Cephalexin-induced haemolytic anaemia: a rare cause of acute renal failure requiring haemodialysis.

Drug-induced haemolytic anaemia (DIHA) is a rare and potentially life-threatening condition associated with various medications, including cephalosporins. DIHA can be either immune-mediated or non-immune-mediated, distinguishable through direct antiglobulin testing, also known as Coombs testing. Cephalexin has been implicated in both forms. Non-immune DIHA likely results from direct drug toxicity to erythrocytes, whereas immune-mediated DIHA, a type II hypersensitivity reaction, involves drug-dependent antibodies and/or autoantibodies and is often triggered by penicillins, cephalosporins and non-steroidal anti-inflammatory drugs. We present a case of a woman in her late fifties who developed acute renal failure necessitating emergent haemodialysis following a single dose of cephalexin. She was subsequently diagnosed with cephalexin-induced autoimmune haemolytic anaemia. This case illustrates the importance of considering DIHA in patients presenting with renal failure and haemolytic anaemia.