At a Glance

Glycoprotein IIb/IIIa inhibitors in clinical use include tirofiban (Aggrastat), eptifibatide (Integrilin), and abciximab (ReoPro). These compounds are very potent antiplatelet agents. They are commonly used in procedures involving cardiac catheterization. In a small percentage of cases, these drugs can also induce a significant thrombocytopenia, with platelet counts often less than 10,000 per micrometer. Inhibition of platelets with glycoprotein IIb/IIIa inhibitors involves a different mechanism from that produced by aspirin, NSAIDs, such as ibuprofen, Plavix, and Prasugrel. Therefore, treatment of patients with glycoprotein IIb/IIIa inhibitors, along with other antiplatelet agents, commonly produces highly significant platelet inhibition that predisposes the patient to major bleeding.


Unlike other platelet inhibitors, particularly clopidogrel (Plavix), to which some patients do not respond and, therefore, may require a platelet function study to determine if the drug is working, it would be extremely rare to require documentation of platelet inhibition by glycoprotein IIb/IIIa inhibitors.


If a patient experiences severe thrombocytopenia on exposure to a glycoprotein IIb/IIIa inhibitor, bleeding in association with the use of this compound may be a result of both an adequate platelet number and a defect in platelet function produced by the drug.

What Lab Results Are Absolutely Confirmatory?

If there is any reason to suspect a glycoprotein IIb/IIIa inhibitor is not inhibiting platelet function, any of the variety of platelet function studies available should determine whether the drug is effective.