It has been reported that rifampicin attenuates an effect of corticosteroid. We observed nonresponsiveness to prednisolone treatment during rifampicin administration in a case of adult nephrotic syndrome. A 21 years old man had the onset of facial edema and ascites in and was diagnosed as nephrotic syndrome (minimal change) at a certain hospital. He was treated with prednisolone and obtained complete remission. He had the complaint of chest pain in May 1984, and was transfered to our hospital. We diagnosed him as nephrotic syndrome and tuberculous pleuritis. We administered him isoniazid 300 mg/day, rifampicin 450 mg/ day, streptomycin 3 g/week and prednisolone 30 mg/day. His urinary protein was not decreased. Subsequently, we administered him predonisolone 60 mg/day. But his urinary protein was not changed. We thought that rifampicin might attenuate the effect of pre-dnisolone. After rifampicin was discontinued, urinary protein was decreased rapidly. He obtained complete remission and was discharged from our hospital. It was reported that a patient with Addison's disease required increased corticosteroid dosage whilst receiving rifampicin and had cortisol catabolism following hepatic microzomal enzyme induction by rifampicin. Our case of nephrotic syndrome showed the nonresponsi-veness to prednisolone treatment during rifampicin administration. The corticosteroid is essential to treatment of nephrotic syndrome and collagen disease, and rifampicin is an important drug in treatment of tuberculosis. We should pay attension to drug interac-tion between corticosteroid and rifampicin in the cases with combination of these drugs.
