Precision nicotine metabolism-informed care for smoking cessation in Crohn's disease: A pilot study

Smoking is a strong risk factor for disease severity in Crohn's disease (CD) and cessation improves outcomes. The nicotine metabolite ratio (NMR) predicts cessation success with pharmacotherapy: varenicline doubles cessation over nicotine replacement therapy (NRT) for "normal", but not "slow" metabolizers. Varenicline side effects are heightened in slow metabolizers. Methods using NMR to optimize cessation pharmacotherapy have not been evaluated in CD.

We aim to determine the prevalence of smoking in a CD population and then assess these smokers' attitudes toward a personalized metabolism-informed care (MIC) approach to cessation.

In this observational study, we surveyed 1098 patients visiting an inflammatory bowel disease center about their smoking history. We then evaluated a subgroup of individuals with CD (n = 32) who participated in a randomized controlled trial of smoking cessation using MIC versus usual care. For MIC, medication selection was informed by the NMR (normal ≥0.31 vs. slow <0.31). The primary outcomes were intervention satisfaction and match rates between NMR and medication choice.

The baseline prevalence of smoking in our CD population was 13%. Intervention participants reported high rates of satisfaction (85%) and chose a medication that matched their NMR result more often in the MIC group (100% vs. 64%, p = 0.01). Six of 16 (37.5%) patients prescribed varenicline discontinued due to side effects.

MIC produced high rates of satisfaction and matching between NMR and medication in CD patients, supporting patient acceptance and feasibility of precision smoking cessation in this population. To reduce smoking in CD, therapies such as MIC are needed to maximize efficacy and minimize side effects.