“The increase in F value and diuretic and natriuretic effects of azosemide with coadministration of ascorbic acid seemed to be due to reduced intestinal first-pass metabolism of azosemide, increased urinary excretion of azosemide, and increased unionized fraction of azosemide at the renal tubular receptor sites.”
“The rationales for this study are that ascorbic acid might inhibit intestinal first-pass effect of azosemide and might increase the unionized fraction of azosemide at the receptor sites.”
“… azosemide (20 … ascorbic acid , the F value (138% vs. 100%), 8-h urinary excretion of azosemide (5.18% vs. 1.32% of oral dose), 8-h urine … ml), and 8-h urinary excretion of sodium (24.6 vs. 15.3 mmol/kg) were greater than controls (without ascorbic acid).”