title: Aspirin and clopidogrel resistance: possible mechanisms and clinical relevance. Part I: Concept of resistance.
abstract: Aspirin and clopidogrel are well established as antiplatelet medication in the treatment of atherothrombotic vascular disease. However, despite treatment, a substantial number of patients experience recurrent ischemic episodes, referred to as aspirin or clopidogrel treatment failure. Various laboratory techniques are available with which to evaluate the effectiveness of antiplatelet drugs. Interestingly, the agreement between the results of the different tests may be poor. The term aspirin or clopidogrel resistance denotes those conditions in which an inadequate inhibitory efficacy of the given antiplatelet agent is detected by an in vitro assay of platelet function. It has been estimated that on average some 30% of patients treated with aspirin, and 20% on clopidogrel, do not achieve an appropriate level of efficacy as concerns platelet activity.
authors.affiliation: University of Szeged, Albert Szent-Györgyi Clinical Center, Faculty of Medicine, Neurology Department, Szeged.
authors.forename: Dávid
authors.initials: D
authors.lastname: Vadász
authors.forename: László K
authors.initials: LK
authors.lastname: Sztriha
authors.forename: Katalin
authors.initials: K
authors.lastname: Sas
authors.forename: László
authors.initials: L
authors.lastname: Vecsei
mesh_terms: D001241:Aspirin / Q000494:pharmacology / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D000077144:Clopidogrel; D004351:Drug Resistance; D006801:Humans; D015539:Platelet Activation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin