The nicotine metabolite ratio (NMR) is a biomarker that represents individual variation in the speed that nicotine is metabolized. The rate of nicotine metabolism alters smoking behavior (eg, amount) and has been validated for personalizing tobacco dependence medication selection to increase treatment efficacy and reduce treatment side effects in the general population of smokers. Although smoking rates are extremely high among those with HIV, the NMR has not been evaluated in this underserved population.
We used baseline data from a smoking cessation clinical trial for smokers with HIV (N = 131) to examine associations between NMR and demographic, smoking, disease-related, and psychological characteristics. Pearson r and analysis of variance were used to identify univariate correlates of NMR, which were then entered into a multiple linear regression model.
In univariate analyses, a higher NMR (faster nicotine metabolism) was associated with being white, and more cigarettes per day, nicotine dependence, exhaled carbon monoxide, and symptoms of depression and anxiety, and using efavirenz. In a multiple regression model, a higher NMR was associated with more cigarettes per day, higher anxiety symptoms, and efavirenz use.
As in other populations, faster nicotine metabolism was associated with the use of more cigarettes and higher anxiety symptoms. Notably, efavirenz use was associated with faster metabolism, which might make it harder to quit smoking for people with HIV treated with that medication. These findings could help guide further study and the clinical use of the NMR to personalize nicotine dependence treatment in this underserved population.
*Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA;
†Pulmonary, Allergy, and Critical Care Division, University of Pennsylvania Presbyterian Medical Center, Philadelphia, PA;
‡Division of Infectious Diseases, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA;
§Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, PA;
║Philadelphia Fight, Philadelphia, PA;
¶Department of Pharmacology and Toxicology, University of Toronto, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada;
#Division of Brain and Therapeutics, Department of Psychiatry, University of Toronto, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; and
**Pulmonary, Allergy and Critical Care Division, University of Pennsylvania School of Medicine, Philadelphia, PA.
Correspondence to: Robert A. Schnoll, PhD, Department of Psychiatry, University of Pennsylvania, 3535 Market Street, 4th Floor, Philadelphia, PA (e-mail: firstname.lastname@example.org).
Supported by National Institute on Drug Abuse grants (R01 DA033681; K24 DA045244) and through core services and support from the Penn Center for AIDS Research (P30 AI045008) and the Penn Mental Health AIDS Research Center (P30 MH097488).
The authors also acknowledge the support from the Canada Research Chairs program (Dr. Tyndale, the Canada Research Chair in Pharmacogenomics), the support of CIHR grant (FDN-154294), and the Campbell Family Mental Health Research Institute of the Centre for Addiction and Mental Health.
R.A.S. receives medication and placebo free of charge from Pfizer for clinical trials and has provided consultation to Pfizer, GlaxoSmithKline, and Curaleaf. R.F.T. has consulted for Quinn Emanuel and Apotex on unrelated topics. R.G. serves on a DSMB for trials of a Pfizer drug unrelated to HIV or smoking cessation. The remaining authors have no conflicts of interest to disclose.
Received June 28, 2018
Accepted October 01, 2018