Comparing and combining naltrexone and acamprosate in relapse prevention of alcoholism: a double-blind, placebo-controlled study.
ABSTRACT Naltrexone and acamprosate have been shown to be effective in relapse prevention of alcoholism via different pharmacologic mechanisms. Since it remains uncertain whether both substances are equally efficient and whether a combination of both drugs potentiates the efficacy, we conducted the first published controlled study comparing and combining both compounds.
After detoxification, 160 patients with alcoholism participated in a randomized, double-blind, placebo-controlled protocol. Patients received naltrexone, acamprosate, naltrexone plus acamprosate, or placebo for 12 weeks. Patients were assessed weekly by interview, self-report, questionnaires, and laboratory screening. Time to first drink, time to relapse, and the cumulative abstinence time were the primary outcome measures.
Naltrexone, acamprosate, and the combined medication were significantly more effective than placebo. Comparing the course of nonrelapse rates between naltrexone and acamprosate, the naltrexone group showed a tendency for a better outcome regarding time to first drink and time to relapse. The combined medication was most effective with significantly lower relapse rates than placebo and acamprosate but not naltrexone.
The results of this study support the efficacy of pharmacotherapeutic strategies in the relapse prevention of alcoholism. Naltrexone and acamprosate, especially in combination, considerably enhance the potential of relapse prevention.
Article: Naltrexone and combined behavioral intervention effects on trajectories of drinking in the COMBINE study.[show abstract] [hide abstract]
ABSTRACT: COMBINE is the largest study of pharmacotherapy for alcoholism in the United States to date, designed to answer questions about the benefits of combining behavioral and pharmacological interventions. Trajectory-based analyses of daily drinking data allowed identification of distinct drinking trajectories in smaller studies and demonstrated significant naltrexone effects even when primary analyses on summary drinking measures were unsuccessful. The objective of this study was to replicate and refine trajectory estimation and to assess effects of naltrexone, acamprosate and therapy on the probabilities of following particular trajectories in COMBINE. It was hypothesized that different treatments may affect different trajectories of drinking. We conducted exploratory analyses of daily indicators of any drinking and heavy drinking using a trajectory-based approach and assessed trajectory membership probabilities and odds ratios for treatment effects. We replicated the trajectories ("abstainer", "sporadic drinker", "consistent drinker") established previously in smaller studies. However, greater numbers of trajectories better described the heterogeneity of drinking over time. Naltrexone reduced the chance to follow a "nearly daily" trajectory and Combined Behavioral Intervention (CBI) reduced the chance to be in an "increasing to nearly daily" trajectory of any drinking. The combination of naltrexone and CBI increased the probability of membership in a trajectory in which the frequency of any drinking declined over time. Trajectory membership was associated with different patterns of treatment compliance. The trajectory-analyses identified specific patterns of drinking that were differentially influenced by each treatment and provided support for hypotheses about the mechanisms by which these treatments work.Drug and alcohol dependence 12/2009; 107(2-3):221-9. · 3.60 Impact Factor
Article: Acamprosate for alcohol dependence: a sex-specific meta-analysis based on individual patient data.[show abstract] [hide abstract]
ABSTRACT: It is unknown whether women derive comparable benefits and have a similar safety and tolerability profile as men from acamprosate, a widely prescribed drug for the maintenance of abstinence in alcohol dependence. The objective of this study was to assess sex-specific differences in the efficacy, safety, and tolerability of acamprosate in the treatment of women and men with alcohol dependence. A sex-specific meta-analysis was conducted based on individual patient data (IPD). Data were obtained from double-blind, randomized controlled trials with quantitative drinking measures in patients with alcohol dependence receiving oral acamprosate or placebo. Sources included PubMed, PsychInfo, and Cochrane electronic databases; reference lists from retrieved articles and presentations at professional meetings; and direct access to authors and companies who provided IPD. Individual records were obtained from 1,317 women and 4,794 men who participated in 22 eligible studies conducted in 18 countries. IPD meta-analyses found a significant beneficial effect of acamprosate relative to placebo across all 4 efficacy end points: an incremental gain of 10.4% (95% CI 7.1 to 13.7, p < 0.001) in percentage of abstinent days, an incremental gain of 11.0% (7.4 to 14.6, p < 0.001) in percentage of no heavy drinking days, an odds ratio of 1.9 (1.6 to 2.2, p < 0.001) for rate of complete abstinence, and an odds ratio of 1.9 (1.6 to 2.3, p < 0.001) for rate of no heavy drinking, over the study duration. Acamprosate was also associated with significantly higher rates of treatment completion (p = 0.004) and medication compliance (p < 0.001) than placebo. Men and women did not differ on any measure of acamprosate efficacy, safety, or tolerability. This sex-specific IPD meta-analysis provides evidence that acamprosate has a significant effect compared with placebo in improving rates of abstinence and no heavy drinking in both women and men with alcohol dependence. Further, acamprosate was associated with significantly higher rates of treatment completion and medication compliance than placebo among both women and men and had a comparable safety and tolerability profile.Alcoholism Clinical and Experimental Research 09/2011; 36(3):497-508. · 3.34 Impact Factor
Article: Pharmacogenetics of naltrexone in asian americans: a randomized placebo-controlled laboratory study.[show abstract] [hide abstract]
ABSTRACT: Recent clinical and laboratory studies have shown that the effects of naltrexone for alcoholism may be moderated by the Asn40Asp single-nucleotide polymorphism (SNP) of the μ-opioid receptor gene (OPRM1). Allele frequencies for this polymorphism, however, have been shown to vary substantially as a function of ethnic background, such that individuals of Asian descent are more likely to carry the minor (Asp40) allele. The objective of this study is to test the naltrexone pharmacogenetic effects of the Asn40Asp SNP in a sample of Asian Americans. This study consists of a double-blinded, randomized, placebo-controlled laboratory trial of naltrexone. Participants (n=35, 10 females; 13 Asn40Asn and 22 Asp40 carriers) were non-treatment-seeking heavy drinkers recruited from the community. After taking naltrexone or placebo, participants completed an intravenous alcohol administration session. The primary outcome measures were subjective intoxication and alcohol craving. Results suggested that Asp40 carriers experienced greater alcohol-induced sedation, subjective intoxication, and lower alcohol craving on naltrexone, as compared to placebo, and to Asn40 homozygotes. There results were maintained when controlling for ALDH2 (rs671) and ADH1B (rs1229984) markers and when examining the three levels of OPRM1 genotype, thereby supporting an OPRM1 gene dose response. These findings provide a much-needed extension of previous studies of naltrexone pharmacogenetics to individuals of Asian descent, an ethnic group more likely to express the minor allele putatively associated with improved biobehavioral and clinical response to this medication. These findings help further delineate the biobehavioral mechanisms of naltrexone and its pharmacogenetics.Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology 09/2011; 37(2):445-55. · 6.99 Impact Factor