin, John; Fischer, Dan; Rosen, Kristen D

2014-08-01

The number of individuals seeking treatment for prescription opioid dependence has increased dramatically, fostering a need for research on this population. The aim of this study was to examine reasons for prescription opioid use among 653 participants with and without chronic pain, enrolled in the Prescription Opioid Addiction Treatment Study, a randomized controlled trial of treatment for prescription opioid dependence. Participants identified initial and current reasons for opioid use. Participants with chronic pain were more likely to report pain as their primary initial reason for use; avoiding withdrawal was rated as the most important reason for current use in both groups. Participants with chronic pain rated using opioids to cope with physical pain as more important, and using opioids in response to social interactions and craving as less important, than those without chronic pain. Results highlight the importance of physical pain as a reason for opioid use among patients with chronic pain. Copyright © 2014 Elsevier Inc. All rights reserved.

Opioid modulation of immunocompetence: Receptor characterization and second messenger involvement

Energy Technology Data Exchange (ETDEWEB)

Hemmick, L.M.

1989-01-01

The purpose of this thesis was to examine the effects of opioids on several indices of immunocompetence, determined the receptor specificity of these effects, and ascertain whether the actions of opioids on lymphocytes could be correlated with activation of second messenger systems. By measuring {sup 45}Ca{sup 2+} uptake into lymphocytes, it was demonstrated that {beta}-endorphin 1-31 ({beta}-END 1-31) enhanced rat thymocyte Ca{sup 2+} uptake in response to concanavalin A (Con A) but not phytohemagglutinin (PHA). Related opioid peptides and alkaloids were unable to mimic the effect, and naloxone did not block it, suggesting that {beta}-END 1-31 acted by binding to specific, non-opioid receptors on the thymocytes. Rat splenocyte Con A-stimulated Ca{sup 2+} uptake was not affected by {beta}-END 1-31. {beta}-END 1-31 did not affect basal Ca{sup 2+} uptake by either cell type. Using ({sup 3}H)thymidine uptake as an index of lymphocyte proliferation, {beta}-END 1-31 and several related opioid peptides reversed prostaglandin E{sub 1} (PGE{sub 1}) suppression of rat lymph node cell Con A- and PHA-stimulated proliferation. Naloxone did not block the reversal. {beta}-END 1-31 was unable to reverse forskolin and cholera toxin suppression of proliferation, indicating that the lowering of cyclic AMP levels was not the mechanism involved. Verapamil inhibition of proliferation was also not reversed by {beta}-END 1-31, suggesting that promotion of Ca{sup 2+} influx was not a major mechanism involved.

The effects of opioid drugs on dopamine mediated locomotor activity in rats

International Nuclear Information System (INIS)

Leathern, L.L.

1986-12-01

Opioid drugs influence various behavioural parameters including locomotor activity in experimental animals. The interaction between the opioid and dopaminergic systems is one possible explanation for the effect of opioid drugs on locomotor activity. In this study behavioural and biochemical assays were done to investigate the interaction between the opioid and dopaminergic systems. Behavioural studies were done by measurement of locomotor activity (LA) of rats after acute or chronic pretreatment with opioid and/or dopaminergic drugs. Biochemical studies were in the form of radioligand binding assays, the effect on the number (Bmax) and affinity (K D ) of receptors was measured after chronic pretreatment with opioid and/or dopaminergic drugs. The opioid drugs used are morphine, nalbuphine and naloxone. Dopaminergic drugs used included: agonists-apomorphine and piribedil; antagonists-pimozide, haloperidol, chlorpromazine. In the acute situation increased LA was obtained with morphine and the DA agonists. A correlation between the behavioural and biochemical assays was found. Chronic pretreatment with morphine enhanced apomorphine induced LA, this supersensitivity was also measured as an increased receptor density (Bmax) of D2 receptors in the striatum. Chronic morphine pretreatment caused a decrease in morphine induced LA, while this subsensitivity was not apparent in the ligand binding assays - where no change in receptor number was observed. Chronic naloxone pretreatment enhanced morphine induced LA, as well as increased the Bmax of opioid receptors in the whole brain. It is concluded that an interaction between the opioid and dopaminergic systems does exist, and may account for the mechanism of action of the opioids

Who Benefits from Chronic Opioid Therapy? Rethinking the Question of Opioid Misuse Risk

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Elizabeth Huber

2016-05-01

Full Text Available Beginning in the late 1990s, a movement began within the pain management field focused upon the underutilization of opioids, thought to be a potentially safe and effective class of pain medication. Concern for addiction and misuse were present at the start of this shift within pain medicine, and an emphasis was placed on developing reliable and valid methods and measures of identifying those at risk for opioid misuse. Since that time, the evidence for the safety and effectiveness of chronic opioid therapy (COT has not been established. Rather, the harmful, dose-dependent deleterious effects have become clearer, including addiction, increased risk of injuries, respiratory depression, opioid induced hyperalgesia, and death. Still, many individuals on low doses of opioids for long periods of time appear to have good pain control and retain social and occupational functioning. Therefore, we propose that the question, “Who is at risk of opioid misuse?” should evolve to, “Who may benefit from COT?” in light of the current evidence.

Genetics Home Reference: opioid addiction

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... Facebook Twitter Home Health Conditions Opioid addiction Opioid addiction Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Opioid addiction is a long-lasting (chronic) disease that can ...

The opioid manager: a point-of-care tool to facilitate the use of the Canadian Opioid Guideline.

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Furlan, Andrea D; Reardon, Rhoda; Salach, Lena

2012-01-01

The Opioid Manager is designed to be used as a point-of-care tool for providers prescribing opioids for chronic noncancer pain. It condenses the key elements from the Canadian Opioid Guideline and can be used as a chart insert. The Opioid Manager has been validated and is available for download from the Guideline's Web site http://nationalpaincentre.mcmaster.ca/opioidmanager/. The Opioid Manager is divided into the following four parts: A) before you write the first script, B) initiation trial, C) maintenance and monitoring, and D) when is it time to decrease the dose or stop the opioid completely? The Opioid Manager has been downloaded by 1,432 users: 47 percent family physicians, 18 percent pharmacists, 13 percent other physicians, and 22 percent miscellaneous. To show how to use the Opioid Manager, the authors created a 10-minute video that is available on the Internet. The Opioid Manager is being translated to French, Spanish, Portuguese, and Farsi.

Chronic Opioid Use After Surgery: Implications for Perioperative Management in the Face of the Opioid Epidemic.

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Hah, Jennifer M; Bateman, Brian T; Ratliff, John; Curtin, Catherine; Sun, Eric

2017-11-01

Physicians, policymakers, and researchers are increasingly focused on finding ways to decrease opioid use and overdose in the United States both of which have sharply increased over the past decade. While many efforts are focused on the management of chronic pain, the use of opioids in surgical patients presents a particularly challenging problem requiring clinicians to balance 2 competing interests: managing acute pain in the immediate postoperative period and minimizing the risks of persistent opioid use after the surgery. Finding ways to minimize this risk is particularly salient in light of a growing literature suggesting that postsurgical patients are at increased risk for chronic opioid use. The perioperative care team, including surgeons and anesthesiologists, is poised to develop clinical- and systems-based interventions aimed at providing pain relief in the immediate postoperative period while also reducing the risks of opioid use longer term. In this paper, we discuss the consequences of chronic opioid use after surgery and present an analysis of the extent to which surgery has been associated with chronic opioid use. We follow with a discussion of the risk factors that are associated with chronic opioid use after surgery and proceed with an analysis of the extent to which opioid-sparing perioperative interventions (eg, nerve blockade) have been shown to reduce the risk of chronic opioid use after surgery. We then conclude with a discussion of future research directions.

Recent opioid use and fall-related injury among older patients with trauma.

Science.gov (United States)

Daoust, Raoul; Paquet, Jean; Moore, Lynne; Émond, Marcel; Gosselin, Sophie; Lavigne, Gilles; Choinière, Manon; Boulanger, Aline; Mac-Thiong, Jean-Marc; Chauny, Jean-Marc

2018-04-23

Evidence for an association between opioid use and risk of falls or fractures in older adults is inconsistent. We examine the association between recent opioid use and the risk, as well as the clinical outcomes, of fall-related injuries in a large trauma population of older adults. In a retrospective, observational, multicentre cohort study conducted on registry data, we included all patients aged 65 years and older who were admitted (hospital stay > 2 d) for injury in 57 trauma centres in the province of Quebec, Canada, between 2004 and 2014. We looked at opioid prescriptions filled in the 2 weeks preceding the trauma in patients who sustained a fall, compared with those who sustained an injury through another mechanism. A total of 67 929 patients were retained for analysis. Mean age was 80.9 (± 8.0) years and 69% were women. The percentage of patients who had filled an opioid prescription in the 2 weeks preceding an injury was 4.9% (95% confidence interval [CI] 4.7%-5.1%) for patients who had had a fall, compared with 1.5% (95% CI 1.2%-1.8%) for those who had had an injury through another mechanism. After we controlled for confounding variables, patients who had filled an opioid prescription within 2 weeks before injury were 2.4 times more likely to have a fall rather than any other type of injury. For patients who had a fall-related injury, those who used opioids were at increased risk of in-hospital death (odds ratio 1.58; 95% CI 1.34-1.86). Recent opioid use is associated with an increased risk of fall and an increased likelihood of death in older adults. © 2018 Joule Inc. or its licensors.

Characteristics of opioid-users whose death was related to opioid-toxicity: a population-based study in Ontario, Canada.

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Parvaz Madadi

Full Text Available The impact of the prescription opioid public health crisis has been illustrated by the dramatic increase in opioid-related deaths in North America. We aimed to identify patterns and characteristics amongst opioid-users whose cause of death was related to opioid toxicity.This was a population-based study of Ontarians between the years 2006 and 2008. All drug-related deaths which occurred during this time frame were reviewed at the Office of the Chief Coroner of Ontario, and opioid-related deaths were identified. Medical, toxicology, pathology, and police reports were comprehensively reviewed. Narratives, semi-quantitative, and quantitative variables were extracted, tabulated, and analyzed.Out of 2330 drug-related deaths in Ontario, 58% were attributed either in whole or in part, to opioids (n = 1359. Oxycodone was involved in approximately one-third of all opioid-related deaths. At least 7% of the entire cohort used opioids that were prescribed for friends and/or family, 19% inappropriately self-administered opioids (injection, inhalation, chewed patch, 3% were recently released from jail, and 5% had been switched from one opioid to another near the time of death. Accidental deaths were significantly associated with personal history of substance abuse, enrollment in methadone maintenance programs, cirrhosis, hepatitis, and cocaine use. Suicides were significantly associated with mental illness, previous suicide attempts, chronic pain, and a history of cancer.These results identify novel, susceptible groups of opioid-users whose cause of death was related to opioids in Ontario and provide the first evidence to assist in quantifying the contribution of opioid misuse and diversion amongst opioid-related mortality in Canada. Multifaceted prevention strategies need to be developed based on subpopulations of opioid users.

Inhibition of GABAergic Neurotransmission by HIV-1 Tat and Opioid Treatment in the Striatum Involves μ-opioid Receptors

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Changqing Xu

2016-11-01

Full Text Available Due to combined antiretroviral therapy (cART, human immunodeficiency virus type 1 (HIV-1 is considered a chronic disease with high prevalence of mild forms of neurocognitive impairments, also referred to as HIV-associated neurocognitive disorders (HAND. Although opiate drug use can exacerbate HIV-1 Tat-induced neuronal damage, it remains unknown how and to what extent opioids interact with Tat on the GABAergic system. We conducted whole-cell recordings in mouse striatal slices and examined the effects of HIV-1 Tat in the presence and absence of morphine (1 μM and damgo (1 μM on GABAergic neurotransmission. Results indicated a decrease in the frequency and amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs and miniature IPSCs (mIPSCs by Tat (5 – 50 nM in a concentration-dependent manner. The significant Tat-induced decrease in IPSCs was abolished when removing extracellular and/or intracellular calcium. Treatment with morphine or damgo alone significantly decreased the frequency, but not amplitude of IPSCs. Interestingly, morphine but not damgo indicated an additional downregulation of the mean frequency of mIPSCs in combination with Tat. Pretreatment with naloxone (1 μM and CTAP (1 μM prevented the Tat-induced decrease in sIPSCs frequency but only naloxone prevented the combined Tat and morphine effect on mIPSCs frequency. Results indicate a Tat- or opioid-induced decrease in GABAergic neurotransmission via µ-opioid receptors with combined Tat and morphine effects involving additional opioid receptor-related mechanisms. Exploring the interactions between Tat and opioids on the GABAergic system may help to guide future research on HAND in the context of opiate drug use.

The opioid epidemic and national guidelines for opioid therapy for chronic noncancer pain: a perspective from different continents.

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Häuser, Winfried; Schug, Stephan; Furlan, Andrea D

2017-05-01

A marked rise in opioid prescriptions for patients with chronic noncancer pain (CNCP) with a parallel increase in opioid abuse/misuse, and resulting deaths was noted in the Unites states in the past decade (opioid epidemic). In response, the US Center of Diseases Control (CDC) developed a guideline for prescribing of opioids for patients with CNCP. To assess (1) if there is an opioid epidemic in Australia, Canada, and Germany (2) to compare Australian, Canadian, German, and Center of Diseases Control guidelines recommendations for long-term opioid therapy for CNCP. National evidence-based guidelines and PubMed were searched for recommendations for opioid prescriptions for CNCP. There are signs of an opioid epidemic in Australia and Canada, but not in Germany. Guidelines in all 4 countries provide similar recommendations: opioids are not the first-line therapy for patients with CNCP; regular clinical assessments of benefits and harms are necessary; excessive doses should be avoided (recommended morphine equivalent daily doses range from 50 to 200 mg/d); stopping rules should be followed. All guidelines do not recommend the use of opioids in chronic pain conditions without an established nociceptive or neuropathic cause such as fibromyalgia and primary headache. Implementation of opioid prescribing guidelines should ensure that physicians prescribe opioids only for appropriate indications in limited doses for selected patients and advice patients on their safe use. These measures could contribute to reduce prescription opioid misuse/abuse and deaths.

Pain volatility and prescription opioid addiction treatment outcomes in patients with chronic pain.

Science.gov (United States)

Worley, Matthew J; Heinzerling, Keith G; Shoptaw, Steven; Ling, Walter

2015-12-01

The combination of prescription opioid dependence and chronic pain is increasingly prevalent and hazardous to public health. Variability in pain may explain poor prescription opioid addiction treatment outcomes in persons with chronic pain. This study examined pain trajectories and pain volatility in patients with chronic pain receiving treatment for prescription opioid addiction. We conducted secondary analyses of adults with chronic pain (n = 149) who received buprenorphine/naloxone (BUP/NLX) and counseling for 12 weeks in an outpatient, multisite clinical trial. Good treatment outcome was defined as urine-verified abstinence from opioids at treatment endpoint (Week 12) and during at least 2 of the previous 3 weeks. Pain severity significantly declined over time during treatment (b = -0.36, p opioid dependence. Patients with greater volatility in subjective pain during treatment have increased risk of returning to opioid use by the conclusion of an intensive treatment with BUP/NLX and counseling. Future research should examine underlying mechanisms of pain volatility and identify related therapeutic targets to optimize interventions for prescription opioid addiction and co-occurring chronic pain. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Antimicrobial activity and mechanism of PDC213, an endogenous peptide from human milk

International Nuclear Information System (INIS)

Sun, Yazhou; Zhou, Yahui; Liu, Xiao; Zhang, Fan; Yan, Linping; Chen, Ling; Wang, Xing; Ruan, Hongjie; Ji, Chenbo; Cui, Xianwei; Wang, Jiaqin

2017-01-01

Human milk has always been considered an ideal source of elemental nutrients to both preterm and full term infants in order to optimally develop the infant's tissues and organs. Recently, hundreds of endogenous milk peptides were identified in human milk. These peptides exhibited angiotensin-converting enzyme inhibition, immunomodulation, or antimicrobial activity. Here, we report the antimicrobial activity and mechanism of a novel type of human antimicrobial peptide (AMP), termed PDC213 (peptide derived from β-Casein 213-226 aa). PDC213 is an endogenous peptide and is present at higher levels in preterm milk than in full term milk. The inhibitory concentration curve and disk diffusion tests showed that PDC213 had obvious antimicrobial against S. aureus and Y. enterocolitica, the common nosocomial pathogens in neonatal intensive care units (NICUs). Fluorescent dye methods, electron microscopy experiments and DNA-binding activity assays further indicated that PDC213 can permeabilize bacterial membranes and cell walls rather than bind intracellular DNA to kill bacteria. Together, our results suggest that PDC213 is a novel type of AMP that warrants further investigation. - Highlights: • PDC213 is an endogenous peptide presenting higher levels in preterm milk. • PDC213 showed obvious antimicrobial against S. aereus and Y. enterocolitica. • PDC213 can permeabilize bacterial membranes and cell walls to kill bacterias. • PDC213 is a novel type of antimicrobial peptides worthy further investigation.

Opioid-free anaesthesia in three dogs

Directory of Open Access Journals (Sweden)

Donna M. White

2017-05-01

Full Text Available Opioid-free anaesthesia (OFA is a relatively new and growing field in human medicine. There are multiple motivations behind this emerging practice with the recognition of several serious potential opioid-related adverse effects including opioid induced hyperalgesia, opioid tolerance and immunomodulatory effects of opioids. Opioids have long been the mainstay of veterinary anaesthesia and pain management practice. The feasibility of OFA in veterinary patients is presented here. A case series of three dogs that underwent OFA for canine ovariohysterectomy is reported. The authors conclude OFA is possible in veterinary medicine; however the move away from the familiar effects of opioids perioperatively is challenging. Gaining experience with these types of protocols for standard procedures in healthy animals, such as neutering, will provide the anaesthetist with the building blocks for more invasive surgeries.

Macroeconomic conditions and opioid abuse.

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Hollingsworth, Alex; Ruhm, Christopher J; Simon, Kosali

2017-12-01

We examine how deaths and emergency department (ED) visits related to use of opioid analgesics (opioids) and other drugs vary with macroeconomic conditions. As the county unemployment rate increases by one percentage point, the opioid death rate per 100,000 rises by 0.19 (3.6%) and the opioid overdose ED visit rate per 100,000 increases by 0.95 (7.0%). Macroeconomic shocks also increase the overall drug death rate, but this increase is driven by rising opioid deaths. Our findings hold when performing a state-level analysis, rather than county-level; are primarily driven by adverse events among whites; and are stable across time periods. Copyright © 2017 Elsevier B.V. All rights reserved.

Targinact--opioid pain relief without constipation?

Science.gov (United States)

2010-12-01

Targinact (Napp Pharmaceuticals Ltd) is a modified-release combination product containing the strong opioid oxycodone plus the opioid antagonist naloxone. It is licensed for "severe pain, which can be adequately managed only with opioid analgesics".1 The summary of product characteristics (SPC) states that "naloxone is added to counteract opioid-induced constipation by blocking the action of oxycodone at opioid receptors locally in the gut". Advertising for the product claims "better pain relief", "superior GI [gastrointestinal] tolerability" and "improved quality of life" "compared to previous treatment in a clinical practice study (n=7836)". Here we consider whether Targinact offers advantages over using strong opioids plus laxatives where required.

Pathway and Cell-Specific Kappa-Opioid Receptor Modulation of Excitatory-Inhibitory Balance Differentially Gates D1 and D2 Accumbens Neuron Activity

Science.gov (United States)

Tejeda, Hugo A.; Wu, Jocelyn; Kornspun, Alana R.; Pignatelli, Marco; Kashtelyan, Vadim; Krashes, Michael J.; Lowell, Brad B.; Carlezon, William A.; Bonci, Antonello

2018-01-01

Endogenous dynorphin signaling via the kappa-opioid receptor (KOR) in the nucleus accumbens (NAcc) powerfully mediates negative affective states and stress reactivity. Excitatory inputs from the hippocampus and amygdala play a fundamental role in shaping the activity of both NAcc D1 and D2 MSNs, which encode positive and negative motivational valences, respectively. However, a circuit-based mechanism by which KOR modulation of excitation-inhibition balance modifies D1 and D2 MSN activity is lacking. Here, we provide a comprehensive synaptic framework wherein presynaptic KOR inhibition decreases excitatory drive of D1 MSN activity by the amygdala, but not hippocampus. Conversely, presynaptic inhibition by KORs of inhibitory synapses on D2 MSNs enhances integration of excitatory drive by the amygdala and hippocampus. In conclusion, we describe a circuit-based mechanism showing differential gating of afferent control of D1 and D2 MSN activity by KORs in a pathway specific manner. PMID:28056342

Risk factors for opioid overdose and awareness of overdose risk among veterans prescribed chronic opioids for addiction or pain.

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Wilder, Christine M; Miller, Shannon C; Tiffany, Elizabeth; Winhusen, Theresa; Winstanley, Erin L; Stein, Michael D

2016-01-01

Rising overdose fatalities among U.S. veterans suggest veterans taking prescription opioids may be at risk for overdose. However, it is unclear whether veterans prescribed chronic opioids are aware of this risk. The objective of this study was to identify risk factors and determine awareness of risk for opioid overdose in veterans treated with opioids for chronic pain, using veterans treated with methadone or buprenorphine for opioid use disorder as a high-risk comparator group. In the current study, 90 veterans on chronic opioid medication, for either opioid use disorder or pain management, completed a questionnaire assessing risk factors, knowledge, and self-estimate of risk for overdose. Nearly all veterans in both groups had multiple overdose risk factors, although individuals in the pain management group had on average a significantly lower total number of risk factors than did individuals in the opioid use disorder group (5.9 versus 8.5, p opioid overdose risk factors (12.1 versus 13.5, p opioid overdose risk factors. Our results suggest that veterans in both groups underestimated their risk for opioid overdose. Expansion of overdose education to include individuals on chronic opioids for pain management and a shift in educational approaches to overdose prevention may be indicated.

Opioids and breast cancer recurrence

DEFF Research Database (Denmark)

Cronin-Fenton, Deirdre P; Heide-Jørgensen, Uffe; Ahern, Thomas P

2015-01-01

BACKGROUND: Opioids may alter immune function, thereby potentially affecting cancer recurrence. The authors investigated the association between postdiagnosis opioid use and breast cancer recurrence. METHODS: Patients with incident, early stage breast cancer who were diagnosed during 1996 through...... 2008 in Denmark were identified from the Danish Breast Cancer Cooperative Group Registry. Opioid prescriptions were ascertained from the Danish National Prescription Registry. Follow-up began on the date of primary surgery for breast cancer and continued until breast cancer recurrence, death......, emigration, 10 years, or July 31, 2013, whichever occurred first. Cox regression models were used to compute hazard ratios and 95% confidence intervals associating breast cancer recurrence with opioid prescription use overall and by opioid type and strength, immunosuppressive effect, chronic use (≥6 months...

Women who abuse prescription opioids: findings from the Addiction Severity Index-Multimedia Version Connect prescription opioid database.

Science.gov (United States)

Green, Traci C; Grimes Serrano, Jill M; Licari, Andrea; Budman, Simon H; Butler, Stephen F

2009-07-01

Evidence suggests gender differences in abuse of prescription opioids. This study aimed to describe characteristics of women who abuse prescription opioids in a treatment-seeking sample and to contrast gender differences among prescription opioid abusers. Data collected November 2005 to April 2008 derived from the Addiction Severity Index Multimedia Version Connect (ASI-MV Connect) database. Bivariate and multivariable logistic regression examined correlates of prescription opioid abuse stratified by gender. 29,906 assessments from 220 treatment centers were included, of which 12.8% (N=3821) reported past month prescription opioid abuse. Women were more likely than men to report use of any prescription opioid (29.8% females vs. 21.1% males, phistory of drug overdose. Men-specific correlates were age screen and identify those at highest risk of prescription opioid abuse. Prevention and intervention efforts with a gender-specific approach are warranted.

Medication-assisted therapy for opioid addiction

OpenAIRE

Tai, Betty; Saxon, Andrew J.; Ling, Walter

2013-01-01

The “Medication-Assisted Therapy for Opioid Addiction” session was chaired by Dr. Betty Tai and had three presenters. The presenters (and their topics) were: Dr. Andrew J. Saxon (Methadone and Buprenorphine for Treatment of Opioid Addiction and HIV Risk Reduction), Dr. Walter Ling (Opioid Antagonist Treatment for Opioid Addiction), and Dr. Betty Tai (Chronic Care Model for Substance Use Disorder).

CRF1-R activation of the dynorphin/kappa opioid system in the mouse basolateral amygdala mediates anxiety-like behavior.

Directory of Open Access Journals (Sweden)

Michael R Bruchas

2009-12-01

Full Text Available Stress is a complex human experience and having both rewarding and aversive motivational properties. The adverse effects of stress are well documented, yet many of underlying mechanisms remain unclear and controversial. Here we report that the anxiogenic properties of stress are encoded by the endogenous opioid peptide dynorphin acting in the basolateral amygdala. Using pharmacological and genetic approaches, we found that the anxiogenic-like effects of Corticotropin Releasing Factor (CRF were triggered by CRF(1-R activation of the dynorphin/kappa opioid receptor (KOR system. Central CRF administration significantly reduced the percent open-arm time in the elevated plus maze (EPM. The reduction in open-arm time was blocked by pretreatment with the KOR antagonist norbinaltorphimine (norBNI, and was not evident in mice lacking the endogenous KOR ligand dynorphin. The CRF(1-R agonist stressin 1 also significantly reduced open-arm time in the EPM, and this decrease was blocked by norBNI. In contrast, the selective CRF(2-R agonist urocortin III did not affect open arm time, and mice lacking CRF(2-R still showed an increase in anxiety-like behavior in response to CRF injection. However, CRF(2-R knockout animals did not develop CRF conditioned place aversion, suggesting that CRF(1-R activation may mediate anxiety and CRF(2-R may encode aversion. Using a phosphoselective antibody (KORp to identify sites of dynorphin action, we found that CRF increased KORp-immunoreactivity in the basolateral amygdala (BLA of wildtype, but not in mice pretreated with the selective CRF(1-R antagonist, antalarmin. Consistent with the concept that acute stress or CRF injection-induced anxiety was mediated by dynorphin release in the BLA, local injection of norBNI blocked the stress or CRF-induced increase in anxiety-like behavior; whereas norBNI injection in a nearby thalamic nucleus did not. The intersection of stress-induced CRF and the dynorphin/KOR system in the BLA was

Peripherally applied opioids for postoperative pain

DEFF Research Database (Denmark)

Nielsen, B N; Henneberg, S W; Schmiegelow, K

2015-01-01

BACKGROUND: Opioids applied peripherally at the site of surgery may produce postoperative analgesia with few side effects. We performed this systematic review to evaluate the analgesic effect of peripherally applied opioids for acute postoperative pain. METHODS: We searched PubMed (1966 to June...... 2013), Embase (1980 to June 2013), and the Cochrane Central Register of Controlled Trials (The Cochrane Library 2013, Issue 6). Randomized controlled trials investigating the postoperative analgesic effect of peripherally applied opioids vs. systemic opioids or placebo, measured by pain intensity...... difference -5 mm, 95% CI: -7 to -3) for peripherally applied opioids vs. placebo and statistically significant increased time to first analgesic (mean difference 153 min, 95% CI: 41-265). When preoperative inflammation was reported (five studies), peripherally applied opioids significantly improved...

Deltorphins: a family of naturally occurring peptides with high affinity and selectivity for delta opioid binding sites.

OpenAIRE

Erspamer, V; Melchiorri, P; Falconieri-Erspamer, G; Negri, L; Corsi, R; Severini, C; Barra, D; Simmaco, M; Kreil, G

1989-01-01

Deltorphins are endogenous linear heptapeptides, isolated from skin extracts of frogs belonging to the genus Phyllomedusa, that have a higher affinity and selectivity for delta opioid binding sites than any other natural compound known. Two deltorphins with the sequence Tyr-Ala-Phe-Asp(or Glu)-Val-Val-Gly-NH2 have been isolated from skin extracts of Phyllomedusa bicolor. The alanine in position 2 is in the D configuration. These peptides, [D-Ala2]deltorphins I and II, show an even higher affi...

42 CFR 8.11 - Opioid treatment program certification.

Science.gov (United States)

2010-10-01

... Substances Act (21 U.S.C. 823(g)(1)) to dispense opioid drugs in the treatment of opioid addiction. An OTP... opioid addiction. (2) To obtain certification from SAMHSA, an OTP must meet the Federal opioid treatment... governmental entities to regulate the use of opioid drugs in the treatment of opioid addiction. The provisions...

Evidence for opioid involvement in the motivation to sing.

Science.gov (United States)

Riters, Lauren V

2010-03-01

Songbirds produce high rates of song within multiple social contexts, suggesting that they are highly motivated to sing and that song production itself may be rewarding. Progress has been made in understanding the neural basis of song learning and sensorimotor processing, however little is known about neurobiological mechanisms regulating the motivation to sing. Neural systems involved in motivation and reward have been conserved across species and in songbirds are neuroanatomically well-positioned to influence the song control system. Opioid neuropeptides within these systems play a primary role in hedonic reward, at least in mammals. In songbirds, opioid neuropeptides and receptors are found throughout the song control system and within several brain regions implicated in both motivation and reward, including the medial preoptic nucleus (POM) and ventral tegmental area (VTA). Growing research shows these regions to play a role in birdsong that differs depending upon whether song is sexually motivated in response to a female, used for territorial defense or sung as part of a flock but not directed towards an individual (undirected song). Opioid pharmacological manipulations and immunocytochemical data demonstrate a role for opioid activity possibly within VTA and POM in the regulation of song production. Although future research is needed, data suggest that opioids may be most critically involved in reinforcing song that does not result in any obvious form of immediate externally mediated reinforcement, such as undirected song produced in large flocks or during song learning. Data are reviewed supporting the idea that dopamine activity underlies the motivation or drive to sing, but that opioid release is what makes song production rewarding. Copyright 2009 Elsevier B.V. All rights reserved.

