Glycoprotein Iib/IIIa antagonists

Patients with acute coronary syndrome and who undergo percutaneous coronary intervention are at a high risk for recurrent adverse cardiovascular events. There is a continuous search for an ideal antiplatelet medication that has a favorable risk benefit profile with a quick onset of peak action. Glycoprotein IIb/IIIa inhibitors (GP IIb/IIIa) were introduced with that precise idea in mind, that it is an intravenous antiplatelet agent with a rapid onset of action, which can be used to achieve maximal antiplatelet activity in patients with acute coronary syndrome (ACS) and those undergoing percutaneous coronary intervention (PCI). Abciximab, eptifibatide, and tirofiban are the three available intravenous GP IIb/IIIa inhibitors of which the latter two are small molecules. Initial trials that examined these agents were done in the balloon angioplasty era when P2Y12 receptor blocker use was not routine. These trials demonstrated a significant reduction in the composite end point of death, myocardial infarction (MI), and urgent target vessel revascularization predominantly driven by a reduction in recurrent MI that included periprocedural events. There is a definite increase in major and minor bleeding with these agents which needs to be weighed against the potential benefits before initiating the drug. More contemporary trials that were done on patients who were adequately treated with P2Y₁₂ inhibitors failed to recreate the initial results, but nevertheless there was still a significant reduction in ischemic events. There is still a role for these agents in patients with high-risk non-ST segment elevation myocardial infarction and ST segment elevation myocardial infarction with heavy thrombus burden, particularly if they have not been adequately pretreated with P2Y₁₂ inhibitors.