Smokers successfully quit smoking with varenicline compared to either bupropion or placebo

The study, published in the Indian Journal of Psychiatry, however, showed that varenicline can significantly improve the continuous abstinence rate (CAR) at the end of treatment, at 24 weeks, and at 52 weeks of follow-up, compared with bupropion.

The Global Burden of Disease (GBD) Study conducted in 2019, showed that smoking tobacco leads to over 8 million deaths each year. Hence, it is important to identify optimal smoking cessation therapy.

Bupropion is an atypical antidepressant and is the first non-nicotine-based drug approved by US FDA (Food and Drug Administration) in 1997 for smoking cessation in adults. It acts by the inhibition of dopamine reuptake into neuronal synaptic vesicles.

Varenicline received FDA approval in 2006 and works as a selective nicotinic receptor partial agonist. It acts by selectively activating the α4β2nAChR, mimicking nicotine's action and causing a moderate and sustained release of mesolimbic dopamine.

Ashish R. Patel, BJ Medical College and Civil Hospital, Ahmedabad, Gujarat, India, and colleagues aimed to compare the efficacy of varenicline versus bupropion by performing a meta-analysis of randomized controlled trials (RCTs). The Patient intervention comparison outcome time (PICOT) format is used in the study.

The study included patients having nicotine use disorder treated with either bupropion or varenicline, and CAR was evaluated at 12, 24, and 52 weeks. The researchers systematically searched the online databases, and following the screening, RCTs involving a comparison of bupropion and varenicline in smoking cessation were included. A meta-analysis was performed of three RCTs comprising 10110 patients by RevMan 5.4.1 software to determine varenicline's efficacy compared with bupropion in smoking cessation.

The authors reported the following findings:

• The CAR at 9- to 12-week follow-up of varenicline is superior to bupropion (OR = 1.79).
• 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.

Based on the findings, the authors inferred that both bupropion and varenicline are effective therapies for smoking cessation. However, the studies had recruited the majority of patients of the African American or White race. Hence, there is a need to compare the efficacy of bupropion versus varenicline in the Asian race, particularly in the Indian population.

"The meta-analysis shows that more smokers quit successfully with varenicline compared with either placebo or bupropion," the researchers wrote. "Furthermore, long-term follow-up studies suggest that varenicline use (three trials of 24 weeks and two trials of 52 weeks) delivered an unequivocal efficacy of varenicline over bupropion for smoking cessation."

Reference:

Patel AR, Panchal JR, Desai CK. Efficacy of varenicline versus bupropion for smoking cessation: A systematic review and meta-analysis of randomized controlled trials. Indian J Psychiatry. 2023 May;65(5):526-533. doi: 10.4103/indianjpsychiatry.indianjpsychiatry_218_22. Epub 2023 May 15. PMID: 37397838; PMCID: PMC10309263.