phytonadione

Phytonadione is Vitamin K1, an essential cofactor in the γ-carboxylation of multiple glutamate residues of clotting factors (II, VII, IX, X) and anticoagulant proteins (C, S, Z). It promotes the biosynthesis of these factors, which are necessary for blood coagulation.

Adult

For prolonged intravenous alimentation, 1 mg per week (equivalent of about 150 μg/day) to prevent hypoprothrombinemia. For biliary obstruction or fistula, 10 mg daily. For hepatocellular disease or long-standing biliary obstruction, 10 mg daily parenterally.

Pediatric

Routine administration of 1 mg intramuscularly at birth for hypoprothrombinemia of the newborn. Dose may need to be increased or repeated if mother received warfarin or anticonvulsant therapy, or if infant develops a bleeding diathesis.

Renal adjustment

In severe hepatitis or cirrhosis (associated with inadequate utilization), large doses of vitamin K or its analogues can paradoxically contribute to a further reduction in prothrombin levels.

• rapid intravenous infusion (can cause severe reactions resembling anaphylaxis)
• subcutaneous route in patients with a coagulopathy (due to risk of bleeding)