Platelet glycoprotein IIb/IIIa inhibitors.

Glycoprotein (GP) IIb/IIIa inhibitors including abciximab, eptifibatide and tirofiban have been studied extensively as short-term adjuncts to short-term heparin and indefinite aspirin in patients with acute coronary syndrome or undergoing percutaneous coronary interventions on native vessels. The drugs provide a small advantage in the composite endpoint of death, myocardial infarction, and need for revascularization at 30 days (1-2% of treated patients) at the expense of an increase in major and potentially fatal bleeding complications (1% of treated patients over heparin plus aspirin alone). Highest-risk patients appear to benefit the most; clopidogrel should also be considered in these patients. Patients undergoing percutaneous interventions on bypass grafts do not benefit. Whether one GP IIb/IIIa inhibitor is superior to another is incompletely clarified. Abciximab causes severe immune-mediated thrombocytopenia (<20,000/microl) in 0.7% of cases; this is more often than eptifibatide or tirofiban (0.2%). Pseudothrombocytopenia should be differentiated. Effective use of GP IIb/IIIa inhibitors for acute coronary syndrome and percutaneous coronary interventions requires discerning clinical judgment. The value of GP IIb/IIIa inhibitors is not established in other forms of vascular disease.