title: No differences in the pharmacodynamics and pharmacokinetics of the thrombin receptor antagonist vorapaxar between healthy Japanese and Caucasian subjects.
abstract: BACKGROUND
  Vorapaxar, a novel antiplatelet agent in advanced clinical development for the prevention and treatment of atherothrombotic disease, is a potent, orally bioavailable thrombin receptor antagonist selective for the protease-activated receptor 1 (PAR-1).
  
  
  METHODS
  Since race/ethnicity may affect the safety, efficacy and dosage of drugs, this study was conducted to evaluate potential differences in the pharmacodynamics, pharmacokinetics and safety of vorapaxar after single (5, 10, 20, or 40 mg) or multiple (0.5, 1, or 2.5 mg once daily) doses in healthy Japanese and matched (gender, age, height, and weight) Caucasian volunteers.
  
  
  RESULTS
  Vorapaxar was well tolerated in both Japanese and Caucasian subjects. Pharmacodynamic and pharmacokinetic profiles of vorapaxar in the two racial/ethnic groups were similar. In both racial groups, complete inhibition of platelet aggregation was achieved most rapidly with vorapaxar 40 mg and was consistently achieved and maintained with a 2.5 mg daily maintenance dose.
  
  
  CONCLUSIONS
  There were no substantial differences in the safety, pharmacokinetics or pharmacodynamics of vorapaxar between Japanese and Caucasian subjects.
authors.affiliation: Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA. teddy.kosoglou2@merck.com
authors.forename: Teddy
authors.initials: T
authors.lastname: Kosoglou
authors.forename: Larisa
authors.initials: L
authors.lastname: Reyderman
authors.forename: Claudia
authors.initials: C
authors.lastname: Kasserra
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Jennings
authors.forename: Sophia
authors.initials: S
authors.lastname: Young
authors.forename: Fengjuan
authors.initials: F
authors.lastname: Xuan
authors.forename: Jinglan
authors.initials: J
authors.lastname: Pei
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Maxwell
authors.forename: James
authors.initials: J
authors.lastname: Schiller
authors.forename: Alan G
authors.initials: AG
authors.lastname: Meehan
authors.forename: David L
authors.initials: DL
authors.lastname: Cutler
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People; D005260:Female; D006801:Humans; D007783:Lactones / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D011725:Pyridines / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D044465:White People; D055815:Young Adult
chemical_list: D007783:Lactones; D010975:Platelet Aggregation Inhibitors; D011725:Pyridines; C530299:vorapaxar