GP IIb/IIIa antagonists. Clinical experience and potential uses in cardiology.

The purpose of this manuscript is to review the available antagonists of platelet glycoprotein (GP) IIb/IIIa. The critical role of platelet aggregation in the pathogenesis of acute coronary syndromes of unstable angina and non-Q-wave myocardial infarction, as well as in mediating abrupt vessel closure and periprocedural infarction after percutaneous coronary interventions, has been recognised recently. Platelet aggregation is mediated through expression of activated GP IIb/IIIa and its subsequent binding to circulating fibrinogen. Inhibition of this interaction with one of 3 commercially available agents has been demonstrated to reduce ischaemic complications of coronary intervention and to reduce the rates of death and myocardial infarction in patients with acute coronary syndromes. Differential pharmacological characteristics of the drugs abciximab, tirofiban and eptifibatide are described and the trials which have defined their role in the management of ischaemic heart disease are reviewed.