USMLE

Glycoprotein IIb/IIIa Inhibitors

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Heme Pharm
  1. Warfarin
  2. Heparin
  3. Low Molecular Weight Heparins (LMWH)
  4. Direct Thrombin Inhibitors (Argatroban, Dabigatran, Bivalirudin)
  5. Thrombolytics (tPA, Streptokinase, Urokinase)
  6. ADP Receptor Inhibitors
  7. PDE3 Inhibitors (Cilostazol, Dipyridamole)
  8. Glycoprotein IIb/IIIa Inhibitors
  9. Factor Xa Inhibitors (Apixaban, Rivaroxaban, Edoxaban)

Summary

GP IIb/IIIa inhibitors are a class of drugs that includes tirofiban, abciximab (ab SIX i mab), and eptifibatide (ep TIF i ba tide). These drugs work to inhibit platelet aggregation, by blocking the interaction of glycoprotein IIb/IIIa on platelets with fibrinogen molecules that would otherwise lead to the creation of a platelet plug during blood clot formation. GP IIb/IIIa inhibitors are indicated in patients with acute coronary syndrome, especially in patients who are undergoing coronary artery stenting procedures.

Key Points

  • GP IIb/IIIa Inhibitors
    • Drug Names
      • Abciximab
      • Eptifibatide
      • Tirofiban
    • Mechanism
      • Competitively inhibit glycoprotein IIb/IIIa receptors on platelets
        • Prevents platelet aggregation
          • Normally, aggregation occurs via fibrinogen cross-linking using glycoprotein IIb/IIIa receptors
        • Similar effect to Glanzmann’s Thrombasthenia
          • Bleeding disorder in which platelets lack glycoprotein IIb/IIIa receptors
    • Clinical Use
      • Prevention of thrombosis for acute coronary syndrome
        • Especially during/after percutaneous coronary interventions (PCI), also known as stenting
        • Used to treat unstable angina and acute coronary syndrome (e.g. NSTEMI)
        • Used in high risk patients
          • Continued ischemia despite dual antiplatelet therapy
          • Large coronary thrombus or thrombotic complication during PCI
    •  Adverse Effects
      • Thrombocytopenia
      • Bleeding