Clozapine is unique among antipsychotics in treating refractory schizophrenia but requires mandatory monitoring due to its most feared adverse effect. What agranulocytosis monitoring schedule is required?

• A Monthly CBC for the entire duration of therapy
• B Weekly CBC for 18 weeks, then fortnightly for one year, then monthly thereafter ✓
• C Weekly CBC for 6 months, then fortnightly thereafter
• D Annual CBC is sufficient as risk is highest in the first 3 months

Explanation

The standard clozapine monitoring schedule requires weekly full blood counts for the first 18 weeks (when agranulocytosis risk is highest, occurring in about 1–2% of patients), then fortnightly for one year, and then monthly for the rest of therapy. Treatment must be stopped if the absolute neutrophil count falls below 1500/mm³. This surveillance program is mandatory through the clozapine patient monitoring service (CPMS) and has significantly reduced mortality from agranulocytosis.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.