Which hematologic complication from clozapine necessitates regular complete blood counts?

• A. Anemia
• B. Leukopenia
• C. Thrombocytopenia
• D. Agranulocytosis

Answer: (D)

Clozapine carries a risk of agranulocytosis, a severe drop in neutrophils that makes infections much more dangerous and requires close monitoring with regular complete blood counts. This hematologic complication is the reason patients on clozapine must have ongoing CBCs to track the neutrophil portion of the white blood cells and to stop treatment if counts fall too low. Other listed problems—anemia (low red cells), leukopenia (low white cells in general), and thrombocytopenia (low platelets)—can occur with various drugs or conditions, but the specific, high-risk issue that drives routine CBC monitoring with clozapine is agranulocytosis.