Syncoumarol acts as an anticoagulant - an inhibitor of blood clotting factors that depend on vitamin K. The in vivo effect consists in the sequential inhibition of factors VII, IX, X and II. Vitamin K promotes the biosynthesis of gamma-carboxyglutamic acid residues in biologically active proteins. It is believed that acenocoumarol delays the formation of clotting factors by inhibiting the regeneration of vitamin K1 epoxide; the degree of inhibition depends on the dosage. The maximum anticoagulant effect can be achieved after 36 - 72 hours.