Warfarin acts by -

Ans. is 'a' i.e., Inhibition of Vitamin K epoxide reductase o During g-carboxylation of the coagulant factor II, VII, IX and X in the liver, active vitamin K (Vit K hydroquinone) is oxidized to an epoxide (vit K epoxide).o Vit K epoxide must be reduced to vit K hydroquinone to become active once again (vit K cycle),o Vit K epoxide is reduced to vit K hydroquinone by vit K reductase.o This vit K reductase is inhibited by oral anticoagulants.