Context

Cigarette smoking is the leading cause of preventable premature death in the world, with an estimated 5 million smoking-related deaths worldwide. Quitting substantially reduces the health risk associated with smoking. Treatments available for smoking cessation include nicotine replacement therapies (NRTs), bupropion and the most recently marketed, varenicline. Varenicline, an analogue of cytisine, is a partial agonist for the α4β2 subtype of nicotinic cholinergic receptors, which are associated with the addictive effects of nicotine. Varenicline may help smokers quit smoking by reducing the rewarding effects of nicotine as well as attenuating the withdrawal symptoms.1 This meta-analysis evaluated the efficacy and safety of partial nicotine agonists, varenicline or cytisine, compared with placebo or other treatments in clinical trials conducted worldwide.