Effect of spironolactone on diuresis and urine sodium and potassium excretion in healthy dogs.
OBJECTIVE
To document the diuretic effect of different oral doses of spironolactone (SP) in healthy dogs.


BACKGROUND
SP is currently mentioned as a diuretic agent in the dog. However, the recommended doses were empirically defined and their corresponding diuretic effect has never been documented in dogs.


METHODS
Eight adult Beagle dogs were used for two separate 2*2 cross-over designs. In the first cross-over, 4 dogs received SP orally for 8 days at 1 and 2mg/kg per day. In the second cross-over the 4 other dogs received SP similarly, but at 4 and 8 mg/kg per day. Dogs were weighed on the first and last day of each period. Plasma SP and canrenone (the main active metabolite of SP) were assayed by high performance liquid chromatography (HPLC). Daily water consumption, urine weight, urine specific gravity, and urine excretion of sodium and potassium were measured during the SP treatment.


RESULTS
Two hours after SP administration, SP was metabolized into canrenone. A significant 14 and 22% decrease in urine potassium excretion was observed at 1 and 2mg/kg, respectively, but not at the two other dose levels. Daily water consumption, urine weight, urine specific gravity, and urine excretion of sodium were not significantly altered by the SP treatment regardless of dose.


CONCLUSIONS
Repeated oral administration of SP at 1, 2, 4 or 8 mg/kg for 8 days had no effect on water and sodium diuresis in healthy dogs.
Jeunesse
E
E
UMR181 de Physiopathologie et Toxicologie Expérimentales INRA, ENVT, National Veterinary School, 23 chemin de Capelles, 31076 Toulouse cedex 03, France.
Woehrle
F
F
Schneider
M
M
Lefebvre
H P
HP
D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods / Q000662:veterinary; D018592:Cross-Over Studies; D004231:Diuresis / Q000187:drug effects*; D004232:Diuretics / Q000097:blood / Q000494:pharmacology* / Q000652:urine; D004283:Dog Diseases / Q000188:drug therapy; D004285:Dogs / Q000097:blood / Q000502:physiology* / Q000652:urine; D004305:Dose-Response Relationship, Drug; D004326:Drinking; D008297:Male; D011188:Potassium / Q000652:urine; D011897:Random Allocation; D012964:Sodium / Q000652:urine; D013148:Spironolactone / Q000097:blood / Q000494:pharmacology* / Q000652:urine; D014556:Urine / Q000737:chemistry*
D004232:Diuretics; D013148:Spironolactone; D012964:Sodium; D011188:Potassium