Antiplatelets: Mechanism of Action and Types

Antiplatelets

• Mechanism of action: Inhibit platelet aggregation, preventing formation of thrombi
• Types:
  1. Aspirin: Irreversibly inhibits COX-1, reducing thromboxane A2 production
  2. Thienopyridines: Inhibit P2Y12 receptor, preventing ADP-mediated platelet activation (e.g., clopidogrel, prasugrel)
  3. Glycoprotein IIb/IIIa inhibitors: Inhibit platelet aggregation by blocking GP IIb/IIIa receptors (e.g., abciximab, eptifibatide)
  4. P2Y12 receptor antagonists: Reversibly inhibit P2Y12 receptor, preventing ADP-mediated platelet activation (e.g., ticagrelor, cangrelor)
• Indications:
  • Acute coronary syndrome (ACS)
  • Percutaneous coronary intervention (PCI)
  • Stroke prevention
  • Peripheral artery disease

Anticoagulants

• Mechanism of action: Inhibit clotting factor activity or prevent clot formation
• Types:
  1. Warfarin: Inhibits vitamin K-dependent clotting factors (II, VII, IX, X)
  2. Direct oral anticoagulants (DOACs):
     • Direct thrombin inhibitors: Inhibit thrombin (e.g., dabigatran)
     • Factor Xa inhibitors: Inhibit FXa (e.g., rivaroxaban, apixaban, edoxaban)
  3. Heparins: Inhibit thrombin and factor Xa (e.g., unfractionated heparin, low-molecular-weight heparins)
  4. Fondaparinux: Inhibits factor Xa
• Indications:
  • Atrial fibrillation (AF)
  • Venous thromboembolism (VTE) prevention and treatment
  • Pulmonary embolism (PE) treatment
  • Mechanical heart valve prophylaxis

Key Differences

• Antiplatelets: Inhibit platelet aggregation, primarily used for arterial thrombosis prevention
• Anticoagulants: Inhibit clotting factor activity, primarily used for venous thrombosis prevention and treatment

Antiplatelets

• Inhibit platelet aggregation, preventing formation of thrombi
• Aspirin: Irreversibly inhibits COX-1, reducing thromboxane A2 production
• Thienopyridines: Inhibit P2Y12 receptor, preventing ADP-mediated platelet activation
• Glycoprotein IIb/IIIa inhibitors: Inhibit platelet aggregation by blocking GP IIb/IIIa receptors
• P2Y12 receptor antagonists: Reversibly inhibit P2Y12 receptor, preventing ADP-mediated platelet activation
• Indicated for:
  • Acute coronary syndrome (ACS)
  • Percutaneous coronary intervention (PCI)
  • Stroke prevention
  • Peripheral artery disease

Anticoagulants

• Inhibit clotting factor activity or prevent clot formation
• Warfarin: Inhibits vitamin K-dependent clotting factors (II, VII, IX, X)
• Direct oral anticoagulants (DOACs):
  • Direct thrombin inhibitors: Inhibit thrombin
  • Factor Xa inhibitors: Inhibit FXa
• Heparins: Inhibit thrombin and factor Xa
• Fondaparinux: Inhibits factor Xa
• Indicated for:
  • Atrial fibrillation (AF)
  • Venous thromboembolism (VTE) prevention and treatment
  • Pulmonary embolism (PE) treatment
  • Mechanical heart valve prophylaxis

Key Differences

• Antiplatelets: Inhibit platelet aggregation, primarily used for arterial thrombosis prevention
• Anticoagulants: Inhibit clotting factor activity, primarily used for venous thrombosis prevention and treatment

Learn about the mechanism of action of antiplatelets, including their types, indications, and effects on platelet aggregation. Understand how they prevent thrombus formation.