Glycoprotein Ilb/IIIa receptor inhibitors

Abciximab is a first-line glycoprotein Ilb/IIIa receptor inhibitor for patients undergoing primary PCI3,15,18 who have not received fibrinolytics. It should not be administered for... 

In patients with NSTE ACS scheduled for early PCI, administration of either abciximab or eptifibatide (double bolus) is recommended. The use of tirofiban in these patients is not recommended, because it has been shown to be inferior to abciximab.2 Medical therapy with glycoprotein Ilb/IIIa receptor inhibitors in patients not undergoing PCI is reserved for higher-risk patients, such as those with positive troponin or ST-segment depression, and patients who have continued or recurrent ischemia despite other antithrombotic therapy.2... 

Doses and contraindications to glycoprotein Ilb/IIIa receptor blockers are described in Table 5-2. Major bleeding and rates of transfusion are increased with administration of a glycoprotein Ilb/IIIa receptor inhibitor in combination with aspirin and an anticoagulant,30 but there is no increased risk of intracranial hemorrhage in the absence of concomitant fibrinolytic treatment. The risk of thrombocytopenia with tirofiban and eptifibatide appears lower than that with abciximab. Bleeding risks appear similar between agents. 

Mechanism of Action A glycoprotein Ilb/IIIa receptor inhibitor that rapidly inhibits platelet aggregation by preventing the binding of fibrinogen to GP Ilb/IIIa receptor sites on platelets. Therapeutic Effect Prevents closure of treated coronary arteries. Prevents acute cardiac ischemic complications. 

Dasgupta H, Blankenship JC, Wood C, et al. Thrombocytopenia complicating treatment witii intravenous glycoprotein Ilb/IIIa receptor inhibitors A pooled analysis. Am Heart J 2000 140 206-211. 

Consider glycoprotein Ilb/IIIa receptor inhibitors in acute coronary syndromes, including unstable angina abciximab, eptifibatide, tirofiban. 

Because the costs for chronic preventative pharmacotherapy are the same for primary and secondary prevention, while the risk of events is higher with secondary prevention, secondary prevention is more cost effective than primary prevention of CHD. Pharmacotherapy demonstrating cost effectiveness to prevent death in the ACS and post-MI patient includes fibrinolytics ( 2,000 to 33,000 cost per year of life saved), aspirin, glycoprotein Ilb/IIIa receptor blockers ( 13,700 to 16,500 per year of life added), (3-blockers (less than 5,000 to 15,000 cost per year of life saved), ACE inhibitors ( 3,000 to 5,000 cost per year of life saved), eplerenone ( 15,300 to 32,400 per year of life gained), statins ( 4,500 to 9,500 per year of life saved) and gemfibrozil ( 17,000 per year of life saved).49-58 Because cost-effectiveness ratios of less than 50,000 per added life-year are considered economically attractive from a societal perspective,49 pharmacotherapy described above for ACS and secondary prevention are standards of care because of their efficacy and cost attractiveness to payors. 

Mechanism of Action An aggregation inhibitor that inhibits the release of adenosine diphosphate from activated platelets, which prevents fibrinogen from binding to glycoprotein Ilb/IIIa receptors on the surface of activated platelets. TherapeuticEffect Inhibits platelet aggregation and thrombus formation. 

Abciximab is a glycoprotein Ilb/IIIa inhibitor and binds to glycoprotein Ilb/IIIA receptors on the surface of platelets, thereby preventing platelet aggregation. It is used as an adjunct to precutaneous coronary intervention (PCI) to prevent ischemic complications in patients at high risk of abrupt closure of the treated vessel. It is contraindicated in active internal bleeding. 

Eptifibatide is a reversible inhibitor of the glycoprotein Ilh/nia receptor, an integrin on the surface of platelets that serves as a key regulator of platelet aggregation. Glycoprotein Ilb/IIIa receptor antagonists help to prevent platelet-induced occlusion of coronary stents. The answer is (E). 

Novel inhibitors of glycoprotein Ilb/IIIa and fibrinogen/von Willebrand interaction include injectable peptides (for example integrilin, 163), orally active peptidomimetics that act as competitive inhibitors, and a monoclonal antibody c7E3 (abciximab), which irreversibly binds to GP Ilb/IIIa. Administered intravenously, circulating abciximab has a plasma half-life of less than 10 minutes. However, the antibody binds tightly to platelets and provides receptor blockade for a period of up to 15 days. 

GLYCOPROTEIN Ilb/IIIa INHIBITORS Glycoprotein Ilb/IIIa is a platelet-surface inte-grin designated This dimeric glycoprotein is a receptor for fibrinogen and von WiUebrand... 

---