Effect of clopidogrel besylate on platelet reactivity in patients with acute coronary syndromes. Comparison with clopidogrel hydrogen sulfate.

OBJECTIVE: The efficacy of clopidogrel therapy in patients with an acute coronary syndrome (ACS) has been established using the clopidogrel hydrogen sulfate (CHS) formulation. In this study we compared the antiplatelet effectiveness of a generic clopidogrel salt, clopidogrel besylate (CB), with the original CHS in patients with an ACS. RESEARCH DESIGN AND METHODS: Ninety-six ACS patients were randomized to receive a 600-mg loading dose of either CHS (n = 45) or CB (n = 51), followed by 75 mg/day. Sixty-eight patients underwent a percutaneous coronary intervention (PCI), whereas 28 were treated conservatively. Platelet aggregatory response, vasodilator-stimulated phosphoprotein (VASP) phosphorylation, P-selectin expression and platelet-leucocyte conjugates were determined before clopidogrel loading (baseline), as well as at 5 days and at 1 month afterwards. RESULTS: No difference in the clopidogrel response variability was observed between patients receiving CHS or CB either at 5 days or at 1 month of follow-up. Similarly, no difference in the inhibition of platelet aggregation, P-selectin expression or in the platelet-leucocyte conjugates was observed between CHS and CB group during the follow-up. CONCLUSIONS: There is no overall significant difference in the antiplatelet efficacy between CB and CHS during their administration in ACS patients for up to 1 month after the episode.