Evidence for opioid involvement in the motivation to sing

Science.gov (United States)

Riters, Lauren V.

2009-01-01

Songbirds produce high rates of song within multiple social contexts, suggesting that they are highly motivated to sing and that song production itself may be rewarding. Progress has been made in understanding the neural basis of song learning and sensorimotor processing, however little is known about neurobiological mechanisms regulating the motivation to sing. Neural systems involved in motivation and reward have been conserved across species and in songbirds are neuroanatomically well-positioned to influence the song control system. Opioid neuropeptides within these systems play a primary role in hedonic reward, at least in mammals. In songbirds, opioid neuropeptides and receptors are found throughout the song control system and within several brain regions implicated in both motivation and reward, including the medial preoptic nucleus (POM) and ventral tegmental area (VTA). Growing research shows these regions to play a role in birdsong that differs depending upon whether song is sexually-motivated in response to a female, used for territorial defense or sung as part of a flock but not directed towards an individual (undirected song). Opioid pharmacological manipulations and immunocytochemical data demonstrate a role for opioid activity possibly within VTA and POM in the regulation of song production. Although future research is needed, data suggest that opioids may be most critically involved in reinforcing song that does not result in any obvious form of immediate externally-mediated reinforcement, such as undirected song produced in large flocks or during song learning. Data are reviewed supporting the idea that dopamine activity underlies the motivation or drive to sing, but that opioid release is what makes song production rewarding. PMID:19995531

Comparison of opioid doctor shopping for tapentadol and oxycodone: a cohort study.

Science.gov (United States)

Cepeda, M Soledad; Fife, Daniel; Vo, Lien; Mastrogiovanni, Gregory; Yuan, Yingli

2013-02-01

Obtaining opioids from multiple prescribers, known as doctor shopping, is 1 example of opioid abuse and diversion. The dual mechanism of action of tapentadol could make tapentadol less likely to be abused than other opioids. The aim of this retrospective cohort study was to compare the risk of shopping behavior between tapentadol immediate release (IR) and oxycodone IR. Subjects exposed to tapentadol or oxycodone with no recent opioid use were included and followed for 1 year. The primary outcome was the proportion of subjects who developed shopping behavior defined as subjects who had opioid prescriptions written by >1 prescriber with ≥1 day of overlap filled at ≥3 pharmacies. The opioids involved in the shopping episodes were assessed. A total of 112,821 subjects were exposed to oxycodone and 42,940 to tapentadol. Shopping behavior was seen in .8% of the subjects in the oxycodone group and in .2% of the subjects in the tapentadol group, for an adjusted odds ratio of 3.5 (95% confidence interval, 2.8 to 4.4). In the oxycodone group, 28.0% of the shopping events involved exclusively oxycodone, whereas in the tapentadol group, .6% of the shopping events involved exclusively tapentadol. Results suggest that the risk of shopping behavior is substantially lower with tapentadol than with oxycodone. The risk of opioid doctor shopping, ie, obtaining opioid prescriptions from multiple prescribers, is lower with tapentadol than with oxycodone. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

Dependence and addiction during chronic opioid therapy.

Science.gov (United States)

Juurlink, David N; Dhalla, Irfan A

2012-12-01

The use of opioids for chronic noncancer pain has increased dramatically over the past 25 years in North America and has been accompanied by a major increase in opioid addiction and overdose deaths. The increase in opioid prescribing is multifactorial and partly reflects concerns about the effectiveness and safety of alternative medications, particularly the nonsteroidal anti-inflammatory drugs. However, much of the rise in opioid prescribing reflects the assertion, widely communicated to physicians in the 1990s, that the risks of dependence and addiction during chronic opioid therapy were low, predictable, and could be minimized by the use of controlled-release opioid formulations. In this narrative review, we offer a critical appraisal of the publications most frequently cited as evidence that the risk of addiction during chronic opioid therapy is low. We conclude that very few well-designed studies support the notion that opioid addiction is rare during chronic opioid therapy and that none can be readily generalized to present-day practice. Despite serious methodological limitations, these studies have been repeatedly mischaracterized as showing that the risk of addiction during chronic opioid therapy is rare. These studies are countered by a larger, more rigorous and contemporary body of evidence demonstrating that dependence and addiction are relatively common consequences of chronic opioid therapy, occurring in up to one-third of patients in some series.

Opioids, pain, the brain, and hyperkatifeia: a framework for the rational use of opioids for pain.

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Shurman, Joseph; Koob, George F; Gutstein, Howard B

2010-07-01

Opioids have relieved more human suffering than any other medication, but their use is still fraught with significant concerns of misuse, abuse, and addiction. This theoretical article explores the hypothesis that opioid misuse in the context of pain management produces a hypersensitivity to emotional distress, termed hyperkatifeia. In the misuse of opioids, neural substrates that mediate positive emotional states (brain reward systems) are compromised, and substrates mediating negative emotional states (brain stress systems) are enhanced. A reflection and early marker of such a nonhomeostatic state may be the development of opioid-induced hyperkatifeia, defined as the increased intensity of the constellation of negative emotional/motivational symptoms and signs observed during withdrawal from drugs of abuse (derived from the Greek "katifeia" for dejection or negative emotional state) and is most likely to occur in subjects in whom the opioid produces a break with homeostasis and less likely to occur when the opioid is restoring homeostasis, such as in effective pain treatment. When the opioid appropriately relieves pain, opponent processes are not engaged. However, if the opioid is administered in excess of need because of overdose, pharmacokinetic variables, or treating an individual without pain, then the body will react to that perturbation by engaging opponent processes in the domains of both pain (hyperalgesia) and negative emotional states (hyperkatifeia). Repeated engagement of opponent processes without time for the brain's emotional systems to reestablish homeostasis will further drive changes in emotional processes that may produce opioid abuse or addiction, particularly in individuals with genetic or environmental vulnerability.

Comparison of craving for opioid in opioid-dependent individuals and people under methadone maintenance treatment

Directory of Open Access Journals (Sweden)

Azita Chehri

2014-02-01

Full Text Available Background: Methadone Maintenance Therapy (MMT is the most important treatment for opioid -dependency recurrence. The aim of this study was to compare the craving level in opioid-dependent individuals and people under methadone maintenance therapy. Methods: In this case – control study, 120 men with opioid dependency were selected through cluster sampling method. They were divided into two groups, 60 people in opioid-dependent group and 60 people in MMT group. Both groups were matched for age, sex, marital status, education, duration of opioid dependency and method of consumption. Then, they completed INCAS Substance Abuse Profile (ISAP, opiate withdrawal symptoms checklist, self–report of craving, Desire for Drug Questionnaire (DDQ, Obsessive Compulsive Drug Use Scale (OCDUS and visual cue-induced craving questionnaire. Data were analyzed by SPSS 15 using t-test and ANOVA. Results: Mean craving for drug significantly was lower in MMT group comparing opioid-dependent group (P<0.01. Conclusion: Methadone Maintenance Therapy decreased the craving for drugs and substances This can have an important role in relapse prevention.

The effect of exercise frequency on neuropathic pain and pain-related cellular reactions in the spinal cord and midbrain in a rat sciatic nerve injury model

Directory of Open Access Journals (Sweden)

Sumizono M

2018-02-01

Full Text Available Megumi Sumizono,1,2 Harutoshi Sakakima,1 Shotaro Otsuka,1 Takuto Terashi,1 Kazuki Nakanishi,1,2 Koki Ueda,1,2 Seiya Takada,1,2 Kiyoshi Kikuchi3 1Course of Physical Therapy, School of Health Sciences, Faculty of Medicine, Kagoshima University, Kagoshima, Japan; 2Kirishima Orthopedics, Kirishima, Japan; 3Division of Brain Science, Department of Physiology, Kurume University School of Medicine, Kurume, Japan Background: Exercise regimens are established methods that can relieve neuropathic pain. However, the relationship between frequency and intensity of exercise and multiple cellular responses of exercise-induced alleviation of neuropathic pain is still unclear. We examined the influence of exercise frequency on neuropathic pain and the intracellular responses in a sciatic nerve chronic constriction injury (CCI model. Materials and methods: Rats were assigned to four groups as follows: CCI and high-frequency exercise (HFE group, CCI and low-frequency exercise (LFE group, CCI and no exercise (No-Ex group, and naive animals (control group. Rats ran on a treadmill, at a speed of 20 m/min, for 30 min, for 5 (HFE or 3 (LFE days a week, for a total of 5 weeks. The 50% withdrawal threshold was evaluated for mechanical sensitivity. The activation of glial cells (microglia and astrocytes, expression of brain-derived neurotrophic factor (BDNF and μ-opioid receptor in the spinal dorsal horn and endogenous opioid in the midbrain were examined using immunohistochemistry. Opioid receptor antagonists (naloxone were administered using intraperitoneal injection. Results: The development of neuropathic pain was related to the activation of glial cells, increased BDNF expression, and downregulation of the μ-opioid receptor in the ipsilateral spinal dorsal horn. In the No-Ex group, neuropathic pain showed the highest level of mechanical hypersensitivity at 2 weeks, which improved slightly until 5 weeks after CCI. In both exercise groups, the alleviation of

Creating opioid dependence in the emergency department.

Science.gov (United States)

Upadhye, Suneel

2018-01-01

Clinical question What is the risk of creating opioid dependence from an ED opioid prescription? Article chosen Barnett ML, Olenski AR, Jena AB. Opioid-prescribing patterns of emergency physicians and risk of long-term use. N Engl J Med 2017;376:663-73, doi:10.1056/NEJMsa1610524. This study examined the risk of creating long-term opioid dependence from a prescription written in an opioid-naive patient in the ED.

CDC Vital Signs: Opioid Painkiller Prescribing

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... Mental Health Services Administration Medication-Assisted Treatment for Opioid Addiction: Facts for Families and Friends Opioid Overdose Prevention ... Abuse Drugs, Brains, and Behavior: The Science of Addiction Opioid and Pain Management CMEs/CEs Prescription Drugs U.S. ...

Hiperalgesia Inducida por Opioides

OpenAIRE

Jiménez Salazar, Andrés

2013-01-01

Los opioides producen analgesia a través de un efecto inhibitorio sobre el sistema nociceptivo principalmente. Hasta la fecha, los opioides siguen siendo los analgésicos más potentes para el manejo de dolor moderado a severo. La Asociación Internacional del Estudio del Dolor (IASP, en inglés) define hiperalgesia como "un aumento de la respuesta a un estímulo que normalmente es doloroso". En contraste, está bien establecido que la terapia crónica con opioides se asocia con el desarrollo de ...

The Relative Potency of Inverse Opioid Agonists and a Neutral Opioid Antagonist in Precipitated Withdrawal and Antagonism of Analgesia and Toxicity

OpenAIRE

Sirohi, Sunil; Dighe, Shveta V.; Madia, Priyanka A.; Yoburn, Byron C.

2009-01-01

Opioid antagonists can be classified as inverse agonists and neutral antagonists. In the opioid-dependent state, neutral antagonists are significantly less potent in precipitating withdrawal than inverse agonists. Consequently, neutral opioid antagonists may offer advantages over inverse agonists in the management of opioid overdose. In this study, the relative potency of three opioid antagonists to block opioid analgesia and toxicity and precipitate withdrawal was exa...

Opioid Therapy for Chronic Nonmalignant Pain

Directory of Open Access Journals (Sweden)

Russell K Portenoy

1996-01-01

Full Text Available Long term administration of an opioid drug for chronic nonmalignant pain continues to be controversial, but is no longer uniformly rejected by pain specialists. This is true despite concerns that the regulatory agencies that oversee physician prescribing of opioid drugs continue to stigmatize the practice. The changing clinical perspective has been driven, in part, by widespread acknowledgement of the remarkably favourable outcomes achieved during opioid treatment of cancer pain. These outcomes contrast starkly with popular teaching about chronic opioid therapy and affirm the potential for prolonged efficacy, tolerable side effects, enhanced function associated with improved comfort and minimal risk of aberrant drug-related behaviours consistent with addiction. A large anecdotal experience in populations with nonmalignant pain suggests that these patients are more heterogeneous and that opioid therapy will greatly benefit some and will contribute to negative outcomes for others. The few controlled clinical trials that have been performed support the safety and efficacy of opioid therapy, but have been too limited to ensure generalization to the clinical setting. A critical review of the medical literature pertaining to chronic pain, opioid pharmacology and addiction medicine can clarify misconceptions about opioid therapy and provide a foundation for patient selection and drug administration. The available data support the view that opioids are no panacea for chronic pain, but should be considered in carefully selected patients using clinically derived guidelines that stress a structured approach and ongoing monitoring of efficacy, adverse effects, functional outcomes and the occurrence of aberrant drug-related behaviours.

Long-term course of opioid addiction.

Science.gov (United States)

Hser, Yih-Ing; Evans, Elizabeth; Grella, Christine; Ling, Walter; Anglin, Douglas

2015-01-01

Opioid addiction is associated with excess mortality, morbidities, and other adverse conditions. Guided by a life-course framework, we review the literature on the long-term course of opioid addiction in terms of use trajectories, transitions, and turning points, as well as other factors that facilitate recovery from addiction. Most long-term follow-up studies are based on heroin addicts recruited from treatment settings (mostly methadone maintenance treatment), many of whom are referred by the criminal justice system. Cumulative evidence indicates that opioid addiction is a chronic disorder with frequent relapses. Longer treatment retention is associated with a greater likelihood of abstinence, whereas incarceration is negatively related to subsequent abstinence. Over the long term, the mortality rate of opioid addicts (overdose being the most common cause) is about 6 to 20 times greater than that of the general population; among those who remain alive, the prevalence of stable abstinence from opioid use is low (less than 30% after 10-30 years of observation), and many continue to use alcohol and other drugs after ceasing to use opioids. Histories of sexual or physical abuse and comorbid mental disorders are associated with the persistence of opioid use, whereas family and social support, as well as employment, facilitates recovery. Maintaining opioid abstinence for at least five years substantially increases the likelihood of future stable abstinence. Recent advances in pharmacological treatment options (buprenorphine and naltrexone) include depot formulations offering longer duration of medication; their impact on the long-term course of opioid addiction remains to be assessed.

The prescription opioid epidemic: an overview for anesthesiologists.

Science.gov (United States)

Alam, Asim; Juurlink, David N

2016-01-01

The objectives for preparing this article were to review the historical context and epidemiology surrounding the North American prescription opioid crisis, to summarize the evidence regarding the benefits and harms of long-term opioid therapy for non-cancer pain, and to outline ways in which anesthesiologists may help ameliorate the problem. We searched PubMed, Google Scholar, and EMBASE™ for relevant articles using various search terms, including pain, opioid epidemic, history of opioid use, perioperative care, and addiction. Related citations were further explored and searched depending on the specific subtopic of interest. In the 1980s and early 1990s, opioids were infrequently used for the treatment of chronic pain. Thereafter, however, physicians were gradually inculcated with the message that long-term opioid therapy was a safe and effective treatment option for patients with chronic non-cancer pain. Pharmaceutical companies supported this growing movement and employed aggressive and sometimes misleading marketing strategies for new opioid formulations. As a result, the practice of prescribing opioids flourished in the late 1990s. The surge in prescribing opioids was accompanied by a marked increase in opioid-related morbidity and mortality. This change in practice transpired despite the absence of randomized trials showing clinically significant benefit from the long-term use of opioids. Subsequently, however, a large and growing body of evidence has emerged quantifying the harms associated with long-term opioid therapy. Anesthesiologists widely prescribe opioids for acute and chronic pain; yet, as a group, they may be largely unaware of the current state of this growing epidemic and what role they can play to rectify this problem. Anesthesiologists are well positioned to take a leadership role in the management of postoperative discharge opioid therapy in an effort to curb the overutilization of opioids. Furthermore, anesthesiologists who regularly

Pain Management in the Opioid-Dependent Pregnant Woman.

Science.gov (United States)

Safley, Rebecca R; Swietlikowski, Jamie

Opioid dependence is an epidemic in the United States, and the percentage of pregnant women who are opioid dependent has increased dramatically in the last decade. Pain management, already a concern for intrapartum and postpartum care, is complicated in the context of opioid dependence. This clinical review surveys the literature on pain management in opioid-dependent pregnant women to summarize current consensus and evidence to guide clinical practice. Points of consensus for pain management in opioid-dependent pregnant women include continual opioid maintenance therapy throughout the pregnancy and the postpartum period; adequate management of acute pain; the contraindication of opioid agonist-antagonists for pain management; and the need for interdisciplinary teams using a multimodal approach to provide optimal care to opioid-dependent pregnant women.

The impact of opioids on the endocrine system.

Science.gov (United States)

Katz, Nathaniel; Mazer, Norman A

2009-02-01

Opioids have been used for medicinal and analgesic purposes for centuries. However, their negative effects on the endocrine system, which have been known for some times, are barely discussed in modern medicine. Therefore, we conducted a systematic review of the impact of opioids on the endocrine system. A review of the English language literature on preclinical and clinical studies of any type on the influence of opioids on the endocrine system was conducted. Preliminary recommendations for monitoring and managing these problems were provided. Long-term opioid therapy for either addiction or chronic pain often induces hypogonadism owing to central suppression of hypothalamic secretion of gonadotropin-releasing hormone. Symptoms of opioid-induced hypogonadism include loss of libido, infertility, fatigue, depression, anxiety, loss of muscle strength and mass, osteoporosis, and compression fractures in both men and women; impotence in men; and menstrual irregularities and galactorrhea in women. In view of the increased use of opioids for chronic pain, it has become increasingly important to monitor patients taking opioids and manage endocrine complications. Therefore, patients on opioid therapy should be routinely screened for such symptoms and for laboratory abnormalities in sex hormones. Opioid-induced hypogonadism seems to be a common complication of therapeutic or illicit opioid use. Patients on long-term opioid therapy should be prospectively monitored, and in cases of opioid-induced hypogonadism, we recommend nonopioid pain management, opioid rotation, or sex hormone supplementation after careful consideration of the risks and benefits.

Innate heart regeneration: endogenous cellular sources and exogenous therapeutic amplification.

Science.gov (United States)

Malliaras, Konstantinos; Vakrou, Styliani; Kapelios, Chris J; Nanas, John N

2016-11-01

The -once viewed as heretical- concept of the adult mammalian heart as a dynamic organ capable of endogenous regeneration has recently gained traction. However, estimated rates of myocyte turnover vary wildly and the underlying mechanisms of cardiac plasticity remain controversial. It is still unclear whether the adult mammalian heart gives birth to new myocytes through proliferation of resident myocytes, through cardiomyogenic differentiation of endogenous progenitors or through both mechanisms. In this review, the authors discuss the cellular origins of postnatal mammalian cardiomyogenesis and touch upon therapeutic strategies that could potentially amplify innate cardiac regeneration. The adult mammalian heart harbors a limited but detectable capacity for spontaneous endogenous regeneration. During normal aging, proliferation of pre-existing cardiomyocytes is the dominant mechanism for generation of new cardiomyocytes. Following myocardial injury, myocyte proliferation increases modestly, but differentiation of endogenous progenitor cells appears to also contribute to cardiomyogenesis (although agreement on the latter point is not universal). Since cardiomyocyte deficiency underlies almost all types of heart disease, development of therapeutic strategies that amplify endogenous regeneration to a clinically-meaningful degree is of utmost importance.

Placebo analgesia: understanding the mechanisms

OpenAIRE

Medoff, Zev M; Colloca, Luana

2015-01-01

Expectations of pain relief drive placebo analgesia. Understanding how expectations of improvement trigger distinct biological systems to shape therapeutic analgesic outcomes has been the focus of recent pharmacologic and neuroimaging studies in the field of pain. Recent findings indicate that placebo effects can imitate the actions of real painkillers and promote the endogenous release of opioids and nonopioids in humans. Social support and observational learning also contribute to placebo a...

The opioid overdose epidemic: opportunities for pharmacists

Directory of Open Access Journals (Sweden)

Wu LT

2017-07-01

Full Text Available Li-Tzy Wu,1–4 Udi E Ghitza,5 Anne L Burns,6 Paolo Mannelli,1 1Department of Psychiatry and Behavioral Sciences, 2Department of Medicine, 3Duke Clinical Research Institute, Duke University School of Medicine, 4Center for Child and Family Policy, Sanford School of Public Policy, Duke University, Durham, NC, 5Center for Clinical Trials Network, National Institute on Drug Abuse, Bethesda, MD, 6American Pharmacists Association, Washington, DC, USA The USA is experiencing an opioid overdose epidemic. It has been driven largely by prescription opioids and intensified by a surge of illicit opioids (e.g., heroin and fentanyl.1,2 Drug-involved overdose, mainly opioids (e.g., prescription opioids and heroin, is a leading cause of accidental death in the USA. The opioid overdose epidemic has been escalating consistently for over a decade.2 Every day, an estimated 91 Americans die from opioid-related overdose.3 Opioid overdose appears to have disproportionally affected men, adults aged 25–64 years, and non-Hispanic whites.2

Benzodiazepine receptor ligand influences on learning: an endogenous modulatory mechanism mediated by benzodiazepines possibly of alimentary origin

Directory of Open Access Journals (Sweden)

I. Izquierdo

1991-01-01

Full Text Available In rats pre-but not post-training ip administration of either flumazenil, a central benzodiazepine (BSD receptor antagonist, or of n-butyl-B-carboline-carboxylate (BCCB, an inverse agonist, enhanced retention of inhibitory avoidance learning. Flumazenil vlocked the enhancing effect of BCCB, and the inhibitory effect of the BZD agonists clonazepam and diazepam also given pre-training. Post-training administration of these drugs had no effects. The peripheral BZD receptor agonist/chloride channel blocker Ro5-4864 had no effect on the inhibitory avoidance task when given ip prior to training, buth it caused enhancement when given immediately post-training either ip or icv. This effect was blocked by PK11195, a competitive antagonist of Ro5-4864. These results suggest that ther is an endogenous mechanism mediated by BZD agonists, which is sensitive to inverse agonists and that normally down-regulates the formation of memories through a mechanism involving GABA-A receptors and the corresponding chloride channels. The most likely agonists for the endogenous mechanism suggested are the diazepam-like BZDs found in brain whose origin is possibly alimentary. Levels of these BZDs in the cortex were found to sharply decrease after inhibitory acoidance training or mere exposure to the training apparatus.

Role of endogenous serotonin in the mechanism of action of radioprotective substances

International Nuclear Information System (INIS)

Konstantinova, M.M.; Nekrasova, I.V.; Gusareva, Eh.V.; Dontsova, G.V.

1978-01-01

A study is made of a correlation between radiomodifying activity of noradrenaline (NA), N-ethylmaleimide (NEM) and a combination of these agents and their effect on the content of endogenous serotonin in cells of Ehrlich's ascites tumor and E. coli B. There is no uniformity in the response of different cells and uniform direction of the changes in their radioresistance and endogenous serotonin content both under the effect of the substances (NA and NEM) given separately and under a combined effect of the protector and the agent, which removes the protective effect or prevents realization of the latter (NEM). This enables us to arrive at a conclusion that endogenous serotonin is not the only factor responsible for the radioprotective effect of the protective substances. At the same time, it is not excluded that endogenous serotonin is involved in the chain of reactions which are necessary for the radioprotective effect to come into play

America's Opioid Epidemic: Supply and Demand Considerations.

Science.gov (United States)

Clark, David J; Schumacher, Mark A

2017-11-01

America is in the midst of an opioid epidemic characterized by aggressive prescribing practices, highly prevalent opioid misuse, and rising rates of prescription and illicit opioid overdose-related deaths. Medical and lay public sentiment have become more cautious with respect to prescription opioid use in the past few years, but a comprehensive strategy to reduce our reliance on prescription opioids is lacking. Addressing this epidemic through reductions in unnecessary access to these drugs while implementing measures to reduce demand will be important components of any comprehensive solution. Key supply-side measures include avoiding overprescribing, reducing diversion, and discouraging misuse through changes in drug formulations. Important demand-side measures center around educating patients and clinicians regarding the pitfalls of opioid overuse and methods to avoid unnecessary exposure to these drugs. Anesthesiologists, by virtue of their expertise in the use of these drugs and their position in guiding opioid use around the time of surgery, have important roles to play in reducing patient exposure to opioids and providing education about appropriate use. Aside from the many immediate steps that can be taken, clinical and basic research directed at understanding the interaction between pain and opioid misuse is critical to identifying the optimal use of these powerful pain relievers in clinical practice.

Irradiation exposure modulates central opioid functions

International Nuclear Information System (INIS)

Dougherty, P.M.; Dafny, N.

1987-01-01

Exposure to low doses of gamma irradiation results in the modification of both the antinociceptive properties of morphine and the severity of naloxone-precipitated withdrawal in morphine-dependent rats. To better define the interactions between gamma irradiation and these opiate-mediated phenomena, dose-response studies were undertaken of the effect of irradiation on morphine-induced antinociception, and on the naloxone-precipitated withdrawal syndrome of morphine-dependent rats. In addition, electrophysiologic studies were conducted in rats after irradiation exposure and morphine treatment correlating with the behavioral studies. The observations obtained demonstrated that the antinociceptive effects of morphine as well as naloxone-precipitated withdrawal were modified in a dose-dependent manner by irradiation exposure. In addition, irradiation-induced changes in the evoked responses obtained from four different brain regions demonstrated transient alterations in both baseline and morphine-treated responses that may reflect the alterations observed in the behavioral paradigms. These results suggest that the effects of irradiation on opiate activities resulted from physiologic alterations of central endogenous opioid systems due to alterations manifested within peripheral targets

Irradiation exposure modulates central opioid functions

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Dougherty, P.M.; Dafny, N.

1987-11-01

Exposure to low doses of gamma irradiation results in the modification of both the antinociceptive properties of morphine and the severity of naloxone-precipitated withdrawal in morphine-dependent rats. To better define the interactions between gamma irradiation and these opiate-mediated phenomena, dose-response studies were undertaken of the effect of irradiation on morphine-induced antinociception, and on the naloxone-precipitated withdrawal syndrome of morphine-dependent rats. In addition, electrophysiologic studies were conducted in rats after irradiation exposure and morphine treatment correlating with the behavioral studies. The observations obtained demonstrated that the antinociceptive effects of morphine as well as naloxone-precipitated withdrawal were modified in a dose-dependent manner by irradiation exposure. In addition, irradiation-induced changes in the evoked responses obtained from four different brain regions demonstrated transient alterations in both baseline and morphine-treated responses that may reflect the alterations observed in the behavioral paradigms. These results suggest that the effects of irradiation on opiate activities resulted from physiologic alterations of central endogenous opioid systems due to alterations manifested within peripheral targets.

The changing landscape of opioid prescribing: long-acting and extended-release opioid class-wide Risk Evaluation and Mitigation Strategy

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Gudin JA

2012-05-01

Full Text Available Jeffrey A GudinEnglewood Hospital and Medical Center, Englewood, NJ, USAAbstract: Prescriptions for opioid analgesics to manage moderate-to-severe chronic noncancer pain have increased markedly over the last decade, as have postmarketing reports of adverse events associated with opioids. As an unintentional consequence of greater prescription opioid utilization, there has been the parallel increase in misuse, abuse, and overdose, which are serious risks associated with all opioid analgesics. In response to these concerns, the Food and Drug Administration announced the requirement for a class-wide Risk Evaluation and Mitigation Strategy (REMS for long-acting and extended-release (ER opioid analgesics in April 2011. An understanding of the details of this REMS will be of particular importance to primary care providers. The class-wide REMS is focused on educating health care providers and patients on appropriate prescribing and safe use of ER opioids. Support from primary care will be necessary for the success of this REMS, as these clinicians are the predominant providers of care and the main prescribers of opioid analgesics for patients with chronic pain. Although currently voluntary, future policy will likely dictate that providers undergo mandatory training to continue prescribing medications within this class. This article outlines the elements of the class-wide REMS for ER opioids and clarifies the impact on primary care providers with regard to training, patient education, and clinical practice.Keywords: long-acting opioid, extended-release opioid, risk, REMS, FDA, primary care

Opioid Analgesics and Nicotine: More Than Blowing Smoke.

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Yoon, Jin H; Lane, Scott D; Weaver, Michael F

2015-09-01

Practitioners are highly likely to encounter patients with concurrent use of nicotine products and opioid analgesics. Smokers present with more severe and extended chronic pain outcomes and have a higher frequency of prescription opioid use. Current tobacco smoking is a strong predictor of risk for nonmedical use of prescription opioids. Opioid and nicotinic-cholinergic neurotransmitter systems interact in important ways to modulate opioid and nicotine effects: dopamine release induced by nicotine is dependent on facilitation by the opioid system, and the nicotinic-acetylcholine system modulates self-administration of several classes of abused drugs-including opioids. Nicotine can serve as a prime for the use of other drugs, which in the case of the opioid system may be bidirectional. Opioids and compounds in tobacco, including nicotine, are metabolized by the cytochrome P450 enzyme system, but the metabolism of opioids and tobacco products can be complicated. Accordingly, drug interactions are possible but not always clear. Because of these issues, asking about nicotine use in patients taking opioids for pain is recommended. When assessing patient tobacco use, practitioners should also obtain information on products other than cigarettes, such as cigars, pipes, smokeless tobacco, and electronic nicotine delivery systems (ENDS, or e-cigarettes). There are multiple forms of behavioral therapy and pharmacotherapy available to assist patients with smoking cessation, and opioid agonist maintenance and pain clinics represent underutilized opportunities for nicotine intervention programs.

