Efficacy of varenicline or bupropion and its association with nicotine metabolite ratio among smokers with COPD

Abstract

Background and objectiveNicotine metabolic ratio (NMR) has been associated with nicotine metabolism and smoking characteristics. However, there are few studies on the potential association between NMR and smoking cessation efficacy in smokers with chronic obstructive pulmonary disease (COPD) in China or elsewhere.MethodsThis study was a stratified block randomized controlled trial for smoking cessation in Chinese smokers with COPD. NMR was used as a stratification factor; slow metabolizers were defined as those with NMR <0.31, and normal metabolizers as those with NMR ≥0.31. Participants were randomly assigned to the varenicline or bupropion group. Follow‐up visits were conducted at 1, 2, 4, 6, 9, 12 and 24 weeks.ResultsTwo hundred twenty‐four participants were recruited and analysed from February 2019 to June 2022. In normal metabolizers, the 9–12 weeks continuous abstinence rate of varenicline (43.1%) was higher than in bupropion (23.5%) (OR = 2.47, 95% CI 1.05–5.78, p = 0.038). There was no significant difference in abstinence rates between treatment groups in slow metabolizers (54.1% vs. 45.9%, OR = 1.39, 95% CI 0.68–2.83, p = 0.366). For slow metabolizers, the total score of side effects in the varenicline group was significantly higher than the bupropion group (p = 0.048), while there was no significant difference in side effects between groups for normal metabolizers (p = 0.360).ConclusionVarenicline showed better efficacy than bupropion in normal metabolizers, and bupropion showed equivalent efficacy in slow metabolizers with less side effects. According to our study, NMR provides a better justification for both scientific research and tailoring optimal pharmacotherapy for smoking cessation among smokers in COPD.image

Recommendations from The Medical Education Editor

“…10 In the June 2024 issue of Respirology, Qin et al report their analysis of smoking cessation efficacy in Chinese patients with chronic obstructive pulmonary disease (COPD) who were randomly treated with varenicline or bupropion for 12 weeks. 11 A total of 224 participants were stratified as slow (NMR <0.31; 55%) or normal (NMR ≥0.31; 45%) metabolisers and followed for 24 weeks from the commencement of therapy. The primary outcome was abstinence at 9-12 weeks, and the secondary outcome was abstinence at 24 weeks and several visits throughout the study.…”