title: Evaluation of an oral direct factor Xa inhibitor anticoagulant in healthy adult horses.
abstract: OBJECTIVE
  To assess whether an oral direct factor Xa inhibitor (DiXaI) anticoagulant drug used at the low end of the recommended dose in people achieves presumed prophylactic plasma concentrations and does not induce bleeding in horses.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Field study.
  
  
  METHODS
  Ten healthy adult horses.
  
  
  METHODS
  A DiXaI was administered at a dose of 0.125 mg/kg every 24 h orally for 4 days. Following a wash-out period of 2 weeks, 8 of 10 horses received daily subcutaneous doses of a low molecular weight heparin (dalteparin) for 4 consecutive days at 50 IU/kg. In both trials, antifactor Xa activity was measured at baseline time and 3 hours after each dose administration. Activated partial thromboplastin time, prothrombin time, hematocrit, erythrocyte agglutination, and platelet aggregation were monitored throughout the study. In addition, an in vitro spiking experiment was performed to demonstrate anticoagulant activity of this DiXaI in horse plasma.
  
  
  RESULTS
  When treated with the DiXaI, this group of horses did not achieve the suggested thromboprophylactic plasma range of antifactor Xa activity (0.1-0.2 IU/mL), except for 1 horse after the first administration of the drug. In contrast, median values of plasma antifactor Xa activity 3 hours after receiving dalteparin were within the prophylactic range (0.16 IU/mL). No hemorrhagic events or erythrocyte agglutination were observed. In vitro addition of this DiXaI caused a concentration-dependent effect in antifactor Xa activity.
  
  
  CONCLUSIONS
  At the low end of the recommended dose in people this oral formulation of DiXaI did not reach prophylactic plasma antifactor Xa activity in this group of healthy adult horses. Further studies are warranted in order to establish the prophylactic dose for horses.
authors.affiliation: Servei de Medicina Interna Equina i Unitat Equina, Fundació Hospital Clínic Veterinari, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, Barcelona, 08310, Spain.
authors.forename: Maria L
authors.initials: ML
authors.lastname: Rodríguez-Pozo
authors.affiliation: Servei de Medicina Interna Equina i Unitat Equina, Fundació Hospital Clínic Veterinari, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, Barcelona, 08310, Spain.
authors.forename: Lara
authors.initials: L
authors.lastname: Armengou
authors.affiliation: Servei de Medicina Interna Equina i Unitat Equina, Fundació Hospital Clínic Veterinari, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, Barcelona, 08310, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Monreal
authors.affiliation: Servei de Medicina Interna Equina i Unitat Equina, Fundació Hospital Clínic Veterinari, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, Barcelona, 08310, Spain.
authors.forename: Judit
authors.initials: J
authors.lastname: Viu
authors.affiliation: Servei de Medicina Interna Equina i Unitat Equina, Fundació Hospital Clínic Veterinari, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, Barcelona, 08310, Spain.
authors.forename: Carla
authors.initials: C
authors.lastname: Cesarini
authors.affiliation: Servei de Medicina Interna Equina i Unitat Equina, Fundació Hospital Clínic Veterinari, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, Barcelona, 08310, Spain.
authors.forename: Eduard
authors.initials: E
authors.lastname: Jose-Cunilleras
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000925:Anticoagulants / Q000008:administration & dosage / Q000494:pharmacology*; D001777:Blood Coagulation / Q000187:drug effects*; D001780:Blood Coagulation Tests / Q000662:veterinary; D017985:Dalteparin / Q000008:administration & dosage / Q000494:pharmacology*; D065427:Factor Xa Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006736:Horses; D007279:Injections, Subcutaneous / Q000662:veterinary; D008297:Male; D010314:Partial Thromboplastin Time / Q000662:veterinary
chemical_list: D000925:Anticoagulants; D065427:Factor Xa Inhibitors; D017985:Dalteparin
keywords: antithrombotic agent; hemostasis; low molecular weight heparin; thromboprophylaxis