Interstitial nephritis in patients with inflammatory bowel disease treatedwith mesalamine

Mesalamines are slow-release formulations: of 5-aminosalicylic acid (5-ASA) and are effective as primary treatment and maintenance therapy in inflamma tory bowel disease. Interstitial nephritis is a recognized side effect. We report two cases of biopsy-confirmed interstitial nephritis in patients bei ng treated with 5-ASA. Both had a trial of steroid therapy. One patient had partial recovery of renal function but the other patient was in chronic re nal failure and likely was approaching the need for dialysis. Interstitial nephritis is an under-recognized complication of 5-ASA therapy. Early ident ification and withdrawal of this drug can lead to a partial or complete rev ersal of renal dysfunction.