Patient-reported opioid analgesic requirements after elective inguinal hernia repair: A call for procedure-specific opioid-administration strategies.

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Mylonas, Konstantinos S; Reinhorn, Michael; Ott, Lauren R; Westfal, Maggie L; Masiakos, Peter T

2017-11-01

A better understanding of the analgesia needs of patients who undergo common operative procedures is necessary as we address the growing opioid public health crisis in the United States. The aim of this study was to evaluate patient experience with our opioid prescribing practice after elective inguinal hernia repairs. A prospective, observational study was conducted between October 1, 2015, and September 30, 2016, in a single-surgeon, high-volume, practice of inguinal hernia operation. Adult patients undergoing elective inguinal herniorrhaphy under local anesthesia with intravenous sedation were invited to participate. All patients were prescribed 10 opioid analgesic tablets postoperatively and were counseled to reserve opioids for pain not controlled by nonopioid analgesics. Their experience was captured by completing a questionnaire 2 to 3 weeks postoperatively during their postoperative visit. A total of 185 patients were surveyed. The majority of the participants were males (177, 95.7%) and ≥60 years old (96, 51.9%). Of the 185 patients, 159 (85.9%) reported using ≤4 opioid tablets; 110 patients (59.5%) reported that they used no opioid analgesics postoperatively. None of the patients was taking opioids within 7 days of their postoperative appointment. Of the 147 patients who were employed, 111 (75.5%) reported missing ≤3 work days, 57 of whom (51.4%) missed no work at all. Patients who were employed were more likely to take opioid analgesics postoperatively (P = .049). Patients who took no opioid analgesics experienced less maximum (P require any opioid analgesics, and nearly all of those who thought that they did need opioids used reserved.

The opioid epidemic and national guidelines for opioid therapy for chronic noncancer pain: a perspective from different continents

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Winfried Häuser

2017-06-01

Conclusion:. Implementation of opioid prescribing guidelines should ensure that physicians prescribe opioids only for appropriate indications in limited doses for selected patients and advice patients on their safe use. These measures could contribute to reduce prescription opioid misuse/abuse and deaths.

Distinct Roles of Opioid and Dopamine Systems in Lateral Hypothalamic Intracranial Self-Stimulation.

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Ide, Soichiro; Takahashi, Takehiro; Takamatsu, Yukio; Uhl, George R; Niki, Hiroaki; Sora, Ichiro; Ikeda, Kazutaka

2017-05-01

Opioid and dopamine systems play crucial roles in reward. Similarities and differences in the neural mechanisms of reward that are mediated by these 2 systems have remained largely unknown. Thus, in the present study, we investigated the differences in reward function in both µ-opioid receptor knockout mice and dopamine transporter knockout mice, important molecules in the opioid and dopamine systems. Mice were implanted with electrodes into the right lateral hypothalamus (l hour). Mice were then trained to put their muzzle into the hole in the head-dipping chamber for intracranial electrical stimulation, and the influences of gene knockout were assessed. Significant differences are observed between opioid and dopamine systems in reward function. µ-Opioid receptor knockout mice exhibited enhanced intracranial electrical stimulation, which induced dopamine release. They also exhibited greater motility under conditions of "despair" in both the tail suspension test and water wheel test. In contrast, dopamine transporter knockout mice maintained intracranial electrical stimulation responding even when more active efforts were required to obtain the reward. The absence of µ-opioid receptor or dopamine transporter did not lead to the absence of intracranial electrical stimulation responsiveness but rather differentially altered it. The present results in µ-opioid receptor knockout mice are consistent with the suppressive involvement of µ-opioid receptors in both positive incentive motivation associated with intracranial electrical stimulation and negative incentive motivation associated with depressive states. In contrast, the results in dopamine transporter knockout mice are consistent with the involvement of dopamine transporters in positive incentive motivation, especially its persistence. Differences in intracranial electrical stimulation in µ-opioid receptor and dopamine transporter knockout mice underscore the multidimensional nature of reward. © The Author

Drug interactions: volatile anesthetics and opioids.

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Glass, P S; Gan, T J; Howell, S; Ginsberg, B

1997-09-01

Multiple drugs are used to provide anesthesia. Volatile anesthetics are commonly combined with opioids. Several studies have demonstrated that small doses of opioid (i.e., within the analgesic range) result in a marked reduction in minimum alveolar concentration (MAC) of the volatile anesthetic that will prevent purposeful movement in 50% of patients at skin incision). Further increases in opioid dose provide only a further small reduction in MAC. Thus, a ceiling effect of the opioid is observed at a MAC value of the volatile anesthetic equal to its MAC awake. Recovery from anesthesia when an opioid is combined with a volatile anesthetic is dependent on the rate of decrease of both drugs to their respective concentrations that are associated with adequate spontaneous ventilation and awakening. Through an understanding of the pharmacodynamic interaction of volatile anesthetics with opioids and the pharmacokinetic processes responsible for the recovery from drug effect, optimal dosing schemes can thus be developed. A review of these pharmacodynamic and pharmacokinetic principles that will allow clinicians to administer drugs to provide a more optimal anesthetic is provided.

Quinolinic Acid, an Endogenous Molecule Combining Excitotoxicity, Oxidative Stress and Other Toxic Mechanisms

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Verónica Pérez-De La Cruz

2012-01-01

Full Text Available Quinolinic acid (QUIN, an endogenous metabolite of the kynurenine pathway, is involved in several neurological disorders, including Huntington's disease, Alzheimer's disease, schizophrenia, HIV associated dementia (HAD etc. QUIN toxicity involves several mechanisms which trigger various metabolic pathways and transcription factors. The primary mechanism exerted by this excitotoxin in the central nervous system (CNS has been largely related with the overactivation of N-methyl-D-aspartate receptors and increased cytosolic Ca 2+ concentrations, followed by mitochondrial dysfunction, cytochrome c release, ATP exhaustion, free radical formation and oxidative damage. As a result, this toxic pattern is responsible for selective loss of middle size striatal spiny GABAergic neurons and motor alterations in lesioned animals. This toxin has recently gained attention in biomedical research as, in addition to its proven excitotoxic profile, a considerable amount of evidence suggests that oxidative stress and energetic disturbances are major constituents of its toxic pattern in the CNS. Hence, this profile has changed our perception of how QUIN-related disorders combine different toxic mechanisms resulting in brain damage. This review will focus on the description and integration of recent evidence supporting old and suggesting new mechanisms to explain QUIN toxicity.

DYNAMICS OF OPIOID SUBSTITUTION TREATMENTIN DIFFERENT INITIAL SUBSTANCE USER OPIOID DEPENDENT PATIENTS.

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Todadze, Kh; Mosia, S

2016-05-01

Injecting drug user size estimation studies carried out in 2009, 2012 and 2015 revealed growing trends of drug abuse in Georgia:estimated number of people who inject drugs (PWID) have been increased from 40000 and 45000 to 50000. Since Soviet period the most popular injective narcotics have been opioids: home-made opium, heroine, buprenorphine and home-made desomorphine ("Krokodile") replacing each other on the black market. Self-made desomorphine typically contains big amounts of different toxic substances and causes significant somatic disorders, especially skin, bone, blood infections, liver and kidney failure; is highly addictive, associates with frequent injections that enhance injecting-related harm, including the risk of HIV transmission, in comparison with typical opioids. The aim of the study was to determine the effectiveness of opioid substitution treatment (OST) on depression and anxiety in opioid dependent clients with history of different opioid substance use. 104 opioid drug users undergoing OST with intensive psychological counseling have been divided in 5 groups according to the principal opioid drug that was abused during past 6 months before starting treatment: heroine, desomorphine, illicit methadone injectors, illicit buprenorphine injectors, and multiple drug abusers consuming opioids as primary drugs. Level of depression (Beck Depression Inventory), anxiety (Spielberger Anxiety Inventory) as well as clinical symptoms, risky behavior, quality of life (WHO), and other data were measured before starting and after 3, 9, 15, 21 months of treatment. The illegal use of psychotropic-narcotics was checked through random urine-testing 1-2 times per patient per month. In all five groups remarkable decrease of depression and anxiety was observed in comparison with the starting data. Before inclusion desomorphine and poly-drug users had the highest scores of depression and anxiety while buprenorphine users manifested the lowest rate. Improvement of

Effect Of A “No Superuser Opioid Prescription” Policy On ED Visits And Statewide Opioid Prescription

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Zachary P. Kahler

2017-07-01

Full Text Available Introduction: The U.S. opioid epidemic has highlighted the need to identify patients at risk of opioid abuse and overdose. We initiated a novel emergency department- (ED based interventional protocol to transition our superuser patients from the ED to an outpatient chronic pain program. The objective was to evaluate the protocol’s effect on superusers’ annual ED visits. Secondary outcomes included a quantitative evaluation of statewide opioid prescriptions for these patients, unique prescribers of controlled substances, and ancillary testing. Methods: Patients were referred to the program with the following inclusion criteria: ≥ 6 visits per year to the ED; at least one visit identified by the attending physician as primarily driven by opioid-seeking behavior; and a review by a committee comprising ED administration and case management. Patients were referred to a pain management clinic and informed that they would no longer receive opioid prescriptions from visits to the ED for chronic pain complaints. Electronic medical record (EMR alerts notified ED providers of the patient’s referral at subsequent visits. We analyzed one year of data pre- and post-referral. Results: A total of 243 patients had one year of data post-referral for analysis. Median annual ED visits decreased from 14 to 4 (58% decrease, 95% CI [50 to 66]. We also found statistically significant decreases for these patients’ state prescription drug monitoring program (PDMP opioid prescriptions (21 to 13, total unique controlled-substance prescribers (11 to 7, computed tomography imaging (2 to 0, radiographs (5 to 1, electrocardiograms (12 to 4, and labs run (47 to 13. Conclusion: This program and the EMR-based alerts were successful at decreasing local ED visits, annual opioid prescriptions, and hospital resource allocation for this population of patients. There is no evidence that these patients diverted their visits to neighboring EDs after being informed that they

(Some) Cellular Mechanisms Influencing the Transcription of Human Endogenous Retrovirus, HERV-Fc1

DEFF Research Database (Denmark)

Laska, Magdalena Janina; Nissen, Kari Konstantin; Nexø, Bjørn Andersen

2013-01-01

DNA methylation and histone acetylation are epigenetic modifications that act as regulators of gene expression. DNA methylation is considered an important mechanism for silencing of retroelements in the mammalian genome. However, the methylation of human endogenous retroviruses (HERVs) is not well...... investigated. The aim of this study was to investigate the transcriptional potential of HERV-Fc1 proviral 5'LTR in more detail, and examined the specific influence of CpG methylation on this LTR in number of cell lines. Specifically, the role of demethylating chemicals e.g. 5-aza-2' deoxycytidine...... and Trichostatin-A, in inducing or reactivating expression of HERV-Fc1 specific sequences and the mechanisms were investigated. In our present study, 5-aza-dC is shown to be a powerful inducer of HERV-Fc1, and at the same time it strongly inhibits methylation of DNA. Treatment with this demethylating agent 5-aza...

What do providers want to know about opioid prescribing? A qualitative analysis of their questions.

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Cushman, Phoebe A; Liebschutz, Jane M; Hodgkin, Joseph G; Shanahan, Christopher W; White, Julie L; Hardesty, Ilana; Alford, Daniel P

2017-01-01

In 2012, the US Food and Drug Administration (FDA) responded to the opioid crisis with a Risk Evaluation and Mitigation Strategy, requiring manufacturers of extended-release/long-acting opioids to fund continuing medical education based on the "FDA Blueprint for Prescriber Education." Topics in the Blueprint are "Assessing Patients for Treatment," "Initiating Therapy, Modifying Dosing, and Discontinuing Use," "Managing Therapy," "Counseling Patients and Caregivers about Safe Use," "General Drug Information," and "Specific Drug Information." Based on the FDA Blueprint, Boston University School of Medicine's "Safe and Competent Opioid Prescribing Education" (SCOPE of Pain) offers live trainings for physicians and other prescribers. During trainings, participants submit written questions about the curriculum and/or their clinical experiences. The objective was to compare themes that arose from questions asked by SCOPE of Pain participants with content of the FDA Blueprint in order to evaluate how well the Blueprint answers prescribers' concerns. The authors conducted qualitative analyses of all 1309 questions submitted by participants in 29 trainings across 16 states from May 2013 to May 2015, using conventional content analysis to code the questions. Themes that emerged from participants' questions were then compared with the Blueprint. Most themes fell into the topic categories of the Blueprint. Five main themes diverged: Participants sought information on (1) safe alternatives to opioids, (2) overcoming barriers to safe opioid prescribing, (3) government regulations of opioid prescribing, (4) the role of marijuana in opioid prescribing, and (5) maintaining a positive provider-patient relationship while prescribing opioids. In addition to learning the mechanics of safe opioid prescribing, providers want to understand government regulations and effective patient communication skills. Aware of the limitations of opioids in managing chronic pain, providers seek advice

Delta opioid receptor on equine sperm cells: subcellular localization and involvement in sperm motility analyzed by computer assisted sperm analyzer (CASA

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Lacalandra Giovanni M

2010-06-01

Full Text Available Abstract Background Opioid receptors and endogenous opioid peptides act not only in the control of nociceptive pathways, indeed several reports demonstrate the effects of opiates on sperm cell motility and morphology suggesting the importance of these receptors in the modulation of reproduction in mammals. In this study we investigated the expression of delta opioid receptors on equine spermatozoa by western blot/indirect immunofluorescence and its relationship with sperm cell physiology. Methods We analyzed viability, motility, capacitation, acrosome reaction and mitochondrial activity in the presence of naltrindole and DPDPE by means of a computer assisted sperm analyzer and a fluorescent confocal microscope. The evaluation of viability, capacitation and acrosome reaction was carried out by the double CTC/Hoechst staining, whereas mitochondrial activity was assessed by means of MitoTracker Orange dye. Results We showed that in equine sperm cells, delta opioid receptor is expressed as a doublet of 65 and 50 kDa molecular mass and is localized in the mid piece of tail; we also demonstrated that naltrindole, a delta opioid receptor antagonist, could be utilized in modulating several physiological parameters of the equine spermatozoon in a dose-dependent way. We also found that low concentrations of the antagonist increase sperm motility whereas high concentrations show the opposite effect. Moreover low concentrations hamper capacitation, acrosome reaction and viability even if the percentage of cells with active mitochondria seems to be increased; the opposite effect is exerted at high concentrations. We have also observed that the delta opioid receptor agonist DPDPE is scarcely involved in affecting the same parameters at the employed concentrations. Conclusions The results described in this paper add new important details in the comprehension of the mammalian sperm physiology and suggest new insights for improving reproduction and for

Global Supply and Demand of Opioids for Pain Management.

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Kunnumpurath, Sreekumar; Julien, Natasha; Kodumudi, Gopal; Kunnumpurath, Anamika; Kodumudi, Vijay; Vadivelu, Nalini

2018-04-04

The goal of this review is to evaluate the global supply and demand of opioids used for pain management and discuss how it relates to the utilization of opioids around the world. The purpose of the review is also to determine the factors that contribute to inappropriate pain management. The total global production of opium for opioid manufacturing is enough to supply the growing global demands. However, licit opioids are only consumed by 20% of the world population. Most people throughout the world had no access to opioid analgesics for pain relief in case of need. Opioid misuse and abuse is not only a phenomena plague by the USA but globally across many countries. Many countries have a lack of availability of opioids, contributing factors being strict government regulations limiting access, lack of knowledge of the efficacy of opioid analgesics in treating acute and chronic pain and palliative care, and the stigma that opioids are highly addictive. For the countries in which opioids are readily available and prescribed heavily, diversion, misuse, abuse, and the resurgence of heroin have become problems leading to morbidity and mortality. It is pertinent to find a balance between having opioids accessible to patients in need, with ensuring that opioids are regulated along with other illicit drugs to decrease abuse potential.

Intentional intrathecal opioid detoxification in 3 patients: characterization of the intrathecal opioid withdrawal syndrome.

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Jackson, Tracy P; Lonergan, Daniel F; Todd, R David; Martin, Peter R

2013-04-01

Intrathecal (IT) drug delivery systems for patients with chronic non-malignant pain are intended to improve pain and quality of life and reduce side effects of systemic use. A subset of patients may have escalating pain, functional decline, and/or intolerable side effects even as IT opioid doses are increased. Discontinuation of IT medications may represent a viable treatment option but strategies to accomplish this are needed. Three patients with intrathecal drug delivery systems (IDDS), inadequate pain control, and declining functionality underwent abrupt IT opioid cessation. This was accomplished through a standardized protocol with symptom-triggered administration of clonidine and buprenorphine, monitored using the clinical opiate withdrawal scale. Symptoms of IT withdrawal were similar in all patients and included diuresis, agitation, hyperalgesia, mild diarrhea, yawning, and taste and smell aversion. Hypertension and tachycardia were effectively controlled by clonidine administration. Classic symptoms of withdrawal, such as piloerection, chills, severe diarrhea, nausea, vomiting, diaphoresis, myoclonus, and mydriasis, were not noted. At 2 to 3 months follow-up, patients reported decreased, but ongoing pain, with improvements in functional capacity and quality of life. This preliminary work demonstrates the safety of abrupt IT opioid cessation utilizing standardized inpatient withdrawal protocols. To our knowledge, these are among the first reported cases of intentional, controlled IT opioid cessation without initiation of an opioid bridge: self-reported pain scores, functional capacity, and quality of life improved. The IT opioid withdrawal syndrome is characterized based upon our observations and a review of the literature. © 2012 The Authors. Pain Practice © 2012 World Institute of Pain.

Detecting aberrant opioid behavior in the emergency department: a prospective study using the screener and Opioid Assessment for Patients with Pain-Revised (SOAPP®-R), Current Opioid Misuse Measure (COMM)™, and provider gestalt.

Science.gov (United States)

Varney, Shawn M; Perez, Crystal A; Araña, Allyson A; Carey, Katherine R; Ganem, Victoria J; Zarzabal, Lee A; Ramos, Rosemarie G; Bebarta, Vikhyat S

2018-03-03

Emergency department (ED) providers have limited time to evaluate patients at risk for opioid misuse. A validated tool to assess the risk for aberrant opioid behavior may mitigate adverse sequelae associated with prescription opioid misuse. We sought to determine if SOAPP-R, COMM, and provider gestalt were able to identify patients at risk for prescription opioid misuse as determined by pharmacy records at 12 months. We conducted a prospective observational study of adult patients in a high volume US ED. Patients completed the SOAPP-R and COMM, and treating EM providers evaluated patients' opioid misuse risk. We performed variable-centered, person-centered, and hierarchical cluster analyses to determine whether provider gestalt, SOAPP-R, or COMM, or a combination, predicted higher misuse risk. The primary outcome was the number of opioid prescriptions at 12 months according to pharmacy records. For 169 patients (mean age 43 years, 51% female, 73% white), correlation analysis showed a strong relationship between SOAPP-R and COMM with predicting the number of opioid prescriptions dispensed at 12 months. Provider scores estimating opioid misuse were not related to SOAPP-R and only weakly associated with COMM. In our adjusted regression models, provider gestalt and SOAPP-R uniquely predicted opioid prescriptions at 6 and 12 months. Using designated cutoff scores, only SOAPP-R detected a difference in the number of opioid prescriptions. Cluster analysis revealed that provider gestalt, SOAPP-R, and COMM scores jointly predicted opioid prescriptions. Provider gestalt and self-report instruments uniquely predicted the number of opioid prescriptions in ED patients. A combination of gestalt and self-assessment scores can be used to identify at-risk patients who otherwise miss the cutoff scores for SOAPP-R and COMM.

Analgesia produced by exposure to 2450-MHz radiofrequency radiation (RFR) is mediated by brain mu- and kappa-opioid receptors

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Salomon, G.; Park, E.J.; Quock, R.M. (Univ. of Illinois, Rockford (United States))

1992-02-26

This study was conducted to identify the opioid receptor subtype(s) responsible for RFR-induced analgesia. Male Swiss Webster mice, 20-25 g, were exposed to 20 mW/cm{sup 2} RFR in a 2,450-MHz waveguide system for 10 min, then tested 15 min later in the abdominal constriction paradigm which detects {mu}- and {kappa}-opioid activity. Immediately following RFR exposure, different groups of mice were pretreated intracerebroventricularly with different opioid receptor blockers with selectivity for {mu}- or {kappa}-opioid receptors. Results show that RFR-induced analgesia was attenuated by higher but not lower doses of the non-selective antagonist naloxone, but the selective {mu}-opioid antagonist {beta}-funaltrexamine and by the selective {kappa}-opioid antagonist norbinaltorphimine. RFR-induced analgesia was also reduced by subcutaneous pretreatment with 5.0 mg/kg of the {mu}-/{kappa}-opioid antagonist({minus})-5,9-diethyl-{alpha}-5,9-dialkyl-2{prime}-hydroxy-6,7-benzomorphan(MR-2266). These findings suggest that RFR-induced analgesia may be mediated by both {mu}- and {kappa}-opioid mechanisms.

Combined autoradiographic-immunocytochemical analysis of opioid receptors and opioid peptide neuronal systems in brain

Energy Technology Data Exchange (ETDEWEB)

Lewis, M.E.; Khachaturian, H.; Watson, S.J.

1985-01-01

Using adjacent section autoradiography-immunocytochemistry, the distribution of (TH)naloxone binding sites was studied in relation to neuronal systems containing (Leu)enkephalin, dynorphin A, or beta-endorphin immunoreactivity in rat brain. Brain sections from formaldehyde-perfused rats show robust specific binding of (TH)naloxone, the pharmacological (mu-like) properties of which appear unaltered. In contrast, specific binding of the delta ligand (TH)D-Ala2,D-Leu5-enkephalin was virtually totally eliminated as a result of formaldehyde perfusion. Using adjacent section analysis, the authors have noted associations between (TH)naloxone binding sites and one, two, or all three opioid systems in different brain regions; however, in some areas, no apparent relationship could be observed. Within regions, the relationship was complex. The complexity of the association between (TH)naloxone binding sites and the multiple opioid systems, and previous reports of co-localization of mu and kappa receptors in rat brain, are inconsistent with a simple-one-to-one relationship between a given opioid precursor and opioid receptor subtype. Instead, since differential processing of the three precursors gives rise to peptides of varying receptor subtype potencies and selectivities, the multiple peptide-receptor relationships may point to a key role of post-translational processing in determining the physiological consequences of opioid neurotransmission.

Gut Homeostasis, Microbial Dysbiosis, and Opioids.

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Wang, Fuyuan; Roy, Sabita

2017-01-01

Gut homeostasis plays an important role in maintaining animal and human health. The disruption of gut homeostasis has been shown to be associated with multiple diseases. The mutually beneficial relationship between the gut microbiota and the host has been demonstrated to maintain homeostasis of the mucosal immunity and preserve the integrity of the gut epithelial barrier. Currently, rapid progress in the understanding of the host-microbial interaction has redefined toxicological pathology of opioids and their pharmacokinetics. However, it is unclear how opioids modulate the gut microbiome and metabolome. Our study, showing opioid modulation of gut homeostasis in mice, suggests that medical interventions to ameliorate the consequences of drug use/abuse will provide potential therapeutic and diagnostic strategies for opioid-modulated intestinal infections. The study of morphine's modulation of the gut microbiome and metabolome will shed light on the toxicological pathology of opioids and its role in the susceptibility to infectious diseases.

Resisting Prescribed Opioids: A Qualitative Study of Decision Making in Patients Taking Opioids for Chronic Noncancer Pain.

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Paterson, Charlotte; Ledgerwood, Kay; Arnold, Carolyn; Hogg, Malcolm; Xue, Charlie; Zheng, Zhen

2016-04-01

Opioids are increasingly prescribed for chronic noncancer pain across the developed world. Clinical guidelines for management of these patients focus on over-use. However, research into other types of long-term medication indicates that many patients minimize drug use whenever possible. To identify the varying influences on patients' decisions about their use of prescribed opioids and explore whether concepts of resistance and minimization of intake apply to these patients. A multiprofessional team performed a qualitative interview study using the constant-comparative method. Patient's decision making was explored in depth and with a thematic analysis utilizing a published "Model of medicine-taking." A purposive sample of 20 participants drawn from two pain clinics in Melbourne, Australia. The sample was biased toward patients interested in nonmedication pain management options. Patients' needs to obtain relief from severe pain, maintain function, and minimize side effects could lead to under-use as well as over-use of prescribed opioids. In keeping with the published Model of medicine-taking, resistance to taking opioids was a common and important influence on behavior. In the face of severe chronic pain, many participants used a variety of strategies to evaluate, avoid, reduce, self-regulate, and replace opioids. Furthermore, participants perceived a resistance to opioids within the system and among some healthcare professionals. This sometimes adversely affected their adherence. Both patients and doctors exhibit aspects of resistance to the use of prescribed opioids for chronic noncancer pain, suggesting that this shared concern could be the basis of a productive therapeutic alliance to improve communication and shared decision making. Clinical guidelines for opioids use for chronic noncancer pain focus on over-use. Our qualitative interview study found that many patients resisted and minimized the use of opioids. Using a published "Model of medicine-taking," we

Secular trends in opioid prescribing in the USA

Directory of Open Access Journals (Sweden)

Pezalla EJ

2017-02-01

Full Text Available Edmund J Pezalla,1 David Rosen,2 Jennifer G Erensen,2 J David Haddox,2,3 Tracy J Mayne2 1Bioconsult, LLC, Wethersfield, 2Purdue Pharma L.P., Stamford, CT, 3Public Health and Community Medicine, Tufts University School of Medicine, Boston, MA, USA Abstract: Opioid abuse and misuse in the USA is a public health crisis. The use of prescription opioid analgesics increased substantially from 2002 through 2010, then plateaued and began to decrease in 2011. This study examined prescriptions of branded and generic immediate- and extended-release opioid analgesics from 1992 to 2016. This was juxtaposed against state and federal policies designed to decrease overutilization and abuse, as well as the launch of new opioid products, including opioids with abuse-deterrent properties (OADPs. The data indicate that these health policies, including the utilization and reimbursement of OADPs, have coincided with decreased opioid utilization. The hypothesis that OADPs will paradoxically increase opioid prescribing is not supported. Keywords: OADP, prescription, utilization trends, legislation, opioids

The relative potency of inverse opioid agonists and a neutral opioid antagonist in precipitated withdrawal and antagonism of analgesia and toxicity.

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Sirohi, Sunil; Dighe, Shveta V; Madia, Priyanka A; Yoburn, Byron C

2009-08-01

Opioid antagonists can be classified as inverse agonists and neutral antagonists. In the opioid-dependent state, neutral antagonists are significantly less potent in precipitating withdrawal than inverse agonists. Consequently, neutral opioid antagonists may offer advantages over inverse agonists in the management of opioid overdose. In this study, the relative potency of three opioid antagonists to block opioid analgesia and toxicity and precipitate withdrawal was examined. First, the potency of two opioid inverse agonists (naltrexone and naloxone) and a neutral antagonist (6beta-naltrexol) to antagonize fentanyl-induced analgesia and lethality was determined. The order of potency to block analgesia was naltrexone > naloxone > 6beta-naltrexol (17, 4, 1), which was similar to that to block lethality (13, 2, 1). Next, the antagonists were compared using withdrawal jumping in fentanyl-dependent mice. The order of potency to precipitate withdrawal jumping was naltrexone > naloxone 6beta-naltrexol (1107, 415, 1). The relative potencies to precipitate withdrawal for the inverse agonists compared with the neutral antagonist were dramatically different from that for antagonism of analgesia and lethality. Finally, the effect of 6beta-naltrexol pretreatment on naloxone-precipitated jumping was determined in morphine and fentanyl-dependent mice. 6beta-Naltrexol pretreatment decreased naloxone precipitated withdrawal, indicating that 6beta-naltrexol is a neutral antagonist. These data demonstrate that inverse agonists and neutral antagonists have generally comparable potencies to block opioid analgesia and lethality, whereas the neutral opioid antagonist is substantially less potent in precipitating opioid withdrawal. These results support suggestions that neutral antagonists may have advantages over inverse agonists in the management of opioid overdose.

Health-Related Quality of Life among Chronic Opioid Users, Nonchronic Opioid Users, and Nonopioid Users with Chronic Noncancer Pain.

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Hayes, Corey J; Li, Xiaocong; Li, Chenghui; Shah, Anuj; Kathe, Niranjan; Bhandari, Naleen Raj; Payakachat, Nalin

2018-02-25

Evaluate the association between opioid therapy and health-related quality of life (HRQoL) in participants with chronic, noncancer pain (CNCP). Medical Expenditure Panel Survey Longitudinal, Medical Conditions, and Prescription Files. Using a retrospective cohort study design, the Mental Health Component (MCS12) and Physical Health Component (PCS12) scores of the Short Form-12 Version 2 were assessed to measure mental and physical HRQoL. Chronic, noncancer pain participants were classified as chronic, nonchronic, and nonopioid users. One-to-one propensity score matching was employed to match chronic opioid users to nonchronic opioid users plus nonchronic opioid users and chronic opioid users to nonopioid users. A total of 5,876 participants were identified. After matching, PCS12 was not significantly different between nonchronic versus nonopioid users (LSM Diff = -0.98, 95% CI: -2.07, 0.10), chronic versus nonopioid users (LSM Diff = -2.24, 95% CI: -4.58, 0.10), or chronic versus nonchronic opioid users (LSM Diff = -2.23, 95% CI: -4.53, 0.05). Similarly, MCS12 was not significantly different between nonchronic versus nonopioid users (LSM Diff = 0.76, 95% CI: -0.46, 1.98), chronic versus nonopioid users (LSM Diff = 1.08, 95% CI: -1.26, 3.42), or chronic versus nonchronic opioid users (LSM Diff = -0.57, 95% CI: -2.90, 1.77). Clinicians should evaluate opioid use in participants with CNCP as opioid use is not correlated with better HRQoL. © Health Research and Educational Trust.

