warfarin inhibits the synthesis of factors II, VII, IX, X, C, and S by blocking reduction of oxidized vitamin K. The enzyme Epoxide Reductase is inhibited by warfarin. The reduced (active) form of vit. K is a cofactor for gamma-glutamyl carboxylase.
Why not PGI2 by way of ASA? Especially given other answer choices of proteins C + S: doesn't warfarin also suppress these?
Warfarin inhibits Vit K dependent synthesis of factors & proteins.
Vit K is necessary for the maturation of clotting factors II, VII, IX, X and protein C & S
So a drug that can inhibit the carboxylation of precursor proteins or in other words inhibit the maturation of the clotting factors will decrease the risk of thrombosis in this patient.