Clozapine is being considered for a patient with treatment-resistant schizophrenia. Which of the following absolute contraindications must be excluded before initiating clozapine?
- A Current tobacco smoking
- B Controlled type 2 diabetes mellitus
- C History of clozapine-induced agranulocytosis ✓
- D Mild QTc prolongation of 450 ms
Correct answer: C. History of clozapine-induced agranulocytosis
Explanation
A prior episode of clozapine-induced agranulocytosis is an absolute contraindication to re-challenge because the risk of fatal bone marrow suppression is dramatically elevated on re-exposure. Tobacco smoking alters clozapine metabolism via CYP1A2 induction and requires dose adjustments, but is not a contraindication. Diabetes and mild QTc prolongation require monitoring and optimisation but are not absolute contraindications.
Reference: Kaplan & Sadock's Synopsis of Psychiatry, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.