Vorapaxar for reduction of thrombotic cardiovascular events in myocardial infarction and peripheral artery disease.

Purpose: The pharmacology, pharmacokinetics, clinical efficacy, adverse effects, dosage and administration, cost, and place in therapy of vorapaxar in the secondary prevention of atherosclerotic events are reviewed.

Summary: Vorapaxar is a highly selective, reversible antagonist of protease-activated receptor-1 expressed on platelets. Vorapaxar competitively inhibits thrombin from activating the receptor, thereby decreasing platelet aggregation. Vorapaxar is rapidly absorbed and distributed, with peak plasma levels being reached within 60-90 minutes. Vorapaxar's effective half-life is three to four days and its terminal elimination half-life is eight days. Vorapaxar sulfate 2.5 mg (equivalent to 2.08 mg of vorapaxar) orally daily without a loading dose was clinically effective for the secondary prevention of ischemic events in patients with a history of myocardial infarction (MI) or with peripheral arterial disease (PAD) without a history of stroke. Phase II and III trials of vorapaxar given with aspirin or a thienopyridine or both demonstrated a reduction in the primary endpoint of cardiovascular death, MI, and stroke in patients with a history of MI or coronary artery disease and PAD. Patients with a history of stroke were found to have an increased rate of intracranial hemorrhage (ICH), which led to a boxed warning placed on vorapaxar's labeling to warn of the increased risk for bleeding in patients with a history of stroke.

Conclusion: Vorapaxar is a novel antiplatelet agent that has demonstrated efficacy in reducing atherosclerotic events in patients with a history of MI or PAD without a history of stroke, transient ischemic attack, or ICH when taken in combination with aspirin and clopidogrel.