Comparing and combining naltrexone and acamprosate in relapse prevention of alcoholism: a double-blind,placebo-controlled study

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.