Eightfold induction of nicotine elimination in perfused rat liver by pretreatment with phenobarbital.

Elimination of nicotine by isolated rat livers was increased eightfold after pretreatment with phenobarbital (PB) as an inducer of cytochrome P-450 while it was only marginally influenced after pretreatment with 5,6-benzoflavone (BF) as an inducer of cytochrome P-448. Initial rates of cotinine formation were enhanced in the same order of magnitude in PB-induced livers. The 14C-nicotine-derived radioactivity excreted into bile within 2 h ranged between 6 -17% of the dose with only 2.7 fold higher values after PB pretreatment compared to controls.