Vorapaxar is an orally bioavailable competitive antagonist of the proteinase-activated receptor (PAR1; K
i = 8.1 nM), also known as the thrombin receptor.
1 It is selective for PAR1 over other PARs, as well as a number of GPCRs, ion channels, and receptors. It inhibits platelet aggregation induced by thrombin (Item No.
13188) and haTRAP (IC
50s = 47 and 25 nM, respectively). Vorapaxar (0.1 mg/kg, i.v.) completely inhibits platelet aggregation in cynomolgus monkeys
ex vivo. Formulations containing vorapaxar are used in the prevention of thrombotic cardiovascular events.