Anticoagulants

Definition of Anticoagulants:

Anticoagulants inhibit various components of the coagulation cascade to prevent thrombus formation, used in conditions at risk for thrombosis.

Heparin and Low Molecular Weight Heparins (LMWHs)

• Examples: Enoxaparin
• Mechanism: Heparin activates antithrombin III, which inactivates thrombin and factor Xa; LMWHs have more selective inhibition of factor Xa.
• Use: Deep vein thrombosis (DVT), pulmonary embolism (PE), atrial fibrillation (AF), prophylaxis in surgery.
• Side Effects: Heparin-induced thrombocytopenia (HIT), bleeding; LMWHs have a lower risk of HIT.

Warfarin

• Mechanism: Vitamin K antagonist; inhibits synthesis of vitamin K-dependent clotting factors II, VII, IX, and X.
• Use: AF, mechanical heart valves, DVT, PE.
• Side Effects: Bleeding, skin necrosis, teratogenicity; requires monitoring of INR.

Direct Oral Anticoagulants (DOACs)

• Examples: Dabigatran, Rivaroxaban, Apixaban, Edoxaban
• Mechanism: Direct inhibition of thrombin (Dabigatran) or factor Xa (Rivaroxaban, Apixaban, Edoxaban).
• Use: Similar indications to warfarin but with fixed dosing and no routine monitoring.
• Side Effects: Bleeding, gastrointestinal disturbances; fewer dietary interactions.

Direct Thrombin Inhibitors

• Examples: Argatroban, Bivalirudin
• Mechanism: Directly inhibit thrombin, preventing fibrin formation.
• Use: HIT, percutaneous coronary interventions.
• Side Effects: Bleeding, potential for thrombocytopenia.

Clinical Considerations:

• Balancing Act: Coagulants must be used cautiously to avoid thrombosis, while anticoagulants require careful monitoring to prevent bleeding.
• Reversal Agents: Availability and knowledge of reversal agents (e.g., vitamin K for warfarin, protamine sulfate for heparin) are critical in managing adverse effects.

Thank you for reading from Firsthope's notes, don't forget to check YouTube videos!