An old lady came with complaint of pain in left calf region. A diagnosis of deep vein thrombosis (DVT) was made and she was put on warfarin therapy. After 3 months, she was brought to hospital with complaint of nose bleed which automatically stopped in few minutes. Her lab repos show INR of 7.0. To avoid hemorrhage, what to do next in addition to discontinuation of the drug?

Vit K acts as a cofactor in the synthesis of clotting factors II, VII , IX and X by liver. Warfarin works as an anticoagulant by inhibiting vitamin K epoxide reductase (VKOR) in the liver. Inhibition of VKOR decreases the synthesis of clotting factors. Overdose of warfarin can result in bleeding. Haematuria is usually first to occur. Other common sites of bleeding are - GIT, nose, and under the skin ecchymoses. Excessive anticoagulant effect and bleeding from warfarin can be prevented by stopping the drug and administering oral or parenteral vitamin K1 (phytonadione). Acute bleeding can be treated by four factor complex or fresh-frozen plasma.