Pharmacokinetics of carbetocin, a long-acting oxytocin analogue, following intravenous administration in horses

• Published in: Equine veterinary journal Vol. 40; no. 7; pp. 658 - 661
• Main Authors: SCHRAMME, A. R., PINTO, C. R. F., DAVIS, J., WHISNANT, C. S., WHITACRE, M. D.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-11-2008
• Subjects: Animals; Area Under Curve; carbetocin; Female; Half-Life; Heart Rate - drug effects; horse; Horse Diseases - blood; Horse Diseases - drug therapy; Horses - blood; Injections, Intravenous - veterinary; oxytocin; Oxytocin - adverse effects; Oxytocin - analogs & derivatives; Oxytocin - pharmacokinetics; Oxytocin - therapeutic use; Pain - chemically induced; Pain - epidemiology; Pain - veterinary; pharmacokinetics; Radioimmunoassay - veterinary; Respiration - drug effects
• ISSN: 0425-1644; 2042-3306
• DOI: 10.2746/042516408X334343

Summary
Reason for performing study: 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.
Objectives: 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).
Potential relevance: Carbetocin is an attractive alternative to oxytocin therapy in broodmare management.