1) Estimate the effect of extended-release naltrexone compared with placebo on alcohol consumption in patients with alcohol use disorder (AUD). 2) Conduct pre-planned subgroup analyses to test whether being abstinent when initiating treatment (lead-in abstinence) or the duration of treatment improves treatment efficacy.
Systematic review and random effects meta-analysis of blinded randomized placebo-controlled trials reporting the effect extended-release naltrexone on alcohol consumption
7 trials evaluating a total of 1500 adults with AUD receiving monthly injections of either placebo or extended-release naltrexone at doses of 150-400mg for 2-6 months and some form of behavioral therapy.
Pooled weighted mean difference (WMD) in drinking days per month and heavy drinking days per month
The WMD was -2.0 (95% CI, -3.4, -0.6; p = 0.03) in favor of extended-release naltrexone for drinking days per month, and -1.2 (95% CI, -0.2, -2.1; p = 0.02) for heavy drinking days per month, indicating that treatment resulted in 2 fewer drinking days per month and 1.2 fewer heavy drinking days per month compared with placebo. Trials not requiring lead-in abstinence and those lasting longer than 3 months reported larger reductions in heavy drinking days per month, WMD -2.0 (95% CI, -3.52, -0.48; p = 0.01) and -1.9 (95% CI, -3.2, -0.5; p = 0.01) respectively. In all cases, the I2 statistics (0-7.2%) did not suggest substantial heterogeneity.
Extended-release naltrexone reduces drinking days and heavy drinking days per month compared with placebo. Reductions are larger with longer duration of treatment