Medication adherence and rate of nicotine metabolism are associated with response to treatment with varenicline among smokers with HIV

Abstract Introduction PLWHA who smoke have shown lower cessation rates within placebo-controlled randomized trials of varenicline. Adherence and rate of nicotine metabolism may be associated with quit rates in such clinical trials. Methods This secondary analysis of a randomized placebo-controlled trial of varenicline for smoking among PLWHA (N=179) examined the relationship between varenicline adherence (pill count, ≥80% of pills), nicotine metabolism (based on the nicotine metabolite ratio; NMR) and end-of-treatment smoking cessation (self-reported 7-day point prevalence abstinence, confirmed with carbon monoxide of ≤ 8ppm, at the end of treatment; EOT). Results Combining varenicline and placebo arms, greater adherence (OR=1.011, 95% CI:1.00-1.02, p=0.051) and faster nicotine metabolism (OR=3.08, 95% CI:1.01-9.37, p=0.047) were related to higher quit rates. In separate models, adherence (OR=1.009, 95% CI:1.004-1.01, p Conclusions Increasing varenicline adherence and ensuring that fast nicotine metabolizers receive varenicline may increase quit rates for PLWHA.