Review of: Anton RF et al, JAMA Intern Med 2020;180(5):1–9

Gabapentin has had mixed results in the treatment of alcohol use disorder (AUD), but it is clearly effective in the treatment of alcohol withdrawal syndrome (AWS). In this study, researchers tested whether gabapentin might be effective specifically in treating adults with AUD who also had a history of AWS.

The investigators conducted a 16-week randomized controlled trial comparing gabapentin to placebo. Ninety patients with AUD and a history of AWS were enrolled (44 in the gabapentin arm, 46 in the placebo arm). Here, AWS was defined as a self-reported history of withdrawal symptoms; however, those with a history of withdrawal seizures were excluded.

Participants were aged 18–70 (94% were white, 77% were men) and drank a mean of 86% of pre-treatment days, with 83% being heavy drinking days (defined as 5 or more drinks per day for men and 4 or more drinks per day for women). They were required to have been abstinent for 3 days prior to randomization. The study took place in an academic medical center and was sponsored by the National Institute on Alcohol Abuse and Alcoholism.

Gabapentin was started at 300 mg at bedtime and titrated over 5 days to 300 mg in the morning, 300 mg at noon, and 600 mg at bedtime. Patients in both groups received nine 20-minute medical management visits.

After 16 weeks, more gabapentin-treated individuals had no heavy drinking days compared with placebo (27% vs 9%, p = 0.02), with a number needed to treat (NNT) of 5.4. More ­gabapentin-treated patients also achieved total abstinence compared to placebo (18% vs 4%, p = 0.04), with an NNT of 6.2. The effect was more pronounced for patients with histories of more severe withdrawal. Among those who had reported less severe withdrawal, there was no difference between gabapentin and placebo. There was more dizziness reported in the gabapentin arm (57%) than in the placebo arm (33%; p = 0.02), but no serious adverse events were reported.

CATR’s Take
Gabapentin reduced heavy drinking days and promoted abstinence in patients with AUD who had withdrawal symptoms. However, the trial doesn’t address the effect of gabapentin beyond 4 months of use, and concerns remain regarding gabapentin misuse, addiction, and interaction with other sedating substances.