Antiplatelet efficacy of long-term treatment with clopidogrel besylate in patients with a history of acute coronary syndrome: comparison with clopidogrel hydrogen sulfate.

The efficacy of clopidogrel therapy in patients with an acute coronary syndrome (ACS) has been established using the clopidogrel hydrogen sulfate (CHS) formulation. We compared the antiplatelet effectiveness of long-term administration of the original CHS with a generic clopidogrel besylate (CB) salt formulation in 86 patients with a history of an ACS. At 1 month after the episode, patients receiving 75 mg/d CHS were randomized to continue with CHS (n = 41) or to switch to 75 mg/d CB (n = 45). Platelet aggregation, vasodilator-stimulated phosphoprotein (VASP) phosphorylation, P-selectin expression, and platelet-leucocyte conjugates were determined before randomization and at 6 months afterward. No difference in any platelet parameter studied was observed between the 2 groups either before randomization or after 6 months of treatment with CHS or CB. We conclude that there is no difference in the antiplatelet efficacy between CB and CHS during long-term administration in patients with a history of an ACS.