Acamprosate and Naltrexone: Similar Efficacy for Reducing Return to Drinking

Most people with alcohol use disorders do not receive treatment, and very few receive medication treatment. Investigators systematically searched the literature to identify double-blind randomized trials of medications for adult outpatients with alcohol dependence (non-randomized studies of health outcomes and adverse effects were included); 123 studies with 22,803 participants were included in the report and 95 in meta-analyses.

• Acamprosate and naltrexone both reduced return to any drinking (numbers needed to treat, 12 and 20, respectively), and there were no differences in head to head comparisons. Naltrexone reduced heavy drinking.
• Acamprosate studies with the lowest risk of bias found no efficacy for the medication.
• Topiramate and nalmefene both reduced several drinking outcomes.
• There was insufficient evidence for improvements in health outcomes for any medication.
• Naltrexone was associated with dizziness, nausea, and vomiting (number needed to harm [NNH], 16, 9, and 24, respectively).
• Acamprosate was associated with anxiety, diarrhea, and vomiting (NNH, 7, 11, and 42, respectively).
• Topiramate was associated with cognitive dysfunction, paresthesias, and taste abnormalities (NNH, 12, 4, and 7, respectively).
• Nalmefene was associated with dizziness, headache, insomnia, nausea, and vomiting (NNH, 7, 26, 10, 7, and 17, respectively).

Comments:

There are a few caveats to consider when interpreting this report. Firstly, disulfiram was not found to have efficacy, but placebo-controlled trials are not optimal for testing the efficacy of a medication that requires that patients know they are taking it. Studies of supervised oral disulfiram have demonstrated efficacy. Secondly, most studies provided psychosocial counseling, which may be necessary for better treatment outcomes, though not easily delivered in primary care settings. Lastly, the medications have side effects and have not been shown to affect outcomes beyond consumption. Nonetheless, medications for alcohol use disorders have modest efficacy for reducing drinking in people with moderate to severe alcohol use disorders.

Richard Saitz, MD, MPH

Reference:

Jonas DE, Amick HR, Feltner C, et al. Pharmacotherapy for adults with alcohol use disorders in outpatient settings. a systematic review and meta-analysis. JAMA. 2014;311:1889–1900.