Clozapine is the most effective antipsychotic for treatment-resistant schizophrenia. The life-threatening haematological adverse effect that necessitates mandatory periodic blood monitoring is:
- A Agranulocytosis ✓
- B Thrombocytopenic purpura
- C Aplastic anaemia
- D Haemolytic anaemia
Correct answer: A. Agranulocytosis
Explanation
Clozapine causes agranulocytosis (absolute neutrophil count < 500/mm3) in approximately 1-2% of patients, which is potentially fatal if infections supervene. Mandatory weekly blood count monitoring for the first 18 weeks and fortnightly thereafter is required under REMS programs. The mechanism involves a reactive norclozapine metabolite that forms hapten-protein complexes triggering immune-mediated neutrophil destruction. Aplastic anaemia is associated with carbamazepine and chloramphenicol.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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