Phenacetin-induced haemolytic anaemia.

Haemolytic anaemia, rarely severe, is a common yet often unrecognized complication of the prolonged use or abuse of phenacetin-containing analgesics. Irregularly contracted (pyknocytes) or fragmented erythrocytes (schistocytes) are commonly present in the peripheral blood in this form of anaemia. It is emphasized that their recognition during screening of blood films may reveal patients previously unsuspected of analgesic abuse and at a stage before the development of the more serious complication of nephropathy. Fourteen such patients, detected during the last 18 months, are briefly described and the pathogenesis and laboratory features of the anaemia reviewed.