Agabio 2023 (Cochrane): baclofen for alcohol use disorder

What they tested

The reviewers gathered randomized trials of baclofen for alcohol use disorder with at least 4 weeks of treatment and 12 weeks of study overall, comparing it with placebo, no treatment or other medicines. The latest search was on 22 November 2021.

They found 17 trials with 1,818 people. Fifteen compared baclofen with placebo, two with acamprosate and two with naltrexone. Daily doses ranged from 30 mg to 300 mg, and in 16 trials people also got psychosocial treatment.

What they found

Against placebo, moderate-certainty evidence found baclofen probably reduces relapse (RR 0.87; 12 studies, 1,057 people). High-certainty evidence found it increases the percentage of days abstinent (mean difference 9.07; 16 studies, 1,273 people). The relapse benefit held in people who had been through detox but not in other subgroups.

Baclofen made no difference to heavy drinking days, drinks per drinking day, craving, anxiety or depression. It did not increase the number of people with at least one side effect or the number who dropped out, but it did increase fatigue, dizziness, sleepiness, dry mouth, tingling (paraesthesia) and muscle spasms or stiffness.

Compared with naltrexone, baclofen may increase the risk of relapse (RR 2.50; 1 study, 60 people) and may reduce the number of people with at least one side effect (RR 0.35; 2 studies, 80 people). The reviewers rated this evidence very low certainty.

Against acamprosate, one study of 60 people found no differences, with very uncertain evidence.

Limits

• The comparisons with naltrexone rest on one or two small studies, so they can't settle which drug works better.
• Everyone had alcohol dependence by DSM-IV or ICD-10 criteria, and 70% were men.
• Most trials lasted 12 weeks, so longer-term effects are less clear.

What it means if you're considering naltrexone

Baclofen has some evidence for helping people stay abstinent, mainly after detox, but not for cutting heavy drinking. The head-to-head evidence against naltrexone is too thin to show either drug is better, though the one trial that measured relapse favoured naltrexone.