title: The Effects of Cyclosporine and Aspirin on Platelet Function in Normal Dogs.
abstract: BACKGROUND
  Cyclosporine increases thromboxane synthesis in dogs, potentially increasing the thrombogenic properties of platelets.
  
  
  OBJECTIVE
  Our hypothesis was that the concurrent administration of low-dose aspirin and cyclosporine would inhibit cyclosporine-associated thromboxane synthesis without altering the antiplatelet effects of aspirin. The objective was to determine the effects of cyclosporine and aspirin on primary hemostasis.
  
  
  METHODS
  Seven healthy dogs.
  
  
  METHODS
  A randomized, crossover study utilized turbidimetric aggregometry and a platelet function analyzer to evaluate platelet function during the administration of low-dose aspirin (1 mg/kg PO q24h), high-dose aspirin (10 mg/kg PO q12h), cyclosporine (10 mg/kg PO q12h), and combined low-dose aspirin and cyclosporine. The urine 11-dehydro-thromboxane-B2 (11-dTXB2 )-to-creatinine ratio also was determined.
  
  
  RESULTS
  On days 3 and 7 of administration, there was no difference in the aggregometry amplitude or the platelet function analyzer closure time between the low-dose aspirin group and the combined low-dose aspirin and cyclosporine group. On day 7, there was a significant difference in amplitude and closure time between the cyclosporine group and the combined low-dose aspirin and cyclosporine group. High-dose aspirin consistently inhibited platelet function. On both days, there was a significant difference in the urinary 11-dTXB2 -to-creatinine ratio between the cyclosporine group and the combined low-dose aspirin and cyclosporine group. There was no difference in the urinary 11-dTXB2 -to-creatinine ratio among the low-dose aspirin, high-dose aspirin, and combined low-dose aspirin and cyclosporine groups.
  
  
  CONCLUSIONS
  Low-dose aspirin inhibits cyclosporine-induced thromboxane synthesis, and concurrent use of these medications does not alter the antiplatelet effects of aspirin.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, MS, 39762-6100.
authors.forename: J
authors.initials: J
authors.lastname: Thomason
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, MS, 39762-6100.
authors.forename: T
authors.initials: T
authors.lastname: Archer
authors.affiliation: Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, MS, 39762-6100.
authors.forename: R
authors.initials: R
authors.lastname: Wills
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, MS, 39762-6100.
authors.forename: S
authors.initials: S
authors.lastname: Press
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, MS, 39762-6100.
authors.forename: A
authors.initials: A
authors.lastname: Mackin
mesh_terms: D000818:Animals; D001241:Aspirin / Q000008:administration & dosage / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects*; D018592:Cross-Over Studies; D016572:Cyclosporine / Q000494:pharmacology*; D004285:Dogs / Q000097:blood*; D007166:Immunosuppressive Agents / Q000494:pharmacology; D009391:Nephelometry and Turbidimetry; D010974:Platelet Aggregation; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D007166:Immunosuppressive Agents; D010975:Platelet Aggregation Inhibitors; D016572:Cyclosporine; D001241:Aspirin
keywords: Canine; Immune-mediated hemolytic anemia; Immunosuppression; Thromboxane