Effects of two nonsteroidal anti-inflammatory drugs, indomethacin and oxaprozin, on the kidney

Publisher Website
Google Scholar
Abstract
Nonsteroidal anti-inflammatory drugs (NSAID) cause Na retention and decrease glomerular filtration rate (GFR). The effects of indomethacin and oxaprozin, a new propionic acid derivative, was studied on renal function of awake, normal human subjects during sustained water diuresis. Neither drug had a long-term effect on GFR or Na clearance (CNa), indomethacin (6 subjects) but not oxaprozin (7 subjects) transiently reduced GFR and CNa. Given over the short term, oxaprozin reduced GFR from 113.7 .+-. 5.7 to 99.8 .+-. 4.7 ml/min (P < 0.01) and in CNa from 0.84 .+-. 0.07 to 0.61 .+-. 0.08 ml/min (P < 0.005). The results were much the same when an additional dose of indomethacin was given to subjects who were receiving the drug for 1 wk. Inference from clearance data at a time when urinary osmolality (Uosm) remained constant but urine flow per GFR (V/GFR) fell suggests that both drugs stimulated proximal tubular Na and fluid resorption. Both suppressed renin and aldosterone levels comparably and reduced K excretion transiently, but only indomethacin caused a sustained change in serum K concentration; serum K rose from 4.32 .+-. 0.10 to 4.56 .+-. 0.11 meq/l (P < 0.05) after 1 wk. Prostaglandin synthesis inhibition may not be the sole mechanism of action of NSAID.