The Impact of Varenicline on Alcohol Consumption in Subjects With Alcohol Use Disorders: Systematic Review and Meta-Analyses

OBJECTIVE Varenicline has been shown to be safe and effective in improving abstinence in smokers. However, results from randomized, placebo-controlled trials using varenicline for alcohol use disorders (AUDs) are inconsistent. The present systematic review and meta-analyses aimed to ascertain whether varenicline improves drinking-related outcomes in subjects with AUDs. DATA SOURCES Ovid, Embase, and Scopus databases were queried using the search terms varenicline, alcoholism, alcohol-related disorders, and drinking behavior for English-language publications until August 29, 2019, of randomized, placebo-controlled trials in humans. STUDY SELECTION A total of 197 articles were identified by the literature search. Studies of subjects with heavy drinking or alcohol dependence/AUD that reported alcohol use-related outcomes were examined. DATA EXTRACTION Weighted mean difference (WMD), standardized mean difference (SMD), and 95% CIs were calculated. The primary outcome of interest was percentage of heavy drinking days. Secondary outcomes included the number of drinks per drinking day, percentage of days abstinent, and change in alcohol craving. RESULTS Ten studies (n = 731, 66.6% male, 55.1% smokers) were included in the systematic review. In meta-analyses, no significant differences in percentage of heavy drinking days (n = 597; WMD = -1.09; 95% CI, -4.86 to 2.69; I² = 22%), number of drinks per drinking day (n = 570; WMD = -0.71; 95% CI, -1.44 to 0.03; I² = 0%), or percentage of days abstinent (n = 439; WMD = 3.89; 95% CI, -1.25 to 9.02; I² = 0%) were noted with varenicline use. Overall risk of bias was low. A statistically significant decrease in craving was observed (n = 436; SMD = -0.63; 95% CI, -1.18 to -0.08; I² = 84%). CONCLUSIONS In the present systematic review and meta-analyses, varenicline was shown to reduce alcohol craving but not improve drinking-related outcomes in subjects with AUDs.