Baclofen for the Treatment of Alcohol Dependence and Possible Role of Comorbid Anxiety

Abstract

Aim: To conduct a double-blind, placebo-controlled randomized clinical trial of baclofen in the treatment of alcohol dependence.

Methods: Out of 69 participants consecutively screened, 42 alcohol-dependent patients were randomized to receive placebo, baclofen 30 mg/day or baclofen 60 mg/day for 12 weeks. All subjects were offered BRENDA, a structured psychosocial therapy for alcohol dependence that seeks to improve motivation for change, enhance strategies to prevent relapse and encourage compliance with treatment.

Results: Intention-to-treat analyses revealed that alcohol consumption (heavy drinking days, drinks per drinking day) significantly reduced across all three groups during the treatment period. There were no statistically significant advantages to treatment on time to first heavy drinking day (relapse) (P = 0.08), nor time to first drink (lapse) (P = 0.18). A post hoc analysis stratifying according to whether there had been a comorbid anxiety disorder, revealed a beneficial effect of baclofen 30 mg/day versus placebo on time to lapse and relapse (P < 0.05). There was also a beneficial effect for baclofen 60 mg/day relative to placebo on time to relapse in this comorbid group (P < 0.05). Both doses of baclofen were well tolerated. There were no serious adverse events.

Conclusions: In spite of the small sample for a 3-arm clinical trial, this study suggests a specific role of baclofen in alcohol-dependent individuals with comorbid anxiety. Replication in larger, fully-powered studies is required.

Fig. 1.

Flow of participants through the trial.

Fig. 2.

Survival curve for time to relapse for participants randomized to either placebo, baclofen 30 mg/day or baclofen 60 mg/day for 12 weeks stratified for (a) ‘no comorbid anxiety’ (n = 25) and (b) ‘comorbid anxiety’ (n = 17). Intention-to-treat analysis. In participants with ‘comorbid anxiety’, significant treatment effects (χ² = 12.43, P < 0.01) emerged between baclofen 30 mg/day and placebo (χ² = 9.10, P < 0.01) and baclofen 60 mg/day and placebo (χ² = 4.55, P < 0.05). Patients were categorized into two groups according to the absence or presence of an anxiety disorder (generalized anxiety disorder, social phobia, obsessive disorder, agoraphobia, panic disorder and/or PTSD) as per the Mini International Neuropsychiatric Interview conducted at baseline.