Current Concepts on Antiplatelet Therapy: Focus on the Novel Thienopyridine and Non-Thienopyridine Agents

Interventional Cardiology Department, St. Ambrogio Clinical Institute, 20149, Milan, Italy.
Advances in Hematology 12/2010; 2010(1687-9104):595934. DOI: 10.1155/2010/595934
Source: PubMed


Thienopyridines are a class of drug targeting the platelet adenosine diphosphate (ADP) 2 receptor. They significantly reduce platelet activity and are therefore clinically beneficial in settings where platelet activation is a key pathophysiological feature, particularly myocardial infarction. Ticlopidine, the first of the class introduced to clinical practice, was soon challenged and almost completely replaced by clopidogrel for its better tolerability. More recently, prasugrel and ticagrelor have been shown to provide a more powerful antiplatelet action compared to clopidogrel but at a cost of higher risk of bleeding complications. Cangrelor, a molecule very similar to ticagrelor, is currently being evaluated against clopidogrel. Considering the key balance of ischemic protection and bleeding risk, this paper discusses the background to the development of prasugrel, ticagrelor, and cangrelor and aims to characterise their risk-benefit profile and possible implementation in daily practice.

Download full-text


Available from: Ravinay Bhindi,
  • [Show abstract] [Hide abstract]
    ABSTRACT: Antiplatelet therapy is used widely with proven benefit for the prevention of further ischemic cardiac complications in patients with known coronary artery disease (CAD) and a history of acute coronary syndrome (ACS). The limitations of conventional antiplatelet therapy with aspirin, clopidogrel, or prasugrel, as well as the fact that rates of recurrent ischemic events still remain high with use of these agents, underscore the need to investigate alternate agents that may further reduce event rates while limiting bleeding risk. The selection of antiplatelet therapy is further influenced by the following: ticagrelor was approved in July 2011 by the United States Food and Drug Administration (FDA), and clopidogrel is slated to become available as a generic productin 2012. We provide an overview of emerging agents for the treatment of CAD and ACS, including the reversible P2Y(12) antagonists ticagrelor, cangrelor, and elinogrel, and a new class of oral protease-activated receptor-1 (PAR-1) inhibitors, vorapaxar and atopaxar.The recently approved P2Y(12) antagonists prasugrel and ticagrelor demonstrate enhanced ability to prevent adverse cardiac outcomes. However, this comes at a cost of a potential increased risk of bleeding. New adverse effects have also emerged, including dyspnea for all of the reversible P2Y(12) antagonists (ticagrelor, cangrelor, and elinogrel) and ventricular pauses for ticagrelor. In addition, the newer P2Y(12) antagonists have a faster onset and offset. Two of these agents, cangrelor and elinogrel, are available as intravenous formulations, which may provide additional benefits in patients who undergo coronary artery bypass graft (CABG) surgery. Trials with the PAR-1 inhibitors have also shown trends toward reductions in cardiac events, but not without the possibility of increased bleeding. More than ever, as the arsenal of antiplatelet therapy expands, health care providers need to understand the pharmacologic and pharmacodynamic differences between conventional and emerging antiplatelet therapies for patients with ACS and CAD. Health care providers must also carefully assess patient-specific factors such as risk of thrombosis, concomitant disease states, age, drug adherence, and aspirin dose, and plan for those patients who will be undergoing CABG when selecting antiplatelet therapy in order to optimally balance bleeding and thrombosis risk.
    Pharmacotherapy 03/2012; 32(3):244-73. DOI:10.1002/j.1875-9114.2012.01021.x · 2.66 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In the title compound, C(16)H(13)ClN(4)S, the thienopyridine fused-ring system is nearly planar (r.m.s. deviation = 0.0333 Å) and forms a dihedral angle of 4.4 (3)° with the attached dihydro-imidazole ring (r.m.s. deviation = 0.0429 Å) allowing for the formation of an intra-molecular (exocyclic amine)N-H⋯N(imine) hydrogen bond. The benzene rings of the disordered (50:50) -N(H)-C(6)H(4)Cl residue form dihedral angles of 59.1 (3) and 50.59 (15)° with the fused ring system. In the crystal, (imidazole amine)N-H⋯N(pyridine) hydrogen bonds lead to a supra-molecular helical chain along the b axis. The chains assemble into layers (ab plane) with inter-digitation of the chloro-benzene rings which results in weak C-H⋯Cl inter-actions in the c-axis direction.
    Acta Crystallographica Section E Structure Reports Online 07/2012; 68(Pt 7):o2135-6. DOI:10.1107/S160053681202658X · 0.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: For several years, clopidogrel plus aspirin has been the dual antiplatelet therapy (DAPT) of choice for patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) with stent implantation. More recently, prasugrel and ticagrelor have demonstrated greater efficacy than clopidogrel. In TRITON-TIMI 38, the risk of TIMI major bleeding unrelated to coronary artery bypass graft (CABG) surgery was similar for prasugrel and clopidogrel after excluding subgroups with increased bleeding risk (previous stroke or transient ischemic event; age ≥75 years; weight <60 kg). In the PLATO trial, rates of TIMI major bleeding were similar for ticagrelor and clopidogrel, but ticagrelor was associated with a significantly higher rate of non-CABG-related TIMI major bleeding. Current evidence suggests that prasugrel or ticagrelor plus aspirin should be the DAPT of choice in patients with ACS undergoing PCI unless they are at particularly high risk of bleeding. No studies have yet compared prasugrel and ticagrelor in ACS patients, however prasugrel and ticagrelor have different side effect profiles, and the choice of agent should be made either as a default choice and/or on an individual patient basis. Ongoing trials in ACS patients will increase the evidence base for new P2Y(12) receptor inhibitors and help to establish the most effective DAPT regimens.
    Cardiovascular Drugs and Therapy 02/2013; 27(3). DOI:10.1007/s10557-013-6444-2 · 3.19 Impact Factor
Show more