Naltrexone, an antagonist for the treatment of heroin dependence. Effects in man.

Archives of General Psychiatry (Impact Factor: 13.75). 07/1973; 28(6):784-91.
Source: PubMed
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    ABSTRACT: Self-report inventories from 35 male methadone patients were examined for possible indicators of intent to choose naltrexone treatment. The index of choice, a composite score derived from the analysis, was developed for each patient and compared to naltrexone treatment status at 6-month follow-up. There was a highly significant relationship between scores on the index of choice and the actual process of naltrexone selection. Patients who elected to detoxify from methadone, who were less confident of their ability to remain opiate-free, and v/ho also expressed greater fear of losing the security that maintenance had helped them attain, intended to choose, exhibited greater interest in, and actually selected naltrexone treatment more often. A significant number of maintenance patients who had been prescribed methadone at higher doses and for longer periods of time rejected naltrexone. Failure is the factor that seems to motivate methadone patients to respond to the selection process. Although perceptions of “failure to remain free of illicit opiates” may have enhanced interest in naltrexone, perceptions of “failure to detoxify from methadone” diminished naltrexone's appeal, and actual “failure to remain free of illicit opiates” following methadone detoxification precluded patient participation. Thus, dilemmas appeared to exist. The index of choice may prove to be effective in the evaluation of these dilemmas encountered by patients throughout the selection process, and recommendations for intervention are made. Cautious application of the index of choice is advised until the relationships with retention and success in naltrexone treatment are more clearly demonstrated in future research.
    The American Journal of Drug and Alcohol Abuse 07/2009; 10(2). · 1.47 Impact Factor
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    ABSTRACT: Impulse control disorders (ICDs) in Parkinson disease (PD) are common and can be difficult to manage. The objective of this study was to determine the efficacy and tolerability of naltrexone, an opioid antagonist, for the treatment of ICDs in PD.METHODS: Patients with PD (n = 50) and an ICD were enrolled in an 8-week, randomized (1:1), double-blind, placebo-controlled study of naltrexone 50-100 mg/d (flexible dosing). The primary outcome measure was response based on the Clinical Global Impression-Change score, and the secondary outcome measure was change in symptom severity using the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) ICD score.RESULTS: Forty-five patients (90%) completed the study. The Clinical Global Impression-Change response rate difference favoring naltrexone in completers was 19.8% (95% confidence interval [CI] -8.7% to 44.2%). While this difference was not significant (odds ratio = 1.6, 95% CI 0.5-5.2, Wald χ(2) [df] = 0.5 [1], p = 0.5), naltrexone treatment led to a significantly greater decrease in QUIP-RS ICD score over time compared with placebo (regression coefficient for interaction term in linear mixed-effects model = -7.37, F[df] = 4.3 [1, 49], p = 0.04). The estimated changes in QUIP-RS ICD scores from baseline to week 8 were 14.9 points (95% CI 9.9-19.9) for naltrexone and 7.5 points (95% CI 2.5-12.6) for placebo.CONCLUSIONS: Naltrexone treatment was not efficacious for the treatment of ICDs in PD using a global assessment of response, but findings using a PD-specific ICD rating scale support further evaluation of opioid antagonists for the treatment of ICD symptoms in PD.CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that in patients with PD and an ICD, naltrexone does not significantly increase the probability of achieving response. However, the study lacked the precision to exclude an important difference in response rates.
    Neurology 07/2014; 83(9). DOI:10.1212/WNL.0000000000000729 · 8.30 Impact Factor
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    ABSTRACT: Thirty rats were given access to 5-μg/ml etonitazene and 0.1-mg/ml quinine solutions during 12 days of 24-h choice testing with a single daily 3-mg/kg naltrexone injection (Group N-CT), two 3-mg/kg naltrexone injections per day (Group 2N-CT), or a single daily vehicle (1-ml/kg saline) injection (Group Sal-CT). Control groups received either the daily naltrexone treatment or saline, and were provided with only water. Both naltrexone groups receiving choice tests displayed signs of precipitated withdrawal upon naltrexone administration. When drug solutions were replaced with water and intraperitoneal injections were terminated, spontaneous withdrawal was displayed by all three choice test groups. The results clearly demonstrate that naltrexone does not block the pharamacological properties of etonitazene in a 24-h choice test paradigm. Thus, procedures for separating taste factors from pharmacological properties of etonitazene with choice testing must employ limited access to the opiate.
    Bulletin of the Psychonomic Society 03/2013; 23(3):241-244. DOI:10.3758/BF03329838