Exogenous and endogenous spatial attention effects on visuospatial working memory.

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Botta, Fabiano; Santangelo, Valerio; Raffone, Antonino; Lupiáñez, Juan; Belardinelli, Marta Olivetti

2010-08-01

In this study, we investigate how exogenous and endogenous orienting of spatial attention affect visuospatial working memory (VSWM). Specifically, we focused on two attentional effects and their consequences on storage in VSWM, when exogenous (Experiment 1) or endogenous (Experiment 2) orienting cues were used. The first effect, known as the meridian effect, is given by a decrement in behavioural performance when spatial cues and targets are presented in locations separated by vertical and/or horizontal meridians. The second effect, known as the distance effect, is given by a decrement in the orienting effects as a function of the spatial distance between cues and targets. Our results revealed a dissociation between exogenous and endogenous orienting mechanisms in terms of both meridian and distance effects. We found that meridian crossing affects performance only when endogenous cues were used. Specifically, VSWM performance with endogenous cueing depended more on the number of meridian crossings than on distance between cue and target. By contrast, a U-shaped distance dependency was observed using exogenous cues. Our findings therefore suggest that exogenous and endogenous orienting mechanisms lead to different forms of attentional bias for storage in VSWM.

Neurobiology of opioid dependence in creating addiction vulnerability [version 1; referees: 3 approved

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Christopher J. Evans

2016-07-01

Full Text Available Opioid drugs are potent modulators of many physiological and psychological processes. When given acutely, they can elicit the signature responses of euphoria and analgesia that societies have coveted for centuries. Repeated, or chronic, use of opioids induces adaptive or allostatic changes that modify neuronal circuitry and create an altered normality — the “drug-dependent” state. This state, at least that exhibited by those maintained continuously on long-acting opioid drugs such as methadone or buprenorphine, is generally indistinguishable from the drug-naïve state for most overt behaviors. The consequences of the allostatic changes (cellular, circuit, and system adaptations that accompany the drug-dependent state are revealed during drug withdrawal. Drug cessation triggers a temporally orchestrated allostatic re-establishment of neuronal systems, which is manifested as opposing physiological and psychological effects to those exhibited by acute drug intoxication. Some withdrawal symptoms, such as physical symptoms (sweating, shaking, and diarrhea resolve within days, whilst others, such as dysphoria, insomnia, and anxiety, can linger for months, and some adaptations, such as learned associations, may be established for life. We will briefly discuss the cellular mechanisms and neural circuitry that contribute to the opioid drug-dependent state, inferring an emerging role for neuroinflammation. We will argue that opioid addictive behaviors result from a learned relationship between opioids and relief from an existing or withdrawal-induced anxiogenic and/or dysphoric state. Furthermore, a future stressful life event can recall the memory that opioid drugs alleviate negative affect (despair, sadness, and anxiety and thereby precipitate craving, resulting in relapse. A learned association of relief of aversive states would fuel drug craving in vulnerable people living in an increasingly stressful society. We suggest that this route to

Isobolographic analysis of the opioid-opioid interactions in a tonic and a phasic mouse model of induced nociceptive pain.

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Miranda, Hugo F; Noriega, Viviana; Zanetta, Pilar; Prieto, Juan Carlos; Prieto-Rayo, Juan Carlos; Aranda, Nicolás; Sierralta, Fernando

2014-07-15

Opioids have been used for the management of pain and coadministration of two opioids may induce synergism. In a model of tonic pain, the acetic acid writhing test and in a phasic model, the hot plate, the antinociceptive interaction between fentanyl, methadone, morphine, and tramadol was evaluated. The potency of opioids in the writhing test compared to the hot plate assay was from 2.5 (fentanyl) to 15.5 (morphine) times, respectively. The ED50 was used in a fixed ratio for each of the six pairs of opioid combinations, which, resulted in a synergistic antinociception except for methadone/tramadol and fentanyl/tramadol which were additive, in the hot plate. The opioid antagonists naltrexone, naltrindole and nor-binaltorphimine, suggests that the synergism of morphine combinations are due to the activation of MOR subtypes with partially contribution of DOR and KOR, however fentanyl and methadone combinations are partially due to the activation of MOR and DOR subtypes and KOR lack of participation. The antinociceptive effects of tramadol combinations, are partially due to the activation of MOR, DOR and KOR opioid subtypes. These results suggets that effectiveness and magnitude of the interactions between opioids are dependent on pain stimulus intensity.

Molecular characterization of opioid receptors

Energy Technology Data Exchange (ETDEWEB)

Howard, A.D.

1986-01-01

The aim of this research was to purify and characterize active opioid receptors and elucidate molecular aspects of opioid receptor heterogeneity. Purification to apparent homogeneity of an opioid binding protein from bovine caudate was achieved by solubilization in the non-ionic detergent, digitonin, followed by sequential chromatography on the opiate affinity matrix, ..beta..-naltrexylethylenediamine-CH-Sepharose 4B, and on the lectine affinity matrix, wheat germ agglutinin-agarose. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE) followed by autoradiography revealed that radioiodinated purified receptor gave a single band. Purified receptor preparations showed a specific activity of 12,000-15,000 fmol of opiate bound per mg of protein. Radioiodinated human beta-endorphin (/sup 125/I-beta-end/sub H/) was used as a probe to investigate the ligand binding subunits of mu and delta opioid receptors. /sup 125/I-beta-end/sub H/ was shown to bind to a variety of opioid receptor-containing tissues with high affinity and specificity with preference for mu and delta sites, and with little, if any, binding to kappa sites. Affinity crosslinking techniques were employed to covalently link /sup 125/I-beta-end/sub H/ to opioid receptors, utilizing derivatives of bis-succinimidyl esters that are bifunctional crosslinkers with specificities for amino and sulfhydryl groups. This, and competition experiments with high type-selective ligands, permitted the assignment of two labeled peptides to their receptor types, namely a peptide of M/sub r/ = 65,000 for mu receptors and one of M/sub r/ = 53,000 for delta receptors.

β-Endorphin via the Delta Opioid Receptor is a Major Factor in the Incubation of Cocaine Craving

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Dikshtein, Yahav; Barnea, Royi; Kronfeld, Noam; Lax, Elad; Roth-Deri, Ilana; Friedman, Alexander; Gispan, Iris; Elharrar, Einat; Levy, Sarit; Ben-Tzion, Moshe; Yadid, Gal

2013-01-01

Cue-induced cocaine craving intensifies, or ‘incubates', during the first few weeks of abstinence and persists over extended periods of time. One important factor implicated in cocaine addiction is the endogenous opioid β-endorphin. In the present study, we examined the possible involvement of β-endorphin in the incubation of cocaine craving. Rats were trained to self-administer cocaine (0.75 mg/kg, 10 days, 6 h/day), followed by either a 1-day or a 30-day period of forced abstinence. Subsequent testing for cue-induced cocaine-seeking behavior (without cocaine reinforcement) was performed. Rats exposed to the drug-associated cue on day 1 of forced abstinence demonstrated minimal cue-induced cocaine-seeking behavior concurrently with a significant increase in β-endorphin release in the nucleus accumbens (NAc). Conversely, exposure to the cue on day 30 increased cocaine seeking, while β-endorphin levels remained unchanged. Intra-NAc infusion of an anti-β-endorphin antibody (4 μg) on day 1 increased cue-induced cocaine seeking, whereas infusion of a synthetic β-endorphin peptide (100 ng) on day 30 significantly decreased cue response. Both intra-NAc infusions of the δ opioid receptor antagonist naltrindole (1 μg) on day 1 and naltrindole together with β-endorphin on day 30 increased cue-induced cocaine-seeking behavior. Intra-NAc infusion of the μ opioid receptor antagonist CTAP (30 ng and 3 μg) had no behavioral effect. Altogether, these results demonstrate a novel role for β-endorphin and the δ opioid receptor in the development of the incubation of cocaine craving. PMID:23800967

Observational study to calculate addictive risk to opioids: a validation study of a predictive algorithm to evaluate opioid use disorder

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Brenton A

2017-05-01

Full Text Available Ashley Brenton,1 Steven Richeimer,2,3 Maneesh Sharma,4 Chee Lee,1 Svetlana Kantorovich,1 John Blanchard,1 Brian Meshkin1 1Proove Biosciences, Irvine, CA, 2Keck school of Medicine, University of Southern California, Los Angeles, CA, 3Departments of Anesthesiology and Psychiatry, University of Southern California, Los Angeles, CA, 4Interventional Pain Institute, Baltimore, MD, USA Background: Opioid abuse in chronic pain patients is a major public health issue, with rapidly increasing addiction rates and deaths from unintentional overdose more than quadrupling since 1999. Purpose: This study seeks to determine the predictability of aberrant behavior to opioids using a comprehensive scoring algorithm incorporating phenotypic risk factors and neuroscience-associated single-nucleotide polymorphisms (SNPs. Patients and methods: The Proove Opioid Risk (POR algorithm determines the predictability of aberrant behavior to opioids using a comprehensive scoring algorithm incorporating phenotypic risk factors and neuroscience-associated SNPs. In a validation study with 258 subjects with diagnosed opioid use disorder (OUD and 650 controls who reported using opioids, the POR successfully categorized patients at high and moderate risks of opioid misuse or abuse with 95.7% sensitivity. Regardless of changes in the prevalence of opioid misuse or abuse, the sensitivity of POR remained >95%. Conclusion: The POR correctly stratifies patients into low-, moderate-, and high-risk categories to appropriately identify patients at need for additional guidance, monitoring, or treatment changes. Keywords: opioid use disorder, addiction, personalized medicine, pharmacogenetics, genetic testing, predictive algorithm

Comparison of the risks of shopping behavior and opioid abuse between tapentadol and oxycodone and association of shopping behavior and opioid abuse.

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Cepeda, M Soledad; Fife, Daniel; Kihm, Mary A; Mastrogiovanni, Greg; Yuan, Yingli

2014-12-01

This study compared the risks of opioid shopping behavior and opioid abuse between tapentadol immediate release and oxycodone immediate release and, to validate the definition of shopping, examined the association between opioid shopping and opioid abuse further. This retrospective cohort study using linked dispensing and diagnosis databases followed opioid-naive patients for development of shopping behavior and/or opioid abuse during 1 year after initial exposure to tapentadol or oxycodone. Shopping was defined by having overlapping opioid prescriptions from >1 prescriber filled at ≥3 pharmacies; abuse by having International Classification of Diseases, 9th revision diagnoses reflecting opioid abuse, addiction, or dependence. To determine their association, we cross-tabulated shopping and opioid abuse and calculated odds ratios. Risks of developing each outcome were estimated using logistic regression. Among 277,401 participants initiating opioid use with tapentadol (39,524) or oxycodone (237,877), 0.6% developed shopping behavior, 0.75% developed abuse. Higher proportions of patients in the oxycodone group developed shopping behavior and abuse than in the tapentadol group (shopping: adjusted odds ratio [95% confidence interval], 0.45 [0.36-0.55]; abuse: 0.44 [0.37-0.54]). Shopping behavior and abuse were associated; of those with shopping behavior, 6.5% had abuse. Age (18 to 64 y), sex (male), prior benzodiazepine use, paying cash, and history (mood disorders, abuse of nonopioid medications, and back pain) were risk factors for developing either outcome. Shopping behavior and abuse measure complementary, but associated, constructs, which further validates the current definition of shopping. The risk of developing either is lower among patients who initiate opioid use with tapentadol than those who initiate opioid use with oxycodone.

Long-term evaluation of opioid treatment in fibromyalgia.

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Peng, Xiaomei; Robinson, Rebecca L; Mease, Philip; Kroenke, Kurt; Williams, David A; Chen, Yi; Faries, Douglas; Wohlreich, Madelaine; McCarberg, Bill; Hann, Danette

2015-01-01

In a 12-month observational study, we evaluated the effect of opioid use on the outcomes in 1700 adult patients with fibromyalgia. Data were evaluated using propensity score matching after patients were divided into cohorts based on their baseline medication use: (1) taking an opioid (concurrent use of tramadol was permitted); (2) taking tramadol (but no opioids); and (3) not taking opioids or tramadol. Changes in outcomes were assessed using the Brief Pain Inventory for severity and pain-related interference (BPI-S, BPI-I), Fibromyalgia Impact Questionnaire (FIQ), Patient Health Questionnaire for depression (PHQ-8), Insomnia Severity Index (ISI), Sheehan Disability Scale (SDS), 7-item Generalized Anxiety Disorder Scale (GAD-7), and economic factors. Time-to-opioid or tramadol discontinuation was analyzed using Kaplan-Meier survival analyses. Compared with the opioid cohort, the nonopioid cohort demonstrated significantly greater reductions (PFIQ, PHQ-8, SDS, and ISI; the tramadol cohort compared with the opioid group showed greater reductions on FIQ and ISI. Reductions in BPI-S and GAD-7 did not differ significantly among cohorts. Compared with the opioid cohort, patients in the tramadol cohort had fewer outpatient visits to health care providers. Few significant differences were found between the tramadol and nonopioid cohorts across outcomes. Although pain severity was reduced over time in all cohorts, opioid users showed less improvement in pain-related interference with daily living, functioning, depression, and insomnia. Overall, the findings show little support for the long-term use of opioid medications in patients with fibromyalgia given the poorer outcomes across multiple assessment domains associated with this cohort.

Pain management and opioid risk mitigation in the military.

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Sharpe Potter, Jennifer; Bebarta, Vikhyat S; Marino, Elise N; Ramos, Rosemarie G; Turner, Barbara J

2014-05-01

Opioid analgesics misuse is a significant military health concern recognized as a priority issue by military leadership. Opioids are among those most commonly prescribed medications in the military for pain management. The military has implemented opioid risk mitigation strategies, including the Sole Provider Program and the Controlled Drug Management Analysis and Reporting Tool, which are used to identify and monitor for risk and misuse. However, there are substantial opportunities to build on these existing systems to better ensure safer opioid prescribing and monitor for misuse. Opioid risk mitigation strategies implemented by the civilian sector include establishing clinical guidelines for opioid prescribing and prescription monitoring programs. These strategies may help to inform opioid risk mitigation in the military health system. Reducing the risk of opioid misuse and improving quality of care for our Warfighters is necessary. This must be done through evidence-based approaches with an investment in research to improve patient care and prevent opioid misuse as well as its sequelae. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.

A case of rhabdomyolysis associated with severe opioid withdrawal.

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Gangahar, Deepali

2015-08-01

While the risk of opioid overdose is widely accepted, the dangers of opioid withdrawal are far less clearly defined. The purpose of this publication is to provide evidence against the erroneous clinical dictum that opioid withdrawal is never life-threatening. This case report (N = 1) illustrates an unfortunate, common scenario of a man abusing prescription opioids and heroin. His attempt at self-detoxification with buprenorphine-naloxone resulted in life-threatening opioid withdrawal. A detailed account of each day of his withdrawal period was documented by patient and family report and review of all medical records. The patient was contacted three months after hospitalization to verify information and determine progress in treatment and abstinence from drugs and alcohol. A review of the literature was completed on severe cases of precipitated and spontaneous opioid withdrawal followed by a discussion of the significance as it relates to this case. Given the widespread use of prescription opioids and opioid maintenance treatment, physicians should be aware of the complications of acute opioid withdrawal and should be equipped to treat these complications. © American Academy of Addiction Psychiatry.

Clinical potential of naloxegol in the management of opioid-induced bowel dysfunction

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Poulsen JL

2014-09-01

Full Text Available Jakob Lykke Poulsen,1 Christina Brock,1,2 Anne Estrup Olesen,1,2 Matias Nilsson,1 Asbjørn Mohr Drewes1,3 1Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark; 2Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark; 3Department of Clinical Medicine, Aalborg University, Aalborg, DenmarkAbstract: Opioid-induced bowel dysfunction (OIBD is a burdensome condition which limits the therapeutic benefit of analgesia. It affects the entire gastrointestinal tract, predominantly by activating opioid receptors in the enteric nervous system, resulting in a wide range of symptoms, such as reflux, bloating, abdominal cramping, hard, dry stools, and incomplete evacuation. The majority of studies evaluating OIBD focus on constipation experienced in approximately 60% of patients. Nevertheless, other presentations of OIBD seem to be equally frequent. Furthermore, laxative treatment is often insufficient, which in many patients results in decreased quality of life and discontinuation of opioid treatment. Novel mechanism-based pharmacological approaches targeting the gastrointestinal opioid receptors have been marketed recently and even more are in the pipeline. One strategy is prolonged release formulation of the opioid antagonist naloxone (which has limited systemic absorption and oxycodone in a combined tablet. Another approach is peripherally acting, µ-opioid receptor antagonists (PAMORAs that selectively target µ-opioid receptors in the gastrointestinal tract. However, in Europe the only PAMORA approved for OIBD is the subcutaneously administered methylnaltrexone. Alvimopan is an oral PAMORA, but only approved in the US for postoperative ileus in hospitalized patients. Finally, naloxegol is a novel, oral PAMORA expected to be approved soon. In this review, the prevalence and pathophysiology of OIBD is presented. As PAMORAs seem to be a promising approach, their potential

Analysis of inflammation-induced depression of home cage wheel running in rats reveals the difference between opioid antinociception and restoration of function

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Kandasamy, Ram; Calsbeek, Jonas J.; Morgan, Michael M.

2016-01-01

Opioids are effective at inhibiting responses to noxious stimuli in rodents, but have limited efficacy and many side effects in chronic pain patients. One reason for this disconnect is that nociception is typically assessed using withdrawal from noxious stimuli in animals, whereas chronic pain patients suffer from abnormal pain that disrupts normal activity. We hypothesized that assessment of home cage wheel running in rats would provide a much more clinically relevant method to assess opioid efficacy to restore normal behavior. Intraplantar injection of Complete Freund’s Adjuvant (CFA) into the right hindpaw depressed wheel running and caused mechanical allodynia measured with the von Frey test in both male and female rats. Administration of an ED50 dose of morphine (3.2 mg/kg) reversed mechanical allodynia, but did not reverse CFA-induced depression of wheel running. In contrast, administration of a low dose of morphine (1.0 mg/kg) restored running for one hour in both sexes, but had no effect on mechanical allodynia. Administration of the atypical opioid buprenorphine had no effect on inflammation-induced depression of wheel running in male or female rats, but attenuated mechanical allodynia in male rats. Administration of buprenorphine and higher doses of morphine depressed wheel running in non-inflamed rats, suggesting that the side effects of opioids interfere with restoration of function. These data indicate that restoration of pain-depressed function requires antinociception in the absence of disruptive side effects. The disruptive side effects of opioids are consistent with the major limitation of opioid use in human pain patients. PMID:27746208

Prescription opioid abuse, pain and addiction: clinical issues and implications.

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Ling, Walter; Mooney, Larissa; Hillhouse, Maureen

2011-05-01

Prescription opioid misuse in the USA has increased over threefold since 1990 to epidemic proportions, with substantial increases in prescription opioid use also reported in other countries, such as Australia and New Zealand. The broad availability of prescription pain medications, coupled with public misconceptions about their safety and addictive potential, have contributed to the recent surge in non-medical use of prescription opioids and corresponding increases in treatment admissions for problems related to opioid misuse. Given competing pressures faced by physicians to both diagnose and treat pain syndromes and identify individuals at risk for addictive disorders, the use of opioids in the treatment of pain poses a significant clinical challenge. This paper reviews the interaction between pain and opioid addiction with a focus on clinical management issues, including risk factors for opioid dependence in patients with chronic pain and the use of assessment tools to identify and monitor at-risk individuals. Treatment options for opioid dependence and pain are reviewed, including the use of the partial µ agonist buprenorphine in the management of concurrent pain and opioid addiction. Physicians should strive to find a reasonable balance between minimising potential adverse effects of opioid medications without diminishing legitimate access to opioids for analgesia. The article discusses the need to identify methods for minimising risks and negative consequences associated with opioid analgesics and poses research directions, including the development of abuse-deterrent opioid formulations, genetic risk factors for opioid dependence and opioid-induced hyperalgesia as a potential target for medication therapy. © 2011 Australasian Professional Society on Alcohol and other Drugs.

Newer approaches to opioid detoxification

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Siddharth Sarkar

2012-01-01

Full Text Available Opioid use disorders present with distressing withdrawal symptoms at the time of detoxification. The pharmacological agents and methods currently in use for detoxification mainly include buprenorphine, methadone, and clonidine. Many other pharmacological agents have been tried for opioid detoxification. This review takes a look at the newer pharmacological options, both opioid agonists and non-agonist medications that have been utilized for detoxification. Peer reviewed articles were identified using PubMed and PsychInfo databases. The keywords included for the search were a combination of ′opioid′ and ′detoxification′ and their synonyms. All the articles published in the last 10 years were screened for. Relevant data was extracted from identified studies. Many newer pharmacological agents have been tried in detoxification of opioids. However, the quest for a safe, efficacious, cost-effective pharmacological option which requires minimal monitoring still continues. The role of non-pharmacological measures and alternative medicine needs further evaluation.

Towards safer use of opioids.

LENUS (Irish Health Repository)

Carson, R W R

2009-09-01

The main aim of our work was to improve the safety of opioid use in our institution, an acute generalhospital with 620 beds. Initially, all reported opioid errors from 2001 - 2006 were audited. The findings directed a range of multidisciplinary staff educational inputs to improve opioid prescribing and administration practice, and encourage drug error reporting. 448 drug errors were reported, of which 54 (12%) involved opioids; of these, 43 (79%) involved codeine, morphine or oxycodone. 31 of the errors (57%) were associated with administration, followed by 12 (22%) with dispensing and 11 (20%) with prescribing. There were 2 reports of definite patient harm. A subsequent audit examined a 17-month period following the introduction of the above teaching: 17 errors were noted, of which 14 (83%) involved codeine, morphine or oxycodone. Again, drug administration was most error-prone, comprising 11 (65%) of reports. However, just 2 (12%) of the reported errors now involved prescribing, which was a reduction.

Evaluation of Analgesic Activity of Papaver libanoticum Extract in Mice: Involvement of Opioids Receptors

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Mohamad Ali Hijazi

2017-01-01

Full Text Available Papaver libanoticum is an endemic plant to Lebanese region (family Papaveraceae that has not been investigated before. The present study aimed to explore the analgesic activity of dried ethanolic extract of Papaver libanoticum (PLE using tail flick, hot plate, and acetic acid induced writhing models in mice. The involvement of opioid receptors in the analgesic mechanism was investigated using naloxone antagonism. Results demonstrated that PLE exhibited a potent dose dependent analgesic activity in all tested models for analgesia. The analgesic effect involved activation of opioid receptors in the central nervous system, where both spinal and supraspinal components might be involved. The time course for analgesia revealed maximum activity after three hours in both tail flick and hot plate methods, which was prolonged to 24 hours. Metabolites of PLE could be responsible for activation of opioid receptors. The EC50 of PLE was 79 and 50 mg/kg in tail flick and hot plate tests, respectively. The total coverage of analgesia by PLE was double that of morphine in both tests. In conclusion, PLE proved to have opioid agonistic activity with a novel feature of slow and prolonged effect. The present study could add a potential tool in the armaments of opioid drugs as a natural potent analgesic and for treatment of opioid withdrawal syndrome.

Sex Differences in Kappa Opioid Receptor Function and Their Potential Impact on Addiction

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Chartoff, Elena H.; Mavrikaki, Maria

2015-01-01

Behavioral, biological, and social sequelae that lead to drug addiction differ between men and women. Our efforts to understand addiction on a mechanistic level must include studies in both males and females. Stress, anxiety, and depression are tightly linked to addiction, and whether they precede or result from compulsive drug use depends on many factors, including biological sex. The neuropeptide dynorphin (DYN), an endogenous ligand at kappa opioid receptors (KORs), is necessary for stress-induced aversive states and is upregulated in the brain after chronic exposure to drugs of abuse. KOR agonists produce signs of anxiety, fear, and depression in laboratory animals and humans, findings that have led to the hypothesis that drug withdrawal-induced DYN release is instrumental in negative reinforcement processes that drive addiction. However, these studies were almost exclusively conducted in males. Only recently is evidence available that there are sex differences in the effects of KOR activation on affective state. This review focuses on sex differences in DYN and KOR systems and how these might contribute to sex differences in addictive behavior. Much of what is known about how biological sex influences KOR systems is from research on pain systems. The basic molecular and genetic mechanisms that have been discovered to underlie sex differences in KOR function in pain systems may apply to sex differences in KOR function in reward systems. Our goals are to discuss the current state of knowledge on how biological sex contributes to KOR function in the context of pain, mood, and addiction and to explore potential mechanisms for sex differences in KOR function. We will highlight evidence that the function of DYN-KOR systems is influenced in a sex-dependent manner by: polymorphisms in the prodynorphin (pDYN) gene, genetic linkage with the melanocortin-1 receptor (MC1R), heterodimerization of KORs and mu opioid receptors (MORs), and gonadal hormones. Finally, we

Sex differences in kappa opioid receptor function and their potential impact on addiction

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Elena eChartoff

2015-12-01

Full Text Available Behavioral, biological and social sequelae that lead to drug addiction differ between men and women. Our efforts to understand addiction on a mechanistic level must include studies in both males and females. Stress, anxiety, and depression are tightly linked to addiction, and whether they precede or result from compulsive drug use depends on many factors, including biological sex. The neuropeptide dynorphin (DYN, an endogenous ligand at kappa opioid receptors (KORs, is necessary for stress-induced aversive states and is upregulated in the brain after chronic exposure to drugs of abuse. KOR agonists produce signs of anxiety, fear, and depression in laboratory animals and humans, findings that have led to the hypothesis that drug withdrawal-induced DYN release is instrumental in negative reinforcement processes that drive addiction. However, these studies were almost exclusively conducted in males. Only recently is evidence available that there are sex differences in the effects of KOR activation on affective state. This review focuses on sex differences in DYN and KOR systems and how these might contribute to sex differences in addictive behavior. Much of what is known about how biological sex influences KOR systems is from research on pain systems. The basic molecular and genetic mechanisms that have been discovered to underlie sex differences in KOR function in pain systems may apply to sex differences in KOR function in reward systems. Our goals are to discuss the current state of knowledge on how biological sex contributes to KOR function in the context of pain,mood and addiction and to explore potential mechanisms for sex differences in KOR function. We will highlight evidence that the function of DYN-KOR systems is influenced in a sex-dependent manner by: polymorphisms in the prodynorphin (pDYN gene, genetic linkage with the melanocortin-1 receptor (MC1R, heterodimerization of KORs and mu opioid receptors (MORs, and gonadal hormones

Sex Differences in Kappa Opioid Receptor Function and Their Potential Impact on Addiction.

Science.gov (United States)

Chartoff, Elena H; Mavrikaki, Maria

2015-01-01

Behavioral, biological, and social sequelae that lead to drug addiction differ between men and women. Our efforts to understand addiction on a mechanistic level must include studies in both males and females. Stress, anxiety, and depression are tightly linked to addiction, and whether they precede or result from compulsive drug use depends on many factors, including biological sex. The neuropeptide dynorphin (DYN), an endogenous ligand at kappa opioid receptors (KORs), is necessary for stress-induced aversive states and is upregulated in the brain after chronic exposure to drugs of abuse. KOR agonists produce signs of anxiety, fear, and depression in laboratory animals and humans, findings that have led to the hypothesis that drug withdrawal-induced DYN release is instrumental in negative reinforcement processes that drive addiction. However, these studies were almost exclusively conducted in males. Only recently is evidence available that there are sex differences in the effects of KOR activation on affective state. This review focuses on sex differences in DYN and KOR systems and how these might contribute to sex differences in addictive behavior. Much of what is known about how biological sex influences KOR systems is from research on pain systems. The basic molecular and genetic mechanisms that have been discovered to underlie sex differences in KOR function in pain systems may apply to sex differences in KOR function in reward systems. Our goals are to discuss the current state of knowledge on how biological sex contributes to KOR function in the context of pain, mood, and addiction and to explore potential mechanisms for sex differences in KOR function. We will highlight evidence that the function of DYN-KOR systems is influenced in a sex-dependent manner by: polymorphisms in the prodynorphin (pDYN) gene, genetic linkage with the melanocortin-1 receptor (MC1R), heterodimerization of KORs and mu opioid receptors (MORs), and gonadal hormones. Finally, we

PSYCHIATRIC COMORBIDITY IN PATIENTS WITH OPIOID DEPENDENCE

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Shihab Kattukulathil

2018-02-01

Full Text Available BACKGROUND Opioid dependence is a major public health problem in Kerala. Presence of psychiatric disorder among opioid dependent patients worsens the scenario. To date no attempts have been made to analyse the magnitude and pattern of comorbid psychiatric disorders in the state. MATERIALS AND METHODS We assessed 30 patients with ICD-10 diagnosis of opioid dependence syndrome for the presence of comorbid psychiatric disorders using structured clinical interview for DSM IV Axis 1 disorder (SCID-1. Patients with opioid withdrawal state, delirium and acute medical emergencies were excluded. RESULTS 56.7% of our subjects had a comorbid psychiatric disorder. Major depressive disorder was the most common one (n=7, 23.3%. Prevalence of other disorders were generalised anxiety disorder (n=6, 20%, bipolar affective disorder (n=3, 10% and schizophrenia (n=1, 3.3%. CONCLUSION Comorbid Psychiatric disorders are highly prevalent in opioid dependence. There is a need for further large sample studies in the areas of comorbidities and in the integrated strategies for the identification and management of both opioid dependence and comorbid psychiatric disorders.

