What is the recommended intravenous (IV) dosage of Vitamin K (phylloquinone) for pediatric patients?

Vitamin K IV Dosage for Pediatric Patients

For reversal of warfarin-induced bleeding or excessive anticoagulation (INR >10), administer IV vitamin K at 30 mcg/kg in pediatric patients, with immediate reversal using fresh frozen plasma or prothrombin complex concentrates for significant bleeding. 1

Clinical Context and Indications

The primary indication for IV vitamin K in pediatric patients is the reversal of vitamin K antagonist (VKA) anticoagulation, particularly in the setting of:

• Major bleeding at any INR level - requires rapid reversal with IV vitamin K plus activated prothrombin concentrate 1
• INR >10 without bleeding - VKAs should be reversed with oral vitamin K (IV can be used if oral route unavailable) 1
• INR 4.5-10 without bleeding - hold VKAs until INR returns to desired range; vitamin K typically not required 1

Dosing Algorithm

For VKA Reversal with Bleeding:

IV vitamin K: 30 mcg/kg 1

• This dose has been documented in pediatric literature for reversal of excess anticoagulation
• Administer slowly IV to avoid infusion-related reactions
• Must be combined with fresh frozen plasma (FFP), prothrombin complex concentrates, or recombinant factor VIIa for immediate reversal in significant bleeding 1

For Neonatal Prophylaxis (Different Context):

While not the primary question, it's important to note that prophylactic vitamin K for newborns is typically given IM, not IV 2, 3. However, for high-risk neonates (premature, birth asphyxia, difficult delivery, maternal drugs inhibiting vitamin K), the first dose can be given by slow IV route 4.

• Preterm infants on parenteral nutrition: 10 mcg/kg/day IV 5, 2

Important Clinical Considerations

Response Monitoring:

• Prothrombin time should shorten within 30 minutes to 2-4 hours after IV vitamin K administration 6
• This rapid response is diagnostic of vitamin K deficiency 2
• INR monitoring should continue to guide additional therapy 1

Common Pitfalls:

• Do not rely on vitamin K alone for acute major bleeding - the onset of action takes hours for full effect, requiring immediate reversal with clotting factor concentrates 1
• Avoid rapid IV infusion - can cause adverse reactions; administer slowly 4
• Limited pediatric data exists - most recommendations are extrapolated from adult studies with the documented 30 mcg/kg dose being the primary pediatric-specific data point 1

Route Selection:

For pediatric VKA reversal, IV route is preferred over oral when:

• Active bleeding is present 1
• Rapid reversal is required 1
• Oral absorption may be compromised 4

The evidence base for IV vitamin K dosing in pediatrics beyond neonatal prophylaxis is limited, with the 30 mcg/kg dose from the American College of Chest Physicians guidelines representing the most specific pediatric recommendation available 1. Most other guidance extrapolates from adult protocols while emphasizing the need for concomitant clotting factor replacement in acute bleeding scenarios 1.