Effects of ibuprofen vs. acetaminophen on renal function and hemody namics in the stressed kidney

We determined the effects of maximal OTC doses of acetaminophen (ACET, 4 g/d) and ibuprofen (IBU, 1.2 g/d) vs. a placebo (PL) in human subjects undergoing progressive renal Stressors. After baseline measures, 12 fit young men & women (age 22-29) underwent 3 d of a low (10 mEq/d) Na diet while taking one of the drugs or PL (separate trials, random order). Day 4 involved dehydration (-1.4% body weight) followed by 45 rain treadmill exercise (65% VO₂max) in the heat (36°C). Mean±SE data are shown below, along with the percent change from baseline to end-exercise. baseline Na-depleled end-exercise exer Δ RPF ACET 745±46 802±59 496±31 -33% (ml/mm) IBU 767±50 748±44 458±24 -40% PL 798±59 843±76 504±48 -37% GFR ACET 119±7 125±8 77±4 -35% (ml/min) IBU 126±8 122±7 73±6 -42% PL 119±7 115±7 83±6 -30% U_NaV ACET 154±22 34±8 10±2 -94% (μEq/min) IBU 110±13 22±5 5±1 -95% PL 147±23 26±8 7±2 -95% The combined stresses of Na-depleuon, dehydration, and exercise in the heat caused dramatic changes in RPF, GFR, and Na excretion. The only drug effect was a significantly greater change in GFR from baseline in the IBU trial (p<0.05 vs. PL). The practical importance of this finding is unknown but appears to cause only minor decrements in fit younger subjects.