What is the recommended dose and administration protocol for vitamin K1 (phytomenadione) IV in the Philippines?

Vitamin K1 (Phytonadione) IV Administration Protocol in the Philippines

For urgent reversal of anticoagulation or treatment of vitamin K deficiency in the Philippines, administer vitamin K1 (phytonadione) 10 mg IV slowly over at least 1 minute, with close monitoring for anaphylactoid reactions. 1, 2

Dosing Guidelines

For Anticoagulant Reversal:

• Severe bleeding or life-threatening situations: 10 mg IV phytonadione administered slowly, not exceeding 1 mg per minute 1, 2
• INR 6-10 without bleeding: 0.5 mg IV (or 2.5 mg oral alternative if IV not necessary) 3
• INR >10 without bleeding: 1 mg IV (or 5 mg oral alternative if IV not necessary) 3

For Vitamin K Deficiency:

• Adults with nutritional deficiency: 2.5-10 mg IV, with subsequent doses determined by prothrombin time response 2
• Severe deficiency: Up to 25 mg may be required initially, with rare instances requiring 50 mg 2

Administration Protocol

1. Preparation:

   • Inspect solution for particulate matter and discoloration before administration 2
   • Dilute with preservative-free 0.9% Sodium Chloride Injection or 5% Dextrose Injection 2
   • Protect from light at all times 2

2. Administration technique:

   • CRITICAL: Administer IV very slowly, not exceeding 1 mg per minute to minimize risk of anaphylactoid reactions 2
   • Monitor patient closely during administration for signs of anaphylaxis (reported in approximately 3 per 100,000 doses) 1
   • Have emergency equipment readily available during administration

3. Monitoring:

   • Check INR within 6-12 hours after administration 3
   • Maximum effect for IV administration occurs within 6-12 hours 1
   • Consider repeat dosing if prothrombin time has not shortened satisfactorily within 6-8 hours 2

Special Considerations

• Anaphylactoid reactions: IV vitamin K administration carries risk of rare but serious anaphylactoid reactions including bronchospasm and cardiac arrest 1. Infuse slowly to minimize risk.

• Overcorrection risk: High doses (>5 mg) can create a hypercoagulable state and cause warfarin resistance for days 4. Use the lowest effective dose.

• Alternative routes: When possible, oral administration is preferred due to similar 24-hour efficacy with lower risk of adverse reactions 3, 5. Consider oral route for non-urgent cases.

• Concomitant therapy: For immediate reversal in life-threatening bleeding, consider prothrombin complex concentrate (PCC) at 25-50 U/kg alongside vitamin K 1

• Storage requirements: Vitamin K1 should be included in hospital emergency antidote stocks (as listed in expert consensus guidelines) 1

Pitfalls to Avoid

1. Too rapid administration: Never administer faster than 1 mg/minute due to anaphylaxis risk 2

2. Subcutaneous injection: Avoid SC route as it has been shown to be less effective than IV or oral administration 1

3. Excessive dosing: Using more than necessary can lead to prolonged warfarin resistance and potential thrombotic complications 4

4. Delayed monitoring: Failure to check INR within 6-12 hours may miss inadequate response requiring additional dosing 3

5. Ignoring alternative routes: For non-urgent cases, oral administration provides similar 24-hour efficacy with lower risk of adverse reactions 3, 5

By following this protocol, healthcare providers in the Philippines can safely and effectively administer IV vitamin K1 for patients requiring urgent anticoagulation reversal or treatment of vitamin K deficiency.