Efficacy of varenicline versus bupropion for smoking cessation: A systematic review and meta-analysis of randomized controlled trials

According to the Global Burden of Disease (GBD) Study conducted in 2019, smoking tobacco leads to over 8 million deaths each year. Hence, it is crucial to identify optimal smoking cessation therapy. To compare the efficacy of varenicline versus bupropion for smoking cessation by performing a meta-analysis of randomized controlled trials (RCTs). Protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO). The Patient intervention comparison outcome time (PICOT) format is used in the study. Patients having nicotine use disorder treated with varenicline or bupropion were included, and the continuous abstinence rate (CAR) was assessed at 12, 24, and 52 weeks. The PubMed and Google Scholar databases were systematically searched, and after the screening, RCTs involving a comparison of varenicline and bupropion in smoking cessation were included. We performed a meta-analysis of three RCTs (10110 patients) by RevMan 5.4.1 statistical software to determine the efficacy of varenicline compared with bupropion in smoking cessation. The CAR at 9- to 12-week follow-up of varenicline is superior to bupropion (OR = 1.79, CI range: 1.59-2.02, P < 0.001). Similarly, the CAR of varenicline is superior to bupropion for weeks 9-24 (1.51, 1.32 to 1.72) and weeks 9-52 (1.60, 1.22 to 2.12), suggesting the absolute advantage of varenicline over bupropion for smoking cessation in terms of efficacy. Both varenicline and bupropion are efficacious therapies for smoking cessation. Compared with bupropion, varenicline can significantly improve the CAR at the end of treatment, at 24 weeks, and at 52 weeks of follow-up.