Why is clozapine considered after failure of other antipsychotics?

• A. Lower cost
• B. Fewer metabolic side effects
• C. No monitoring required
• D. Agranulocytosis risk requiring regular WBC monitoring

Answer: (D)

Clozapine is kept in reserve for treatment-resistant schizophrenia because, despite its strong efficacy in those who don’t respond to other antipsychotics, it carries a serious risk of agranulocytosis. That potential for life-threatening drop in white blood cells is why patients on clozapine require regular blood monitoring to catch neutropenia early. The monitoring is built into the treatment plan: frequent white blood cell and absolute neutrophil count checks, especially in the initial months, with the frequency gradually decreasing if counts stay stable. This safety burden is the main reason clinicians try other antipsychotics first and only move to clozapine after those have failed.

The other options don’t fit because clozapine is not chosen for lower cost, and it does not have fewer metabolic side effects—it can cause weight gain and metabolic issues. It also does require monitoring, so “no monitoring required” is incorrect. The key factor driving its position as a later option is the agranulocytosis risk that necessitates ongoing lab surveillance.