[Medication of the month. Prasugrel (Efient): potent thienopyridine antiplatelet agent]

Prasugrel (Efient), a thienopyridine of third generation, is a prodrug that, like clopidogrel, requires conversion to an active metabolite before binding to the platelet P2Y12 receptor to confer antiplatelet activity. At the currently studied doses, prasugrel inhibits adenosine diphosphate-induced platelet aggregation more rapidly, more consistently, and to a greater extent than do standard and higher doses of clopidogrel. The risk of myocardial ischemic events in patients with acute coronary syndromes has been shown to be reduced by means of platelet inhibition. Dual-antiplatelet therapy with aspirin and clopidogrel has become the cornerstone of treatment to prevent thrombotic complications of acute coronary syndromes and percutaneous coronary intervention. In patients with acute coronary syndromes (TRITON-TIMI 38 trial), prasugrel therapy was associated with significantly reduced rates of ischemic events, including stent thrombosis, but with an increased risk of major bleeding. Subjects with diabetes mellitus tended to even have a greater reduction in ischemic events with prasugrel. In Belgium, Efient is currently reimbursed for 1 year in patients with an acute coronary syndrome and scheduled for a percutaneous coronary intervention (PCI) who present at least one of the following criteria: primary PCI for ST-elevation myocardial infarction, stent thrombosis despite treatment with clopidogrel, or diabetes mellitus.