Aim: To evaluate the efficacy of naltrexone maintenance treatment in preventing relapse in opioid addicts after detoxification.
Design: A systematic review according to the methodology developed by the Cochrane Collaboration based on either randomized controlled trials (RCTs) or controlled clinical trials (CCTs).
Participants: Seven hundred and seven heroin dependent in- and out-patients, or former heroin addicts dependent on methadone and participating in a naltrexone treatment programme; 89% were male.
Intervention: Maintenance treatments on opiate dependent people after detoxification, comparing naltrexone with placebo, pharmacological or behavioural treatments.
Measurements: The outcomes considered were successfully completed treatment, opioid use under treatment (re)-incarcerations during the study period, mean duration of treatment.
Findings: The outcomes tended to be slightly although not significantly in favour of the naltrexone groups. Use of naltrexone in addition to behavioural treatment significantly decreased the probability of (re-)incarceration (OR=0.30; 95% CI 0.12, 0.76). The difficulties in producing a quantitative analysis were due mainly to the heterogeneity of the included studies.
Conclusions: From the available clinical trials performed up to this time, there is insufficient evidence to justify the use of naltrexone in maintenance treatment of opioid addicts.