Case Reports

azotemia developed in two patients after cimetidine treatment. Renal biopsy in Patient 2 showing acute interstitial nephritis and the recrudescence of azotemia after Patient l's inadvertant rechallenge with the drug strongly indicate cimetidine's nephrotoxicity. The relation of the enhanced delayed hypersensitivity caused by H2-receptor blockade is proposed as a possible mechanism by which cimetidine causes interstitial nephritis. RECENT REPORTS have suggested that cimetidine may cause acute renal failure (1-5). This association is more clearly proved by the following two cases of acute inter-stitial nephritis