Pharmacotherapeutic group: Diuretics, furosemide. ATCvet code: QC03CA01
Furosemide is a potent loop diuretic that increases urinary volume. It inhibits electrolyte resorption in the proximal and distal renal tubules and in the ascending Loop of Henle. Excretion of sodium ions, chloride ions and to a lesser extent, potassium ions is enhanced, as is water excretion. Furosemide has no effect on carbonic anhydrase.
Furosemide is excreted unchanged in the urine.
After oral administration of the product (5 mg/kg), furosemide is rapidly absorbed with maximum plasma levels (Cmax of 2126 ng/mL) occurring within 1.1 hour. The terminal half life of elimination is 2.6 hours.
Furosemide is predominantly eliminated via the kidneys in the urine (70%) and via the faeces. Plasma protein binding of furosemide is 91% and estimated distribution volume is 0,52 L/kg. Furosemide metabolizes in very small amounts (main metabolite: 4-chloro-5-sulfamoyl-anthranilic-acid, no diuretic activity).
In dogs, after oral administration, furosemide causes a dose-dependent increase in urine volume starting 1 hour after administration, reaching a maximum 2-3 hours post administration and lasting approximately 6 hours.