Search results for "naltrexone"
showing 10 items of 23 documents
Glutamate and opioid antagonists modulate dopamine levels evoked by innately attractive male chemosignals in the nucleus accumbens of female rats
2017
Sexual chemosignals detected by vomeronasal and olfactory systems mediate intersexual attraction in rodents, and act as a natural reinforcer to them. The mesolimbic pathway processes natural rewards, and the nucleus accumbens receives olfactory information via glutamatergic projections from the amygdala. Thus, the aim of this study was to investigate the involvement of the mesolimbic pathway in the attraction toward sexual chemosignals. Our data show that female rats with no previous experience with males or their chemosignals display an innate preference for male-soiled bedding. Focal administration of the opioid antagonist b-funaltrexamine into the posterior ventral tegmental area does no…
Patients’ experiences of continued treatment with extended-release naltrexone: a Norwegian qualitative study
2022
Abstract Background The opioid antagonist extended-release naltrexone (XR-NTX) in the treatment of opioid use disorder (OUD) is effective in terms of safety, abstinence from opioid use and retention in treatment. However, it is unclear how patients experience and adjust to losing the possibility of achieving an opioid effect. This qualitative study is the first to explore how people with opioid dependence experience XR-NTX treatment, focusing on the process of treatment over time. Methods Using a purposive sampling strategy, semi-structured interviews were undertaken with 19 persons with opioid use disorder (15 men, four women, 22–55 years of age) participating in a clinical trial of XR-NTX…
Diffusion of naltrexone across reconstituted human oral epithelium and histomorphological features
2006
Abstract In transbuccal absorption a major limitation could be the low permeability of the mucosa which implies low drug bioavailability. The ability of naltrexone hydrochloride (NLX) to penetrate a resembling histologically human buccal mucosa was assessed and the occurrence of any histomorphological changes observed. We used reconstituted human oral (RHO) non-keratinised epithelium as mucosal section and a Transwell diffusion cells system as bicompartmental model. Buccal permeation was expressed in terms of drug flux ( J s ) and permeability coefficients ( K p ). Data were collected using both artificial and natural human saliva. The main finding was that RHO does not restrain NLX permeat…
Sensitivity of neuronal nicotinic acetylcholine receptors to the opiate antagonists naltrexone and naloxone: receptor blockade and up-regulation
2003
In HEK293 cells stably expressing alpha4beta2 nAChRs, naltrexone, but not naloxone, blocked alpha4beta2 nAChRs via an open-channel blocking mechanism. In primary hippocampal cultures, naltrexone inhibited alpha7 nAChRs up-regulated by nicotine, and in organotypic hippocampal cultures naltrexone caused a time-dependent up-regulation of functional alpha7 nAChRs that was detected after removal of the drug. These results indicate that naltrexone could be used as a smoking cessation aid.
Naltrexone antagonizes acetaldehyde-induced increments in dopamine neurons activity
2014
Abstract Acetaldehyde is the main metabolite of ethanol ingested through alcoholic beverages. Traditionally considered aversive is presently being viewed as an activating agent of the mesolimbic dopamine system but underlying mechanisms are only partially known. Here we show that acetaldehyde-induced increase in firing rate, burst firing and spikes/burst of antidromically-identified ventro-tegmental area Nucleus Accumbens-projecting neurons are abolished by pretreatment with the opiate unselective antagonist naltrexone (1mg/kg/ip). Similar effects are obtained after administration of naloxone (0.1mg/kg/iv). These results indicate: 1) endogenous opiate system(s) participate in acetaldehyde-i…
δ 1‐OPIOID receptor‐mediated controlofacetylcholine (ACh) release in human neocortex slices
1998
In slices of human neocortex, prelabelled with [3H]-choline, the release of [3H]-acetylcholine reflects the evoked release of endogenous acetylcholine which was elicited by the same electrical stimulation paradigm. [3H]-Acetylcholine release was depressed by the delta-opioid receptor agonist D-Pen2-D-Pen5-enkephalin. When the nerve endings were depolarized by elevating extracellular potassium the evoked [3H]-acetylcholine release was similarly depressed by D-Pen2-D-Pen5-enkephalin in the absence, but not in the presence, of tetrodotoxin which blocks action potential propagation. Therefore, the delta-opioid receptor inhibiting [3H]-acetylcholine release should not be located to cholinergic n…
Treatments for Opioid Dependence and Methadone
2016
Abstract This chapter is focused on opioid dependence treatment and is framed in a holistic perspective. Specifically, there are three main approaches to pharmacological treatment of opioid dependence: opioid detoxification, agonist maintenance, and antagonist maintenance. There is a great amount of evidence supporting the efficacy of methadone and buprenorphine or the combination of buprenorphine–naloxone for the treatment of opioid withdrawal and their clinical utility as pharmacotherapy in long-term maintenance programs. Secondary or adjunctive medications such as heroin, naltrexone, and alpha-2-adrenergics are also reviewed. The need for further research and to overcome nonscientificall…
Bioavailability in vivo of naltrexone following transbuccal administration by an electronically-controlled intraoral device: a trial on pigs.
2010
Naltrexone (NLX), an opioid antagonist, is widely used in the treatment of opiate addiction, alcoholism and smoking cessation. Its current peroral administration induces various adverse side effects and has limited efficacy since bioavailability and patient compliance are poor. The development of a long-acting drug delivery system of NLX may overcome the current drawbacks and help in the improvement of treatment of addiction. The primary endpoints of this study were: a) to compare the NLX bioavailability and pharmacokinetics after delivering a single transbuccal dose, released by a prototype of intraoral device, versus an intravenous (I.V.) bolus of the same drug dose; b) to verify the func…
Improved effect of the combination naltrexone/D-penicillamine in the prevention of alcohol relapse-like drinking in rats
2014
Opioid antagonists are licensed drugs for treating alcohol use disorders; nonetheless, clinical studies have evidenced their limited effectiveness. Preclinical findings indicate that opioid receptor (OR) antagonists, such as naltrexone (NTX), reduce the alcohol deprivation effect (ADE). However, a detailed analysis of published data shows the existence of a delayed increase in ethanol consumption after continuous OR blockade, a phenomenon originally called as ‘delayed ADE’. We have recently reported that D-penicillamine (DP) is able to prevent ADE through a mechanism dependent on the inactivation of acetaldehyde, the main metabolite of ethanol. Hypothetically, OR activation would be trigge…
Controlled delivery of naltrexone by an intraoral device: in vivo study on human subjects.
2013
Naltrexone is widely used in the treatment of opiate addiction but its current peroral administration is characterized by low bioavailability with various side effects. The development of a long-acting transbuccal delivery device (IntelliDrug) for NLX may be useful to improve patient compliance and the therapy effectiveness. The aims of the study are (a) to test basic safety and effectiveness of controlled transbuccal drug delivery on human subjects; (b) to compare NLX bioavailability following transbuccal delivery vs per os conventional delivery; and (c) to test the hypothesis that transbuccal delivery is more efficient than the conventional route. In this randomized cross-over pilot study…