Efficacy and Safety of Naltrexone and Acamprosate in the Treatment of Alcohol Dependence: a Systematic Review

Aims: To ascertain the efficacy and safety of naltrexone and acamprosate in the treatment of alcohol dependence.

Methods: Systematic review of the literature (1990-2002) and meta-analysis of full published randomized and controlled clinical trials assessing acamprosate or naltrexone therapy in alcohol dependence. Estimates of effect were calculated according to the fixed-effects model.

Measurements: Relapse and abstinence rates, cumulative abstinence duration and treatment compliance were considered as primary outcomes. Findings Thirty-three studies met the inclusion criteria. Acamprosate was associated with a significant improvement in abstinence rate [odds ratio (OR): 1.88 (1.57, 2.25), P < 0.001] and days of cumulative abstinence [WMD: 26.55 (17.56, 36.54]. Short-term administration of naltrexone reduced the relapse rate significantly [OR: 0.62 (0.52, 0.75), P < 0.001], but was not associated with a significant modification in the abstinence rate [OR: 1.26 (0.97,1.64), P = 0.08]. There were insufficient data to ascertain naltrexone's efficacy over more prolonged periods. Acamprosate had a good safety pattern and was associated with a significant improvement in treatment compliance [OR: 1.29 (1.13,1.47), P < 0.001]. Naltrexone's side effects were more numerous, yet the drug was nevertheless tolerated acceptably without being associated with a lower adherence to treatment (OR: 0.94 (0.80, 1.1), P = 0.5). However, overall compliance was relatively low with both medications.

Conclusions: Both acamprosate and naltrexone are effective as adjuvant therapies for alcohol dependence in adults. Acamprosate appears to be especially useful in a therapeutic approach targeted at achieving abstinence, whereas naltrexone seems more indicated in programmes geared to controlled consumption. Both drugs are safe and acceptably tolerated but issues of compliance need to be addressed adequately to assure their usefulness in clinical practice.