Prescribing Safety Assessment (PSA) Practice Exam

Which medication is known to cause neutropenia?

1. Ibuprofen

2. Clozapine

3. Aspirin

4. Metformin

The correct answer is: Clozapine

Clozapine is recognized for its association with neutropenia, specifically a potentially severe reduction in the white blood cell count known as agranulocytosis. This side effect is particularly important in clinical practice because it can lead to an increased risk of infections, which necessitates regular monitoring of the patient's blood cell counts when on this medication. The mechanism by which clozapine causes neutropenia is believed to involve idiosyncratic immune-mediated reactions that can damage bone marrow. In contrast, while ibuprofen, aspirin, and metformin may have various side effects, they are not primarily linked with neutropenia. Nonsteroidal anti-inflammatory drugs like ibuprofen and aspirin can affect platelet function and have gastrointestinal implications but are not associated with peripheral blood neutrophil reductions. Metformin is an antidiabetic medication that might lead to vitamin B12 deficiency over prolonged use, but does not commonly cause neutropenia. Therefore, clozapine stands out as the medication specifically noted for this blood disorder, emphasizing the importance of vigilance during its use.