Opioid withdrawal increases transient receptor potential vanilloid 1 activity in a protein kinase A-dependent manner.

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Spahn, Viola; Fischer, Oliver; Endres-Becker, Jeannette; Schäfer, Michael; Stein, Christoph; Zöllner, Christian

2013-04-01

Hyperalgesia is a cardinal symptom of opioid withdrawal. The transient receptor potential vanilloid 1 (TRPV1) is a ligand-gated ion channel expressed on sensory neurons responding to noxious heat, protons, and chemical stimuli such as capsaicin. TRPV1 can be inhibited via μ-opioid receptor (MOR)-mediated reduced activity of adenylyl cyclases (ACs) and decreased cyclic adenosine monophosphate (cAMP) levels. In contrast, opioid withdrawal following chronic activation of MOR uncovers AC superactivation and subsequent increases in cAMP and protein kinase A (PKA) activity. Here we investigated (1) whether an increase in cAMP during opioid withdrawal increases the activity of TRPV1 and (2) how opioid withdrawal modulates capsaicin-induced nocifensive behavior in rats. We applied whole-cell patch clamp, microfluorimetry, cAMP assays, radioligand binding, site-directed mutagenesis, and behavioral experiments. Opioid withdrawal significantly increased cAMP levels and capsaicin-induced TRPV1 activity in both transfected human embryonic kidney 293 cells and dissociated dorsal root ganglion (DRG) neurons. Inhibition of AC and PKA, as well as mutations of the PKA phosphorylation sites threonine 144 and serine 774, prevented the enhanced TRPV1 activity. Finally, capsaicin-induced nocifensive behavior was increased during opioid withdrawal in vivo. In summary, our results demonstrate an increased activity of TRPV1 in DRG neurons as a new mechanism contributing to opioid withdrawal-induced hyperalgesia. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Role of ATP-sensitive potassium channels in the piracetam induced blockade of opioid effects.

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Rehni, Ashish K; Singh, Nirmal; Jindal, Seema

2007-12-01

The present study has been designed to investigate the effect of piracetam on morphine/ buprenorphine-induced antinociception in rats and effect of piracetam on morphine or minoxidil induced relaxation in KCl-precontracted isolated rat aortic ring preparation. Nociceptive threshold was measured by the tail flick test in rats. The cumulative dose responses of morphine or minoxidil were recorded in KCl-precontracted isolated rat aortic ring preparation. Piracetam attenuated buprenorphine-induced antinociception in rats. Piracetam significantly reduced the morphine and minoxidil induced relaxation in KCl precontracted isolated rat aortic ring preparation suggesting that piracetam interferes with opioid receptor and ATP-sensitive potassium channel (KATP) opener mediated responses in vitro. Thus, it may be suggested that piracetam attenuates opioid effects by an opioid receptor-KATP channel linked mechanism.

μ opioid receptor activation hyperpolarizes respiratory-controlling Kölliker-Fuse neurons and suppresses post-inspiratory drive.

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Levitt, Erica S; Abdala, Ana P; Paton, Julian F R; Bissonnette, John M; Williams, John T

2015-10-01

In addition to reductions in respiratory rate, opioids also cause aspiration and difficulty swallowing, indicating impairment of the upper airways. The Kölliker-Fuse (KF) maintains upper airway patency and a normal respiratory pattern. In this study, activation of μ opioid receptors in the KF reduced respiratory frequency and tidal volume in anaesthetized rats. Nerve recordings in an in situ preparation showed that activation of μ opioid receptors in the KF eliminated the post-inspiration phase of the respiratory cycle. In brain slices, μ opioid agonists hyperpolarized a distinct population (61%) of KF neurons by activation of an inwardly rectifying potassium conductance. These results suggest that KF neurons that are hyperpolarized by opioids could contribute to opioid-induced respiratory disturbances, particularly the impairment of upper airways. Opioid-induced respiratory effects include aspiration and difficulty swallowing, suggesting impairment of the upper airways. The pontine Kölliker-Fuse nucleus (KF) controls upper airway patency and regulates respiration, in particular the inspiratory/expiratory phase transition. Given the importance of the KF in coordinating respiratory pattern, the mechanisms of μ opioid receptor activation in this nucleus were investigated at the systems and cellular level. In anaesthetized, vagi-intact rats, injection of opioid agonists DAMGO or [Met(5) ]enkephalin (ME) into the KF reduced respiratory frequency and amplitude. The μ opioid agonist DAMGO applied directly into the KF of the in situ arterially perfused working heart-brainstem preparation of rat resulted in robust apneusis (lengthened low amplitude inspiration due to loss of post-inspiratory drive) that was rapidly reversed by the opioid antagonist naloxone. In brain slice preparations, activation of μ opioid receptors on KF neurons hyperpolarized a distinct population (61%) of neurons. As expected, the opioid-induced hyperpolarization reduced the excitability of

Variants of opioid system genes are associated with non-dependent opioid use and heroin dependence

NARCIS (Netherlands)

Randesi, Matthew; van den Brink, Wim; Levran, Orna; Blanken, Peter; Butelman, Eduardo R; Yuferov, Vadim; da Rosa, Joel Correa; Ott, Jurg; van Ree, Jan M; Kreek, Mary Jeanne

2016-01-01

BACKGROUND: Heroin addiction is a chronic, relapsing brain disease. Genetic factors are involved in the development of drug addiction. The aim of this study was to determine whether specific variants in genes of the opioid system are associated with non-dependent opioid use and heroin dependence.

Variants of opioid system genes are associated with non-dependent opioid use and heroin dependence

NARCIS (Netherlands)

Randesi, Matthew; van den Brink, Wim; Levran, Orna; Blanken, Peter; Butelman, Eduardo R.; Yuferov, Vadim; da Rosa, Joel Correa; Ott, Jurg; van Ree, Jan M.; Kreek, Mary Jeanne

2016-01-01

Heroin addiction is a chronic, relapsing brain disease. Genetic factors are involved in the development of drug addiction. The aim of this study was to determine whether specific variants in genes of the opioid system are associated with non-dependent opioid use and heroin dependence. Genetic

Study on distribution of reservoir endogenous microbe and oil displacement mechanism

Directory of Open Access Journals (Sweden)

Ming Yue

2017-02-01

Full Text Available In order to research oil displacement mechanism by indigenous microbial communities under reservoir conditions, indigenous microbial flooding experiments using the endogenous mixed bacterium from Shengli Oilfield were carried out. Through microscopic simulation visual model, observation and analysis of distribution and flow of the remaining oil in the process of water flooding and microbial oil displacement were conducted under high temperature and high pressure conditions. Research has shown that compared with atmospheric conditions, the growth of the microorganism metabolism and attenuation is slowly under high pressure conditions, and the existence of the porous medium for microbial provides good adhesion, also makes its growth cycle extension. The microbial activities can effectively launch all kinds of residual oil, and can together with metabolites, enter the blind holes off which water flooding, polymer flooding and gas flooding can’t sweep, then swap out remaining oil, increase liquidity of the crude oil and remarkably improve oil displacement effect.

Reduced emotional and corticosterone responses to stress in μ-opioid receptor knockout mice

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Ide, Soichiro; Sora, Ichiro; Ikeda, Kazutaka; Minami, Masabumi; Uhl, George R.; Ishihara, Kumatoshi

2014-01-01

The detailed mechanisms of emotional modulation in the nervous system by opioids remain to be elucidated, although the opioid system is well known to play important roles in the mechanisms of analgesia and drug dependence. In the present study, we conducted behavioral tests of anxiety and depression and measured corticosterone concentrations in both male and female μ-opioid receptor knockout (MOP-KO) mice to reveal the involvement of μ-opioid receptors in stress-induced emotional responses. MOP-KO mice entered more and spent more time in the open arms of the elevated plus maze compared with wild-type mice. MOP-KO mice also displayed significantly decreased immobility in a 15 min tail-suspension test compared with wild-type mice. Similarly, MOP-KO mice exhibited significantly decreased immobility on days 2, 3, and 4 in a 6 min forced swim test conducted for 5 consecutive days. The increase in plasma corticosterone concentration induced by tail-suspension, repeated forced swim, or restraint stress was reduced in MOP-KO mice compared with wild-type mice. Corticosterone levels were not different between wild-type and MOP-KO mice before stress exposure. In contrast, although female mice tended to exhibit fewer anxiety-like responses in the tail-suspension test in both genotypes, no significant gender differences were observed in stress-induced emotional responses. These results suggest that MOPs play an important facilitatory role in emotional responses to stress, including anxiety- and depression-like behavior and corticosterone levels. PMID:19596019

Opioid Prescriptions by Specialty in Ohio, 2010-2014.

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Weiner, Scott G; Baker, Olesya; Rodgers, Ann F; Garner, Chad; Nelson, Lewis S; Kreiner, Peter W; Schuur, Jeremiah D

2018-05-01

The current US opioid epidemic is attributed to the large volume of prescribed opioids. This study analyzed the contribution of different medical specialties to overall opioids by evaluating the pill counts and morphine milligram equivalents (MMEs) of opioid prescriptions, stratified by provider specialty, and determined temporal trends. This was an analysis of the Ohio prescription drug monitoring program database, which captures scheduled medication prescriptions filled in the state as well as prescriber specialty. We extracted prescriptions for pill versions of opioids written in the calendar years 2010 to 2014. The main outcomes were the number of filled prescriptions, pill counts, MMEs, and extended-released opioids written by physicians in each specialty, and annual prescribing trends. There were 56,873,719 prescriptions for the studied opioids dispensed, for which 41,959,581 (73.8%) had prescriber specialty type available. Mean number of pills per prescription and MMEs were highest for physical medicine/rehabilitation (PM&R; 91.2 pills, 1,532 mg, N = 1,680,579), anesthesiology/pain (89.3 pills, 1,484 mg, N = 3,261,449), hematology/oncology (88.2 pills, 1,534 mg, N = 516,596), and neurology (84.4 pills, 1,230 mg, N = 573,389). Family medicine (21.8%) and internal medicine (17.6%) wrote the most opioid prescriptions overall. Time trends in the average number of pills and MMEs per prescription also varied depending on specialty. The numbers of pills and MMEs per opioid prescription vary markedly by prescriber specialty, as do trends in prescribing characteristics. Pill count and MME values define each specialty's contribution to overall opioid prescribing more accurately than the number of prescriptions alone.

Discovery of a novel site of opioid action at the innate immune pattern-recognition receptor TLR4 and its role in addiction.

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Jacobsen, Jonathan Henry W; Watkins, Linda R; Hutchinson, Mark R

2014-01-01

Opioids have historically, and continue to be, an integral component of pain management. However, despite pharmacokinetic and dynamic optimization over the past 100 years, opioids continue to produce many undesirable side effects such as tolerance, reward, and dependence. As such, opioids are liable for addiction. Traditionally, opioid addiction was viewed as a solely neuronal process, and while substantial headway has been made into understanding the molecular and cellular mechanisms mediating this process, research has however, been relatively ambivalent to how the rest of the central nervous system (CNS) responds to opioids. Evidence over the past 20 years has clearly demonstrated the importance of the immunocompetent cells of the CNS (glia) in many aspects of opioid pharmacology. Particular focus has been placed on microglia and astrocytes, who in response to opioids, become activated and release inflammatory mediators. Importantly, the mechanism underlying immune activation is beginning to be elucidated. Evidence suggests an innate immune pattern-recognition receptor (toll-like receptor 4) as an integral component underlying opioid-induced glial activation. The subsequent proinflammatory response may be viewed akin to neurotransmission creating a process termed central immune signaling. Translationally, we are beginning to appreciate the importance of central immune signaling as it contributes to many behavioral actions of addiction including reward, withdrawal, and craving. As such, the aim of this chapter is to review and integrate the neuronal and central immune signaling perspective of addiction. © 2014 Elsevier Inc. All rights reserved.

Possible Opioid Shopping and its Correlates.

Science.gov (United States)

Walker, Alexander M; Weatherby, Lisa B; Cepeda, M Soledad; Bradford, Daniel; Yuan, Yingli

2017-11-01

We created an operational definition of possible opioid shopping in US commercial health insurance data and examined its correlates. The population consisted of 264,204 treatment courses in persons with a fill for an opioid or diuretic prescription in 2012 and a second within 18 months. We examined counts of prescribers and pharmacies and the numbers of fills and overlaps for ability to discriminate courses of opioids from diuretics, which were a negative control. The most discriminatory measure, indicating possible shopping behavior, was cross-tabulated against other prescriptions filled and diagnoses as found in insurance claims. The associations between claims characteristics and shopping behavior were assessed in a logistic regression. A definition that classified possible "moderate" or "extensive" shopping when a person obtained drug through at least 3 practices and at least 3 pharmacies over 18 months was highly discriminatory between opioid and diuretic treatment. Overlaps between fills and number of fills did not improve the discrimination. Data from insurance claims strongly predicted moderate-to-extensive levels of possible shopping (c=0.82). Prominent among 20 significant predictors were: state of residence; amount of opioid dispensed; self-payment; use of nonspecialist prescribers; high use of anxiolytics, hypnotics, psychostimulants, and antipsychotics; and use of both immediate release and extended-release or long-acting opioids. The use of ≥3 prescribing practices and ≥3 dispensing pharmacies over 18 months sharply discriminated courses of opioid treatment from courses of diuretics. This pattern of fills was additionally associated with the numbers of nonspecialist and self-paid fills, the total morphine milligram equivalents dispensed, and heavier use of drugs for anxiety, sleep, attention, and psychosis.

Opioid withdrawal signs and symptoms in children: frequency and determinants.

Science.gov (United States)

Fisher, Deborah; Grap, Mary Jo; Younger, Janet B; Ameringer, Suzanne; Elswick, R K

2013-01-01

The purpose of this study was to, in a pediatric population, describe the frequency of opioid withdrawal signs and symptoms and to identify factors associated with these opioid withdrawal signs and symptoms. Opioids are used routinely in the pediatric intensive care population for analgesia, sedation, blunting of physiologic responses to stress, and safety. In children, physical dependence may occur in as little as 2-3 days of continuous opioid therapy. Once the child no longer needs the opioid, the medications are reduced over time. A prospective, descriptive study was conducted. The sample of 26 was drawn from all patients, ages 2 weeks to 21 years admitted to the Children's Hospital of Richmond pediatric intensive care unit (PICU) and who have received continuous infusion or scheduled opioids for at least 5 days. Data collected included: opioid withdrawal score (WAT-1), opioid taper rate (total dose of opioid per day in morphine equivalents per kilogram [MEK]), pretaper peak MEK, pretaper cumulative MEK, number of days of opioid exposure prior to taper, and age. Out of 26 enrolled participants, only 9 (45%) had opioid withdrawal on any given day. In addition, there was limited variability in WAT-1 scores. The most common symptoms notes were diarrhea, vomit, sweat, and fever. For optimal opioid withdrawal assessments, clinicians should use a validated instrument such as the WAT-1 to measure for signs and symptoms of opioid withdrawal. Further research is indicated to examine risk factors for opioid withdrawal in children. Copyright © 2013 Elsevier Inc. All rights reserved.

Using [11C]diprenorphine to image opioid receptor occupancy by methadone in opioid addiction: clinical and preclinical studies.

Science.gov (United States)

Melichar, Jan K; Hume, Susan P; Williams, Tim M; Daglish, Mark R C; Taylor, Lindsay G; Ahmad, Rabia; Malizia, Andrea L; Brooks, David J; Myles, Judith S; Lingford-Hughes, Anne; Nutt, David J

2005-01-01

Substitute methadone prescribing is one of the main modes of treatment for opioid dependence with established evidence for improved health and social outcomes. However, the pharmacology underpinning the effects of methadone is little studied despite controversies about dosing in relation to outcome. We therefore examined the relationship between methadone dose and occupation of opioid receptors in brain using the positron emission tomography (PET) radioligand [(11)C]diprenorphine in humans and rats. Eight opioid-dependent subjects stable on their substitute methadone (18-90 mg daily) had an [(11)C]diprenorphine PET scan at predicted peak plasma levels of methadone. These were compared with eight healthy controls. No difference in [(11)C]diprenorphine binding was found between the groups, with no relationship between methadone dose and occupancy. Adult male Sprague-Dawley rats that had been given an acute i.v. injection of methadone hydrochloride (0.35, 0.5, 0.7, or 1.0 mg kg(-1)) before [(11)C]diprenorphine showed a dose-dependent increase in biodistribution but no reduction in [(11)C]diprenorphine binding. We suggest that the lack of a dose-dependent relationship between methadone dose, either given chronically in human or acutely in rat, and occupancy of opioid receptor measured with [(11)C]diprenorphine PET is related to efficacy of this opioid agonist at very low levels of opioid receptor occupancy. This has implications for understanding the actions of methadone in comparison with other opioid drugs such as partial agonists and antagonists.

The convulsive and electroencephalographic changes produced by nonpeptidic delta-opioid agonists in rats: comparison with pentylenetetrazol.

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Jutkiewicz, Emily M; Baladi, Michelle G; Folk, John E; Rice, Kenner C; Woods, James H

2006-06-01

delta-Opioid agonists produce convulsions and antidepressant-like effects in rats. It has been suggested that the antidepressant-like effects are produced through a convulsant mechanism of action either through overt convulsions or nonconvulsive seizures. This study evaluated the convulsive and seizurogenic effects of nonpeptidic delta-opioid agonists at doses that previously were reported to produce antidepressant-like effects. In addition, delta-opioid agonist-induced electroencephalographic (EEG) and behavioral changes were compared with those produced by the chemical convulsant pentylenetetrazol (PTZ). For these studies, EEG changes were recorded using a telemetry system before and after injections of the delta-opioid agonists [(+)-4-[(alphaR)-alpha-[(2S,5R)-2,5-dimethyl-4-(2-propenyl)-1-piperazinyl]-(3-methoxyphenyl)methyl]-N,N-diethylbenz (SNC80) and [(+)-4-[alpha(R)-alpha-[(2S,5R)-2,5-dimethyl-4-(2-propenyl)-1-piperazinyl]-(3-hydroxyphenyl)methyl]-N,N-diethylbenzamide [(+)-BW373U86]. Acute administration of nonpeptidic delta-opioid agonists produced bilateral ictal and paroxysmal spike and/or sharp wave discharges. delta-Opioid agonists produced brief changes in EEG recordings, and tolerance rapidly developed to these effects; however, PTZ produced longer-lasting EEG changes that were exacerbated after repeated administration. Studies with antiepileptic drugs demonstrated that compounds used to treat absence epilepsy blocked the convulsive effects of nonpeptidic delta-opioid agonists. Overall, these data suggest that delta-opioid agonist-induced EEG changes are not required for the antidepressant-like effects of these compounds and that neural circuitry involved in absence epilepsy may be related to delta-opioid agonist-induced convulsions. In terms of therapeutic development, these data suggest that it may be possible to develop delta-opioid agonists devoid of convulsive properties.

Kappa-opioid receptors mediate the antidepressant-like activity of hesperidin in the mouse forced swimming test.

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Filho, Carlos B; Del Fabbro, Lucian; de Gomes, Marcelo G; Goes, André T R; Souza, Leandro C; Boeira, Silvana P; Jesse, Cristiano R

2013-01-05

The opioid system has been implicated as a contributing factor for major depression and is thought to play a role in the mechanism of action of antidepressants. This study investigated the involvement of the opioid system in the antidepressant-like effect of hesperidin in the mouse forced swimming test. Our results demonstrate that hesperidin (0.1, 0.3 and 1 mg/kg; intraperitoneal) decreased the immobility time in the forced swimming test without affecting locomotor activity in the open field test. The antidepressant-like effect of hesperidin (0.3 mg/kg) in the forced swimming test was prevented by pretreating mice with naloxone (1 mg/kg, a nonselective opioid receptor antagonist) and 2-(3,4-dichlorophenyl)-Nmethyl-N-[(1S)-1-(3-isothiocyanatophenyl)-2-(1-pyrrolidinyl)ethyl] acetamide (DIPPA (1 mg/kg), a selective κ-opioid receptor antagonist), but not with naloxone methiodide (1 mg/kg, a peripherally acting opioid receptor antagonist), naltrindole (3 mg/kg, a selective δ-opioid receptor antagonist), clocinnamox (1 mg/kg, a selective μ-opioid receptor antagonist) or caffeine (3 mg/kg, a nonselective adenosine receptor antagonist). In addition, a sub-effective dose of hesperidin (0.01 mg/kg) produced a synergistic antidepressant-like effect in the forced swimming test when combined with a sub-effective dose of morphine (1 mg/kg). The antidepressant-like effect of hesperidin in the forced swimming test on mice was dependent on its interaction with the κ-opioid receptor, but not with the δ-opioid, μ-opioid or adenosinergic receptors. Taken together, these results suggest that hesperidin possesses antidepressant-like properties and may be of interest as a therapeutic agent for the treatment of depressive disorders. Published by Elsevier B.V.

PLGA-Curcumin Attenuates Opioid-Induced Hyperalgesia and Inhibits Spinal CaMKIIα

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Hu, Xiaoyu; Huang, Fang; Szymusiak, Magdalena; Tian, Xuebi; Liu, Ying; Wang, Zaijie Jim

2016-01-01

Opioid-induced hyperalgesia (OIH) is one of the major problems associated with prolonged use of opioids for the treatment of chronic pain. Effective treatment for OIH is lacking. In this study, we examined the efficacy and preliminary mechanism of curcumin in attenuating OIH. We employed a newly developed PLGA-curcumin nanoformulation (PLGA-curcumin) in order to improve the solubility of curcumin, which has been a major obstacle in properly characterizing curcumin’s mechanism of action and efficacy. We found that curcumin administered intrathecally or orally significantly attenuated hyperalgesia in mice with morphine-induced OIH. Furthermore, we demonstrated that the effects of curcumin on OIH correlated with the suppression of chronic morphine-induced CaMKIIα activation in the superficial laminae of the spinal dorsal horn. These data suggest that PLGA-curcumin may reverse OIH possibly by inhibiting CaMKIIα and its downstream signaling. PMID:26744842

PLGA-Curcumin Attenuates Opioid-Induced Hyperalgesia and Inhibits Spinal CaMKIIα.

Directory of Open Access Journals (Sweden)

Xiaoyu Hu

Full Text Available Opioid-induced hyperalgesia (OIH is one of the major problems associated with prolonged use of opioids for the treatment of chronic pain. Effective treatment for OIH is lacking. In this study, we examined the efficacy and preliminary mechanism of curcumin in attenuating OIH. We employed a newly developed PLGA-curcumin nanoformulation (PLGA-curcumin in order to improve the solubility of curcumin, which has been a major obstacle in properly characterizing curcumin's mechanism of action and efficacy. We found that curcumin administered intrathecally or orally significantly attenuated hyperalgesia in mice with morphine-induced OIH. Furthermore, we demonstrated that the effects of curcumin on OIH correlated with the suppression of chronic morphine-induced CaMKIIα activation in the superficial laminae of the spinal dorsal horn. These data suggest that PLGA-curcumin may reverse OIH possibly by inhibiting CaMKIIα and its downstream signaling.

Dark chocolate receptors: epicatechin-induced cardiac protection is dependent on delta-opioid receptor stimulation.

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Panneerselvam, Mathivadhani; Tsutsumi, Yasuo M; Bonds, Jacqueline A; Horikawa, Yousuke T; Saldana, Michelle; Dalton, Nancy D; Head, Brian P; Patel, Piyush M; Roth, David M; Patel, Hemal H

2010-11-01

Epicatechin, a flavonoid, is a well-known antioxidant linked to a variety of protective effects in both humans and animals. In particular, its role in protection against cardiovascular disease has been demonstrated by epidemiologic studies. Low-dose epicatechin, which does not have significant antioxidant activity, is also protective; however, the mechanism by which low-dose epicatechin induces this effect is unknown. Our laboratory tested the hypothesis that low-dose epicatechin mediates cardiac protection via opioid receptor activation. C57BL/6 mice were randomly assigned to 1 of 10 groups: control, epicatechin, naloxone (nonselective opioid receptor antagonist), epicatechin + naloxone, naltrindole (δ-specific opioid receptor antagonist), epicatechin + naltrindole, norbinaltorphimine (nor-BNI, κ-specific opioid receptor antagonist), epicatechin + nor-BNI, 5-hydroxydecanoic acid [5-HD, ATP-sensitive potassium channel antagonist], and epicatechin + 5-HD. Epicatechin (1 mg/kg) or other inhibitors (5 mg/kg) were administered by oral gavage or intraperitoneal injection, respectively, daily for 10 days. Mice were subjected to 30 min coronary artery occlusion followed by 2 h of reperfusion, and infarct size was determined via planimetry. Whole heart homogenates were assayed for downstream opioid receptor signaling targets. Infarct size was significantly reduced in epicatechin- and epicatechin + nor-BNI-treated mice compared with control mice. This protection was blocked by naloxone, naltrindole, and 5-HD. Epicatechin and epicatechin + nor-BNI increased the phosphorylation of Src, Akt, and IκBα, while simultaneously decreasing the expression of c-Jun NH(2)-terminal kinase and caspase-activated DNase. All signaling effects are consistent with opioid receptor stimulation and subsequent cardiac protection. Naloxone, naltrindole, and 5-HD attenuated these effects. In conclusion, epicatechin acts via opioid receptors and more specifically through the δ-opioid receptor to

Nurses and opioids: results of a bi-national survey on mental models regarding opioid administration in hospitals.

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Guest, Charlotte; Sobotka, Fabian; Karavasopoulou, Athina; Ward, Stephen; Bantel, Carsten

2017-01-01

Pain remains insufficiently treated in hospitals. Increasing evidence suggests human factors contribute to this, due to nurses failing to administer opioids. This behavior might be the consequence of nurses' mental models about opioids. As personal experience and conceptions shape these models, the aim of this prospective survey was to identify model-influencing factors. A questionnaire was developed comprising of 14 statements concerning ideations about opioids and seven questions concerning demographics, indicators of adult learning, and strength of religious beliefs. Latent variables that may underlie nurses' mental models were identified using undirected graphical dependence models. Representative items of latent variables were employed for ordinal regression analysis. Questionnaires were distributed to 1,379 nurses in two London, UK, hospitals (n=580) and one German (n=799) hospital between September 2014 and February 2015. A total of 511 (37.1%) questionnaires were returned. Mean (standard deviation) age of participants were 37 (11) years; 83.5% participants were female; 45.2% worked in critical care; and 51.5% had more than 10 years experience. Of the nurses, 84% were not scared of opioids, 87% did not regard opioids as drugs to help patients die, and 72% did not view them as drugs of abuse. More English (41%) than German (28%) nurses were afraid of criminal investigations and were constantly aware of side effects (UK, 94%; Germany, 38%) when using opioids. Four latent variables were identified which likely influence nurses' mental models: "conscious decision-making"; "medication-related fears"; "practice-based observations"; and "risk assessment". They were predicted by strength of religious beliefs and indicators of informal learning such as experience but not by indicators of formal learning such as conference attendance. Nurses in both countries employ analytical and affective mental models when administering the opioids and seem to learn from experience

Is chronic fatigue syndrome an autoimmune disorder of endogenous neuropeptides, exogenous infection and molecular mimicry?

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Staines, Donald R

2004-01-01

Chronic fatigue syndrome is a disorder characterised by prolonged fatigue and debility and is mostly associated with post-infection sequelae although ongoing infection is unproven. Immunological aberration is likely and this may prove to be associated with an expanding group of vasoactive neuropeptides in the context of molecular mimicry and inappropriate immunological memory. Vasoactive neuropeptides including vasoactive intestinal peptide (VIP) and pituitary adenylate activating polypeptide (PACAP) belong to the secretin/glucagon superfamily and act as hormones, neurotransmitters, immune modulators and neurotrophes. They are readily catalysed to smaller peptide fragments by antibody hydrolysis. They and their binding sites are immunogenic and are known to be associated with a range of autoimmune conditions. Vasoactive neuropeptides are widely distributed in the body particularly in the central, autonomic and peripheral nervous systems and have been identified in the gut, adrenal gland, reproductive organs, vasculature, blood cells and other tissues. They have a vital role in maintaining vascular flow in organs, and in thermoregulation, memory and concentration. They are co-transmitters for acetylcholine, nitric oxide, endogenous opioids and insulin, are potent immune regulators with primarily anti-inflammatory activity, and have a significant role in protection of the nervous system to toxic assault, promotion of neural development and the maintenance of homeostasis. This paper describes a biologically plausible mechanism for the development of CFS based on loss of immunological tolerance to the vasoactive neuropeptides following infection, significant physical exercise or de novo. It is proposed that release of these substances is accompanied by a loss of tolerance either to them or their receptor binding sites in CFS. Such an occurrence would have predictably serious consequences resulting from compromised function of the key roles these substances perform. All

State Emergency Department Opioid Guidelines: Current Status.

