Effect of acetylsalicylic acid on renal function in systemic lupus erythematosus

Glomerular filtration rate (GFR; 51Cr-EDTA clearance), serum creatinine concentration and urinary excretion of prostaglandins were measured in 8 patients with systemic lupus erythematosus (SLE) before and after 2 weeks of treatment with acetylsalicylic acid (ASA). ASA 65 mg/kg or up to 4 g/daily was given as a sustained release preparation. The serum salicylate concentration ranged from 0.3 to 1.6 mmol/l. Serum creatinine after 1 and 2 weeks and GFR after 2 weeks of ASA treatment showed no significant changes. There was a clearcut decrease in urinary excretion of prostaglandins PGE2 and PGF2 alpha, by 44% and 50%, respectively. It is concluded that therapeutic doses of ASA do not cause deterioration of GFR in patients with SLE and normal or moderately reduced renal function.