People who are regular smokers often frequently drink alcohol, and vice versa. The co-use of these substances can be problematic when smokers are trying to quit using tobacco. Alcohol use increases the risk for relapse during a smoking quit attempt and regular smokers who also drink heavily have more health problems than individuals who only smoke or only drink. Given the high co-occurrence of smoking and drinking and the health risks associated with the co-use of these substances, heavy drinking smokers are especially in need of an effect treatment for smoking cessation. Yet, there are no medications or treatment guidelines for clinicians that are specifically tailored to heavy drinking smokers, despite the evidence that traditional smoking cessation treatments are not effective in this sub-group of smokers. Therefore, developing effective smoking cessation treatments for heavy drinking smokers represents is a research priority.
Varenicline is a medication that helps people quit smoking and that may also be effective in reducing alcohol use. Recent studies have indicated that varenicline reduces the pleasurable effects of alcohol, as well as alcohol craving and consumption in alcohol dependent individuals. These findings suggest that varenicline is a promising medication for smoking cessation in heavy drinking smokers, as reducing alcohol craving and consumption may help prevent smoking relapse in this sub-group.
In early abstinence, one of the most reliable predictors of relapse is the occurrence of a single smoking lapse (or, “a slip”), which is generally defined as smoking at least a puff of a cigarette. As many as 95% of smokers who experience a lapse during a quit attempt will eventually relapse to regular smoking. Additionally, alcohol consumption increases the chance of a smoking lapse occurring, and, therefore, may contribute to the difficultly that heavy drinking smokers have when trying to quit smoking. Recent evidence suggests that varenicline reduces the probability of a smoking lapse occurring, but it is unknown whether varenicline can reduce the occurrence of the smoking lapses that are caused by alcohol in heavy drinking smokers.
To address this important gap in the literature, the proposed human laboratory study will use two laboratory procedures, namely alcohol administration and a behavioral smoking lapse task, to examine the effects of varenicline in heavy-drinking smokers. Specifically, 22 heavy drinking smokers will receive varenicline or placebo and will complete two separate laboratory sessions, in which they will consume a placebo or alcohol beverage. After drinking the beverage, the participants will complete a recently developed smoking lapse task, in which they are given the choice to smoke a cigarette or receive money the longer they can resist smoking. This design will provide key evidence whether varenicline can be used as an effective medication for smoking cessation in heavy drinking smokers by measuring its effects on response to alcohol and subsequent ability to resist a smoking lapse. We hypothesize that varenicline, compared to placebo, will reduce cigarette and alcohol craving, reduce the pleasurable effects of aalcohol and cigarette smoking, and improve performance on the smoking lapse task by increasing the participant’s ability to resist smoking. Furthermore, we hypothesize that varenicline’s ability to reduce the pleasurable effects of alcohol will be directly predictive of individual performance on the smoking lapse task. Since heavy drinking smokers have been shown to be relatively treatment-resistant, the results of the current study could have sizable implications for supporting varenicline as a potential tailored medication for this sizable and at-risk sub-group.