Baclofen: its effectiveness in reducing harmful drinking, craving, and negative mood. A meta-analysis

Background and Aims There are a limited number of pharmacotherapies licensed for alcohol use disorders (AUDs). Baclofen is gamma-aminobutyric acid B (GABA-B) agonist which is used increasingly as an off-label treatment. A meta-analysis of randomized controlled trials (RCTs) was conducted to determine the efficacy of baclofen in reducing drinking behaviour, craving, depression and anxiety compared with placebo. Methods Random-effects meta-analyses were computed on outcome data from 12 RCTs comparing baclofen with placebo. Included RCTs provided data on at least one of the primary outcome measures (drinking-related: heavy drinking days, abstinent days, abstinence rates) or secondary outcome measures (craving, anxiety, depression). Results Baclofen had a significant effect on abstinence rates when using intention-to-treat analysis [total n baclofen=307, total n control=283: odds ratio (OR)=2.67, 95% confidence interval (CI) =1.03, 6.93; Z=2.01, P=0.04, I-2=76%, number needed to treat=8]. No other significant effects of treatment efficacy [e.g. heavy drinking days: standardized mean differences (SMD)=-0.26, 95% CI=-0.68, 0.15; Z=1.24, P=0.21, I-2=95%] or mechanism of action (e.g. craving: SMD=-0.13, 95% CI=-0.36, 0.09; Z=1.18, P=0.24, I-2=87%) were observed. There was substantial heterogeneity in effect sizes across each analysis. Conclusions As a treatment for alcohol use disorders, baclofen is associated with higher rates of abstinence than placebo. However, there is no superior effect of baclofen on increasing number of abstinent days, or decreasing heavy drinking, craving, anxiety or depression. These results suggest that the current increasing use of baclofen as a treatment for alcohol use disorders is premature.