title: Nicotine chemistry, metabolism, kinetics and biomarkers.
abstract: Nicotine underlies tobacco addiction, influences tobacco use patterns, and is used as a pharmacological aid to smoking cessation. The absorption, distribution and disposition characteristics of nicotine from tobacco and medicinal products are reviewed. Nicotine is metabolized primarily by the liver enzymes CYP2A6, UDPglucuronosyltransferase (UGT), and flavin-containing monooxygenase (FMO). In addition to genetic factors, nicotine metabolism is influenced by diet and meals, age, sex, use of estrogen-containing hormone preparations, pregnancy and kidney disease, other medications, and smoking itself. Substantial racial/ethnic differences are observed in nicotine metabolism, which are likely influenced by both genetic and environmental factors. The most widely used biomarker of nicotine intake is cotinine, which may be measured in blood, urine, saliva, hair, or nails. The current optimal plasma cotinine cut-point to distinguish smokers from non-smokers in the general US population is 3 ng ml(-1). This cut-point is much lower than that established 20 years ago, reflecting less secondhand smoke exposure due to clear air policies and more light or occasional smoking.
authors.affiliation: Division of Clinical Pharmacology and Experimental Therapeutics, University of California, San Francisco, P. O. Box 1220, San Francisco, CA 94143-1220, USA. nbenowitz@medsfgh.ucsf.edu
authors.forename: Neal L
authors.initials: NL
authors.lastname: Benowitz
authors.forename: Janne
authors.initials: J
authors.lastname: Hukkanen
authors.forename: Peyton
authors.initials: P
authors.lastname: Jacob
mesh_terms: D015415:Biomarkers / Q000032:analysis; D003367:Cotinine / Q000378:metabolism; D006801:Humans; D009538:Nicotine / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D018722:Nicotinic Agonists / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D012907:Smoking / Q000378:metabolism*; D016540:Smoking Cessation / Q000379:methods; D014018:Tissue Distribution; D014029:Tobacco Use Disorder / Q000534:rehabilitation; D014026:Nicotiana
chemical_list: D015415:Biomarkers; D018722:Nicotinic Agonists; D009538:Nicotine; D003367:Cotinine