Severe reversible neutropenia following treatment of prostate cancer with flutamide

Flutamide was administered to a patient in conjunction with orchiectomy for stage D2 prostate cancer. Subsequently, profound neutropenia developed with a neutrophil count of 0.28 x 10⁹/l. Bone marrow aspirate showed granulocyte hypoplasia and maturation arrest consistent with drug induced injury. Neutrophil count returned to normal after discontinuation of flutamide and administration of a short course of granulocyte colony- stimulating factor. Other medications were continued with no effect on neutrophil count. The appearance of the bone marrow and the return of neutrophils after the discontinuation of flutamide indicate that flutamide may have contributed to neutropenia.