Methimazole-Induced Agranulocytosis and Granulocyte-Colony Stimulating Factor

Abstract

To the Editor: Agranulocytosis represents a life-threatening complication of methimazole therapy, occurring in 0.1% to 1% of patients (1). Course and duration of agranulocytosis may be highly variable (2). Recently, human hematopoietic growth factors, especially granulocyte-macrophage colony stimulating factor (GM-CSF), have proved useful in the treatment of idiopathic aplastic anemia, idiopathic neutropenia, and chemotherapy-associated agranulocytosis (3, 4). That GM-CSF might also be useful in drug-induced allergic-toxic agranulocytosis is suggested in a case report by Delannoy and Gehenot (5). To support this hypothesis we report successful GM-CSF treatment of a 36-year-old woman who had methimazole-induced agranulocytosis. Four weeks before admission, the