Tobacco use during a clinical trial of mecamylamine for alcohol dependence: Medication effects on smoking and associations with reductions in drinking

Mecamylamine is a nicotinic acetylcholine receptor (nAChR) antagonist that was recently used in a clinical trial to treat alcohol use disorder (AUD) in both smokers and non-smokers. The current manuscript reports a reanalysis of data from this clinical trial in which we examine changes in smoking that occurred over the course of the trial. We focused on examining the effects of mecamylamine on smoking and the association between reductions in alcohol use and smoking. Participants were the subgroup of smokers who participated in the clinical trial of mecamylamine (10 mg/day) to treat their AUD (n = 76). Smoking was assessed prior to randomization and tracked throughout the course of the 12-week medication treatment phase. Participants were categorized as treatment responders or non-responders based on their changes in drinking over the course of the clinical trial. Participants showed a reduction in smoking over the course of the clinical trial, but there were no significant differences in smoking outcomes between the mecamylamine and placebo groups. Among moderate/high dependence smokers, those who successfully reduced drinking showed a significant reduction in cigarettes smoked per day over the clinical trial. Mecamylamine had no detectable effect on smoking outcomes. Reductions in alcohol use predicted more favorable smoking outcomes among moderate/high tobacco dependence smokers irrespective of medication condition. The reduction in smoking among patients who decreased their alcohol use responders highlights an opportunity for patients being treated for AUD to reduce their smoking.