Gabapentin may promote abstinence in alcohol use disorder

A recent study shows evidence for a biomarker of efficacious treatment that may be used to assess other glutamatergic or GABAergic medications for alcohol use disorder (AUD) and related conditions, as well as provide insight into the means through which gabapentin may promote abstinence in individuals with AUD.

“Although gabapentin has demonstrated efficacy in mitigating alcohol withdrawal symptoms and preventing relapse drinking in individuals with AUD, the neurobiological mechanisms of action underlying these therapeutic effects remain unknown,” the investigators said.

To address this, a 16-week randomized clinical trial was conducted to examine the changes in GABA and glutamate levels in the dorsal anterior cingulate cortex (dACC) as candidate mechanisms of action in 68 adults with AUD, including a history of alcohol withdrawal syndrome.

Participants were randomly assigned to receive either gabapentin 1,200 mg/day (n=37) or placebo (n=31); they also received nine medical management visits after ≥72 hours of abstinence.

The investigators acquired proton MR spectroscopy estimates of dACC levels of GABA (n=67) and glutamate (n=64) prior to treatment initiation and again approximately 14 days following randomization. Percent days abstinent was reported through timeline follow-back interview.

The effects of gabapentin on GABA and glutamate levels significantly correlated with percent days abstinent during early treatment. Gabapentin specifically led to greater increases in glutamate and greater decreases in GABA levels in participants who remained mostly or entirely abstinent, but the opposite in those who drank on more than half of the days preceding the second scan.

In addition, gabapentin-treated participants with greater increases in glutamate levels during early treatment experienced significantly more percent days abstinent across the remainder of the study as compared with those who received placebo.