Effects of water deprivation for 48 hours on the pharmacokinetics and pharmacodynamics of furosemide in rats.

The effects of water deprivation for 48 h on the pharmacokinetics and pharmacodynamics of furosemide were examined after intravenous, 8 mg/kg body weight, and oral administration, 16 mg/kg body weight, of furosemide to control and water deprived rats. After i.v. administration, the total body and nonrenal clearances decreased significantly in water-deprived rats. The urine output, urinary excretion of sodium, potassium and chloride based on grams of kidney weight, and the diuretic, natriuretic and chloruretic efficiencies decreased significantly in water-deprived rats after both intravenous and oral administration of furosemide, suggesting that the dose of furosemide for water-deprived patients may require modification.