Death from drug-induced hemolytic anemia

Fatal hemolytic anemia occurred in a 71-year-old man after trimethoprim-sulfamethoxazole was given for presumed cystitis. Administration of this combination has previously caused multiple hematologic reactions by affecting folic acid metabolism. Megaloblastic anemia and neutropenia have been produced by both of these agents, while sulfamethoxazole alone has induced acute hemolytic anemia in patients with hereditary deficiency of glucose-6-phosphate dehydrogenase. Although hematologic complications of trimethoprim-sulfamethoxazole treatment usually follow long-term or high-dose therapy, acute reactions apparently may occur at lower doses as well.