NMR helps tailor treatment for smoking cessation in smokers with COPD

Among smokers with chronic obstructive pulmonary disease (COPD), use of varenicline seems better than bupropion in normal metabolizers, but bupropion displays similar efficacy and less side effects in slow metabolizers, reports a study.

A team of investigators performed a stratified block randomized controlled trial for smoking cessation in a total of 224 Chinese smokers with COPD, recruited from February 2019 to June 2022. They randomly assigned participants to either the varenicline or bupropion group, with follow-up visits at 1, 2, 4, 6, 9, 12, and 24 weeks.

The investigating team used nicotine metabolic ratio (NMR) as a stratification factor. Normal metabolizers were characterized as participants with NMR ≥0.31, while slow metabolizers were those with NMR <0.31.

Among normal metabolizers, varenicline showed a higher rate of continuous abstinence (9‒12 weeks) than bupropion (43.1 percent vs 23.5 percent; odds ratio [OR], 2.47, 95 percent confidence interval [CI], 1.05‒5.78; p=0.038). However, no significant between-group difference in abstinence rates was observed among slow metabolizers (54.1 percent vs 45.9 percent; OR, 1.39, 95 percent CI, 0.68‒2.83; p=0.366).

Additionally, there were more side effects noted in the varenicline group than the bupropion group among slow metabolizers (p=0.048), but no significant difference was seen between the two treatment groups among normal metabolizers (p=0.360).

“According to our study, NMR provides a better justification for both scientific research and tailoring optimal pharmacotherapy for smoking cessation among smokers in COPD,” the investigators said.