What is the primary safety concern in clozapine therapy that requires routine monitoring?

• A. Hypertension
• B. Weight gain
• C. Seizures
• D. Agranulocytosis

Answer: (D)

The main safety concern with clozapine is agranulocytosis, a dangerous and potentially life-threatening drop in neutrophils that severely impairs the body’s ability to fight infections. Because this risk can develop suddenly, routine blood monitoring is required to detect early neutropenia. Typically, patients have baseline CBC with differential, then regular absolute neutrophil count checks—weekly for the first 6 months, then every 2 weeks for the next 6 months, and monthly thereafter. If the neutrophil count falls below a critical threshold, clozapine is held and the patient evaluated. Other adverse effects like hypertension, weight gain, or seizures can occur, but the mandated monitoring for clozapine is specifically tied to preventing and detecting agranulocytosis.