Varenicline and cytisine are efficacious aids to smoking cessation. Varenicline is more efficacious than bupropion and may be more efficacious than nicotine patch.

Varenicline is a nicotine receptor partial agonist. Eleven trials of varenicline for long-term smoking cessation and one of varenicline for relapse prevention are available. In cessation trials, varenicline demonstrated significant effects on long-term abstinence, more than doubling the likelihood of abstinence. In a double-blind, discontinuation trial of varenicline, people who were abstinent at the end of 12 weeks of varenicline therapy and continued on varenicline, had higher 6-month quit rates than abstinent smokers who were switched to placebo at the 12-week time point.

Three trials have compared varenicline to bupropion in a double placebo design. When pooled there was a significantly greater benefit from varenicline. Quit rates amongst people using bupropion were however slightly lower than expected.

Indirect evidence suggests that varenicline may be more effective than the nicotine patch but the direct evidence is inconclusive.

Cytisine is a nicotine receptor partial agonist like varenicline. A product containing cytisine, Tabex, has been licensed and used as a smoking cessation aid in some Eastern European countries for more than 40 years. One high quality randomized trial has now shown a statistically and clinically significant effect on 12 month abstinence.

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West R, Zatonski W, Cedzynska M, et al. Placebo-controlled trial of cytisine for smoking cessation. N Engl J Med. 2011; 365(13): 1193-1200.