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Broida, Robert I; Gronowski, Tanner; Kalnow, Andrew F; Little, Andrew G; Lloyd, Christopher M

2017-04-01

The purpose of this study was to evaluate and categorize current state-sponsored opioid guidelines for the practice of emergency medicine (EM). We conducted a comprehensive search of EM-specific opioid prescribing guidelines and/or policies in each state to determine current state involvement in EM opioid prescribing, as well as to evaluate some of the specifics of each guideline or policy. The search was conducted using an online query and a follow-up email request to each state chapter of ACEP. We found that 17 states had emergency department-specific guidelines. We further organized the guidelines into four categories: limiting prescriptions for opioids with 67 total recommendations; preventing/diverting abuse with 56 total recommendations; addiction-related guidelines with 29 total recommendations; and a community resources section with 24 total recommendations. Our results showed that current state guidelines focus on providers limiting opioid pain prescriptions and vetting patients for possible abuse/diversion. This study highlights the 17 states that have addressed opioid prescribing guidelines and categorizes their efforts to date. It is hoped that this study will provide the basis for similar efforts in other states.

Opioid mediated activity and expression of mu and delta opioid receptors in isolated human term non-labouring myometrium.

LENUS (Irish Health Repository)

Fanning, Rebecca A

2013-01-05

The existence of opioid receptors in mammalian myometrial tissue is now widely accepted. Previously enkephalin degrading enzymes have been shown to be elevated in pregnant rat uterus and a met-enkephalin analogue has been shown to alter spontaneous contractility of rat myometrium. Here we have undertaken studies to determine the effects of met-enkephalin on in vitro human myometrial contractility and investigate the expression of opioid receptors in pregnant myometrium. Myometrial biopsies were taken from women undergoing elective caesarean delivery at term. Organ bath experiments were used to investigate the effect of the met-enkephalin analogue [d-Ala 2, d-met 5] enkephalin (DAMEA) on spontaneous contractility. A confocal immunofluorescent technique and real time PCR were used to determine the expression of protein and mRNA, respectively for two opioid receptor subtypes, mu and delta. DAMEA had a concentration dependent inhibitory effect on contractile activity (1 × 10(-7)M-1 × 10(-4)M; 54% reduction in contractile activity, P<0.001 at 1 × 10(-4)M concentration). Mu and delta opioid receptor protein sub-types and their respective mRNA were identified in all tissues sampled. This is the first report of opioid receptor expression and of an opioid mediated uterorelaxant action in term human non-labouring myometrium in vitro.

Enkephalins: Endogenous Analgesics with an Emerging Role in Stress Resilience

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Mathilde S. Henry

2017-01-01

Full Text Available Psychological stress is a state of mental or emotional strain or tension that results from adverse or demanding circumstances. Chronic stress is well known to induce anxiety disorders and major depression; it is also considered a risk factor for Alzheimer’s disease. Stress resilience is a positive outcome that is associated with preserved cognition and healthy aging. Resilience presents psychological and biological characteristics intrinsic to an individual conferring protection against the development of psychopathologies in the face of adversity. How can we promote or improve resilience to chronic stress? Numerous studies have proposed mechanisms that could trigger this desirable process. The roles of enkephalin transmission in the control of pain, physiological functions, like respiration, and affective disorders have been studied for more than 30 years. However, their role in the resilience to chronic stress has received much less attention. This review presents the evidence for an emerging involvement of enkephalin signaling through its two associated opioid receptors, μ opioid peptide receptor and δ opioid peptide receptor, in the natural adaptation to stressful lifestyles.

Provider confidence in opioid prescribing and chronic pain management: results of the Opioid Therapy Provider Survey

Science.gov (United States)

Pearson, Amy CS; Moman, Rajat N; Moeschler, Susan M; Eldrige, Jason S; Hooten, W Michael

2017-01-01

Introduction Many providers report lack of confidence in managing patients with chronic pain. Thus, the primary aim of this study was to investigate the associations of provider confidence in managing chronic pain with their practice behaviors and demographics. Materials and methods The primary outcome measure was the results of the Opioid Therapy Provider Survey, which was administered to clinicians attending a pain-focused continuing medical education conference. Nonparametric correlations were assessed using Spearman’s rho. Results Of the respondents, 55.0% were women, 92.8% were white, and 56.5% were physicians. Primary care providers accounted for 56.5% of the total respondents. The majority of respondents (60.8%) did not feel confident managing patients with chronic pain. Provider confidence in managing chronic pain was positively correlated with 1) following an opioid therapy protocol (P=0.001), 2) the perceived ability to identify patients at risk for opioid misuse (P=0.006), and 3) using a consistent practice-based approach to improve their comfort level with prescribing opioids (Pcorrelated with the perception that treating pain patients was a “problem in my practice” (P=0.005). Conclusion In this study, the majority of providers did not feel confident managing chronic pain. However, provider confidence was associated with a protocolized and consistent practice-based approach toward managing opioids and the perceived ability to identify patients at risk for opioid misuse. Future studies should investigate whether provider confidence is associated with measurable competence in managing chronic pain and explore approaches to enhance appropriate levels of confidence in caring for patients with chronic pain. PMID:28652805

The Combination Very Low-Dose Naltrexone–Clonidine in the Management of Opioid Withdrawal

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Mannelli, Paolo; Peindl, Kathleen; Wu, Li-Tzy; Patkar, Ashwin A.; Gorelick, David A.

2013-01-01

Background The management of withdrawal absorbs substantial clinical efforts in opioid dependence (OD). The real challenge lies in improving current pharmacotherapies. Although widely used, clonidine causes problematic adverse effects and does not alleviate important symptoms of opioid withdrawal, alone or in combination with the opioid antagonist naltrexone. Very low-dose naltrexone (VLNTX) has been shown to attenuate withdrawal intensity and noradrenaline release following opioid agonist taper, suggesting a combination with clonidine may result in improved safety and efficacy. Objectives We investigated the effects of a VLNTX–clonidine combination in a secondary analysis of data from a double-blind, randomized opioid detoxification trial. Methods Withdrawal symptoms and treatment completion were compared following VLNTX (.125 or .25 mg/day) and clonidine (.1–.2 mg q6h) in 127 individuals with OD undergoing 6-day methadone inpatient taper at a community program. Results VLNTX was more effective than placebo or clonidine in reducing symptoms and signs of withdrawal. The use of VLNTX in combination with clonidine was associated with attenuated subjective withdrawal compared with each medication alone, favoring detoxification completion in comparison with clonidine or naltrexone placebo. VLNTX/clonidine was effective in reducing symptoms that are both undertreated and well controlled with clonidine treatment and was not associated with significant adverse events compared with other treatments. Conclusions and Scientific Significance Preliminary results elucidate neurobiological mechanisms of OD and support the utility of controlled studies on a novel VLNTX + low-dose clonidine combination for the management of opioid withdrawal. PMID:22233189

Opioid-use disorder among patients on long-term opioid therapy: impact of final DSM-5 diagnostic criteria on prevalence and correlates.

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Boscarino, Joseph A; Hoffman, Stuart N; Han, John J

2015-01-01

Previously, we estimated the prevalence and risk factors for prescription opioid-use disorder among outpatients on opioid therapy using the Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 and DSM-4 criteria. However, at the time, the DSM-5 criteria were not finalized. In the current study, we analyzed these data using the final DSM-5 criteria and compared these results. Using electronic records from a large US health care system, we identified outpatients receiving five or more prescription orders for opioid therapy in the past 12 months for noncancer pain (mean prescription orders =10.72; standard deviation =4.96). In 2008, we completed diagnostic interviews with 705 of these patients using the DSM-4 criteria. In the current study, we reassessed these results using the final DSM-5 criteria. The lifetime prevalence of DSM-5 opioid-use disorders using the final DSM-5 criteria was 58.7% for no or few symptoms (DSM-4 criteria indicated that the majority of patients with lifetime DSM-4 opioid dependence were now classified as having mild opioid-use disorder, based on the DSM-5 criteria (53.6%; 95% CI =44.1-62.8). In ordinal logistic regression predicting no/few, mild, moderate, and severe opioid-use disorder, the best predictors were age DSM-5 criteria, including the elimination of tolerance and withdrawal, inclusion of craving and abuse symptoms, and introduction of a new graded severity classification, the prevalence of opioid-use disorders has changed, while many of the DSM-4 risk factors for opioid dependence were similar. To our knowledge, this is one of the first studies to compare the final results for DSM-5 versus DSM-4 prescription opioid-use disorders among a high-risk patient population.

Risk Factors for Opioid-Use Disorder and Overdose.

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Webster, Lynn R

2017-11-01

Opioid analgesics are recognized as a legitimate medical therapy for selected patients with severe chronic pain that does not respond to other therapies. However, opioids are associated with risks for patients and society that include misuse, abuse, diversion, addiction, and overdose deaths. Therapeutic success depends on proper candidate selection, assessment before administering opioid therapy, and close monitoring throughout the course of treatment. Risk assessment and prevention include knowledge of patient factors that may contribute to misuse, abuse, addiction, suicide, and respiratory depression. Risk factors for opioid misuse or addiction include past or current substance abuse, untreated psychiatric disorders, younger age, and social or family environments that encourage misuse. Opioid mortality prevalence is higher in people who are middle aged and have substance abuse and psychiatric comorbidities. Suicides are probably undercounted or frequently misclassified in reports of opioid-related poisoning deaths. Greater understanding and better assessment are needed of the risk associated with suicide risk in patients with pain. Clinical tools and an evolving evidence base are available to assist clinicians with identifying patients whose risk factors put them at risk for adverse outcomes with opioids.

Hiperalgesia asociada al tratamiento con opioides

OpenAIRE

A. Gil Martín; M. Moreno García; J. Sánchez-Rubio Ferrández; T. Molina García

2014-01-01

La hiperalgesia inducida por opioides es una reacción paradójica caracterizada por una percepción intensificada de dolor relacionada con el uso de estos medicamentos en ausencia de progresión de la enfermedad o de síndrome de retirada. A diferencia de los casos de tolerancia, definida como pérdida de potencia analgésica durante el uso prolongado de opioides, no se produce mejoría con el escalado de dosis. La hiperalgesia inducida por opioides se ha manifestado en pacientes con dosis de manten...

Bilateral Breast Reduction Without Opioid Analgesics: A Comparative Study.

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Parsa, Fereydoun Don; Cheng, Justin; Stephan, Brad; Castel, Nikki; Kim, Leslie; Murariu, Daniel; Parsa, Alan A

2017-09-01

Breast reduction has traditionally been performed under general anesthesia with adjunct opioid use. However, opioids are associated with a wide variety of adverse effects, including nausea, vomiting, constipation, postoperative sedation, dizziness, and addiction. This study compares bilateral breast reduction using a multimodal opioid-free pain management regimen vs traditional general anesthesia with adjunct opioids. A total of 83 female patients were enrolled in this study. Group 1 includes a retrospective series of 39 patients that underwent breast reduction via general anesthesia with adjunct opioid use. This series was compared to 2 prospective groups of patients who did not receive opioids either preoperatively or intraoperatively. In group 2, twenty-six patients underwent surgery under intravenous sedation and local anesthesia. In group 3, eighteen patients underwent surgery with general anesthesia. All patients in groups 2 and 3 received preoperative gabapentin and celecoxib along with infiltration of local anesthetics during the operation and prior to discharge to the Post-Anesthesia Care Unit (PACU). Primary outcome measures included the duration of surgery, time from end of operation to discharge home, postoperative opioid and antiemetic use, and unplanned postoperative hospitalizations. When compared to group 1, groups 2 and 3 experienced a shorter time from end of operation to discharge home (P opioid use (P opioid-free bilateral breast reduction either under local or general anesthesia as an outpatient. This method resulted in significantly less morbidity, use of opioids postoperatively, as well as unplanned hospital admissions compared to "traditional" breast reduction under general anesthesia with the use of opioids. 3. © 2017 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com

Opioid Overdose

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... Updated: 03/10/2016 Medications to Treat OPIOID ADDICTION Methadone Naltrexone Buprenorphine Related SAMHSA Resources Behavioral Health ... Systems Integration Health Disparities Health Financing Health Information Technology HIV, AIDS, and Viral Hepatitis Homelessness and Housing ...

Behavioral intervention to reduce opioid overdose among high-risk persons with opioid use disorder: A pilot randomized controlled trial.

Directory of Open Access Journals (Sweden)

Phillip Oliver Coffin

Full Text Available The United States is amidst an opioid epidemic, including synthetic opioids that may result in rapid death, leaving minimal opportunity for bystander rescue. We pilot tested a behavioral intervention to reduce the occurrence of opioid overdose among opioid dependent persons at high-risk for subsequent overdose.We conducted a single-blinded randomized-controlled trial of a repeated dose motivational interviewing intervention (REBOOT to reduce overdose versus treatment as usual, defined as information and referrals, over 16 months at the San Francisco Department of Public Health from 2014-2016. Participants were 18-65 years of age, had opioid use disorder by Structured Clinical Interview, active opioid use, opioid overdose within 5 years, and prior receipt of naloxone kits. The intervention was administered at months 0, 4, 8, and 12, preceded by the assessment which was also administered at month 16. Dual primary outcomes were any overdose event and number of events, collected by computer-assisted personal interview, as well as any fatal overdose events per vital records.A total of 78 persons were screened and 63 enrolled. Mean age was 43 years, 67% were born male, 65% White, 17% African-American, and 14% Latino. Ninety-two percent of visits and 93% of counseling sessions were completed. At baseline, 33.3% of participants had experienced an overdose in the past four months, with a similar mean number of overdoses in both arms (p = 0.95; 29% overdosed during follow-up. By intention-to-treat, participants assigned to REBOOT were less likely to experience any overdose (incidence rate ratio [IRR] 0.62 [95%CI 0.41-0.92, p = 0.019 and experienced fewer overdose events (IRR 0.46, 95%CI 0.24-0.90, p = 0.023, findings that were robust to sensitivity analyses. There were no differences between arms in days of opioid use, substance use treatment, or naloxone carriage.REBOOT reduced the occurrence of any opioid overdose and the number of overdoses

Context-dependent links between song production and opioid-mediated analgesia in male European starlings (Sturnus vulgaris.

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Cynthia A Kelm-Nelson

Full Text Available Little is known about the neural mechanisms that ensure appropriate vocal behaviors within specific social contexts. Male songbirds produce spontaneous (undirected songs as well as female-directed courtship songs. Opioid neuropeptide activity in specific brain regions is rewarding, at least in mammals, and past studies suggest that the opioid met-enkephalin in such areas is more tightly linked to undirected than female-directed song. Recent data using a song-associated place preference paradigm further suggest that production of undirected but not directed song is tightly linked to intrinsic reward. Opioids have analgesic properties. Therefore, if production of undirected song is closely linked to opioid-mediated reward, the production of undirected but not directed song should be associated with analgesia. Consistent with this prediction, in male starlings we identified a positive correlation between analgesia (decreased reactivity to a hot water bath and undirected song (in non-breeding season condition males in affiliative flocks but not female-directed song (in breeding season condition males presented with females. When breeding condition males were divided according to social status, a negative correlation was found in subordinate males (i.e. males that failed to acquire a nest box. These data are consistent with the hypotheses 1 that the production of undirected song is facilitated or maintained by opioids (and/or other neuromodulators that also induce analgesia and 2 that production of female-directed song is not linked in the same way to release of the same neuromodulators. Results also demonstrate a link between analgesia and song in subordinate individuals lacking a nesting territory within the breeding season. Overall, the findings indicate that distinct neural mechanisms regulate communication in different social contexts and support the working hypothesis that undirected but not directed song is tightly linked to opioid release.

Induction of synaptic long-term potentiation after opioid withdrawal.

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Drdla, Ruth; Gassner, Matthias; Gingl, Ewald; Sandkühler, Jürgen

2009-07-10

mu-Opioid receptor (MOR) agonists represent the gold standard for the treatment of severe pain but may paradoxically also enhance pain sensitivity, that is, lead to opioid-induced hyperalgesia (OIH). We show that abrupt withdrawal from MOR agonists induces long-term potentiation (LTP) at the first synapse in pain pathways. Induction of opioid withdrawal LTP requires postsynaptic activation of heterotrimeric guanine nucleotide-binding proteins and N-methyl-d-aspartate receptors and a rise of postsynaptic calcium concentrations. In contrast, the acute depression by opioids is induced presynaptically at these synapses. Withdrawal LTP can be prevented by tapered withdrawal and shares pharmacology and signal transduction pathways with OIH. These findings provide a previously unrecognized target to selectively combat pro-nociceptive effects of opioids without compromising opioid analgesia.

Access to opioids: a global pain management crisis.

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Buitrago, Rosa

2013-03-01

The lack of availability of opioids in many countries has created a pain management crisis. Because the Single Convention on Narcotic Drugs requires governments to report annual opioid statistics, there is a need for methods to calculate individual nations' opioid needs. Ways to address this need are discussed.

The opioid ketobemidone has a NMDA blocking effect

DEFF Research Database (Denmark)

Andersen, S; Dickenson, A H; Kohn, M

1996-01-01

There are clinical observations that neurogenic pain can respond well to the opioid ketobemidone, in contrast to pethidine and morphine. This has led us to the hypothesis that the analgesic effect of ketobemidone in neurogenic pain may be due to both opioid as well as additional non-opioid effect...

Therapeutic targeting strategies using endogenous cells and proteins.

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Parayath, Neha N; Amiji, Mansoor M

2017-07-28

Targeted drug delivery has become extremely important in enhancing efficacy and reducing the toxicity of therapeutics in the treatment of various disease conditions. Current approaches include passive targeting, which relies on naturally occurring differences between healthy and diseased tissues, and active targeting, which utilizes various ligands that can recognize targets expressed preferentially at the diseased site. Clinical translation of these mechanisms faces many challenges including the immunogenic and toxic effects of these non-natural systems. Thus, use of endogenous targeting systems is increasingly gaining momentum. This review is focused on strategies for employing endogenous moieties, which could serve as safe and efficient carriers for targeted drug delivery. The first part of the review involves cells and cellular components as endogenous carriers for therapeutics in multiple disease states, while the second part discusses the use of endogenous plasma components as endogenous carriers. Further understanding of the biological tropism with cells and proteins and the newer generation of delivery strategies that exploits these endogenous approaches promises to provide better solutions for site-specific delivery and could further facilitate clinical translations. Copyright © 2017 Elsevier B.V. All rights reserved.

Computational opioid prescribing: a novel application of clinical pharmacokinetics.

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Linares, Oscar A; Linares, Annemarie L

2011-01-01

We implemented a pharmacokinetics-based mathematical modeling technique using algebra to assist prescribers with point-of-care opioid dosing. We call this technique computational opioid prescribing (COP). Because population pharmacokinetic parameter values are needed to estimate drug dosing regimen designs for individual patients using COP, and those values are not readily available to prescribers because they exist scattered in the vast pharmacology literature, we estimated the population pharmacokinetic parameter values for 12 commonly prescribed opioids from various sources using the bootstrap resampling technique. Our results show that opioid dosing regimen design, evaluation, and modification is feasible using COP. We conclude that COP is a new technique for the quantitative assessment of opioid dosing regimen design evaluation and adjustment, which may help prescribers to manage acute and chronic pain at the point-of-care. Potential benefits include opioid dose optimization and minimization of adverse opioid drug events, leading to potential improvement in patient treatment outcomes and safety.

A practical and ethical solution to the opioid scheduling conundrum

Directory of Open Access Journals (Sweden)

Schatman ME

2013-12-01

Full Text Available Michael E Schatman,1 Beth D Darnall21Foundation for Ethics in Pain Care, Bellevue, WA, USA; 2Stanford University School of Medicine, Division of Pain Medicine, Palo Alto, CA, USAAbuse-deterrent formulations (ADFs of opioids have been in existence since the 1970s,1 with abuse-deterrent mechanisms including physical barriers (eg, barriers to crushing, chemical additives such as opioid antagonists or irritants, and prodrugs that require conversion of the medication into their active forms in the gastrointestinal tract.2 A recent systematic review and meta-analysis3 found no difference between ADFs and non-ADFs in terms of efficacy or adverse events including nausea, vomiting, dizziness, headache, somnolence, constipation, and pruritus. Notably, the efficacy of ADFs in preventing abuse is not yet established, and therefore the authors could only comment on their "potential … to deter or resist some of the common forms of tampering associated with opioid misuse and abuse". While Turk et al2 have elucidated the complexity of producing high-quality research on the efficacy of ADFs to reduce opioid abuse, recent data are encouraging. For example, since Purdue Pharma’s (Stamford, CT, USA voluntary reformulation of OxyContin® to an ADF in 2010, abuse of the medication has decreased significantly.4–6 As a specific example, National Poison Data System statistics indicated a 36% reduction in abuse exposure for OxyContin following ADF reformulation. Meanwhile, researchers for Purdue Pharma found an increase in abuse exposure for other single-entity oxycodone products and a 42% increase in abuse exposure for heroin during the same time frame.7 Although OxyContin has been the most investigated abuse deterrent formulation, ADFs of other opioids have demonstrated promise in preliminary investigations.8,9

Swim stress reduces chronic pain in mice through an opioid mechanism.

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Carmody, J; Cooper, K

1987-03-09

Chronic nociception has been studied in male mice by means of the formalin test in which forelimb motor behaviour is scored after subcutaneous formalin injection. The rating remained above 2.0 for 30 min after the injection (scale range 0-3). The magnitude of the nociception has been compared with that reported in other animal types. Mice are more sensitive than rats, cats and monkeys. The stress of a swim of 3 min has been found to reduce nociception by up to 25%. This analgesia is wholly opioid in nature, being abolished by a moderate dose of naloxone (1 mg/kg).

Treating opioid dependence. Growing implications for primary care.

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Krantz, Mori J; Mehler, Philip S

2004-02-09

Almost 3 million Americans have abused heroin. The most effective treatment for this concerning epidemic is opioid replacement therapy. Although, from a historical perspective, acceptance of this therapy has been slow, growing evidence supports its efficacy. There are 3 approved medications for opioid maintenance therapy: methadone hydrochloride, levomethadyl acetate, and buprenorphine hydrochloride. Each has unique characteristics that determine its suitability for an individual patient. Cardiac arrhythmias have been reported with methadone and levomethadyl, but not with buprenorphine. Due to concerns about cardiac risk, levomethadyl use has declined and the product may ultimately be discontinued. These recent safety concerns, specifics about opioid detoxification and maintenance, and new federal initiatives were studied. Opioid detoxification has a role in both preventing acute withdrawal and maintaining long-term abstinence. Although only a minority of eligible patients are engaged in treatment, opioid maintenance therapy appears to offer the greatest public health benefits. There is growing interest in expanding treatment into primary care, allowing opioid addiction to be managed like other chronic illnesses. This model has gained wide acceptance in Europe and is now being implemented in the United States. The recent Drug Addiction Treatment Act enables qualified physicians to treat opioid-dependent patients with buprenorphine in an office-based setting. Mainstreaming opioid addiction treatment has many advantages; its success will depend on resolution of ethical and delivery system issues as well as improved and expanded training of physicians in addiction medicine.

Chronic suppression of μ-opioid receptor signaling in the nucleus accumbens attenuates development of diet-induced obesity in rats.

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Lenard, N R; Zheng, H; Berthoud, H-R

2010-06-01

To test the hypothesis that micro-opioid receptor signaling in the nucleus accumbens contributes to hedonic (over)eating and obesity. To investigate the effects of chronic micro-opioid antagonism in the nucleus accumbens core or shell on intake of a palatable diet, and the development of diet-induced obesity in rats. Chronic blockade of micro-opioid receptor signaling in the nucleus accumbens core or shell was achieved by means of repeated injections (every 4-5 days) of the irreversible receptor antagonist beta-funaltrexamine (BFNA) over 3-5 weeks. The diet consisted of either a choice of high-fat chow, chocolate-flavored Ensure and regular chow (each nutritionally complete) or regular chow only. Intake of each food item, body weight and body fat mass were monitored throughout the study. The BFNA injections aimed at either the core or shell of the nucleus accumbens resulted in significantly attenuated intake of palatable diet, body weight gain and fat accretion, compared with vehicle control injections. The injection of BFNA in the core did not significantly change these parameters in chow-fed control rats. The injection of BFNA in the core and shell differentially affected intake of the two palatable food items: in the core, BFNA significantly reduced the intake of high-fat, but not of Ensure, whereas in the shell, it significantly reduced the intake of Ensure, but not of high-fat, compared with vehicle treatment. Endogenous micro-opioid receptor signaling in the nucleus accumbens core and shell is necessary for palatable diet-induced hyperphagia and obesity to fully develop in rats. Sweet and non-sweet fatty foods may be differentially processed in subcomponents of the ventral striatum.

Healthy Adult Male Facial Skin Surface Lipid Pheromone p.o. to Treat Opioid Addiction

Science.gov (United States)

2018-03-20

Opioid Addiction; Opioid Abuse, Continuous Use; Opioid Use; Opioid-Related Disorders; Paternal Pheromone Deficiency; Opioid Dependence; Opioid Abuse; Opioid-use Disorder; Opioid Intoxication; Opioid Abuse, Episodic

Different amounts of ejaculatory activity, a natural rewarding behavior, induce differential mu and delta opioid receptor internalization in the rat's ventral tegmental area.

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Garduño-Gutiérrez, René; León-Olea, Martha; Rodríguez-Manzo, Gabriela

2013-12-06

Opioid receptors internalize upon specific agonist stimulation. The in vivo significance of receptor internalization is not well established, partly due to the limited in vivo models used to study this phenomenon. Ejaculation promotes endogenous opioid release which activates opioid receptors at the brain, including the mesolimbic system and medial preoptic area. The objective of the present work was to analyze if there was a correlation between the degree of in vivo mu (MOR) and delta opioid receptor (DOR) internalization in the ventral tegmental area and the execution of different amounts of ejaculatory behavior of male rats. To this aim, we analyzed the brains of rats that ejaculated once or six successive times and of sexually exhausted rats with an established sexual inhibition, using immunofluorescence and confocal microscopy. Results showed that MOR and DOR internalization increased as a consequence of ejaculation. There was a relationship between the amount of sexual activity executed and the degree of internalization for MOR, but not for DOR. MOR internalization was larger in rats that ejaculated repeatedly than in animals ejaculating only once. Significant DOR internalization was found only in animals ejaculating once. Changes in MOR, DOR and beta arrestin2 detection, associated to sexual activity, were also found. It is suggested that copulation to satiety might be useful as a model system to study the biological significance of receptor internalization. © 2013 Published by Elsevier B.V.

Pain in the management of opioid use disorder

Directory of Open Access Journals (Sweden)

Sirohi S

2016-11-01

Full Text Available Sunil Sirohi,1 Amit K Tiwari21Laboratory of Endocrine and Neuropsychiatric Disorders, Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA, 2Department of Pharmacology and Experimental Therapeutics, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH, USAOpioids remain the drug of choice for the clinical management of moderate to severe pain. However, in addition to their most effective analgesic actions, opioids also produce a sense of well-being and euphoria, which may trigger significant concerns associated with their use.1 In fact, there has been an alarming increase in prescription opioid use, abuse and illicit use; and according to the National Center for Health Statistics, the total number of deaths related to opioid overdose has more than tripled from 2011 to 2014.2–5 Although representing 5.0 % of the global population, studies report that Americans consume 80% of the global opioid supply,3 and the United States is experiencing an opioid abuse epidemic.6 Considering this unprecedented rise in opioid consumption, the United States Centers for Disease Control and Prevention has listed prescription opioid overdose among one of the 10 most important public health problems in all the 50 states.7

Opioid Addiction

Science.gov (United States)

... breathing rate nausea, vomiting constipation physical agitation poor decision making abandoning responsibilities slurred speech sleeping more or less than normal mood swings euphoria (feeling high) irritability depression lowered motivation anxiety attacks. Symptoms of opioid overdose An overdose ...

Medication-Assisted Treatment For Opioid Addiction in Opioid Treatment Programs. Treatment Improvement Protocol (TIP) Series 43

Science.gov (United States)

Tinkler, Emily; Vallejos Bartlett, Catalina; Brooks, Margaret; Gilbert, Johnatnan Max; Henderson, Randi; Shuman, Deborah, J.

2005-01-01

TIP 43 provides best-practice guidelines for medication-assisted treatment of opioid addiction in opioid treatment programs (OTPs). The primary intended audience for this volume is substance abuse treatment providers and administrators who work in OTPs. Recommendations in the TIP are based on both an analysis of current research and determinations…

The challenge of perioperative pain management in opioid-tolerant patients

Science.gov (United States)

Coluzzi, Flaminia; Bifulco, Francesca; Cuomo, Arturo; Dauri, Mario; Leonardi, Claudio; Melotti, Rita Maria; Natoli, Silvia; Romualdi, Patrizia; Savoia, Gennaro; Corcione, Antonio

2017-01-01

The increasing number of opioid users among chronic pain patients, and opioid abusers among the general population, makes perioperative pain management challenging for health care professionals. Anesthesiologists, surgeons, and nurses should be familiar with some pharmacological phenomena which are typical of opioid users and abusers, such as tolerance, physical dependence, hyperalgesia, and addiction. Inadequate pain management is very common in these patients, due to common prejudices and fears. The target of preoperative evaluation is to identify comorbidities and risk factors and recognize signs and symptoms of opioid abuse and opioid withdrawal. Clinicians are encouraged to plan perioperative pain medications and to refer these patients to psychiatrists and addiction specialists for their evaluation. The aim of this review was to give practical suggestions for perioperative management of surgical opioid-tolerant patients, together with schemes of opioid conversion for chronic pain patients assuming oral or transdermal opioids, and patients under maintenance programs with methadone, buprenorphine, or naltrexone. PMID:28919771

Silver resistance in Gram-negative bacteria: a dissection of endogenous and exogenous mechanisms.

