Pharmacodynamic evaluation of 4 angiotensin-converting enzyme inhibitors in healthy adult horses.

Authors: Afonso T, Giguère S, Rapoport G, Berghaus L J, Barton M H, Coleman A E

Journal: Journal of veterinary internal medicine

DOI: 10.1111/jvim.12153 PubMed: 23952255Log in to save

Summary

# Editorial Summary: ACE Inhibitor Efficacy in Horses Whilst ACE inhibitors are routinely prescribed for equine cardiovascular conditions, evidence supporting their clinical use remains limited, prompting this pharmacodynamic comparison of four commonly administered drugs. Eight healthy horses received oral doses of benazepril, ramipril, quinapril, or perindopril in a randomized crossover design, with serum ACE activity measured at multiple timepoints over 48 hours using kinetic spectrophotometry. Benazepril at 0.5 mg/kg demonstrated substantially superior performance, achieving maximum ACE inhibition of 86.9% and 24-hour inhibition of 60.3%, significantly outperforming the other three agents; all four drugs produced measurable reductions in indirect blood pressure, though differences between drugs were not statistically significant. Food intake did not materially affect benazepril's pharmacodynamics, and repeated daily dosing showed no cumulative effect on serum enzyme inhibition. For practitioners selecting ACE inhibitors in equine cardiovascular cases, benazepril at 0.5 mg/kg emerges as the most effective option for achieving sustained ACE inhibition, though the clinical significance of superior serum inhibition and modest blood pressure effects warrants further investigation in disease populations.

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Practical Takeaways

•Benazepril 0.5 mg/kg administered orally once daily is the most effective ACE inhibitor for serum ACE inhibition in horses and should be the drug of choice for cardiovascular conditions
•Food does not significantly impact benazepril pharmacodynamics, so it can be administered without fasting requirements in clinical practice
•Dosing does not need adjustment for repeated daily administration as no cumulative effect occurs over a 7-day period

Key Findings

•Benazepril at 0.5 mg/kg produced significantly higher maximum ACE inhibition (86.9%) compared to ramipril, quinapril, and perindopril
•ACE inhibition at 24 hours post-administration was highest with benazepril 0.5 mg/kg (60.3%) versus other tested drugs
•All four ACE inhibitors produced significant decreases in indirect blood pressure over time, but differences between drugs were not statistically significant
•Once-daily oral benazepril for 7 days showed no cumulative effect on ACE inhibition in horses

Conditions Studied

cardiovascular disordershypertension

Related References

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