Cigarette Smoking and Heavy Alcohol Drinking: The Challenges and Opportunities for Combination Treatments

OBJECTIVE: Pharmacological treatments that can concomitantly address cigarette smoking and heavy drinking stand to improve healthcare delivery for these highly prevalent co-occurring conditions. This superiority trial tested the combination of varenicline plus naltrexone versus varenicline alone for smoking cessation and drinking reduction among heavy drinking smokers. METHODS: This was a phase 2, randomized, double-blind, clinical trial. Participants (n=165) were daily smokers who drank heavily and received either (a) varenicline tartrate 1 mg twice daily plus naltrexone 50 mg once daily, or (b) varenicline tartrate 1 mg twice daily plus matched placebo pills for 12-weeks. Primary outcomes were (a) 7-day point prevalence of nicotine abstinence bioverified by breath carbon monoxide (CO) reading of ≤ 5 ppm at the 26-week follow-up, and (b) drinks per drinking day during the 12-week treatment phase. RESULTS: Smoking abstinence at week 26 was significantly higher in the varenicline plus placebo condition than the varenicline plus naltrexone condition (n=37 [45.1%] versus n=22 [26.5%]; χ(2)[1] = 6.22, p=.015). For drinks per drinking day, there was a trend towards a main effect of medication [β=0.86, SE=0.44, t(1,250)=1.94, p=.054], favoring the combination of varenicline plus naltrexone over varenicline alone across the 12-week treatment phase. CONCLUSIONS: These findings suggest that smoking cessation and drinking reduction can be concomitantly targeted with pharmacotherapy and that while varenicline alone may be sufficient as a smoking cessation aid in heavy drinking smokers, the combination of varenicline plus naltrexone may confer benefits with regards to drinking outcomes, particularly during the 12-week period of active medication treatment. TRIAL REGISTRATION: ClinicalTrials.gov NCT02698215.