Which safety parameter is critically monitored for patients on clozapine due to risk of agranulocytosis?

• A. Platelet count only
• B. Liver enzyme levels
• C. Absolute neutrophil count (ANC)
• D. Serum potassium

Answer: (C)

Agranulocytosis is a dangerous drop in neutrophils, the white blood cells that defend against infections. Clozapine carries this specific risk, so the key safety check is the absolute neutrophil count. Tracking ANC directly measures how many neutrophils are in circulation; detecting a decline early lets clinicians pause or adjust treatment to prevent serious infections.

Other parameters don’t target this risk as directly. Platelet counts relate to bleeding risk, not the neutrophil-mediated infection risk; liver enzyme levels flag potential liver injury rather than neutropenia; serum potassium reflects electrolyte balance and related complications, not the danger produced by neutrophil depletion.