Haloperidol Decanoate-Induced Pancytopenia: A Case Report

Blood dyscrasias, including pancytopenia, can rarely occur as adverse effects of antipsychotic drug therapy. While neutropenia is more common, pancytopenia remains an infrequent but serious hematological complication. We present the case of an 85-year-old African-American female with a history of schizophrenia, stabilized on haloperidol decanoate, who developed pancytopenia during her outpatient care. Her blood counts progressively declined, leading to hospitalization. Hematology evaluation ruled out infectious or neoplastic causes, implicating haloperidol decanoate-induced pancytopenia. The pancytopenia improved gradually over three months after discontinuing haloperidol decanoate. Our case highlights the importance of monitoring and timely intervention in such cases. We discuss the rarity of pancytopenia with antipsychotics and the potential mechanisms and challenging management of this condition.