Phenacetin-induced hemolytic anemia.

The hematological features of phenacetin-induced hemolytic anemia are presented in order to make the physician aware of the abnormalities which suggest the use of an oxidant drug. The presence of "bitten out" red cells is the commonest initial clue to the existence of drug-induced hemolytic anemia. The diagnosis is confirmed by the demonstration of Heinz bodies and sulfhemoglobinemia. Early recognition of this form of drug-abuse may avert the development or progression of analgesic nephropathy.