Which antipsychotic requires regular blood monitoring due to agranulocytosis risk?

Which antipsychotic requires regular blood monitoring due to agranulocytosis risk?

• A. Haloperidol
• B. Olanzapine
• C. Clozapine
• D. Risperidone

Answer: (C)

The main safety concept is that agranulocytosis, a dangerous drop in neutrophils, requires regular blood testing when using certain antipsychotics. Clozapine has a significant risk of agranulocytosis, so patients must have baseline CBC with differential and ongoing monitoring. The monitoring schedule is tight at the start: weekly CBCs for the first six months, then every two weeks for the next six months, and then monthly thereafter. This allows early detection of neutropenia or agranulocytosis before infections develop. Other antipsychotics like haloperidol, olanzapine, and risperidone do not carry the same mandated blood-monitoring requirement, though they have other potential side effects.

The main safety concept is that agranulocytosis, a dangerous drop in neutrophils, requires regular blood testing when using certain antipsychotics. Clozapine has a significant risk of agranulocytosis, so patients must have baseline CBC with differential and ongoing monitoring. The monitoring schedule is tight at the start: weekly CBCs for the first six months, then every two weeks for the next six months, and then monthly thereafter. This allows early detection of neutropenia or agranulocytosis before infections develop. Other antipsychotics like haloperidol, olanzapine, and risperidone do not carry the same mandated blood-monitoring requirement, though they have other potential side effects.