Baclofen as Add-On to Standard Psychosocial Treatment for Alcohol Dependence: a Randomized, Double-Blind, Placebo-Controlled Trial With 1 Year Follow-Up

• RCTs conducted to date yielded conflicting results that require additional research to establish whether baclofen does or does not have therapeutic efficacy in alcohol dependence.
• No between baclofen–placebo arms differences were found in the primary outcomes: percentages of heavy drinking and abstinent days.
• A significant reduction in the secondary outcomes—levels of distress, depression and craving and improved HRQL occurred for both arms.
• More placebo-controlled trials are needed to either verify or discard a possible clinical efficacy of baclofen for alcohol dependence.

BackgroundLimited clinical trials and case-reports yielded conflicting results regarding the efficacy of baclofen (a GABAB agonist) in the treatment of alcohol dependence. The aim of this study was to test the efficacy and tolerability of baclofen in alcohol dependent patients in Israel.MethodsThe study was a double-blind, placebo-controlled, randomized trial comparing 50 mg/day of baclofen to placebo over 12 weeks, in addition to a standard psychosocial intervention program, with 26-week and 52-week follow-up observations. The percentages of heavy drinking days and abstinent days were the primary outcome measures, and craving, distress and depression levels; self-efficacy; social support from different sources; and health-related quality of life (HRQL) were secondary outcomes. Tolerability was also examined.ResultsSixty-four patients were randomized; 62% completed the 12-week trial and 37% completed the 52-week follow-up. No between group differences were found in the percentages of heavy drinking and abstinent days. A significant reduction in levels of distress, depression and craving and improved HRQL occurred for both arms, whereas self-efficacy and social support remained unchanged in both groups. No adverse events were observed.ConclusionsUnlike previous positive trials in Italy, and similarly to a negative trial in the USA, we found no evidence of superiority of baclofen over placebo in the treatment of alcohol dependence. However, the high placebo response undermines the validity of this conclusion. Therefore, more placebo-controlled trials are needed to either verify or discard a possible clinical efficacy of baclofen for alcohol dependence.