Aspirin-induced depression of renal function.

We observed elevation of serum creatinine and blood urea nitrogen and decrease in creatine clearance in patients taking anti-inflammatory doses of aspirin. In 13 of 23 patients with systemic lupus erythematosus increases in serum creatinine ranged from 27 to 163 per cent, and those in urea nitrogen from 42 to 270 per cent. Sequential creatinine-clearance studies, available in 11 of the 13 patients, demonstrated decreases up to 58 per cent. Patients with aspirin-induced changes in renal function were more likely to have active renal disease (P =0.035) or hypocomplementemia (P =0.030). Four of 22 patients with rheumatoid arthritis and two of three normal volunteers also demonstrated biochemical changes. The rate of aspirin-induced alterations was significantly higher in systemic lupus erythematosus (P =0.007) than in rheumatoid arthritis. Aspirin, and other nonsteroidal anti-inflammatory agents, can have a major reversible effect on renal function that may influence the interpretation of clinical data.