A study of repeated administration of fenbufen in patients with chronic rheumatic disorders and renal impairment.

Male and female patients suffering from rheumatoid arthritis with normal renal function or with renal impairment were treated in hospital with 300 mg of fenbufen 8 hourly for fourteen days. Concentrations of fenbufen and its principal metabolites were measured by high pressure liquid chromatography on days 0, 7, 10 and 14 and also four days after discontinuation of the drug. Renal impairment does not produce cumulation of either fenbufen or its major metabolites in the plasma. The metabolite profile of the drug was similar to that observed in patients with normal renal function.