Aplastic anemia is most commonly reported with which antipsychotics?

• A. Chlorpromazine and trifluoperazine
• B. Haloperidol
• C. Olanzapine
• D. Quetiapine

Answer: (A)

Aplastic anemia is a rare but serious bone marrow failure where the production of all blood cell lines drops. Among antipsychotics, the strongest historical signal for this rare adverse effect comes from the older phenothiazines, especially chlorpromazine and trifluoperazine, which have been reported in case reports and pharmacovigilance data to be linked to bone marrow suppression leading to aplastic anemia. This association is not common, but it is well recognized enough that these drugs are singled out in safety histories. Haloperidol is more commonly discussed for extrapyramidal and hematologic issues like rare neutropenia, but not as strongly tied to aplastic anemia as the phenothiazines. Olanzapine and quetiapine are less associated with this risk, though no drug is completely devoid of potential rare hematologic effects.