Aim: To characterize the pharmacokinetics (PKs), pharmacodynamics (PDs), and tolerability of different dose regimens of prasugrel in healthy Chinese subjects.
Methods: This was a single-centered, open-label, parallel-design study. Subjects received a single loading dose (LD) of prasugrel followed by once-daily maintenance dose (MD) for 10 d. They were enrolled into 3 groups: 60 mg LD/10 mg MD; 30 mg LD/7.5 mg MD; 30 mg LD/5 mg MD. Blood samples were collected after the first and last dose. The serum concentration of the active metabolite of prasugrel was determined using a LC/MS/MS method. Platelet aggregation was assessed using the VerifyNow-P2Y(12) assay.
Results: Thirty-six healthy native Chinese subjects (19 males) aged 18-45 were enrolled; mean age and body weight were similar across the treatment groups (n=12 for each). The metabolite AUC(0-4) and C(max) increased dose-proportionally across the dose range of 5 mg to 60 mg. The median T(max) was 0.5 h in all groups. The PD parameters, indicated by the inhibition of ADP-induced platelet aggregation, were met more rapidly in the 60 mg group than the 30 mg group after the LD (94%-98%). This high degree of inhibition of platelet aggregation was maintained following the 10 mg MD (87%-90%) and was lower in the 7.5 mg and 5 mg MD groups (79%-83% and 64%-67%, respectively). Prasugrel was well tolerated in healthy Chinese subjects for single doses up to 60 mg and a MD of 10 mg for 10 d.
Conclusion: The PKs and PDs of the active metabolite of prasugrel were similar to those in Chinese subjects reported by a previous bridging study, which demonstrated that the exposure to the active metabolite in Chinese subjects was higher than in Caucasians.