title: Pharmacodynamic evaluation of 4 angiotensin-converting enzyme inhibitors in healthy adult horses.
abstract: BACKGROUND
  Angiotensin-converting enzyme (ACE) inhibitors are used in horses with cardiovascular disorders despite the paucity of available data regarding their efficacy.
  
  
  OBJECTIVE
  The degree of serum ACE inhibition varies considerably between drugs.
  
  
  METHODS
  Eight healthy adult horses.
  
  
  METHODS
  Randomized prospective study. Horses were fasted overnight prior to receiving one of 4 ACE inhibitors intragastrically, administered at one of 2 dosages, using a randomized Latin square design (benazepril: 0.5 and 0.25 mg/kg; ramipril: 0.3 and 0.1 mg/kg; quinapril: 0.25 and 0.125 mg/kg; perindopril: 0.1 and 0.05 mg/kg). Serum ACE activity was measured using a kinetic spectrophotometric method.
  
  
  RESULTS
  There was a significant effect of drug and dosage on maximum ACE inhibition (I(max)), ACE inhibition 24 hours after administration (I(24h)), and area under the curve (AUC(0-48h)). Benazepril at 0.5 mg/kg resulted in significantly higher I(max) (86.9 ± 7.0%) and I(24h) (60.3 ± 7.9%) compared to the other drugs. There was a significant decrease in indirect blood pressure (BP) over time after administration of each drug, but differences in BP were not significantly different between drugs. Pharmacodynamic variables measured after administration of benazepril to horses with free access to hay were not significantly different from those obtained after fasting. Administration of benazepril orally once daily for 7 days did not result in a cumulative effect on ACE inhibition.
  
  
  CONCLUSIONS
  Of the ACE inhibitors tested, oral benazepril (0.5 mg/kg) is the most effective at inhibiting serum ACE activity in healthy horses.
authors: Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA.
authors: T
authors: T
authors: Afonso
authors: S
authors: S
authors: Giguère
authors: G
authors: G
authors: Rapoport
authors: L J
authors: LJ
authors: Berghaus
authors: M H
authors: MH
authors: Barton
authors: A E
authors: AE
authors: Coleman
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000493:pharmacokinetics* / Q000494:pharmacology*; D000818:Animals; D019540:Area Under Curve; D001794:Blood Pressure / Q000187:drug effects*; D005508:Food Deprivation; D006207:Half-Life; D006736:Horses
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors
keywords: ACE inhibitor; Benazepril; Cardiology; Equine; Perindopril; Quinapril; Ramipril