Successful relatively low-dose corticosteroid therapy for diclofenac-induced acute interstitial nephritis with severe renal failure.

We report a case of nephrotic syndrome and acute renal failure that developed in a 73-year-old woman after six months of treatment with the non-steroidal anti-inflammatory drug (NSAID) diclofenac. Renal biopsy revealed interstitial nephritis and minimal change nephropathy. Despite discontinuation of treatment with diclofenac, she subsequently became anuric and required hemodialysis for progressive azotemia. Since her anuria was persistent, treatment with prednisone at a dose of 30 mg/day was started. With progressive increase in urine output after the initiation of corticosteroid treatment, a constant decrease in serum creatinine was observed along with improvement of creatinine clearance. In addition, the increased urinary excretion of beta2-microglobulin (beta2MG) and N-acetyl-beta-D-glucosaminidase (NAG) on admission was also improved during the treatment. Our findings suggest that corticosteroid treatment should be reserved for patients with the protracted deterioration of renal function even after discontinuation of offending trigger agents.