Varenicline for Smoking Cessation in Light Smokers

Introduction: As the prevalence of cigarette smoking has declined, the proportion of smokers who smoke less than 10 cigarettes/day (cpd) has increased. Varenicline may provide an effective pharmacotherapeutic treatment option for increasing smoking abstinence rates among light smokers. Methods: We conducted a randomized, placebo-controlled clinical trial evaluating the efficacy of varenicline for increasing smoking abstinence rates among light smokers (5-10 cpd). Participants received varenicline or placebo for 12 weeks. Outcomes were assessed at 3 and 6 months. Results: Ninety-three participants were randomized. Fifty-two percent of participants terminated the study early. At end-of-treatment (3 months), the point prevalence smoking abstinence rate was 53.3% in the varenicline group compared to 14.5% in placebo (odds ratio [OR]: 6.69, 95% confidence interval [CI]: 2.48-18.06, P <.001), and the prolonged smoking abstinence rate was 40.0% and 8.3%, respectively (OR: 7.33, 95% CI: 2.24-23.98, P =.001). At end-of-study (6 months), the point prevalence smoking abstinence rate was 40.0% in the varenicline group compared to 20.8% in placebo (OR: 2.53, 95% CI: 1.01-6.34, P =.047), and the prolonged smoking abstinence rate was 31.1% and 8.3%, respectively (OR: 4.97, 95% CI: 1.49-16.53, P =.009). The estimated magnitude of the treatment effect remained consistent across the various missing data assumptions and in analyses that adjusted for gender. Nausea and sleep disturbance were more commonly reported in the varenicline group. Conclusions: Varenicline was safe and effective for increasing long-term smoking abstinence rates in a population of predominantly White light cigarette smoker. The efficacy of varenicline in this study was comparable to that observed in heavier smokers. Implications: Our findings demonstrate that varenicline is effective for increasing smoking cessation in light smokers. Our findings have implications for advancing the treatment of light smokers in clinical practice.