title: Clopidogrel Response Variability: Review of the Literature and Practical Considerations.
abstract: Dual antiplatelet therapy with aspirin and a P2Y12 inhibitor is standard therapy following acute coronary syndrome and percutaneous coronary intervention. Despite the use of potent antiplatelet agents, vascular events continue to occur. Lack of response to clopidogrel therapy has been widely investigated using various methods of platelet function testing. These studies have consistently found an association between poor clopidogrel response and an increased risk of vascular events. Strategies to overcome this problem include higher clopidogrel doses or the use of an alternative P2Y12 agent. To date, the majority of studies investigating tailored antiplatelet therapy have failed to show any reduction in clinical events likely due to the low-risk population studied. Despite this lack of benefit from altering therapy, platelet function testing may be done in certain patient populations. Patients at high risk of deleterious outcomes from stent thrombosis may be an appropriate patient population for platelet function testing to ensure adequate response to therapy. In addition, emerging data suggests a potential role for platelet function testing to assess for bleeding risk. The purpose of this article is to review the key studies demonstrating response variability to clopidogrel therapy, strategies to overcome variability, and practical considerations for the clinician.
authors.affiliation: Methodist Healthcare, University Hospital, Memphis, TN, USA Department of Clinical Pharmacy, University of Tennessee College of Pharmacy, Memphis, TN, USA.
authors.forename: Carrie S
authors.initials: CS
authors.lastname: Oliphant
authors.affiliation: Department of Pharmaceutical and Nutrition Care-Nebraska Medicine, Omaha, NE, USA College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, USA.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Trevarrow
authors.affiliation: College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, USA pdobesh@unmc.edu.
authors.forename: Paul P
authors.initials: PP
authors.lastname: Dobesh
mesh_terms: D000077144:Clopidogrel; D006470:Hemorrhage / Q000139:chemically induced / Q000517:prevention & control; D006801:Humans; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D010979:Platelet Function Tests / Q000592:standards; D013927:Thrombosis / Q000188:drug therapy / Q000517:prevention & control; D013988:Ticlopidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D017211:Treatment Failure
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine
keywords: P2Y12 inhibitors; clopidogrel; clopidogrel response; high platelet reactivity; platelet function testing