What is the incidence of clozapine-associated neutropenia (any neutropenia) and its severe rate?

• A. 2.8%, severe 0.9%
• B. 1%, 0.3%
• C. 5%, 1%
• D. 0.5%, 0.1%

Answer: (A)

The main idea here is understanding how often clozapine can cause neutropenia and how that risk splits into any neutropenia versus the more serious severe form. Any neutropenia means a drop in neutrophils that falls below the normal range, while severe neutropenia (agranulocytosis) is a much deeper decrease that poses a high risk for life-threatening infection. In people treated with clozapine, neutropenia tends to appear early, and large data sets show about 2–3% of patients experience some degree of neutropenia, with severe cases around the 0.5–1% range. The option listing about 2.8% for any neutropenia and 0.9% for severe neutropenia fits well within these typical estimates, making it the best choice. The other options fall outside the commonly observed ranges, either underestimating or overestimating the risk.