Name: Vitamin K1 (Phytonadione)
Class: Anticoagulant Antagonist
Mechanism: Vit. K is necessary for g-carboxylation of thrombin, factors VII, IX, & X, and proteins C & S. The g-carboxylated residues are required for binding Ca2+, which is essential for their activity.
Absorption: Oral or SC preferred. IV admin. may cause shock or anaphylaxis.
Dist.:
Metabolism.:
Excretion, t½:
Toxicity/S.E.s: IV admin. may cause shock or anaphylaxis.
Utility: Reverse excessive bleeding due to warfarin—indicated for severe or continued bleeding if warfarin dosage adjustment is unsuccessful.
Special Features: Significant improvement in hemostasis may require as long as 24 hr. If immediate hemostasis is necessary, fresh frozen plasma should be infused.