How to Administer Vitamin K Diluted in Normal Saline
Dilute vitamin K in 25 to 50 mL of normal saline and administer intravenously over 15 to 30 minutes, not exceeding 1 mg per minute. 1
Dilution Specifications
When preparing intravenous vitamin K:
- Acceptable diluents: 0.9% Sodium Chloride (normal saline), 5% Dextrose Injection, or 5% Dextrose and Sodium Chloride Injection 2
- Volume: 25 to 50 mL of diluent 1
- Preservative-free requirement: All diluents must be preservative-free, as benzyl alcohol has been associated with toxicity in newborns 2
- No other diluents should be used 2
Administration Protocol
Infusion Rate and Timing
- Maximum infusion rate: Do not exceed 1 mg per minute 2
- Total infusion time: 15 to 30 minutes 1
- Immediate administration: Start infusion immediately after mixing with diluent 2
Critical Safety Considerations
Route preference hierarchy:
The intravenous route should be considered unavoidable only in urgent situations requiring rapid reversal, such as major bleeding from warfarin. While older preparations carried anaphylactic risk, current formulations have eliminated this concern 1.
Dosing for Warfarin Reversal
For anticoagulant-induced bleeding:
- Standard dose: 10 mg IV 3
- Range: 2.5 to 10 mg, up to 25 mg initially (rarely 50 mg may be required) 2
- Onset of action: INR reduction occurs in 4 to 6 hours 1
- Redosing: If INR remains ≥1.4 within 24-48 hours, repeat with vitamin K 10 mg IV 3
Important Caveats
Discard unused portions: Both unused dilution and unused ampule contents must be discarded after preparation 2
Light protection: Protect vitamin K from light at all times during storage and administration 2
Visual inspection: Always inspect for particulate matter and discoloration before administration 2
Delayed effect: Vitamin K does not provide immediate correction of coagulopathy. For major bleeding requiring urgent reversal, it must be accompanied by prothrombin complex concentrates (PCC) or fresh frozen plasma 1, 3. The vitamin K ensures durable reversal after the immediate effect of clotting factor replacement.
Intravenous administration is more predictable and rapid (4-6 hours) compared to oral (18-24 hours) or subcutaneous (unpredictable) routes 1, making it the preferred parenteral route when rapid reversal is needed despite the general preference for subcutaneous administration in non-urgent situations.