A portion of the results from this study was presented at the International Veterinary Emergency and Critical Care Symposium held at San Antonia, TX, September 2010.
Original Article – Research
Pharmacodynamics of Multi-Dose Low Molecular Weight Heparin in Healthy Horses
Article first published online: 10 APR 2013
© Copyright 2013 by The American College of Veterinary Surgeons
Volume 42, Issue 4, pages 448–454, May 2013
How to Cite
Whelchel, D. D., Tennent-Brown, B. S., Giguère, S. and Epstein, K. L. (2013), Pharmacodynamics of Multi-Dose Low Molecular Weight Heparin in Healthy Horses. Veterinary Surgery, 42: 448–454. doi: 10.1111/j.1532-950X.2013.12008.x
- Issue published online: 15 MAY 2013
- Article first published online: 10 APR 2013
- Manuscript Accepted: 14 NOV 2011
- Manuscript Received: 3 MAY 2011
- the American College of Veterinary Surgeons
To compare the pharmacodynamics of once daily and twice daily administration of low molecular weight heparin (LMWH) administration in horses.
Randomized cross over study.
Adult mixed breed healthy mares (n = 6).
LMWH (dalteparin) was administered (50 U/kg subcutaneously) either every 12 or 24 hours for 3 consecutive days. Anti-factor Xa activity was measured before and at select time points after LMWH administration. Packed cell volume (PCV), platelet count, partial thromboplastin time (PTT), and anti-thrombin (AT) activity were monitored throughout the study.
No changes in PCV, platelet count, or AT activity were detected with either frequency of daily LMWH administration. Values for PTT increased throughout the study but never exceeded the normal reference interval. Anti-factor Xa activity was maintained within or above the suggested thromboprophylactic range (0.1–0.2 U/mL) when LMWH was administered twice daily, but fell below this range ∼16 hours after administration when given once daily. For both once and twice daily LMWH administration, the area under the curve was significantly greater after the last dose of LMWH when compared to the first dose.
Administration of LMWH once or twice daily for 3 consecutive days appears to be safe in healthy adult horses. Anti-factor Xa activity was maintained within or above the suggested thromboprophylactic range for 24 hours with twice daily LMWH administration but not with once daily administration.