Quinidine-induced agranulocytosis

A case of agranulocytosis in an 86-year-old man after 8 weeks treatment with quinidine sulfate is described. Acute phase serum from the patient demonstrated antineutrophil activity by the microgranulocytotoxicity assay. Review of the literature reveals that more than one mechanism could cause this idiosyncratic immune-mediated agranulocytosis.