Fig. (1). Pathways for nicotine degradation.
Once absorbed in the bloodstream nicotine is degraded, in the liver, by a variety of enzymatic pathway to give rise to identifiable and measurable reaction products. Abbreviations: CYP2A6 - cytochrome P450 2A6; AOX – Aldehyde oxidase; UGT1 – UDP-glucuronosyltransferase; t’-3’-HC – 3’-hydroxy cotinine.