Pharmacodynamics and Pharmacokinetics of Eptifibatide in Patients With Acute Coronary Syndromes Prospective Analysis From PURSUIT

Background Platelet deposition and aggregation are central to the pathogenesis of ischemic complications of acute coronary syndromes (ACS). Pharmacodynamic effects of the platelet glycoprotein IIb/IIIa antagonist eptifibatide have been delineated in healthy subjects but not in patients with ACS. We assessed effects of eptifibatide on ex vivo platelet aggregation in patients enrolled in the Platelet glycoprotein IIb/IIIa in Unstable angina: Receptor Suppression Using Integrilin (eptifibatide) Therapy (PURSUIT) trial of ACS. Methods and Results Patients were randomly assigned to an intravenous bolus (180 μg/kg) and 72-hour infusion of eptifibatide (2.0 μg/kg per minute, n=48) or placebo (n=50). We assessed correlations of plasma eptifibatide levels with receptor occupancy and inhibition of ex vivo platelet aggregation at 5 minutes and 1, 4, 24, 48, and 72 hours during treatment and 4 and 8 hours after termination of infusion. Blood was collected in buffered citrate and d-phenylalanyl-l-prolyl-l-arginine chl...