Pharmacokinetics of carbetocin, a long-acting oxytocin analogue, following intravenous administration in horses.
BACKGROUND
Current therapy protocols to treat persistent post mating endometritis and retained fetal membranes in mares typically include the administration of ecbolic drugs. Evaluation of the pharmacokinetics and tolerability of carbetocin, a long-acting oxytocin analogue, after i.v. administration is required.


OBJECTIVE
To determine the pharmacokinetic parameters (principally half-life) of carbetocin in horses.


METHODS
Five mature mares and one gelding received 0.175 mg carbetocin i.v. All animals were monitored periodically throughout the study for elevation in rectal temperature, heart rate, respiratory rate and signs of pain or discomfort. Plasma samples were collected for determination of carbetocin concentrations by radioimmunoassay.


RESULTS
Administration of carbetocin was well tolerated by all horses and its half-life was 17.2 min.


CONCLUSIONS
The half-life of carbetocin is greater than that previously reported for oxytocin (6.8 min).


CONCLUSIONS
Carbetocin is an attractive alternative to oxytocin therapy in broodmare management.
Schramme
A R
AR
North Carolina State University, College of Veterinary Medicine, Department of Population Health and Pathobiology, 4700 Hillsborough Street, Raleigh, North Carolina 27606, USA.
Pinto
C R F
CR
Davis
J
J
Whisnant
C S
CS
Whitacre
M D
MD
D000818:Animals; D019540:Area Under Curve; D005260:Female; D006207:Half-Life; D006339:Heart Rate / Q000187:drug effects; D006734:Horse Diseases / Q000097:blood / Q000188:drug therapy; D006736:Horses / Q000097:blood*; D007275:Injections, Intravenous / Q000662:veterinary; D010121:Oxytocin / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000627:therapeutic use; D010146:Pain / Q000139:chemically induced / Q000453:epidemiology / Q000662:veterinary; D011863:Radioimmunoassay / Q000662:veterinary; D012119:Respiration / Q000187:drug effects
D010121:Oxytocin; C020731:carbetocin