Interstitial Nephritis Caused by Trimethoprim-Sulfamethoxazole in Renal Transplant Recipients

Abstract

THE COMBINATION drug trimethoprim-sulfamethoxazole is widely used in renal transplant recipients to treat urinary tract infections and opportunistic infections with organisms such as<i>Pneumocystis carinii</i>and<i>Nocardia</i>, and has recently been recommended as prophylaxis against<i>Pneumocystis</i>pneumonitis. To our knowledge, deterioration of renal allograft function from interstitial nephritis in association with trimethoprim-sulfamethoxazole administration has been recorded only once.¹The following reports suggest that interstitial nephritis caused by trimethoprim-sulfamethoxazole may occur more frequently and that the drug should be used with caution in renal transplant recipients. <h3>Report of Cases</h3><h3>Case 1.—</h3> A 50-year-old woman with chronic glomerulonephritis received a renal transplant from a cadaver donor on Sept 28, 1975. Initial renal function was good. In November 1975 she had a rejection episode that responded to intravenous administration of methylprednisolone, 30 mg/kg. On Jan 14, 1976, a staphylococcal septicemia developed and was treated with nafcillin sodium. Ten days later she again