Otto CM, Rieser TM, Brooks MB, et alEvidence of hypercoagulability in dogs with parvoviral enteritis. J Am Vet Med Assoc 2000;217:1500–1504.
Donahue SM, Otto CM. Thromboelastography: a tool for measuring hypercoagulability, hypocoagulability, and fibrinolysis. J Vet Emerg Crit Care 2005;15:9–16.
Weinkle TK, Center SA, Randolph JF, et alEvaluation of prognostic factors, survival rates, and treatment protocols for immune-mediated hemolytic anemia in dogs: 151 cases (1993–2002). J Am Vet Med Assoc 2005;226:1869–1880.
LaRue MJ, Murtaugh RJ. Pulmonary thromboembolism in dogs: 47 cases (1986–1987). J Am Vet Med Assoc 1990;197:1368–1372.
Johnson LR, Lappin MR, Baker DC. Pulmonary thromboembolism in 29 dogs: 1985–1995. J Vet Intern Med 1999;13:338–345.
Van Winkle TJ, Hackner SG, Liu SM. Clinical and pathological features of aortic thromboembolism in 36 dogs. J Vet Emerg Crit Care 1993;3:13–21.
Littman MP, Dambach DM, Vaden SL, et alFamilial proteinlosing enteropathy and protein-losing nephropathy in Soft Coated Wheaten Terriers: 222 cases (1983–1997). J Vet Intern Med 2000;14:68–80.
Moore KE, Morris N, Dhupa N, et alRetrospective study of streptokinase administration in 46 cats with arterial thromboembolism. J Vet Emerg Crit Care 2000;10:245–257.
Hwang DH. Species variation in platelet aggregation. In: Longnecker GL, ed. The platelets, physiology and pharmacology. New York: Academic Press Inc, 1985;289–305.
Brainard BM, Meredith CP, Callan MB, et alChanges in platelet function, hemostasis, and prostaglandin expression after treatment with nonsteroidal anti-inflammatory drugs with various cyclooxygenase selectivities in dogs. Am J Vet Res 2007;68:251–257.
Yusuf S, Zhao F, Mehta SR, et alEffects of clopidogrel in addition to aspirin in patients with acute coronary syndromes without ST-segment elevation. N Engl J Med 2001;345:494–502.
Hogan DF, Andrews DA, Green HW, et alAntiplatelet effects and pharmacodynamics of clopidogrel in cats. J Am Vet Med Assoc 2004;225:1406–1411.
Wong PC, Crain EJ, Watson CA, et alClopidogrel versus prasugrel in rabbits—effects on thrombosis, haemostasis, platelet function and response variability. Thromb Haemost 2009;101:108–115.
Coomber BL, Mitchell GB, Starr AE, et alClopidogrel induced suppression of bovine platelet activation in vitro and a preliminary study of its effect on the development of Mannheimia haemolytica induced pneumonia. Vet J 2006;171:126–134.
Hong TT, Huang J, Driscoll E, et alThe antithrombotic effect of melagatran in combination with clopidogrel and/or aspirin (carotid artery primary thrombosis study). J Cardiovasc Pharmacol 2005;46:526–533.
Pereillo JM, Maftouh M, Andrieu A, et alStructure and stereochemistry of the active metabolite of clopidogrel. Drug Metab Dispos 2002;30:1288–1295.
Savi P, Pereillo JM, Uzabiaga MF, et alIdentification and biological activity of the active metabolite of clopidogrel. Thromb Haemost 2000;84:891–896.
Mega JL, Close SL, Wiviott SD, et alCytochrome p-450 polymorphisms and response to clopidogrel. N Engl J Med 2009;360:354–362.
Simon T, Verstuyft C, Mary-Krause M, et alGenetic determinants of response to clopidogrel and cardiovascular events. N Engl J Med 2009;360:363–375.
Chauret N, Gauthier A, Martin J, et alIn vitro comparison of cytochrome P450-mediated metabolic activities in human, dog, cat, and horse. Drug Metab Dispos 1997;25:1130–1136.
Bahrami G, Mohammadi B, Sisakhtnezhad S. High-performance liquid chromatographic determination of inactive carboxylic acid metabolite of clopidogrel in the human serum: application to a bioequivalence study. J Chromatogr B Analyt Technol Biomed Life Sci 2008;864:168–172.
Born GV. Aggregation of blood platelets by adenosine diphosphate and its reversal. Nature 1962;194:927–929.
Craft RM, Chavez JJ, Bresee SJ, et alA novel modification of the Thrombelastograph assay, isolating platelet function, correlates with optical platelet aggregation. J Lab Clin Med 2004;143:301–309.
