How is a vitamin K (phytonadione) injection prepared?

Preparation of Vitamin K (Phytonadione) Injection

Phytonadione (vitamin K1) injection is available as a sterile, aqueous colloidal solution that requires no further preparation before administration via intravenous, intramuscular, or subcutaneous routes. 1

Formulation Details

Phytonadione injectable emulsion is a yellow, sterile, aqueous colloidal solution with the following characteristics:

• pH range: 3.5 to 7.0
• Each 0.5 mL contains:
  • 1 mg phytonadione (Vitamin K1)
  • 10 mg polysorbate 80
  • 10.4 mg propylene glycol
  • 0.17 mg sodium acetate anhydrous
  • 0.0002 mL glacial acetic acid
  • Nitrogen-flushed to displace air in the container 1

Administration Routes and Considerations

Intravenous Administration

• Should be administered slowly, typically over 15-30 minutes in 25-50 mL normal saline
• Maximum single dose should not exceed 10 mg
• Provides more rapid correction of INR (4-6 hours) compared to oral administration
• Risk of anaphylactic reaction is approximately 3 per 100,000 doses 2

Intramuscular Administration

• Ready to use without further preparation
• Commonly used in neonates for prophylaxis of vitamin K deficiency bleeding
• Single dose administration is effective for preventing classical and early vitamin K deficiency bleeding 3

Subcutaneous Administration

• Not recommended due to unpredictable absorption 2
• Associated with higher risk of cutaneous reactions including localized eczematous or morphea-form reactions 4

Dosing Considerations

For Anticoagulant Reversal

• Initial dose should be administered IV (not exceeding 10 mg)
• For patients with elevated INR and bleeding, concurrent administration with prothrombin complex concentrate is recommended
• Dosing based on severity:
  • For INR 2-4: 25 U/kg PCC with 5-10 mg vitamin K
  • For INR 4-6: 35 U/kg PCC with 5-10 mg vitamin K
  • For INR >6: 50 U/kg PCC with 5-10 mg vitamin K 2

For Pediatric Patients

• Preterm and term infants up to 12 months on parenteral nutrition: 10 μg/kg/day
• Older children on parenteral nutrition: 200 μg/day 2

Storage and Handling

• The injectable emulsion should be stored at controlled room temperature
• Protect from light
• The air above the liquid in individual containers is displaced with nitrogen during manufacturing 1

Important Precautions

• Anaphylactic reactions can occur with IV administration (3 per 100,000 doses)
• Doses >10 mg vitamin K can prevent re-warfarinization for days and may create a prothrombotic state
• When reversing anticoagulation, INR should be monitored regularly over the next week, as some patients may require additional vitamin K 2
• Cutaneous reactions may occur at injection sites, particularly with subcutaneous administration, and can persist for months 4

Phytonadione injection is a ready-to-use formulation that requires no further preparation before administration, making it convenient for emergency use in anticoagulant reversal and other clinical scenarios requiring rapid vitamin K supplementation.