Science.gov (United States)

Randall, Christopher P; Gupta, Arya; Jackson, Nicole; Busse, David; O'Neill, Alex J

2015-04-01

To gain a more detailed understanding of endogenous (mutational) and exogenous (horizontally acquired) resistance to silver in Gram-negative pathogens, with an emphasis on clarifying the genetic bases for resistance. A suite of microbiological and molecular genetic techniques was employed to select and characterize endogenous and exogenous silver resistance in several Gram-negative species. In Escherichia coli, endogenous resistance arose after 6 days of exposure to silver, a consequence of two point mutations that were both necessary and sufficient for the phenotype. These mutations, in ompR and cusS, respectively conferred loss of the OmpC/F porins and derepression of the CusCFBA efflux transporter, both phenotypic changes previously linked to reduced intracellular accumulation of silver. Exogenous resistance involved derepression of the SilCFBA efflux transporter as a consequence of mutation in silS, but was additionally contingent on expression of the periplasmic silver-sequestration protein SilE. Silver resistance could be selected at high frequency (>10(-9)) from Enterobacteriaceae lacking OmpC/F porins or harbouring the sil operon and both endogenous and exogenous resistance were associated with modest fitness costs in vitro. Both endogenous and exogenous silver resistance are dependent on the derepressed expression of closely related efflux transporters and are therefore mechanistically similar phenotypes. The ease with which silver resistance can become selected in some bacterial pathogens in vitro suggests that there would be benefit in improved surveillance for silver-resistant isolates in the clinic, along with greater control over use of silver-containing products, in order to best preserve the clinical utility of silver. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

Environmental toxin acrolein alters levels of endogenous lipids, including TRP agonists: A potential mechanism for headache driven by TRPA1 activation

Directory of Open Access Journals (Sweden)

Emma Leishman

2017-01-01

Full Text Available Exposure to airborne toxins can trigger headaches, but the mechanisms are not well understood. Some environmental toxins, such as acrolein, activate transient receptor potential ankyrin 1 (TRPA1, a receptor involved in pain sensation that is highly expressed in the trigeminovascular system. It has been shown in rat models that repeated exposure to acrolein induces trigeminovascular sensitization to both TRPA1 and TRP vanilloid 1 (TRPV1 agonists, a phenomenon linked to headache. In this study, we test the hypothesis that the sensitization of trigeminovascular responses in rats after acrolein exposure via inhalation is associated with changes in levels of endogenous lipids, including TRPV1 agonists, in the trigeminal ganglia, trigeminal nucleus, and cerebellum. Lipidomics analysis of 80 lipids was performed on each tissue after acute acrolein, chronic acrolein, or room air control. Both acute and chronic acrolein exposure drove widespread alterations in lipid levels. After chronic acrolein exposure, levels of all 6 N-acyl ethanolamines in the screening library, including the endogenous cannabinoid and TRPV1 agonist, N-arachidonoyl ethanolamine, were elevated in trigeminal tissue and in the cerebellum. This increase in TRPV1 ligands by acrolein exposure may indicate further downstream signaling, in that we also show here that a combination of these TRPV1 endogenous agonists increases the potency of the individual ligands in TRPV1-HEK cells. In addition to these TRPV1 agonists, 3 TRPV3 antagonists, 4 TRPV4 agonists, and 25 orphan lipids were up and down regulated after acrolein exposure. These data support the hypothesis that lipid signaling may represent a mechanism by which repeated exposure to the TRPA1 agonist and environmental toxin, acrolein, drives trigeminovascular sensitization. Keywords: Lipidomics, Endogenous cannabinoid, TRPA1, TRPV1, Lipoamine, Acrolein, Migraine

Reviewing opioid use, monitoring, and legislature: Nursing perspectives

Directory of Open Access Journals (Sweden)

Deniece A. Jukiewicz

2017-10-01

Full Text Available The phenomena of prescription opioid misuse and abuse have a complicated history of contributing factors including policies, practices, and prescribing leading to contemporary phenomena. Some factors implicated in the opioid drug abuse problem include inefficient prescribing and improper use, lack of knowledge related to interpretation and assessment of pain levels, and decreased oversight and regulation from government and policy agents. Nurses, often frontline providers, need to be knowledgeable and embrace the guidelines, and necessary implications associated with both prescribing and administration of opioids. Additionally, all providers including physicians, physician assistants, nurse practitioners, and bedside nurses must have a firm understanding of the improper use and abuse of opioids. The examination and review of opioid policies at the state and federal level has revealed inconsistency with regulations, policies, and guidelines that have lead to the current situation. The use of an interdisciplinary team with nurses and various other practitioners is a good strategy to help reduce this problem. Keywords: Abuse, Administration, Legislature, Nursing, Opioid, Overdose, Policy, Prescribing

Preventing Opioid Use Disorders among Fishing Industry Workers

Directory of Open Access Journals (Sweden)

Angela Wangari Walter

2018-03-01

Full Text Available Fishing industry workers are at high risk for work-related musculoskeletal disorders (MSDs and injuries. Prescription opioids used to treat pain injuries may put these workers at increased risk for developing substance disorders. Using a Community-Based Participatory Research approach, formative research was conducted to inform the eventual development of relevant interventions to prevent and reduce opioid use disorders among fishing industry workers. Qualitative interviews (n = 21 were conducted to assess: knowledge and attitudes about opioid use disorders; features of fishing work that might affect use and/or access to treatment; and community and organizational capacity for prevention and treatment. Participants reported numerous pathways connecting commercial fishing with opioid use. The combination of high stress and physically tasking job duties requires comprehensive workplace interventions to prevent chronic pain and MSDs, in addition to tailored and culturally responsive treatment options to address opioid use disorders in this population. Public health programs must integrate workplace health and safety protection along with evidence-based primary, secondary, and tertiary interventions in order to address opioid use disorders, particularly among workers in strenuous jobs.

Endogenous Cartilage Repair by Recruitment of Stem Cells.

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Im, Gun-Il

2016-04-01

Articular cartilage has a very limited capacity for repair after injury. The adult body has a pool of stem cells that are mobilized during injury or disease. These cells exist inside niches in bone marrow, muscle, adipose tissue, synovium, and other connective tissues. A method that mobilizes this endogenous pool of stem cells will provide a less costly and less invasive alternative if these cells successfully regenerate defective cartilage. Traditional microfracture procedures employ the concept of bone marrow stimulation to regenerate cartilage. However, the regenerated tissue usually is fibrous cartilage, which has very poor mechanical properties compared to those of normal hyaline cartilage. A method that directs the migration of a large number of autologous mesenchymal stem cells toward injury sites, retains these cells around the defects, and induces chondrogenic differentiation that would enhance success of endogenous cartilage repair. This review briefly summarizes chemokines and growth factors that induce recruitment, proliferation, and differentiation of endogenous progenitor cells, endogenous cell sources for regenerating cartilage, scaffolds for delivery of bioactive factors, and bioadhesive materials that are necessary to bring about endogenous cartilage repair.

Knowledge of Opioid Overdose and Attitudes to Supply of Take-Home Naloxone Among People with Chronic Noncancer Pain Prescribed Opioids.

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Nielsen, Suzanne; Peacock, Amy; Lintzeris, Nicholas; Bruno, Raimondo; Larance, Briony; Degenhardt, Louisa

2018-03-01

Take-home naloxone (THN) is recommended in response to pharmaceutical opioid-related mortality. Some health professionals are reluctant to discuss THN for fear of causing offense. The aims of this study were to assess knowledge of opioid overdose and attitudes toward THN for opioid overdose reversal in people with chronic noncancer pain (CNCP). Prospective cohort study. Australia, September to October 2015. A subset of participants (N = 208) from a cohort of people prescribed restricted opioids for CNCP. Questions added in the two-year telephone interviews examined knowledge of overdose symptoms and attitudes toward community supply of naloxone. Associations with overdose risk factors and naloxone supply eligibility criteria with attitudes toward naloxone were explored. Fourteen percent reported ever experiencing opioid overdose symptoms. Participants correctly identified fewer than half of the overdose signs and symptoms. After receiving information on naloxone, most participants (60%), thought it was a "good" or "very good" idea. Few participants reported that they would be "a little" (N = 21, 10%) or "very" offended (N = 7, 3%) if their opioid prescriber offered them naloxone. Positive attitudes toward THN were associated with male gender (odds ratio [OR] = 1.96, 95% confidence interval [CI] = 1.09-3.50), past year cannabis use (OR = 2.52, 95% CI = 1.03-6.16), and past year nicotine use (OR = 2.11, 95% CI = 1.14-3.91). Most participants had positive attitudes toward THN but low knowledge about opioid overdose symptoms. Strategies for educating patients and their caregivers on opioid toxicity are needed. THN may be best targeted toward those with risk factors in terms of overdose prevention and acceptability.

Atypical Opioid Mechanisms of Control of Injury-Induced Cutaneous Pain by Delta Receptors

Science.gov (United States)

2017-07-01

i.e. mu opioid receptor agonists such as morphine) cause unacceptable side effects including addiction . Injuries suffered most frequently by active...slides. The slides were then processed for fluorescent in situ hybridization with RNAscope technology (ACD Biosystems) to detect Oprd1 mRNA, as...tissue as done in Bardoni et al., Neuron, 2014) and negative controls (no probe). Controls indicated that the technology and reagents work as expected

Managing Opioid Addiction Risk in Plastic Surgery during the Perioperative Period.

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Demsey, Daniel; Carr, Nicholas J; Clarke, Hance; Vipler, Sharon

2017-10-01

Opioid addiction is a public health crisis that affects all areas of medicine. Large numbers of the population across all racial and economic demographics misuse prescription opioids and use illicit opioids. The current understanding is that opioid misuse is a disease that requires treatment, and is not an issue of choice or character. Use of opioid medication is a necessary part of postoperative analgesia, but many physicians are unsure of how to do this safely given the risk of patients developing an opioid misuse disorder. This review gives an update of the current state of the opioid crisis, explains how current surgeons' prescribing practices are contributing to it, and gives recommendations on how to use opioid medication safely in the perioperative period.

m-Trifluoromethyl-diphenyl diselenide promotes resilience to social avoidance induced by social defeat stress in mice: Contribution of opioid receptors and MAPKs.

Science.gov (United States)

Rosa, Suzan Gonçalves; Pesarico, Ana Paula; Nogueira, Cristina Wayne

2018-03-02

Depressive symptoms precipitated by stress are prevalent in population. In experimental models of social stress, endogenous opioids mediate different aspects of defensive and submissive behaviors. The present study investigated the opioid receptors, mitogen-activated protein kinase (MAPKs) and protein kinase B (Akt) contribution to m-trifluoromethyl-diphenyl diselenide [(m-CF 3 -PhSe) 2 ] effects on social avoidance induced by social defeat stress (SDS). Adult Swiss mice were subjected to SDS and treated with (m-CF 3 -PhSe) 2 (5 to 25mg/kg) for 7days. After that, the mice performed locomotor and social avoidance tests. The opioid receptors, MAPKs and Akt protein contents were determined in the prefrontal cortical samples of mice. Firstly, the mice were segregated in susceptible or resilient subpopulation based on their social avoidance induced by stress. (m-CF 3 -PhSe) 2 (25mg/kg) was effective against the stress-induced social avoidance and improved social interaction behavior in mice. SDS increased the μ and κ protein contents but reduced those of δ opioid receptors in susceptible mice. Resilient and (m-CF 3 -PhSe) 2 -treated mice had no alteration in the levels of opioid receptors. Moreover, (m-CF 3 -PhSe) 2 was effective against the increase of c-Jun N-terminal kinase (JNK) and the decrease of Akt phosphorylation protein contents induced by SDS in susceptible mice. The protein content of extracellular signal-regulated kinase (ERK) phosphorylation was reduced in both susceptible and resilient mice, whereas p38 mitogen-activated protein kinase (p38 MAPK) phosphorylation was increased only in resilient mice. (m-CF 3 -PhSe) 2 was partially effective against the pERK decrease and ineffective against the increase in p38 MAPK phosphorylation in mice subjected to SDS. These results suggest that the modulation of protein contents of opioid receptors, JNK and Akt phosphorylation is associated with resilience to SDS promoted by (m-CF 3 -PhSe) 2 in mice. Copyright �

Curcumin Attenuates Opioid Tolerance and Dependence by Inhibiting Ca2+/Calmodulin-Dependent Protein Kinase II α Activity

Science.gov (United States)

Hu, Xiaoyu; Huang, Fang; Szymusiak, Magdalena

2015-01-01

Chronic use of opioid analgesics has been hindered by the development of opioid addiction and tolerance. We have reported that curcumin, a natural flavonoid from the rhizome of Curcuma longa, attenuated opioid tolerance, although the underlying mechanism remains unclear. In this study, we tested the hypothesis that curcumin may inhibit Ca2+/calmodulin-dependent protein kinase II α (CaMKIIα), a protein kinase that has been previously proposed to be critical for opioid tolerance and dependence. In this study, we used state-of-the-art polymeric formulation technology to produce poly(lactic-co-glycolic acid) (PLGA)-curcumin nanoparticles (nanocurcumin) to overcome the drug’s poor solubility and bioavailability, which has made it extremely difficult for studying in vivo pharmacological actions of curcumin. We found that PLGA-curcumin nanoparticles reduced the dose requirement by 11- to 33-fold. Pretreatment with PLGA-curcumin (by mouth) prevented the development of opioid tolerance and dependence in a dose-dependent manner, with ED50 values of 3.9 and 3.2 mg/kg, respectively. PLGA-curcumin dose-dependently attenuated already-established opioid tolerance (ED50 = 12.6 mg/kg p.o.) and dependence (ED50 = 3.1 mg/kg p.o.). Curcumin or PLGA-curcumin did not produce antinociception by itself or affect morphine (1–10 mg/kg) antinociception. Moreover, we found that the behavioral effects of curcumin on opioid tolerance and dependence correlated with its inhibition of morphine-induced CaMKIIα activation in the brain. These results suggest that curcumin may attenuate opioid tolerance and dependence by suppressing CaMKIIα activity. PMID:25515789

[Mechanisms of endogenous drug resistance acquisition by spontaneous chromosomal gene mutation].

Science.gov (United States)

Fukuda, H; Hiramatsu, K

1997-05-01

Endogenous resistance in bacteria is caused by a change or loss of function and generally genetically recessive. However, this type of resistance acquisition are now prevalent in clinical setting. Chromosomal genes that afford endogenous resistance are the genes correlated with the target of the drug, the drug inactivating enzymes, and permeability of the molecules including the antibacterial agents. Endogenous alteration of the drug target are mediated by the spontaneous mutation of their structural gene. This mutation provides much lower affinity of the drugs for the target. Gene expression of the inactivating enzymes, such as class C beta-lactamase, is generally regulated by regulatory genes. Spontaneous mutations in the regulatory genes cause constitutive enzyme production and provides the resistant to the agent which is usually stable for such enzymes. Spontaneous mutation in the structural gene gives the enzyme extra-spectrum substrate specificity, like ESBL (Extra-Spectrum-beta-Lactamase). Expression of structural genes encoding the permeability systems are also regulated by some regulatory genes. The spontaneous mutation of the regulatory genes reduce an amount of porin protein. This mutation causes much lower influx of the drug in the cell. Spontaneous mutation in promoter region of the structural gene of efflux protein was observed. This mutation raised the gene transcription and overproduced efflux protein. This protein progresses the drug efflux from the cell.

Nurses and opioids: results of a bi-national survey on mental models regarding opioid administration in hospitals

Directory of Open Access Journals (Sweden)

Guest C

2017-03-01

Full Text Available Charlotte Guest,1 Fabian Sobotka,2 Athina Karavasopoulou,3 Stephen Ward,3 Carsten Bantel4,5 1Pain Medicine, Chelsea and Westminster Hospital NHS Foundation Trust, London, UK; 2Division of Epidemiology and Biometry, Department of Health Services Research, Faculty 6, Medicine and Health Sciences, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany; 3Pain Service, Barts Health, St Bartholomew’s Hospital, London, UK; 4Department of Anaesthesiology, Intensive Care, Emergency Medicine and Pain Therapy, Oldenburg University, Klinikum Oldenburg Campus, Oldenburg, Germany; 5Department of Surgery and Cancer, Anaesthetics Section, Imperial College London, Chelsea and Westminster Hospital Campus, London, UK Objective: Pain remains insufficiently treated in hospitals. Increasing evidence suggests human factors contribute to this, due to nurses failing to administer opioids. This behavior might be the consequence of nurses’ mental models about opioids. As personal experience and conceptions shape these models, the aim of this prospective survey was to identify model-influencing factors. Material and methods: A questionnaire was developed comprising of 14 statements concerning ideations about opioids and seven questions concerning demographics, indicators of adult learning, and strength of religious beliefs. Latent variables that may underlie nurses’ mental models were identified using undirected graphical dependence models. Representative items of latent variables were employed for ordinal regression analysis. Questionnaires were distributed to 1,379 nurses in two London, UK, hospitals (n=580 and one German (n=799 hospital between September 2014 and February 2015. Results: A total of 511 (37.1% questionnaires were returned. Mean (standard deviation age of participants were 37 (11 years; 83.5% participants were female; 45.2% worked in critical care; and 51.5% had more than 10 years experience. Of the nurses, 84% were not scared of opioids, 87

Are endogenous feline leukemia viruses really endogenous?

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Stewart, H; Jarrett, O; Hosie, M J; Willett, B J

2011-10-15

Full length endogenous feline leukemia virus (FeLV) proviruses exist within the genomes of many breeds of domestic cat raising the possibility that they may also exist in a transmissible exogenous form. Such viruses would share receptor usage with the recombinant FeLV-B subgroup, a viral subgroup that arises in vivo by recombination between exogenous subgroup A virus (FeLV-A) and endogenous FeLV. Accordingly, all isolates of FeLV-B made to date have contained a "helper" FeLV-A, consistent with their recombinatorial origin. In order to assess whether endogenous viruses are transmitted between cats, we examined primary isolates of FeLV for which the viral subgroup had been determined for the presence of a subgroup B virus that lacked an FeLV-A. Here we describe the identification of two primary field isolates of FeLV (2518 and 4314) that appeared to contain subgroup B virus only by classical interference assays, raising the possibility of between-host transmission of endogenous FeLV. Sequencing of the env gene and U3 region of the 3' long terminal repeat (LTR) confirmed that both viral genomes contained endogenous viral env genes. However the viral 3' LTRs appeared exogenous in origin with a putative 3' recombination breakpoint residing at the 3' end of the env gene. Further, the FeLV-2518 virions also co-packaged a truncated FeLV-A genome containing a defective env gene, termed FeLV-2518(A) whilst no helper subgroup A viral genome was detected in virions of FeLV-4314. The acquisition of an exogenous LTR by the endogenous FeLV in 4314 may have allowed a recombinant FeLV variant to outgrow an exogenous FeLV-A virus that was presumably present during first infection. Given time, a similar evolution may also occur within the 2518 isolate. The data suggest that endogenous FeLVs may be mobilised by acquisition of exogenous LTRs yielding novel viruses that type biologically as FeLV-B. Copyright © 2011 Elsevier B.V. All rights reserved.

Endogenous Control Mechanisms of FAK and PYK2 and Their Relevance to Cancer Development and Therapy

KAUST Repository

Naser, Rayan Mohammad Mahmoud; Aldehaiman, Abdullah; Diaz Galicia, Miriam Escarlet; Arold, Stefan T.

2018-01-01

Focal adhesion kinase (FAK) and its close paralogue, proline-rich tyrosine kinase 2 (PYK2), are key regulators of aggressive spreading and metastasis of cancer cells. While targeted small-molecule inhibitors of FAK and PYK2 are showing promising antitumor activity, their clinical long-term efficacy may be undermined by the strong capacity of cancer cells to evade anti-kinase drugs. In healthy cells, the expression and/or function of FAK and PYK2 is tightly controlled through modulation of gene expression, competing alternatively spliced forms, non-coding RNAs, and proteins that directly or indirectly affect kinase activation or protein stability. The molecular factors involved are frequently deregulated in cancer cells. Here, we review the endogenous mechanisms controlling FAK and PYK2, and discuss how these mechanisms could inspire or improve anticancer therapies.

Endogenous Control Mechanisms of FAK and PYK2 and Their Relevance to Cancer Development and Therapy

KAUST Repository

Naser, Rayan Mohammad Mahmoud

2018-05-10

Focal adhesion kinase (FAK) and its close paralogue, proline-rich tyrosine kinase 2 (PYK2), are key regulators of aggressive spreading and metastasis of cancer cells. While targeted small-molecule inhibitors of FAK and PYK2 are showing promising antitumor activity, their clinical long-term efficacy may be undermined by the strong capacity of cancer cells to evade anti-kinase drugs. In healthy cells, the expression and/or function of FAK and PYK2 is tightly controlled through modulation of gene expression, competing alternatively spliced forms, non-coding RNAs, and proteins that directly or indirectly affect kinase activation or protein stability. The molecular factors involved are frequently deregulated in cancer cells. Here, we review the endogenous mechanisms controlling FAK and PYK2, and discuss how these mechanisms could inspire or improve anticancer therapies.

The evolution of chronic opioid therapy and recognizing addiction.

Science.gov (United States)

Daum, Akiva M; Berkowitz, Oren; Renner, John A

2015-05-01

Chronic pain is one of the most common complaints in the United States. Opioids have become a frequently prescribed treatment for patients with chronic nonmalignant pain. Concurrently, opioid use disorders have risen to epidemic levels. Studies investigating iatrogenic opioid addiction have been of limited quality. Aberrant drug-related behaviors may be warning signs of impending addiction. Proper screening and close monitoring are essential for managing patients on opioids for chronic nonmalignant pain.

Effectiveness of ketamine as an adjuvant to opioid-based therapy in decreasing pain associated with opioid tolerance in adults undergoing orthopedic surgery: a systematic review protocol.

Science.gov (United States)

Bennett, Marsha; Bonanno, Laura; Kuhn, William

2016-10-01

The objective of this systematic review is to examine the best available evidence on the clinical effectiveness of ketamine as an adjuvant to opioid-based therapy versus opioid-based therapy alone in decreasing perioperative pain associated with opioid tolerance in adult patients, aged 18-70 years, undergoing orthopedic surgical procedures.The following question guides the systematic review: does the administration of ketamine as an adjuvant to opioid-based therapy, compared to opioid-based therapy alone, improve perioperative pain relief in opioid-tolerant adult patients undergoing orthopedic surgical procedures?

Chronic Pain, Chronic Opioid Addiction: a Complex Nexus.

Science.gov (United States)

Salsitz, Edwin A

2016-03-01

Over the past two decades, there has been a significant increase in the prescribing of opioids, with associated increases in opioid addiction and overdose deaths. This article reviews the evidence for the effectiveness and risk of developing an opioid use disorder (OUD) in those patients treated with chronic opioid therapy (COT) for chronic non-cancer pain (CNCP). Rates of development of OUD range from 0-50 %, and aberrant drug related behaviors (ADRBs) are reported to be 20 %. Health care providers must properly assess, screen, and carefully monitor patients on COT utilizing evidence-based tools.

Opioid prescriptions before and after high-energy trauma

DEFF Research Database (Denmark)

Zwisler, Stine T; Hallas, Jesper; Larsen, Morten S

2015-01-01

OBJECTIVE: To describe the legal use of opioids in adult patients before and after high-energy trauma. DESIGN: The study was a retrospective database study. SETTING: Clinical care outside hospitals. PATIENTS: All patients who suffered high-energy trauma and were brought to Odense University...... Hospital (OUH), Denmark, in 2007 and 2008 were retrieved from the trauma database. These patients were linked with data on opioid use from the regional prescription database. In all, 938 patients were included. MAIN OUTCOME MEASURE: Redemption of opioid prescription during the 6 months prior...... to a multitrauma or redemption of two or more prescriptions for opioids 6 months or later after a multitrauma. RESULTS: Of the 938 patients brought to OUH with severe trauma within the study period, 61 patients died (7 percent) and six of these had redeemed prescriptions for opioids within 6 months prior...

Healthcare resource use and costs of opioid-induced constipation among non-cancer and cancer patients on opioid therapy

DEFF Research Database (Denmark)

Søndergaard, Jens; Christensen, Helene Nordahl; Ibsen, Rikke

2017-01-01

-based cohort study including patients ≥18 years of age initiating ≥4 weeks opioid therapy (1998–2012) in Denmark. A measure of OIC was constructed based on data from Danish national health registries, and defined as ≥1 diagnosis of constipation, diverticulitis, mega colon, ileus/subileus, abdominal pain....../acute abdomen or haemorrhoids and/or ≥2 subsequent prescription issues of laxatives. Total healthcare resource utilization and costs (including pharmacy dispense, inpatient-, outpatient-, emergency room- and primary care) were estimated according to OIC status, opioid treatment dosage and length, gender, age...... characteristics of non-cancer OIC patients showed a higher frequency of strong opioid treatment (69% versus 41%), long-term opioid treatment (1189 days versus 584 days), advanced age (73 years versus 61 years), and cardiovascular disease (31% versus 19%) compared to those without OIC (P 

Endogenous antipyretics.

Science.gov (United States)

Roth, Joachim

2006-09-01

The febrile increase of body temperature is regarded as a component of the complex host response to infection or inflammation that accompanies the activation of the immune system. Late phases of fever appear mediated by pro-inflammatory cytokines called endogenous pyrogens. The rise of body temperature is beneficial because it accelerates several components of the activated immune system. To prevent an excessive and dangerous rise of body temperature the febrile response is controlled, limited in strength and duration, and sometimes even prevented by the actions of endogenous antipyretic substances liberated systemically or within the brain during fever. In most cases the antipyretic effects are achieved by an inhibitory influence on the formation or action of endogenous pyrogens, or by effects on neuronal thermoregulatory circuits that are activated during fever. Endogenous antipyretic substances include steroid hormones, neuropeptides, cytokines and other molecules. It is the purpose of this review to consider the current state in the research on endogenous antipyretic systems.

Monocular channels have a functional role in endogenous orienting.

Science.gov (United States)

Saban, William; Sekely, Liora; Klein, Raymond M; Gabay, Shai

2018-03-01

The literature has long emphasized the role of higher cortical structures in endogenous orienting. Based on evolutionary explanation and previous data, we explored the possibility that lower monocular channels may also have a functional role in endogenous orienting of attention. Sensitive behavioral manipulation was used to probe the contribution of monocularly segregated regions in a simple cue - target detection task. A central spatially informative cue, and its ensuing target, were presented to the same or different eyes at varying cue-target intervals. Results indicated that the onset of endogenous orienting was apparent earlier when the cue and target were presented to the same eye. The data provides converging evidence for the notion that endogenous facilitation is modulated by monocular portions of the visual stream. This, in turn, suggests that higher cortical mechanisms are not exclusively responsible for endogenous orienting, and that a dynamic interaction between higher and lower neural levels, might be involved. Copyright © 2018 Elsevier Ltd. All rights reserved.

Opioid-use disorder among patients on long-term opioid therapy: impact of final DSM-5 diagnostic criteria on prevalence and correlates

Directory of Open Access Journals (Sweden)

Boscarino JA

2015-08-01

Full Text Available Joseph A Boscarino,1 Stuart N Hoffman,1 John J Han2 1Center for Health Research, 2Department of Pain Medicine, Geisinger Clinic, Danville, PA, USAAims: Previously, we estimated the prevalence and risk factors for prescription opioid-use disorder among outpatients on opioid therapy using the Diagnostic and Statistical Manual of Mental Disorders (DSM-5 and DSM-4 criteria. However, at the time, the DSM-5 criteria were not finalized. In the current study, we analyzed these data using the final DSM-5 criteria and compared these results.Methods: Using electronic records from a large US health care system, we identified outpatients receiving five or more prescription orders for opioid therapy in the past 12 months for noncancer pain (mean prescription orders =10.72; standard deviation =4.96. In 2008, we completed diagnostic interviews with 705 of these patients using the DSM-4 criteria. In the current study, we reassessed these results using the final DSM-5 criteria.Results: The lifetime prevalence of DSM-5 opioid-use disorders using the final DSM-5 criteria was 58.7% for no or few symptoms (<2, 28.1% for mild symptoms (2–3, 9.7% for moderate symptoms (4–5, and 3.5% for severe symptoms (six or more. Thus, the lifetime prevalence of “any” prescription opioid-use disorder in this cohort was 41.3% (95% confidence interval [CI] =37.6–45.0. A comparison to the DSM-4 criteria indicated that the majority of patients with lifetime DSM-4 opioid dependence were now classified as having mild opioid-use disorder, based on the DSM-5 criteria (53.6%; 95% CI =44.1–62.8. In ordinal logistic regression predicting no/few, mild, moderate, and severe opioid-use disorder, the best predictors were age <65 years, current pain impairment, trouble sleeping, suicidal thoughts, anxiety disorders, illicit drug use, and history of substance abuse treatment.Conclusion: Given the final DSM-5 criteria, including the elimination of tolerance and withdrawal, inclusion of

Help, Resources and Information: National Opioids Crisis

Science.gov (United States)

... Search Search Help, Resources and Information National Opioids Crisis Search Search Need Help? Call the National Helpline ... HHS 5-POINT STRATEGY TO COMBAT THE OPIOIDS CRISIS BETTER ADDICTION PREVENTION, TREATMENT, AND RECOVERY SERVICES BETTER ...

Incidence of iatrogenic opioid dependence or abuse in patients with pain who were exposed to opioid analgesic therapy: a systematic review and meta-analysis.

