A Double-Blind Randomized Placebo-Controlled Trial of Oral Naltrexone for Heavy-Drinking Smokers Seeking Smoking Cessation Treatment

BackgroundPost hoc analyses of 2 randomized controlled trials suggest naltrexone may reduce alcohol use and improve smoking cessation outcomes among heavy drinkers receiving smoking cessation treatment. However, no studies have been conducted specifically to examine naltrexone for this purpose or to test whether naltrexone has benefit when added to smoking cessation counseling that explicitly addresses heavy drinking. MethodsWe recruited heavy-drinking smokers from the community and randomized them to receive 10weeks of either (i) 50mg naltrexone (n=75) or (ii) placebo (n=75) daily. Participants received 6weeks of transdermal nicotine patch and 6 sessions of counseling that addressed both heavy drinking and smoking. Participants were followed for 26weeks after their target quit smoking date. ResultsAcross medication conditions, there were substantial reductions at follow-up in percent heavy drinking days (primary outcome) and average drinks per week (secondary outcome). However, participants receiving naltrexone did not differ significantly from those receiving placebo on percent heavy drinking days (effect size d=-0.04, 95% CI [-0.30, 0.22], p=0.76) or average drinks per week (d=-0.09, 95% CI [-0.35, 0.18], p=0.54) during follow-up. Naltrexone compared to placebo was not associated with a significant increase in smoking abstinence rates during follow-up, odds ratio=0.93, 95% CI [0.46, 1.86], p=0.83. The effect of naltrexone on these outcomes was not significantly moderated by current alcohol dependence or gender. ConclusionsResults indicate that heavy-drinking smokers, including those with current alcohol dependence, can make substantial reductions in drinking in the context of smoking cessation treatment. However, this study provided no evidence that naltrexone is efficacious for enhancing reductions in drinking or improving smoking cessation in this population. Limitations of this study included lower-than-desired sample size and modest adherence to study medication.