title: Effects of dipyrone, meloxicam, or the combination on hemostasis in conscious dogs.
abstract: OBJECTIVE
  To compare the effects of dipyrone, meloxicam, and of the combination of these drugs on hemostasis in dogs.
  
  
  METHODS
  Prospective, blinded, randomized crossover study.
  
  
  METHODS
  Research laboratory at a veterinary teaching hospital.
  
  
  METHODS
  Six adult dogs.
  
  
  METHODS
  Animals received 4 intravenous treatments with 15-day washout intervals: control (physiological saline, 0.1 mL/kg), meloxicam (0.2 mg/kg), dipyrone (25 mg/kg), and dipyrone-meloxicam (25 and 0.2 mg/kg, respectively). A jugular catheter was placed for drug injection and for collecting samples for whole blood platelet aggregation (WBPA) and thromboelastometry assays at baseline, 1, 2, 3, 5, and 8 hours after treatment administration. The percent change from baseline of lag time and of the area under the curve (AUC) of impedance changes in response to collagen-induced platelet activation were recorded during WBPA. Thromboelastometry-derived parameters included clotting time, clot formation time, alpha-angle, and maximum clot firmness. The buccal mucosal bleeding time was evaluated by a blinded observer at baseline, 1, 3, and 5 hours after treatment injection.
  
  
  RESULTS
  No significant changes in WBPA and thromboelastometry were recorded in the control treatment. Dipyrone significantly (P < 0.05) increased the lag time for 2 hours and decreased the AUC for 3 hours after injection. Meloxicam did not alter WBPA. Dipyrone-meloxicam significantly increased lag time for 2 hours and decreased the AUC for 5 hours after treatment injection. Experimental treatments did not differ from the control treatment for thromboelastometry and buccal mucosal bleeding time.
  
  
  CONCLUSIONS
  While meloxicam does not alter hemostasis by the methods evaluated, dipyrone inhibits platelet aggregation for up to 3 hours. Meloxicam-dipyrone combination causes more prolonged inhibition of platelet function than dipyrone alone. Decreased platelet aggregation induced by dipyrone and dipyrone-meloxicam does not appear to impact the viscoelastic properties of the blood clot nor increase the risk of bleeding in dogs without preexisting hemostatic disorders.
authors.affiliation: Department of Anesthesiology, Faculdade de Medicina, Universidade Estadual Paulista (UNESP), CEP 18618-970, Botucatu, Brazil.
authors.forename: Felipe S
authors.initials: FS
authors.lastname: Zanuzzo
authors.affiliation: Departments of Veterinary Surgery and Anesthesiology, Clinical Veterinary Sciences.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Teixeira-Neto
authors.affiliation: Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista (UNESP), CEP 18618-970, Botucatu, Brazil.
authors.forename: Camila M
authors.initials: CM
authors.lastname: Thomazini
authors.affiliation: Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista (UNESP), CEP 18618-970, Botucatu, Brazil.
authors.forename: Regina K
authors.initials: RK
authors.lastname: Takahira
authors.affiliation: Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610.
authors.forename: Bobbi
authors.initials: B
authors.lastname: Conner
authors.affiliation: Department of Anesthesiology, Faculdade de Medicina, Universidade Estadual Paulista (UNESP), CEP 18618-970, Botucatu, Brazil.
authors.forename: Miriely S
authors.initials: MS
authors.lastname: Diniz
mesh_terms: D000818:Animals; D001780:Blood Coagulation Tests / Q000662:veterinary; D018592:Cross-Over Studies; D004177:Dipyrone / Q000008:administration & dosage / Q000494:pharmacology*; D004285:Dogs; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D006487:Hemostasis / Q000187:drug effects; D007262:Infusions, Intravenous; D008297:Male; D000077239:Meloxicam; D010974:Platelet Aggregation / Q000187:drug effects*; D011446:Prospective Studies; D013843:Thiazines / Q000008:administration & dosage / Q000494:pharmacology*; D013844:Thiazoles / Q000008:administration & dosage / Q000494:pharmacology*; D013916:Thrombelastography / Q000662:veterinary
chemical_list: D013843:Thiazines; D013844:Thiazoles; D004177:Dipyrone; D000077239:Meloxicam
keywords: NSAIDs; canine; coagulation; platelet function; thromboelastometry