An Invited Commentary article accompanying this study notes that research on the use of anticonvulsants for the treatment of alcohol withdrawal began to emerge in the 1970s, based in part on the typical occurrence of seizures and autonomic hyperactivity during withdrawal. The consensus is that they are useful adjuncts in the treatment of withdrawal, but that they do not fully substitute for benzodiazepines, which remain the treatment of choice.
It is hypothesised that anticonvulsants might also be beneficial in the chronic treatment of alcohol dependence, to induce and maintain abstinence and prevent relapse. Preliminary research has suggested that gabapentin may potentially have an effect in alcohol-dependent individuals, and the present study was designed to provide a more definitive evaluation of its safety and efficacy in this setting. The highest (1800mg/day) and lowest (900mg/day) FDA approved doses were evaluated in this dose-ranging study.
The single centre US study recruited treatment-seeking volunteers with alcohol dependence who had been abstinent for at least three days. Those at risk of significant withdrawal were excluded, as were those dependent on another substance other than alcohol and nicotine. Gabapentin was found to have a statistically significant linear dose effect on rate of complete abstinence (p=0.04) and no heavy drinking (p=0.02) over the 12-week double-blind phase of the study, with the largest effects seen in the 1800mg dose group (NNT of 8; 95% CI 6 to ∞, for abstinence and 5; 3-78, for no heavy drinking).
The study did however have a large dropout rate, which is often seen in trials of substance dependence. In addition it was a single site study, and the results may not be generalisable to other treatment settings and populations. Larger studies in more diverse populations are required to replicate and extend these findings.
The authors of the Invited Commentary note that the study population were able to abstain from alcohol for several days prior to initiating gabapentin, and that it would be useful to determine in future research whether the efficacy of gabapentin depends on such an initial period of abstinence, and whether it is only effective in patients with mild-moderate dependence who are able to stop drinking for a few days at a time (suggesting more of a role in the primary care). It is not known whether there are any plans to seek regulatory approval of gabapentin for alcohol dependence, and if so whether further trials would be required to confirm efficacy and safety.