Conditions: Smoking
Keywords: smoking nicotine tobacco dependence cessation abstinence
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 506
Healthy volunteers: yes

Brief summary:
This study provides an opportunity to combine varenicline and bupropion SR and capitalize on the potential additive benefit. The investigators hypothesize that this will further increase long-term (≥ 6 months) smoking abstinence rates.

Detailed description:
Cigarette smoking is the single most important preventable cause of morbidity, mortality and excess health care costs in the United States and accounts for 30% of U.S. cancer deaths. Varenicline and bupropion SR (sustained-release) are non nicotine pharmacotherapies FDA-indicated for the treatment of tobacco dependence in cigarette smokers. Although varenicline has proven greater efficacy than bupropion SR, both medications are associated with high end-of-treatment smoking abstinence rates. However, almost two-thirds of smokers treated with varenicline report smoking at 6 months. Because varenicline and bupropion SR have different mechanisms of action and different neuropharmacologic targets, combination pharmacotherapy with these agents may increase long-term smoking abstinence rates above what is observed with single-agent therapy. In our recent pilot study of combination therapy with varenicline and bupropion SR, we observed treatment to be well-tolerated with 7-day point prevalence smoking abstinence rates of 71% (95% CI: 54-85%) at 3 months and 58% (95% CI: 41-74%) at 6 months. Determining the efficacy of combination therapy compared to single-agent therapy has immediate and important clinical implications. In this study, we will conduct a randomized, multicenter, controlled clinical trial evaluating the efficacy of combination therapy with varenicline and bupropion SR compared to varenicline and placebo in 506 cigarette smokers at the Mayo Clinic in Rochester, MN, and the University of Minnesota in Minneapolis, MN.

Arms:
arm 1: Everyone randomized to this arm will receive varenicline (up to 1mg bid) and bupropion SR (150 mg bid)for 12 weeks. They will be followed up by study for an additional 9 months post end of medication - for a total of 1 year study participation. Everyone will receive behavioral counseling for the full year. arm 2: Everyone randomized to this arm will receive varenicline (up to 1mg bid) and placebo (0 mg bid)for 12 weeks. They will be followed up by study for an additional 9 months post end of medication - for a total of 1 year study participation. Everyone will receive behavioral counseling for the full year.

Interventions: intervention 1: Varenicline intervention 2: placebo intervention 3: bupropion SR
Intervention descriptions: intervention 1: varenicline - 1 mg bid for 12 weeks intervention 2: placebo for 12 weeks intervention 3: bupropion sr - 150 mg bid for 12 weeks

Protocol document: