Drugs » Anti-platelets

Anti-platelets

Antiplatelet Drugs: (Anti-thrombotic Drugs)
Antiplatelet drugs are a group of drugs that decrease platelet aggregation and inhibit thrombus formation. They are widely used in primary and secondary prophylaxis of thrombotic cerebrovascular or cardiovascular disease (arterial circulation).

Pharmacological action

• In event of a breach in continuity on the intima, platelets aggregate (they stick to each other) and this aggregated mass sticks to the damaged vessel wall and release ADP, thromboxane A₂ (TXA₂), which promotes further aggregation.
• Thus a platelet plug is formed and this platelet plug is the main constituent of the thrombus.
• Antiplatelet drugs are more useful in arterial thrombosis, whereas anticoagulants are more effective in venous thrombosis.
• Prostacyclin (PGI₂), synthesized in the intima of blood vessels is a strong inhibitor of platelet aggregation. A balance between TXA₂ released from platelet and PGI₂ released from vessels wall appears to control intravascular thrombus formation healthy individuals.
• Platelets also play a role in atherogenesis as they get deposited in atheromatous plaques.

Drugs interfering with platelet function are

• Cyclooxygenase inhibitor
  • Aspirin (low dose)
• Adenosine di phosphate receptor inhibitor
  • Clopidogrel
  • Ticlopidine
• Glycoprotein IIB/ III A inhibitor (IV use only)
  • Abciximab
• Adenosine reuptake inhibitor
  • Dipyridamole