Effect of Naproxen on Renal Haemodynamics in Elderly Patients with Arthritis

The effects of naproxen on renal haemodynamics were observed in ten elderly arthritic patients who were otherwise healthy and without clinical evidence of renal disease. Glomerular filtration rate (GFR,51Cr-EDTA clearance) and effective renal plasma flow (ERPF, 125I-iodohippurate clearance) were measured after 2 weeks' treatment with naproxen 500 mg twice daily and again after 2 weeks off the drug, in random order. Baseline values for GFR and ERPF were within normal limits (mean 72 ml/min/1.73 m2, 110° predicted and 326 ml/min/1.73 m2, 111° predicted, respectively). On naproxen, ERPF and renal blood flow decreased by 10° and 9°, respectively (−32 ml/min/1.73 m2; p=0.05 and −49 ml/min/1.73 m2; p