title: A head-to-head pharmacodynamic comparison of prasugrel vs. ticagrelor after switching from clopidogrel in patients with coronary artery disease: results of a prospective randomized study.
abstract: Pharmacodynamic (PD) studies comparing prasugrel and ticagrelor have reached inconsistent findings. Therefore, a comprehensive investigation comparing the PD effects of prasugrel vs. ticagrelor after switching from clopidogrel therapy, exploring both loading dose (LD) and maintenance dose (MD) regimens represented the aim of this study.
  
  
  
  Patients (n = 110) with coronary artery disease were randomized to prasugrel (60 mg LD/10 mg MD q.d.) or ticagrelor (180 mg LD/90 mg MD b.i.d) therapy for 1 week. Pharmacodynamic assessments were conducted using three assays (vasodilator-stimulated phosphoprotein, VerifyNow P2Y12, and light transmittance aggregometry, LTA) at baseline, 30 min, 2, 24 h, and 1 week. The impact of initiating ticagrelor MD 12 vs. 24 h after LD administration was also assessed. Switching clopidogrel-treated patients to an LD of prasugrel or ticagrelor was associated with a reduction in platelet reactivity at 30 min and was sustained at all time points up to 1 week with the MD (P < 0.001 for all assays). Platelet reactivity was similar with prasugrel and ticagrelor with all assays at 30 min, 2 h, and 1 week (P > 0.05 for all time points), with the exception of LTA at 30 min (lower with prasugrel; P = 0.003). At 24 h, platelet reactivity was lower among patients initiating ticagrelor MD after 12 vs. 24 h post-LD. Rates of high platelet reactivity (HPR) were markedly reduced and similar between groups.
  
  
  
  Prasugrel and ticagrelor exert similar levels of P2Y12 inhibition achieving more potent PD effects and reduced HPR rates compared with clopidogrel which are reached promptly following LD and sustained with MD.
  
  
  
  NCT01852175.
authors: University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA.
authors: Fabiana
authors: F
authors: Rollini
authors: University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA.
authors: Francesco
authors: F
authors: Franchi
authors: University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA.
authors: Jung Rae
authors: JR
authors: Cho
authors: University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA.
authors: Christopher
authors: C
authors: DeGroat
authors: University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA.
authors: Mona
authors: M
authors: Bhatti
authors: University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA.
authors: Ana
authors: A
authors: Muniz-Lozano
authors: University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA.
authors: Kamaldeep
authors: K
authors: Singh
authors: University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA.
authors: Elisabetta
authors: E
authors: Ferrante
authors: University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA.
authors: Ryan E
authors: RE
authors: Wilson
authors: University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA.
authors: Elizabeth C
authors: EC
authors: Dunn
authors: University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA.
authors: Martin M
authors: MM
authors: Zenni
authors: University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA.
authors: Luis A
authors: LA
authors: Guzman
authors: University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA.
authors: Theodore A
authors: TA
authors: Bass
authors: University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA dominick.angiolillo@jax.ufl.edu dominickjangiolillo@hotmail.com.
authors: Dominick J
authors: DJ
authors: Angiolillo
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives; D001792:Blood Platelets; D000077144:Clopidogrel; D003324:Coronary Artery Disease; D006801:Humans; D010975:Platelet Aggregation Inhibitors; D010979:Platelet Function Tests; D000068799:Prasugrel Hydrochloride; D011446:Prospective Studies; D000077486:Ticagrelor; D013988:Ticlopidine / Q000031:analogs & derivatives
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D000068799:Prasugrel Hydrochloride; D000077486:Ticagrelor; D000241:Adenosine; D013988:Ticlopidine
keywords: Clopidogrel; Pharmacodynamics; Platelet reactivity; Prasugrel; Ticagrelor