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Abciximab Pharmacodynamics Are Unaffected by Antecedent Therapy with Other GPIIb/IIIa Antagonists in Non-human Primates

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Date 2003 Mar 26
PMID 12652146
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Abstract

Background: Tirofiban and eptifibatide are currently approved for the medical stabilization of non-ST segment elevation acute coronary syndromes. In patients undergoing percutaneous coronary intervention (PCI) during infusion of these drugs, conversion to abciximab, which has long term proven clinical efficacy and cost-effectiveness, following PCI may be desirable. The purpose of this study was to determine if the binding or pharmacodynamics of abciximab is affected by a prior infusion of either tirofiban or eptifibatide.

Methods: In vitro binding experiments were performed to determine if prior exposure to tirofiban or eptifibatide altered the affinity and extent of binding of abciximab to GPIIb/IIIa. For in vivo experiments, cynomolgus monkeys were pretreated with a bolus and 18 hour infusion of saline, tirofiban, or eptifibatide. At the end of the initial treatment, a bolus and 12 hr infusion of abciximab was started without delay. Inhibition of platelet aggregation, GPIIb/IIIa receptor blockade and abciximab pharmacokinetics were measured during and after both infusions.

Results: Equilibrium binding of abciximab in vitro was unaffected by tirofiban or eptifibatide. The extent and duration of abciximab inhibition of ex vivo platelet aggregation, receptor blockade, and abciximab pharmacokinetics in monkeys during and after the abciximab infusion were not affected by prior infusion of the animals with tirofiban or eptifibatide.

Conclusions: In vitro and in vivo studies revealed that the molecular interaction of abciximab with the platelet GPIIb/IIIa receptor is not altered by immediate prior exposure of platelets to small molecule GPIIb/IIIa antagonists. These preclinical studies suggest that the efficacy of abciximab should not be impaired if it is initiated following termination of therapy with small molecule GPIIb/IIIa antagonists.

References
1.
Kleiman N, Raizner A, Jordan R, Wang A, Norton D, Mace K . Differential inhibition of platelet aggregation induced by adenosine diphosphate or a thrombin receptor-activating peptide in patients treated with bolus chimeric 7E3 Fab: implications for inhibition of the internal pool of GPIIb/IIIa receptors. J Am Coll Cardiol. 1995; 26(7):1665-71. DOI: 10.1016/0735-1097(95)00391-6. View

2.
Rebello S, Huang J, Faul J, Lucchesi B . Role of extracellular ionized calcium in the in vitro assessment of GPIIb/IIIa receptor antagonists. J Thromb Thrombolysis. 1999; 9(1):23-8. DOI: 10.1023/a:1018679708251. View

3.
Smith J, Steinhubl S, Lincoff A, Coleman J, Lee T, HILLMAN R . Rapid platelet-function assay: an automated and quantitative cartridge-based method. Circulation. 1999; 99(5):620-5. DOI: 10.1161/01.cir.99.5.620. View

4.
Marciniak Jr S, Jordan R, Mascelli M . Effect of Ca2+ chelation on the platelet inhibitory ability of the GPIIb/IIIa antagonists abciximab, eptifibatide and tirofiban. Thromb Haemost. 2001; 85(3):539-43. View

5.
Lev E, Osende J, Richard M, Robbins J, Delfin J, Rodriguez O . Administration of abciximab to patients receiving tirofiban or eptifibatide: effect on platelet function. J Am Coll Cardiol. 2001; 37(3):847-55. DOI: 10.1016/s0735-1097(00)01181-5. View