Table 1.

A summary of studies linking the NMR to responses to treatment for smoking cessation.

Author(s) and yearStudy designPopulationMain findings
Lerman et al. (2006; ref. 88)Randomized trial of transdermal nicotine vs. nicotine nasal spray480 treatment seeking smokers ≥18 years, ≥10 cigarettes/daySlower metabolizers randomized to transdermal nicotine had higher quit rates vs. fast metabolizers; no effect for nasal spray
Patterson et al. (2008; ref. 80)Placebo-controlled, randomized trial that examined the efficacy of a standard course of bupropion670 participants age 18–65, ≥10 CPDBupropion improved quit rates for fast metabolizers but not slow metabolizers
Ho et al. (2009; ref. 76)Double-blind, placebo-controlled study that evaluated nicotine gum755 African-American/Black smokers “light smokers” (< 10 CPD), ≥18 yearsSlower metabolizers had higher quit rates with both placebo and nicotine gum
Schnoll et al. (2009; ref. 78)Validation study that evaluated whether NMR predicted outcomes for transdermal nicotine568 participants interested in cessation treatment, age 18–65, ≥10 CPDFaster metabolizers were 50% less likely to be abstinent at 8-week follow-up
Schnoll et al. (2013; ref. 79)Proof-of-concept randomized placebo-controlled trial to evaluate high dose transdermal nicotine for faster metabolizers87 participants with faster metabolism interested in cessation treatment, age 18–55, ≥10 CPDHigh dose NRT did not improve abstinence at 8-week follow-up compared to standard dose NRT
Lerman et al. (2015; ref. 83)NMR-stratified randomized placebo-controlled trial1246 treatment-seeking smokers, 18–65 years old, ≥10 CPD. Excluded for psychiatric diagnosis/substance use.Significant NMR-by-treatment interaction: varenicline more efficacious than NRT for faster metabolizers and equivalent for slower metabolizers
Kaufman et al. (2015; ref. 64)Effectiveness study designed to evaluate the long-term use of transdermal NRT499 treatment-seeking smokers, ≥18 years, ≥10 CPDFaster metabolizers had lower quit rates than slower metabolizers
Vaz et al. (2015; ref. 114)RCT of NRT for pregnant women of transdermal patch vs. placebo662 women, 12–24 weeks gestation at recruitment, ≥10 CPD prior to pregnancy, ≥5 CPD during pregnancyIncreases in NMR were associated with lower odds of achieving cessation at 1-month and delivery
Ebbert et al. (2016; ref. 82)Participants from one arm of a treatment trial who received nicotine lozenges152 treatment-seeking smokers age ≥18 who used smokeless tobacco as a primary tobacco productNMR did not predict abstinence at 3-months but was positively correlated with lozenge use
Glatard et al. (2017; ref. 81)Participants self-selected either varenicline or NRT194 treatment-seeking smokers 18–65, ≥10 CPDVarenicline outperformed NRT for faster metabolizers
Wells et al. (2017; ref. 85)MIC pilot RCT81 smokers, ≥18 years, ≥5 CPD. Excluded for serious/unstable psychiatric illnessApproximately 90% of participants endorsed MIC; MIC tripled the odds of receiving the matched medication
Fix et al. (2017; ref. 58)Longitudinal observational study of spontaneous quitters874 daily and nondaily smokers from 5 countriesSmokers with a higher NMR more likely to quit and quit for longer duration
Clyde et al. (2018; ref. 87)RCT (varenicline, NRT, or long-term NRT + adjunct nicotine product)499 treatment-seeking smokers; limited exclusion criteria, which did not include history of psychiatric illness but did exclude for substance useNMR did not predict treatment outcomes (Limitation: limited number of slower metabolizers)
Shahab et al. (2019; ref. 86)Prospective observational study; participants selected treatment without knowledge of NMR1556 treatment-seeking smokers ≥16 yearsNMR did not predict treatment outcomes (Limitation: participants not randomized)
  • Abbreviations: MIC, metabolism informed care; NRT, nicotine replacement therapy; NMR, nicotine metabolite ratio; RCT, randomized controlled trial.