Long-term smokeless tobacco (ST) use is known to increase the risk for oropharyngeal cancer, heart attack, and stroke. Varenicline has recently been demonstrated to increase ST abstinence rates among Swedish snus users. We have conducted a pilot study to obtain preliminary evidence of efficacy of varenicline for the treatment of ST users in Midwestern United States.
We conducted a randomized, placebo-controlled Phase II clinical trial to evaluate the potential efficacy of 12 weeks of varenicline for the treatment of ST users with an a priori decision rule that a 1-tailed p < .20 for the comparison of the primary endpoint was evidence to conclude that future studies were warranted. Subjects were followed for 6 months after randomization.
We randomized 76 subjects (38 varenicline and 38 placebo). Subjects were similar at baseline with a mean age of 41 years, and all were male. The biochemically confirmed point prevalence tobacco abstinence rates at end of treatment were 55.3% for varenicline and 42.1% for placebo (p = .126) and 47.4% and 31.6% (p = .080), respectively, at 6 months. Point prevalence ST abstinence rates at end of treatment for varenicline were 57.9% and 42.1% for placebo (p = .084) and 57.9% and 31.6% (p = .011), respectively, at 6 months. Varenicline was associated with significantly less craving compared with placebo. Varenicline was well tolerated with nausea and sleep disturbance being the most common side effects.
Varenicline decreases craving and may be effective for increasing tobacco abstinence rates among ST users. Larger trials may be warranted to confirm these results.