The effect of enalapril on furosemide‐activated renin–angiotensin–aldosterone system in healthy dogs

This study was designed to evaluate the efficacy of enalapril in suppressing ACE activity and furosemide‐induced circulating RAAS activation. Failure to do so would suggest that this failure may be a drug class effect. We hypothesized that enalapril would suppress ACE activity and furosemide‐induced circulating RAAS activation. Sixteen healthy hound dogs. The effect of furosemide (2 mg/kg PO, q12 h; Group F) and furosemide plus enalapril (0.5 mg/kg PO, q12 h; Group FE) on circulating RAAS was determined by plasma ACE activity, 4–6 h post‐treatment, and urinary A:C on days −1, −2, 1, 4, and 7. There was a significant increase in the average urine aldosterone‐to‐creatinine ratio (UAldo:C) after administration of furosemide (P < 0.05). Enalapril inhibited ACE activity (P < 0.0001) but did not significantly reduce aldosterone excretion. A significant (P < 0.05) increase in the UAldo:C was maintained for the 7 days of the study in both groups. Enalapril decreased plasma ACE activity; however, it did not suppress furosemide‐induced RAAS activation, as determined by the UAldo:C. While enalapril blunts ACE activity, the absence of circulating RAAS suppression may be due to angiotensin II reactivation, alternative RAAS pathways, and furosemide overriding concurrent ACE inhibition, all indicating the existence of aldosterone breakthrough (ABT). Along with similar findings with benazepril, it appears that failure to suppress aldosterone suppression...
Source: Journal of Veterinary Pharmacology and Therapeutics - Category: Veterinary Research Authors: Tags: Short Communication Source Type: research