title: Chronic oral therapy with enalapril in normal ponies.
abstract: Enalapril is an angiotensin converting enzyme (ACE) inhibitor that is frequently used in human, feline and canine patients with cardiac disease. Its use has been associated with impotence in human patients. The purpose of this study was to evaluate if enalapril (0.5mg/kg PO, q24h) is likely to alter behavior in stallions and to assess its effect on ACE activity at the standard dose used in dogs and cats. Twelve pony stallions were evaluated by physical examination and echocardiography followed by treatment with enalapril (n=6) or placebo (n=6) for 2 months. After one month, blood was drawn and stored to evaluate ACE activity in the 2 groups. At the end of the study, repeat physical examination and echocardiography were performed. Physical examination, echocardiographic indices, and reproductive performance were unchanged and there was no suppression of ACE activity. Results of this study suggest that enalapril (0.5mg/kg PO, q24h) is either poorly absorbed in the horse or is inadequately converted to the active form of the drug, enalaprilat.
authors.affiliation: Department of Clinical Studies, New Bolton Center, Section of Sports Medicine, University of Pennsylvania Veterinary School, Kennett Square, PA 19348, USA. sleeper@vet.upenn.edu
authors.forename: Meg M
authors.initials: MM
authors.lastname: Sleeper
authors.forename: Sue M
authors.initials: SM
authors.lastname: McDonnell
authors.forename: John J
authors.initials: JJ
authors.lastname: Ely
authors.forename: Virginia B
authors.initials: VB
authors.lastname: Reef
mesh_terms: D000284:Administration, Oral; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage* / Q000378:metabolism / Q000493:pharmacokinetics; D000818:Animals; D004452:Echocardiography / Q000379:methods / Q000662:veterinary*; D004656:Enalapril / Q000008:administration & dosage* / Q000378:metabolism / Q000493:pharmacokinetics; D007172:Erectile Dysfunction / Q000139:chemically induced / Q000662:veterinary; D006331:Heart Diseases / Q000188:drug therapy / Q000201:enzymology / Q000662:veterinary*; D006734:Horse Diseases / Q000188:drug therapy* / Q000201:enzymology; D006736:Horses; D007408:Intestinal Absorption; D008297:Male; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*; D017211:Treatment Failure
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D004656:Enalapril; D007703:Peptidyl-Dipeptidase A