Agranulocytosis incidence in clozapine with monitoring?

• A. Approximately 1%
• B. Approximately 0.38%
• C. Approximately 0.01%
• D. Approximately 5%

Answer: (B)

Clozapine carries a small but serious risk of agranulocytosis, a dangerous drop in neutrophils that can lead to severe infections. Because this condition can progress rapidly, regular blood monitoring is essential so neutrophil counts are caught early and the medication can be stopped before serious harm occurs. With such monitoring in place, the incidence of agranulocytosis tends to be a few per thousand rather than a large percentage. Approximately 0.38% is within that range and reflects real-world data from monitoring programs, where the risk is kept in check by stopping clozapine when neutrophil counts fall below safety thresholds.

In practice, the highest risk occurs in the early weeks to months after starting treatment, which is why close monitoring is most frequent early on. If agranulocytosis does develop, withdrawal of the drug typically leads to recovery of neutrophils with appropriate care.