What is the recommended dose of Vitamin K (Vit K) for injection?

Vitamin K Injection Dosing

For emergency reversal of warfarin-associated major bleeding, administer vitamin K 10 mg IV by slow injection, combined with prothrombin complex concentrate for rapid INR correction. 1

Emergency Reversal of Anticoagulation

For life-threatening bleeding due to vitamin K antagonists:

• Administer 10 mg IV vitamin K by slow injection (not to exceed 10 mg per dose) 1, 2
• Infuse slowly to minimize anaphylactoid reaction risk (3 per 100,000 doses) 2
• Combine with four-factor prothrombin complex concentrate for rapid reversal 2
• Do not exceed 10 mg doses, as higher doses create a prothrombotic state and prevent re-anticoagulation for days 2

The American College of Chest Physicians guidelines emphasize that IV vitamin K is preferred over oral administration in emergency situations due to more rapid onset, though oral administration shows similar INR reduction by 24 hours. 1 The key advantage of IV administration is sustaining the effects of prothrombin complex concentrate given its short half-life. 1

Non-Emergency Over-Anticoagulation

For INR 6-10 without bleeding:

• Oral vitamin K 1-2.5 mg reduces INR from 5.0-9.0 to 2.0-5.0 within 24-48 hours 3
• For INR >10 without bleeding, use oral vitamin K 5 mg 3
• Oral route is preferred over IV to avoid anaphylactoid reactions and over subcutaneous to avoid cutaneous reactions 3

Important caveat: Subcutaneous injection is not recommended, as studies show vitamin K 0.5 mg IV achieved INR <5 in 95% of patients versus only 45% with 3 mg SC at 24 hours. 1

Neonatal Prophylaxis and Treatment

Hemorrhagic disease prophylaxis:

• 0.5-1 mg IM within one hour of birth 4, 5
• Single IM dose is most effective for preventing late vitamin K deficiency bleeding 5, 6

Hemorrhagic disease treatment:

• 1 mg SC or IM for newborns with active bleeding 4
• Higher doses may be necessary if mother received oral anticoagulants 4
• Response should occur within 2-4 hours; failure indicates alternative diagnosis 4

For high-risk neonates (premature, birth asphyxia, maternal anticoagulant use), the first dose must be IM or slow IV, with repeated doses based on clinical status. 5

Parenteral Nutrition Supplementation

For patients receiving parenteral nutrition:

• Weekly IV supply of 250-500 mcg phylloquinone from lipid emulsions is sufficient to restore and maintain normal plasma levels 1
• Adult multivitamin preparations providing additional 150 mcg cover requirements and maintain carboxylation status of non-coagulation proteins 1
• Caution: Doses >150 mcg may cause vitamin K antagonist resistance in patients on warfarin 1

Liver Disease Considerations

Limited efficacy in hepatic dysfunction:

• Subcutaneous vitamin K does not modify coagulation parameters in liver disease 2
• IV vitamin K may temporarily correct INR in cholestatic liver disease but has minimal effect in other forms of liver failure 2
• For acute liver injury: 5-10 mg IV as single dose, though efficacy is limited when hepatic synthetic function is severely impaired 2

For cholestatic liver disease or jaundiced patients with decompensated cirrhosis, parenteral vitamin K supplementation is recommended, though evidence for routine use in other liver failure types is limited. 2

Vitamin K Deficiency Treatment

For documented deficiency:

• Oral vitamin K 1-2 mg daily for adults with fat malabsorption syndromes 1
• If oral supplementation fails, refer for specialist assessment and consideration of IM injections 1
• Maintain zinc-to-copper ratio of 8-15:1 when supplementing, as high-dose vitamin E can exacerbate vitamin K deficiency 1

Pediatric VTE Management

For reversal in children on warfarin:

• Follow adult dosing algorithms based on INR 1
• For INR >10 without bleeding, reverse with oral vitamin K 1
• For major bleeding at any INR, reverse rapidly with IV vitamin K plus activated prothrombin concentrate 1