Efficacy of glycoprotein IIb/IIIa-receptor inhibitors during percutaneous coronary intervention

The clinical efficacy of glycoprotein (GP) IIb/IIIa-receptor inhibitors is discussed. Over the past 10 years, GP IIb/IIIa-receptor inhibitors have become the standard of care for patients undergoing percutaneous coronary intervention (PCI). Abciximab, a monoclonal antibody fragment inhibitor of GP IIb/IIIa receptors, has been found to significantly reduce the frequency of death or myocardial infarction in patients undergoing PCI in several large trials. Board use of abciximab for this indication was precluded by the high cost of this agent. Significant benefits of the small-molecule GP IIb/IIIa-receptor inhibitor epitifibatide in patients undergoing PCI led to substantially greater use of GP IIb/IIIa-receptor inhibitors in these patients because of the considerably lower cost of this agent. Positive results of trials of abciximab and eptifibatide in patients receiving PCI can be attributed to the fact that the dosage regimens of these agents in large trials consistently inhibited > 80% of platelet aggregation, particularly during the critical periprocedural period. In contrast, the nonpeptide GP IIb/IIIa-receptor inhibitor tirofiban yielded negative results in two large trials, probably because of < 80% inhibition of platelet aggregation with the dosage regimen used, especially during the first hour of therapy when PCI is performed. Large clinical trials strongly support the use of abciximab or eptifibatide, but not tirofiban, in patients undergoing PCI.