Gabapentin for smoking cessation: a preliminary investigation of efficacy.

Gabapentin affects the glutamate and gamma amino butyric acid (GABA) neurotransmitters through which it may facilitate smoking abstinence. To obtain preliminary estimates of efficacy of gabapentin for smoking cessation, we conducted a single-arm, open-label study of gabapentin, 1,800-mg/day administered in three equal divided doses for 8 weeks. A total of 50 adult smokers were enrolled. All participants received a brief behavioral intervention at each medication visit. A total of 37 participants completed all follow-up assessments. At end-of-treatment the biochemically confirmed point-prevalence and prolonged smoking abstinence rates were 28% (95% CI=16%-42%) and 24% (95% CI=13%-38%), respectively. At 6 months, the biochemically confirmed point-prevalence and prolonged smoking abstinence rates were 20% (95% CI=10%-34%) and 16% (95% CI=7%-29%), respectively. Among subjects who continued to smoke and completed the follow-up assessments, the reported number of cigarettes smoked per day (mean+/-standard deviation) was significantly less than at baseline: -10.0+/-8.2 (p<.001). Adverse effects were minor and well tolerated. Our results suggest that gabapentin may increase smoking abstinence. An adequately powered randomized clinical trial assessing different doses of this drug against a placebo would be the reasonable next step.