Agranulocytosis is a side effect of which medication commonly used as an antipsychotic?

• A. Clozaril
• B. Haloperidol
• C. Risperdal
• D. Seroquel

Answer: (A)

Agranulocytosis is a dangerous, potentially life-threatening drop in neutrophil white blood cells, which greatly raises infection risk. Among antipsychotics, this severe blood dyscrasia is most famously linked to clozapine. Because of this risk, clozapine requires strict blood monitoring: baseline white blood cell and neutrophil counts, then weekly checks for the first six months, biweekly checks for the next six months, and monthly checks thereafter, under appropriate monitoring programs. Clozapine is typically used for treatment-resistant schizophrenia, where other antipsychotics haven't helped. Other antipsychotics like haloperidol, risperidone, and quetiapine have different dominant side-effect profiles (such as extrapyramidal symptoms or metabolic effects) and do not carry the same mandated agranulocytosis monitoring, which is why clozapine stands out as the drug associated with this risk.