Smoking cessation and duloxetine toxicity: A case report.

Objective: Psychiatric medications are among the drugs affected by cigarette smoke, and because of the high prevalence of smoking in the psychiatric community, psychiatric patients are particularly at risk when entering the smoke-free environment of a hospital.

Case Summary: Polycyclic aromatic hydrocarbons present in cigarette smoke are well-known inducers of cytochrome P450 (CYP) enzymes. CYP1A2 induction by cigarette smoking increases metabolic clearance of substrates of this enzyme; smoking cessation results in a decrease in CYP1A2 activity, which causes an increase in serum substrate levels.