Combining Varenicline and Naltrexone for Smoking Cessation

This study is a double-blind, randomized clinical trial using a two group medication design consisting of the combination of VAR (1 mg twice daily) + NTX (50 mg once daily) and VAR (1 mg twice daily) + PLA (matched to NTX), for smoking cessation in a sample of heavy drinking daily smokers who want to quit smoking and reduce drinking. All participants will be daily smokers (≥ 5 cig/day) who are also heavy drinkers according to the National Institute on Alcohol Abuse and Alcoholism (NIAAA) guidelines: for men, \> 14 drinks per week or ≥ 5 drinks per occasion at least once per month over the past 12 months; for women, \> 7 drinks per week or ≥ 4 drinks per occasion at least once per month over the past 12 months. A total of 274 participants will be randomized, 137 to each medication group.