Reversible non-oliguric impairment of renal function during azapropazone treatment.

An impairment of the renal function was observed in three patients who received azapropazone for various rheumatic disorders with simultaneous hyperuricaemia. A distinct increase in serum creatinine occurred in all patients. In one case the renal biopsy suggested a hypersensitivity reaction with a consequent acute tubulo-interstitial nephritis as the mechanism of the impaired renal function. The renal insufficiency was reversible in all cases after the withdrawal of azapropazone.