Science.gov (United States)

Higgins, C; Smith, B H; Matthews, K

2018-06-01

The prevalence and incidence of chronic conditions, such as pain and opioid dependence, have implications for policy development, resource allocation, and healthcare delivery. The primary objective of the current review was to estimate the incidence of iatrogenic opioid dependence or abuse after treatment with opioid analgesics. Systematic electronic searches utilised six research databases (Embase, Medline, PubMed, Cinahl Plus, Web of Science, OpenGrey). A 'grey' literature search and a reference search of included articles were also undertaken. The PICOS framework was used to develop search strategies and the findings are reported in accordance with the PRISMA Statement. After eligibility reviews of 6164 articles, 12 studies (involving 310 408 participants) were retained for inclusion in the meta-analyses. A random effects model (DerSimonian-Laird method) generated a pooled incidence of opioid dependence or abuse of 4.7%. There was little within-study risk of bias and no significant publication bias; however, substantial heterogeneity was found among study effects (99.78%). Sensitivity analyses indicated that the diagnostic criteria selected for identifying opioid dependence or abuse (Diagnostic Statistical Manual (DSM-IV) vs International Classification of Diseases (ICD-9)) accounted for 20% and duration of exposure to opioid analgesics accounted for 18% of variance in study effects. Longer-term opioid analgesic exposure, and prescription of strong rather than weak opioids, were associated with a significantly lower incidence of opioid dependence or abuse. The incidence of iatrogenic opioid dependence or abuse was 4.7% of those prescribed opioids for pain. Further research is required to confirm the potential for our findings to inform prevention of this serious adverse event. Copyright © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.

Influence of intravenous opioid dose on postoperative ileus.

Science.gov (United States)

Barletta, Jeffrey F; Asgeirsson, Theodor; Senagore, Anthony J

2011-07-01

Intravenous opioids represent a major component in the pathophysiology of postoperative ileus (POI). However, the most appropriate measure and threshold to quantify the association between opioid dose (eg, average daily, cumulative, maximum daily) and POI remains unknown. To evaluate the relationship between opioid dose, POI, and length of stay (LOS) and identify the opioid measure that was most strongly associated with POI. Consecutive patients admitted to a community teaching hospital who underwent elective colorectal surgery by any technique with an enhanced-recovery protocol postoperatively were retrospectively identified. Patients were excluded if they received epidural analgesia, developed a major intraabdominal complication or medical complication, or had a prolonged workup prior to surgery. Intravenous opioid doses were quantified and converted to hydromorphone equivalents. Classification and regression tree (CART) analysis was used to determine the dosing threshold for the opioid measure most associated with POI and define high versus low use of opioids. Risk factors for POI and prolonged LOS were determined through multivariate analysis. The incidence of POI in 279 patients was 8.6%. CART analysis identified a maximum daily intravenous hydromorphone dose of 2 mg or more as the opioid measure most associated with POI. Multivariate analysis revealed maximum daily hydromorphone dose of 2 mg or more (p = 0.034), open surgical technique (p = 0.045), and days of intravenous narcotic therapy (p = 0.003) as significant risk factors for POI. Variables associated with increased LOS were POI (p POI and prolonged LOS, particularly when the maximum hydromorphone dose per day exceeds 2 mg. Clinicians should consider alternative, nonopioid-based pain management options when this occurs.

Novel approaches for the treatment of psychostimulant and opioid abuse - focus on opioid receptor-based therapies.

Science.gov (United States)

Bailey, Chris P; Husbands, Stephen M

2014-11-01

Psychostimulant and opioid addiction are poorly treated. The majority of abstinent users relapse back to drug-taking within a year of abstinence, making 'anti-relapse' therapies the focus of much current research. There are two fundamental challenges to developing novel treatments for drug addiction. First, there are three key stimuli that precipitate relapse back to drug-taking: stress, presentation of drug-conditioned cue, taking a small dose of drug. The most successful novel treatment would be effective against all three stimuli. Second, a large number of drug users are poly-drug users: taking more than one drug of abuse at a time. The ideal anti-addiction treatment would, therefore, be effective against all classes of drugs of abuse. In this review, the authors discuss the clinical need and animal models used to uncover potential novel treatments. There is a very broad range of potential treatment approaches and targets currently being examined as potential anti-relapse therapies. These broadly fit into two categories: 'memory-based' and 'receptor-based' and the authors discuss the key targets here within. Opioid receptors and ligands have been widely studied, and research into how different opioid subtypes affect behaviours related to addiction (reward, dysphoria, motivation) suggests that they are tractable targets as anti-relapse treatments. Regarding opioid ligands as novel 'anti-relapse' medication targets, research suggests that a 'non-selective' approach to targeting opioid receptors will be the most effective.

Opioid interruptions, pain, and withdrawal symptoms in nursing home residents.

Science.gov (United States)

Redding, Sarah E; Liu, Sophia; Hung, William W; Boockvar, Kenneth S

2014-11-01

Interruptions in opioid use have the potential to cause pain relapse and withdrawal symptoms. The objectives of this study were to observe patterns of opioid interruption during acute illness in nursing home residents and examine associations between interruptions and pain and withdrawal symptoms. Patients from 3 nursing homes in a metropolitan area who were prescribed opioids were assessed for symptoms of pain and withdrawal by researchers blinded to opioid dosage received, using the Brief Pain Inventory Scale and the Clinical Opioid Withdrawal Scale, respectively, during prespecified time periods. The prespecified time periods were 2 weeks after onset of acute illness (eg, urinary tract infection), and 2 weeks after hospital admission and nursing home readmission, if they occurred. Opioid dosing was recorded and a significant interruption was defined as a complete discontinuation or a reduction in dose of >50% for ≥1 day. The covariates age, sex, race, comorbid conditions, initial opioid dose, and initial pain level were recorded. Symptoms pre- and post-opioid interruptions were compared and contrasted with those in a group without opioid interruptions. Sixty-six patients receiving opioids were followed for a mean of 10.9 months and experienced a total of 104 acute illnesses. During 64 (62%) illnesses, patients experienced any reduction in opioid dosing, with a mean (SD) dose reduction of 63.9% (29.9%). During 39 (38%) illnesses, patients experienced a significant opioid interruption. In a multivariable model, residence at 1 of the 3 nursing homes was associated with a lower risk of interruption (odds ratio = 0.073; 95% CI, 0.009 to 0.597; P pain score (difference -0.50 [2.66]; 95% CI, -3.16 to 2.16) and withdrawal score (difference -0.91 [3.12]; 95% CI, -4.03 to 2.21) after the interruption as compared with before interruption. However, when compared with patients without interruptions, patients with interruptions experienced larger increases in pain scores

Comparison of periodontal manifestations in amphetamine and opioids' consumers

Directory of Open Access Journals (Sweden)

Masoome Eivazi

2016-03-01

Full Text Available Background: Drug abuse is one of the most important etiologic and deteriorating factors in periodontal disease. Amphetamines and opioids, the most commonly used drugs worldwide, play an important role in this regard. The aim of this study was to compare the periodontal status of amphetamines and opioids consumers in Kermanshah city, Iran in 1393. Methods: Three drug rehabilitation clinics were selected randomly in Kermanshah. According to inclusion and exclusion criteria, 20 amphetamine consumers and 20 opioid consumers were selected randomly and participated in this study. A questionnaire for drug use and periodontal variables was designed. The collected data were entered into SPSS-18 software and Mann-Whitney and t-test were used for statistical analysis. Results: Pocket depth, gingival index and gingival bleeding in amphetamines users were more than those in opioids consumers (P<0.021. Plaque index and gingival recession in opioids users were more than those of amphetamines consumers (P<0.001. The number of periodontal disease cases in amphetamines group were 13 persons (65% and in opioids group 8 persons (40%. Conclusion: Our study showed that periodontal hygine in amphetamine consumers was worse than opioid consumers.

Opioid-use disorder among patients on long-term opioid therapy: impact of final DSM-5 diagnostic criteria on prevalence and correlates

Science.gov (United States)

Boscarino, Joseph A; Hoffman, Stuart N; Han, John J

2015-01-01

Aims Previously, we estimated the prevalence and risk factors for prescription opioid-use disorder among outpatients on opioid therapy using the Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 and DSM-4 criteria. However, at the time, the DSM-5 criteria were not finalized. In the current study, we analyzed these data using the final DSM-5 criteria and compared these results. Methods Using electronic records from a large US health care system, we identified outpatients receiving five or more prescription orders for opioid therapy in the past 12 months for noncancer pain (mean prescription orders =10.72; standard deviation =4.96). In 2008, we completed diagnostic interviews with 705 of these patients using the DSM-4 criteria. In the current study, we reassessed these results using the final DSM-5 criteria. Results The lifetime prevalence of DSM-5 opioid-use disorders using the final DSM-5 criteria was 58.7% for no or few symptoms (DSM-5 criteria (53.6%; 95% CI =44.1–62.8). In ordinal logistic regression predicting no/few, mild, moderate, and severe opioid-use disorder, the best predictors were age DSM-5 criteria, including the elimination of tolerance and withdrawal, inclusion of craving and abuse symptoms, and introduction of a new graded severity classification, the prevalence of opioid-use disorders has changed, while many of the DSM-4 risk factors for opioid dependence were similar. To our knowledge, this is one of the first studies to compare the final results for DSM-5 versus DSM-4 prescription opioid-use disorders among a high-risk patient population. PMID:26316838

Primary care for opioid use disorder

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Mannelli P

2016-08-01

Full Text Available Paolo Mannelli,1 Li-Tzy Wu1–41Department of Psychiatry and Behavioral Sciences, 2Department of Medicine, 3Duke Clinical Research Institute, Duke University Medical Center, 4Center for Child and Family Policy, Sanford School of Public Policy, Duke University, Durham, NC, USARecent reports on prescription opioid misuse and abuse have described unprecedented peaks of a national crisis and the only answer is to expand prevention and treatment, including different levels of care.1 Nonetheless, concerns remain about the ability of busy primary care settings to manage problem opioid users along with other patients. In particular, proposed extensions of buprenorphine treatment, a critically effective intervention for opioid use disorder (OUD, are cautiously considered due to the potential risk of misuse or abuse.2 General practitioners are already facing this burden daily in the treatment of chronic pain, and expert supervision and treatment model adjustment are needed to help improve outcomes. Approximately 20% of patients in primary care have noncancer pain symptoms, with most of them receiving opioid prescriptions by their physicians, and their number is increasing.3 Pain diagnoses are comparable in severity to those of tertiary centers and are complicated by significant psychiatric comorbidity, with a measurable lifetime risk of developing OUD.4,5 Some primary care physicians report frustration about opioid abuse and diversion by their patients; support from pain specialists would improve their competence, the quality f their performance, and the ability to identify patients at risk of opioid misuse.6 Thus, buprenorphine treatment should not be adding to a complex clinical scenario. To this end, the promising models of care emphasize the integration of medical with psychological and pharmacological expertise for the management of OUD. 

Desipramine in opioid-dependent cocaine abusers maintained on buprenorphine vs methadone.

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Oliveto, A H; Feingold, A; Schottenfeld, R; Jatlow, P; Kosten, T R

1999-09-01

Cocaine abuse occurs in 40% to 60% of patients entering opioid maintenance treatment, and effective pharmacotherapies are needed for this combined dependence. This 13-week, randomized, double-blind, placebo-controlled trial evaluated the efficacy of desipramine hydrochloride (0 or 150 mg/d) plus buprenorphine hydrochloride (12 mg/d) or methadone hydrochloride (65 mg/d) in 180 opioid-dependent cocaine abusers (124 men, 56 women). Supervised urine samples were obtained thrice weekly, and self-reported cocaine and heroin use was reported once weekly. Desipramine plasma levels were determined at weeks 4 and 10. In men, opioid abstinence was increased more rapidly over time when treated with methadone than with buprenorphine, whereas cocaine abstinence was increased more with buprenorphine than with methadone. In women, opioid abstinence was increased the least rapidly when treated with buprenorphine plus placebo, while cocaine abstinence was increased more rapidly over time when treated with methadone than with buprenorphine. Regardless of sex or opioid medication, desipramine increased opioid and cocaine abstinence more rapidly over time than placebo. Self-reported opioid use confirmed these findings. Desipramine plasma levels were higher in women than in men, particularly those on buprenorphine maintenance. Higher desipramine plasma levels were associated with greater opioid, but not cocaine, abstinence. Desipramine may be a useful adjunctive medication in facilitating opioid and cocaine abstinence in opioid-maintained patients. The efficacy of opioid medications to treat opioid or cocaine dependence may differ by sex. These findings highlight the importance of including sex as a factor when examining treatment outcome in these types of trials.

Influence of clonidine and ketamine on m-RNA expression in a model of opioid-induced hyperalgesia in mice.

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Henning Ohnesorge

Full Text Available We investigated the influence of morphine and ketamine or clonidine in mice on the expression of genes that may mediate pronociceptive opioid effects.C57BL/6 mice received morphine injections thrice daily using increasing doses (5-20 mg∙kg(-1 for 3 days (sub-acute, n=6 or 14 days (chronic, n=6 and additionally either s-ketamine (5 mg∙kg(-1, n=6 or clonidine (0.1 mg∙kg(-1, n=6. Tail flick test and the assessment of the mechanical withdrawal threshold of the hindpaw was performed during and 4 days after cessation of opioid treatment. Upon completion of the behavioural testing the mRNA-concentration of the NMDA receptor (NMDAR1 and β-arrestin 2 (Arrb2 were measured by PCR.Chronic opioid treatment resulted in a delay of the tail flick latency with a rapid on- and offset. Simultaneously the mice developed a static mechanical hyperalgesia with a delayed onset that that outlasted the morphine treatment. Sub-acute morphine administration resulted in a decrease of NMDAR1 and Arrb2 whereas during longer opioid treatment the expression NMDAR1 and Arrb2 mRNA increased again to baseline values. Coadministration of s-ketamine or clonidine resulted in a reversal of the mechanical hyperalgesia and inhibited the normalization of NMDAR1 mRNA expression but had no effect on the expression of Arrb2 mRNA.In the model of chronic morphine therapy the antinociceptive effects of morphine are represented by the thermal analgesia while the proniceptive effects are represented by the mechanical hyperalgesia. The results indicate that the regulation of the expression of NMDAR1 and Arrb2 may be associated to the development of OIH in mice.The results indicate that co-administration of clonidine or ketamine may influence the underlying mechanisms of OIH.

Evolving paradigms in the treatment of opioid-induced bowel dysfunction.

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Poulsen, Jakob Lykke; Brock, Christina; Olesen, Anne Estrup; Nilsson, Matias; Drewes, Asbjørn Mohr

2015-11-01

In recent years prescription of opioids has increased significantly. Although effective in pain management, bothersome gastrointestinal adverse effects are experienced by a substantial proportion of opioid-treated patients. This can lead to difficulties with therapy and subsequently inadequate pain relief. Collectively referred to as opioid-induced bowel dysfunction, these adverse effects are the result of binding of exogenous opioids to opioid receptors in the gastrointestinal tract. This leads to disturbance of three important gastrointestinal functions: motility, coordination of sphincter function and secretion. In the clinic this manifests in a wide range of symptoms such as reflux, bloating, abdominal cramping, hard, dry stools, and incomplete evacuation, although the most known adverse effect is opioid-induced constipation. Traditional treatment with laxatives is often insufficient, but in recent years a number of novel pharmacological approaches have been introduced. In this review the pathophysiology, symptomatology and prevalence of opioid-induced bowel dysfunction is presented along with the benefits and caveats of a suggested consensus definition for opioid-induced constipation. Finally, traditional treatment is appraised and compared with the latest pharmacological developments. In conclusion, opioid antagonists restricted to the periphery show promising results, but use of different definitions and outcome measures complicate comparison. However, an international working group has recently suggested a consensus definition for opioid-induced constipation and relevant outcome measures have also been proposed. If investigators within this field adapt the suggested consensus and include symptoms related to dysfunction of the upper gut, it will ease comparison and be a step forward in future research.

Cocaine Dysregulates Opioid Gating of GABA Neurotransmission in the Ventral Pallidum

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Scofield, Michael D.; Rice, Kenner C.; Cheng, Kejun; Roques, Bernard P.

2014-01-01

The ventral pallidum (VP) is a target of dense nucleus accumbens projections. Many of these projections coexpress GABA and the neuropeptide enkephalin, a δ and μ opioid receptor (MOR) ligand. Of these two, the MOR in the VP is known to be involved in reward-related behaviors, such as hedonic responses to palatable food, alcohol intake, and reinstatement of cocaine seeking. Stimulating MORs in the VP decreases extracellular GABA, indicating that the effects of MORs in the VP on cocaine seeking are via modulating GABA neurotransmission. Here, we use whole-cell patch-clamp on a rat model of withdrawal from cocaine self-administration to test the hypothesis that MORs presynaptically regulate GABA transmission in the VP and that cocaine withdrawal changes the interaction between MORs and GABA. We found that in cocaine-extinguished rats pharmacological activation of MORs no longer presynaptically inhibited GABA release, whereas blocking the MORs disinhibited GABA release. Moreover, MOR-dependent long-term depression of GABA neurotransmission in the VP was lost in cocaine-extinguished rats. Last, GABA neurotransmission was found to be tonically suppressed in cocaine-extinguished rats. These substantial synaptic changes indicated that cocaine was increasing tone on MOR receptors. Accordingly, increasing endogenous tone by blocking the enzymatic degradation of enkephalin inhibited GABA neurotransmission in yoked saline rats but not in cocaine-extinguished rats. In conclusion, our results indicate that following withdrawal from cocaine self-administration enkephalin levels in the VP are elevated and the opioid modulation of GABA neurotransmission is impaired. This may contribute to the difficulties withdrawn addicts experience when trying to resist relapse. PMID:24431463

Opioid pharmaceuticals and addiction: the issues, and research directions seeking solutions.

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Walwyn, Wendy M; Miotto, Karen A; Evans, Christopher J

2010-05-01

There are few pharmaceuticals superior to opiates for the treatment of pain. However, with concerns of addiction, withdrawal and questionable efficacy for all types of pain, these compounds are far from a magical panacea for pain-relief. As it is unlikely that other classes of compounds will supersede the opioids in the very near future, it is important to both optimize current opioid therapies and curb the astounding diversion of opioids from their intended analgesic use to non-medical abuse. In optimizing opioid therapeutics it is necessary to enhance the clinical awareness of the benefits of treating pain and combine this with aggressive strategies to reduce diversion for non-medical use. At the heart of the issue of opioid misuse is the role of opioid systems in the reward circuitry, and the adaptive processes associated with repetitive opioid use that manifest during withdrawal. Emerging pharmacological insights of opioid receptors will be reviewed that provide future hope for developing opioid-based analgesics with reduced addictive properties and perhaps, reduced opponent processes. In addition, with the increased understanding of nociceptive circuitry and the molecules involved in transmitting pain, new therapeutic targets have become evident that may result in effective analgesics either alone or in combination with current opioid therapies.

Development and preliminary validation of the Opioid Abuse Risk Screener

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Patricia Henrie-Barrus

2016-05-01

Full Text Available Prescription opioid drug abuse has reached epidemic proportions. Individuals with chronic pain represent a large population at considerable risk of abusing opioids. The Opioid Abuse Risk Screener was developed as a comprehensive self-administered measure of potential risk that includes a wide range of critical elements noted in the literature to be relevant to opioid risk. The creation, refinement, and preliminary modeling of the item pool, establishment of preliminary concurrent validity, and the determination of the factor structure are presented. The initial development and validation of the Opioid Abuse Risk Screener shows promise for effective risk stratification.

Mechanisms of Sucrose and Non-Nutritive Sucking in Procedural Pain Management in Infants

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Sharyn Gibbins

2001-01-01

Full Text Available The administration of sucrose with and without non-nutritive sucking (NNS has been examined for relieving procedural pain in newborn infants. The calming and pain-relieving effects of sucrose are thought to be mediated by endogenous opioid pathways activated by sweet taste. The orogustatory effects of sucrose have been demonstrated in animal newborns, and in preterm and full term human infants during painful procedures. In contrast to sucrose, the analgesic effects of NNS are hypothesized to be activated through nonopioid pathways by stimulation of orotactile and mechanoreceptor mechanisms. Although there is uncertainty as to whether the effects of sucrose and NNS are synergistic or additive, there is sufficient evidence to support the efficacy of combining the two interventions for procedural pain relief in infants. In this review article, the underlying mechanisms of sucrose and NNS, separately and in combination for relieving procedural pain in preterm and full term infants, are examined. Clinical and research implications are addressed.

Comparative Analysis of Inpatient Costs for Obstetrics and Gynecology Surgery Patients Treated With IV Acetaminophen and IV Opioids Versus IV Opioid-only Analgesia for Postoperative Pain.

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Hansen, Ryan N; Pham, An T; Lovelace, Belinda; Balaban, Stela; Wan, George J

2017-10-01

Recovery from obstetrics and gynecology (OB/GYN) surgery, including hysterectomy and cesarean section delivery, aims to restore function while minimizing hospital length of stay (LOS) and medical expenditures. Our analyses compare OB/GYN surgery patients who received combination intravenous (IV) acetaminophen and IV opioid analgesia with those who received IV opioid-only analgesia and estimate differences in LOS, hospitalization costs, and opioid consumption. We performed a retrospective analysis of the Premier Database between January 2009 and June 2015, comparing OB/GYN surgery patients who received postoperative pain management with combination IV acetaminophen and IV opioids with those who received only IV opioids starting on the day of surgery and continuing up to the second postoperative day. We performed instrumental variable 2-stage least-squares regressions controlling for patient and hospital covariates to compare the LOS, hospitalization costs, and daily opioid doses (morphine equivalent dose) of IV acetaminophen recipients with that of opioid-only analgesia patients. We identified 225 142 OB/GYN surgery patients who were eligible for our study of whom 89 568 (40%) had been managed with IV acetaminophen and opioids. Participants averaged 36 years of age and were predominantly non-Hispanic Caucasians (60%). Multivariable regression models estimated statistically significant differences in hospitalization cost and opioid use with IV acetaminophen associated with $484.4 lower total hospitalization costs (95% CI = -$760.4 to -$208.4; P = 0.0006) and 8.2 mg lower daily opioid use (95% CI = -10.0 to -6.4), whereas the difference in LOS was not significant, at -0.09 days (95% CI = -0.19 to 0.01; P = 0.07). Compared with IV opioid-only analgesia, managing post-OB/GYN surgery pain with the addition of IV acetaminophen is associated with decreased hospitalization costs and reduced opioid use.

Use of diagnosis codes for detection of clinically significant opioid poisoning in the emergency department: A retrospective analysis of a surveillance case definition.

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Reardon, Joseph M; Harmon, Katherine J; Schult, Genevieve C; Staton, Catherine A; Waller, Anna E

2016-02-08

Although fatal opioid poisonings tripled from 1999 to 2008, data describing nonfatal poisonings are rare. Public health authorities are in need of tools to track opioid poisonings in near real time. We determined the utility of ICD-9-CM diagnosis codes for identifying clinically significant opioid poisonings in a state-wide emergency department (ED) surveillance system. We sampled visits from four hospitals from July 2009 to June 2012 with diagnosis codes of 965.00, 965.01, 965.02 and 965.09 (poisoning by opiates and related narcotics) and/or an external cause of injury code of E850.0-E850.2 (accidental poisoning by opiates and related narcotics), and developed a novel case definition to determine in which cases opioid poisoning prompted the ED visit. We calculated the percentage of visits coded for opioid poisoning that were clinically significant and compared it to the percentage of visits coded for poisoning by non-opioid agents in which there was actually poisoning by an opioid agent. We created a multivariate regression model to determine if other collected triage data can improve the positive predictive value of diagnosis codes alone for detecting clinically significant opioid poisoning. 70.1 % of visits (Standard Error 2.4 %) coded for opioid poisoning were primarily prompted by opioid poisoning. The remainder of visits represented opioid exposure in the setting of other primary diseases. Among non-opioid poisoning codes reviewed, up to 36 % were reclassified as an opioid poisoning. In multivariate analysis, only naloxone use improved the positive predictive value of ICD-9-CM codes for identifying clinically significant opioid poisoning, but was associated with a high false negative rate. This surveillance mechanism identifies many clinically significant opioid overdoses with a high positive predictive value. With further validation, it may help target control measures such as prescriber education and pharmacy monitoring.

Yiguanjian cataplasm attenuates opioid dependence in a mouse

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Gao, Shuai; Gao, Hong; Fan, Yuchen; Zhang, Guanghua; Sun, Fengkai; Zhao, Jing; Li, Feng; Yang, Yang; Wang, Kai

2016-08-01

To investigate the effect of Yiguanjian (YGJ) cataplasm on the development of opioid dependence in a mouse model of naloxone-induced opioid withdrawal syndrome. One hundred Swiss albino mice, of equal male to female ratio, were randomly and equally divided into 10 groups. A portion (3 cm2) of the backside hair of the mice was removed 1 day prior to the experiment. Morphine (5 mg/kg) was intraperitoneally administered twice daily for 5 days. YGJ cataplasm was prepared and pasted on the bare region of the mice immediately before morphine administration on day 3 and subsequently removed at the end day 5. On day 6, naloxone (8 mg/kg) was intraperitoneally injected to precipitate opioid withdrawal syndrome. Behavioral observation was performed in two 30-min phases immediately after naloxone injection. The YGJ cataplasm significantly and dose-dependently attenuated morphine-naloxone- induced experimental opioid withdrawal, in terms of withdrawal severity score and the frequencies of jumping, rearing, forepaw licking, and circling behaviors. However, YGJ cataplasm treatment did not alter the acute analgesic effect of morphine. YGJ cataplasm could attenuate opioid dependence and its associated withdrawal symptoms. Therefore, YGJ cataplasm could serve as a potential therapy for opioid addiction in the future.

Changes in misuse and abuse of prescription opioids following implementation of Extended-Release and Long-Acting Opioid Analgesic Risk Evaluation and Mitigation Strategy.

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Bucher Bartelson, Becki; Le Lait, M Claire; Green, Jody L; Cepeda, M Soledad; Coplan, Paul M; Maziere, Jean-Yves; Wedin, Gregory P; Dart, Richard C

2017-09-01

An unintended consequence of extended-release (ER) and long-acting (LA) prescription opioids is that these formulations can be more attractive to abusers than immediate-release (IR) formulations. The US Food and Drug Administration recognized these risks and approved the ER/LA Opioid Analgesic Risk Evaluation and Mitigation Strategy (ER/LA REMS), which has a goal of reducing opioid misuse and abuse and their associated consequences. The primary objective of this analysis is to determine whether ER/LA REMS implementation was associated with decreased reports of misuse and abuse. Data from the Researched Abuse, Diversion and Addiction-Related Surveillance (RADARS(R)) System Poison Center Program were utilized. Poison center cases are assigned a reason for exposure, a medical outcome, and a level of health care received. Rates adjusted for population and drug utilization were analyzed over time. RADARS System Poison Center Program data indicate a notable decrease in ER/LA opioid rates of intentional abuse and misuse as well as major medical outcomes or hospitalizations following implementation of the ER/LA REMS. While similar decreases were observed for the IR prescription opioid group, the decreasing rate for the ER/LA opioids exceeded the decreasing rates for the IR prescription opioids and was distinctly different than that for the prescription stimulants, indicating that the ER/LA REMS program may have had an additional effect on decreases in opioid abuse and intentional misuse beyond secular trends. Copyright © 2017 John Wiley & Sons, Ltd.

Site-specific effects of the nonsteroidal anti-inflammatory drug lysine clonixinate on rat brain opioid receptors.

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Ortí, E; Coirini, H; Pico, J C

1999-04-01

In addition to effects in the periphery through inhibition of prostaglandin synthesis, several lines of evidence suggest that nonsteroidal anti-inflammatory drugs (NSAIDs) act in the central nervous system. The possibility that the central action of NSAIDs involves regulation of opioid receptors was investigated by quantitative autoradiography of mu, delta, and kappa sites in rat brain slices. Increased (p lysine clonixinate. Labeling of delta receptors was lower in the lateral septum, and kappa sites decreased in thalamic nuclei. These effects were not mediated through direct interaction with opioid-binding sites, since receptor-binding assays using rat brain membranes confirmed that clonixinate up to 1 x 10(-4) mol/l does not inhibit mu, delta, and kappa receptor specific binding. Central effects of NSAIDs might, therefore, involve interaction with the opioid receptor system through indirect mechanisms.

Association of childhood abuse and prescription opioid use in early adulthood.

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Austin, Anna E; Shanahan, Meghan E; Zvara, Bharathi J

2018-01-01

Previous research has examined the association of childhood abuse with opioid misuse and dependence in adulthood. However, little research has focused specifically on prescription opioids, and no studies have examined associations with prescription opioid use, a potential pathway to later opioid misuse and dependence. The aim of the present study was to examine the association of childhood emotional, physical, and sexual abuse with prescription opioid use in early adulthood. We used data from Waves I (12-18years) and IV (24-32years) of the National Longitudinal Study of Adolescent to Adult Health. At Wave IV, respondents reported experiences of childhood abuse occurring prior to age 18years and prescription opioid use in the last four weeks. We conducted multivariable logistic regression to examine associations of childhood abuse with recent prescription opioid use. In multivariable models adjusted for respondent sex, race/ethnicity, age, and socioeconomic status, childhood emotional abuse (OR=1.57, 95% CI 1.29, 1.90), physical abuse (OR=1.46, 95% CI 1.14, 1.87), and any childhood abuse (OR=1.51, 95% CI 1.24, 1.82) were significantly associated with recent prescription opioid use. Given continued increases in prescription opioid use and opioid-related morbidity and mortality in the U.S., understanding upstream social and environmental factors associated with prescription opioid use is important to strengthening and expanding current prevention and intervention strategies. Future research is needed to examine factors potentially mediating the association between childhood abuse and prescription opioid use in order to provide additional insights for prevention and intervention efforts. Copyright © 2017 Elsevier Ltd. All rights reserved.