The study comprises an 8-week double-blind, within-subjects, crossover design of varenicline (up to 2mg per day) plus either prazosin (up to 8mg per day) (V+P) or placebo (V) with 20 heavy drinking smokers. Each medication phase is 3 weeks with a 2-week medication washout in between. Participants are asked to make a practice quit attempt for 3 days the last week of each medication phase.~This is an exploratory study to look at two primary aims:~Evaluate the effect of prazosin on sleep disturbance caused by varenicline in heavy drinking smokers prior to quitting smoking.~Hypothesis: V+P will result in lower rates of vivid dreams and insomnia symptoms/sleep discontinuity than V alone.~Evaluate the effect of prazosin on sleep disturbance caused by varenicline during smoking cessation in heavy drinking smokers.~Hypothesis: V+P will result in lower rates of vivid dreams and insomnia symptoms/sleep discontinuity than V alone We will also investigate the combined effects of prazosin and varenicline on smoking behavior (i.e., smoking urge) and alcohol consumption (i.e., drinks per drinking day) as exploratory aims.
The purpose of this study is to examine the effect of varenicline and prazosin on smoking, drinking, and sleep among cigarette smokers who report heavy alcohol use. Varenicline is an FDA approved smoking cessation medication. Some smokers report sleep problems when taking varenicline. This study will test whether using prazosin, which is an FDA-approved blood pressure medication, in combination with varenicline reduces sleep problems that can be associated with using varenicline for smoking cessation. In addition, the study will examine the combined effects of these medications on smoking and drinking.~Hypothesis: Varenicline plus prazosin will result in lower rates of vivid dreams and insomnia symptoms/sleep discontinuity than varenicline alone prior to the 3-day practice quit attempt.~Hypothesis: Varenicline plus prazosin will result in lower rates of vivid dreams and insomnia symptoms/sleep discontinuity than varenicline alone during the 3-day practice quit attempt.