Title: Cytisine Versus Nicotine for Smoking Cessation
Abstract: Cytisine is a partial agonist that binds the nicotine acetylcholine receptor. Placebo-controlled trials indicate that its use almost doubles the chances of quitting smoking at 6 months in individuals seeking tobacco abstinence. In this study the authors investigated whether cytisine was as effective as nicotine-replacement therapy in helping smokers to quit. This is a pragmatic, open-label, non-inferiority trial in New Zealand. 1310 adult daily smokers who were motivated to quit and called the national quit line were randomly assigned in a 1:1 ratio to receive cytisine for 25 days or nicotine-replacement therapy for 8 weeks. Cytisine was provided by mail and was free of charge, and nicotine-replacement therapy was provided through vouchers for low-cost patches along with gum or lozenges. Low-intensity, telephone-delivered behavioral support was provided to both groups via the quitline. Primary outcome was self-reported continuous abstinence at 1 month. At 1 month, 40% of participants receiving cytisine reported continuous abstinence from smoking and 31% of participants receiving nicotine-replacement therapy reported continuous abstinence. The difference was 9.3 percentage points (95% confidence interval, 4.2-14.5). Cytisine was also more effective for continuous abstinence than nicotine-replacement therapy at 1 week, 2 months, and 6 months. A prespecified group analysis of the primary outcome demonstrated cytisine was superior to nicotine-replacement therapy among women, and noninferior among men. Self-reported adverse events over 6 months occurred more frequently in the cytisine group (288 events among 204 participants) than in the nicotine-replacement group (174 events among 134 participants). Adverse events consisted primarily of nausea and vomiting and sleep disorders. Participants in the cytisine group reported fewer symptoms of tobacco withdrawal and found smoking less rewarding and reduced the number of cigarettes smoked per day.