Schizophrenia and smoking

J Clin Psychiatry. 2012 Jun;73(6):e725-7. doi: 10.4088/JCP.12f07732.


Smoking is associated with the induction of the CYP 1A2 enzyme, and hence with diminished levels of drugs metabolized by this enzyme. This article presents a hypothetical patient, diagnosed with schizophrenia, who smokes about 10 cigarettes a day. The progress of the patient is examined across several follow up meetings, each of which presents a fresh clinical problem related to smoking and its interaction with the medication. Clinical guidance for each problem is presented along with a brief discussion on the subject. The article concludes with a discussion of other pharmacokinetic considerations related to smoking and its treatment in patients with schizophrenia.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Clozapine / pharmacokinetics*
  • Clozapine / therapeutic use
  • Cytochrome P-450 CYP1A2 / drug effects*
  • Cytochrome P-450 CYP1A2 / metabolism
  • Enzyme Induction / drug effects*
  • Enzyme Induction / physiology
  • Humans
  • Inactivation, Metabolic* / physiology
  • Male
  • Schizophrenia / drug therapy*
  • Schizophrenia / metabolism
  • Schizophrenic Psychology
  • Smoking / adverse effects*
  • Smoking / psychology
  • Smoking Cessation / methods


  • Cytochrome P-450 CYP1A2
  • Clozapine