United States Pharmacopeial Convention. General chapter 621. Chromatography. In: The United States pharmacopeia and the national formulary. USP 32–NF 27. Rockville, Md: US Pharmacopeial Convention, 2009;865–867.
Xiang YZ, Kang LY, Gao XM, et alStrategies for antiplatelet targets and agents. Thromb Res 2008;123:35–49.
Storey RF, Sanderson HM, White AE, et alThe central role of the P2T receptor in amplification of human platelet activation, aggregation, secretion and procoagulant activity. Br J Haematol 2000;110:925–934.
Ganter MT, Hofer CK. Coagulation monitoring: current techniques and clinical use of viscoelastic point-of-care coagulation devices. Anesth Analg 2008;106:1366–1375.
Lang T, Toller W, Gütl M, et alDifferent effects of abciximab and cytochalasin D on clot strength in thrombelastography. J Thromb Haemost 2004;2:147–153.
Hechler B, Cattaneo M, Gachet C. The P2 receptors in platelet function. Semin Thromb Hemost 2005;31:150–161.
Hechler B, Eckly A, Ohlmann P, et alThe P2Y1 receptor, necessary but not sufficient to support full ADP-induced platelet aggregation, is not the target of the drug clopidogrel. Br J Haematol 1998;103:858–866.
Feher G, Feher A, Pusch G, et alThe genetics of antiplatelet drug resistance. Clin Genet 2009;75:1–18.
Heptinstall S, Glenn JR, May JA, et alClopidogrel resistance. Catheter Cardiovasc Interv 2004;63:397–398.
Johnson GJ, Leis LA, Dunlop PC. Thromboxane-insensitive dog platelets have impaired activation of phospholipase C due to receptor-linked G-protein dysfunction. J Clin Invest 1993;92:2469–2479.
Weber A, Braun M, Hohlfeld T, et alRecovery of platelet function after discontinuation of clopidogrel treatment in healthy volunteers. Br J Clin Pharmacol 2001;52:333–336.
Heilmann E, Friese P, Anderson S, et alBiotinylated blood platelets: a new approach to the measurement of platelet life span. Br J Haematol 1993;85:729–735.
Ho PM, Peterson ED, Wang L, et alIncidence of death and acute myocardial infarction associated with stopping clopidogrel after acute coronary syndrome (Erratum published in JAMA 2008;299:2390). JAMA 2008;299:532–539.
Narita T, Sato R, Motoishi K, et alThe interaction between orally administered non-steroidal anti-inflammatory drugs and prednisolone in healthy dogs. J Vet Med Sci 2007;69:353–363.
Ksycinska H, Rudzki P, Bukowska-Kiliszek M. Determination of clopidogrel metabolite (SR26334) in human plasma by LC-MS. J Pharm Biomed Anal 2006;41:533–539.
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Objective—To determine pharmacodynamic and pharmacokinetic properties of clopidogrel and the metabolite SR 26334 in dogs.
Animals—9 mixed-breed dogs.
Procedures—8 dogs received clopidogrel (mean ± SD 1.13 ± 0.17 mg/kg, PO, q 24 h) for 3 days; 5 of these dogs subsequently received a lower dose of clopidogrel (0.5 ± 0.18 mg/kg, PO, q 24 h) for 3 days. Later, 5 dogs received clopidogrel (1.09 ± 0.12 mg/kg, PO, q 24 h) for 5 days. Blood samples were collected for optical platelet aggregometry, citrated native and platelet mapping thrombelastography (TEG), and measurement of plasma drug concentrations. Impedance aggregometry was performed on samples from 3 dogs in each 3-day treatment group.
Results—ADP-induced platelet aggregation decreased (mean ± SD 93 ± 6% and 80 ± 22% of baseline values, respectively) after 72 hours in dogs in both 3-day treatment groups; duration of effect ranged from > 3 to > 7 days. Platelet mapping TEG and impedance aggregometry yielded similar results. Citrated native TEG was not different among groups. Clopidogrel was not detected in any samples; in dogs given 1.13 ± 0.17 mg/kg, maximum concentration of SR 26334 (mean ± SD, 0.206 ± 0.2 μg/mL) was detected 1 hour after administration.
Conclusions and Clinical Relevance—Clopidogrel inhibited ADP-induced platelet aggregation in healthy dogs and may be a viable antiplatelet agent for use in dogs.
Impact for Human Medicine—Pharmacodynamic effects of clopidogrel in dogs were similar to effects reported in humans; clopidogrel may be useful in studies involving dogs used to investigate human disease.
Supported by the Morris Animal Foundation (MAF D07CA-303) and the University of Georgia Clinical Research Committee.
Presented in abstract form at the American College of Veterinary Internal Medicine Forum, San Antonio, Tex, June 2008.