FK-453 is a potent antagonist of non-xanthine adenosine A1 receptor with diuretic and renal vasodilatory activity.

FK-453 (50, 100, and 200 mg; three single oral) Glomerular filtration rate (clearance of 51Cr-labeled EDTA) rose by 18.0%, 3 h after the administration of 100 mg of FK-453 and by 18.3% and 23.5%, 2 and 3 h, respectively, after the 200 mg dose. There were statistically significant increases in urine flow rate and osmolar clearance, as well as absolute and fractional excretions of sodium, phosphate, bicarbonate, chloride, magnesium, and uric acid in response to FK-453.[2]