The opiate antagonist naltrexone suppresses ethanol-reinforced behavior in animals and decreases ethanol intake in humans. However, the mechanisms underlying these actions are not well understood. Experiments were designed to test the hypothesis that naltrexone attenuates the rewarding properties of ethanol by interfering with ethanol-induced stimulation of dopamine activity in the nucleus accu...

The purpose of this experiment was to examine the effects of the endogenous opioid system on forearm muscle pain and muscle sympathetic nerve activity (MSNA) during dynamic fatiguing exercise. Twelve college-age men (24 +/- 4 yr) performed graded (1-min stages; 30 contractions/min) handgrip to fatigue 1 h after the ingestion of either 60 mg codeine, 50 mg naltrexone, or placebo. Pain (0-10 scal...

While oral naltrexone has a demonstrated ability to decrease alcohol reinforcement, it also has pharmacotherapeutic limitations, such as a small treatment effect size, adverse events, and plasma level fluctuations. The pharmacokinetic profile of naltrexone could be enhanced by intramuscular administration, which would sustain its release over several weeks and keep plasma levels relatively cons...

In synaptosomal membranes from rat brain cortex, in the presence of 150 mM NaCl, the opioid antagonist [3H]naltrexone bound to two populations of receptor sites with affinities of 0.27 and 4.3 nM, respectively. Guanosine-5'-(3-thiotriphosphate) had little modulating effect and did not alter the biphasic nature of ligand binding. On the other hand, receptor-selective opioids differentially inhib...

Naltrexone and acamprosate reduce relapse in alcohol dependence. They have not yet been compared in a published trial. The aim of this study was to compare the efficacy of these compounds in conditions similar to those in routine clinical practice. Random allocation to a year of treatment with naltrexone (50 mg/day) or acamprosate (1665-1998 mg/day) was made in 157 recently detoxified alcohol-d...

Background: Since the number of drug users is increasing, applying a method of detoxification with fewer side effects during withdrawal from opioids and greater reliability seems to be necessary. In addition, without maintenance treatment, there will be limited success of treatment. This study aimed to compare success rates of detoxification with sublingual buprenorphine and clonidine and to ev...

Compared with naloxone, two opiate antagonists (naltrexone and S-20682) were tested in the intact dog in order to reverse respiratory depression, induced by fentanyl 50 micrograms kg-1 i.v. Respiratory rate and arterial blood-gases were measured at 5, 30, 60, 120, 180 and 240 min after the additional i.v. injection of the antagonist (1 microgram kg-1). Only S-20682, but not naloxone or naltrexo...

Naltrexone, an antagonist of μ-opioid receptors, is clinically used as adjuvant therapy of alcohol dishabituation. The aim of the present work was to test the effect of 1 mg/kg body weight of naltrexone to revert oxidative stress-related biochemical alterations, in the hippocampus and serum of chronic alcoholic adult rats. Malondialdehyde concentration was increased and glutathione peroxidase a...

Objective: Management of borderline personality disorder (BPD) is a difficult challenge due to the complex features of this disorder. This article reviews the use of naltrexone in the treatment of BPD. Method: Published articles and clinical trials were searched in Google Scholar, MedLine, ELSEVIER, and Cochrane database of systematic reviews abstracts in English language between 1990 and 2017....

Male Sprague-Dawley rats were fitted with two cannulae in the VTA and one cannula in the NTS for co-administration of the micro-opioid receptor agonist DAMGO in one site and the opioid antagonist naltrexone in the other. Injection of DAMGO into the VTA or the NTS stimulated feeding. The increase in food intake after DAMGO injection into the VTA was decreased following injection of naltrexone in...