MoA: blocks VKORC1 (vitamin K epoxide reductase – subunit C1) stopping the regeneration of VitK1 epoxide. Result: decreases activation of VitK-dependent clotting factors (VII, IX, X, II) made by the liver. This ultimately reduces prothrombin & decreases thrombin.

inhibits synthesis of vitK dependant factors and protein C and S

Indications:

• Venous thrombosis
• PE
• Thrombotic AF complications
• prophylaxis

Contraindications:

• When risk of haemorrhage > benefit of coag.
• Recent surgery of: CNS, eye
• Bleeding tendencies: active ulceration or overt bleeding (resp, GI, GU, aneurysms/dissections, pericarditis.
• Pregnancy → passes through placenta → foetal haemorrhage

Route: PO

Frequency: daily → need to re-evaluate INR & prothrombin time (PT).

High PT & high INR = blood takes longer to clot.