Which antipsychotic requires regular CBC monitoring due to risk of agranulocytosis?

• A. Haloperidol
• B. Clozapine
• C. Risperidone
• D. Olanzapine

Answer: (B)

Clozapine requires regular CBC monitoring because it carries a notable risk of agranulocytosis, a dangerous drop in neutrophils that can leave the body unable to fight infections. Because of this, monitoring is built into its use: a baseline blood count before starting, then close observation with weekly CBCs for the first six months, followed by more spaced checks (typically every one to two weeks for a period, then monthly if counts stay stable). This careful surveillance helps catch a dangerous decrease in white cells early, allowing for prompt action to prevent serious infection.

Other antipsychotics like haloperidol, risperidone, and olanzapine do not have the same requirement for routine CBC monitoring due to agranulocytosis; they have different side effect profiles (EPS, metabolic effects, sedation, etc.), but not this specific hematologic risk that demands serial blood counts.