What are the indications for injecting Vitamin K (Vitamin K1) in patients, including those with bleeding disorders, liver disease, or taking anticoagulation therapy, such as warfarin (Coumadin), and in newborns?

Indications for Injecting Vitamin K

Vitamin K injection is indicated for life-threatening or major bleeding with elevated INR, emergency surgery requiring rapid anticoagulation reversal, and prophylaxis of hemorrhagic disease in newborns.

Life-Threatening or Major Bleeding

For patients with serious bleeding and elevated INR, administer 5-10 mg IV vitamin K by slow infusion over 30 minutes, combined with 4-factor prothrombin complex concentrate (PCC) 25-50 U/kg IV for immediate reversal. 1, 2, 3

• PCC achieves INR correction within 5-15 minutes, while vitamin K alone takes hours, making combination therapy essential for emergent situations. 1, 2
• Always co-administer vitamin K with PCC because factor VII in PCC has only a 6-hour half-life, requiring vitamin K to stimulate endogenous production of vitamin K-dependent clotting factors. 1, 2
• The dosing algorithm for PCC based on INR is: 25 U/kg if INR 2-4,35 U/kg if INR 4-6, and 50 U/kg if INR >6. 1

Emergency Surgery Requiring Rapid Reversal

For patients on warfarin requiring emergency surgery, immediately administer 4-factor PCC 25-50 U/kg IV plus vitamin K 5-10 mg by slow IV infusion over 30 minutes, targeting INR <1.5. 1, 2

• This combination achieves surgical hemostasis within 15 minutes compared to hours with fresh frozen plasma (FFP). 1
• FFP should only be used if PCC is unavailable due to slower onset, need for ABO matching, and risk of fluid overload. 1

Severe Over-Anticoagulation Without Active Bleeding

For INR >10 without bleeding, administer 5 mg oral vitamin K (preferred route) or 5-10 mg IV vitamin K if oral route is unavailable, as the risk of spontaneous major bleeding is 3.9% at 90 days. 1, 2, 4

• Oral administration is preferred for non-emergency situations due to lower risk of anaphylactoid reactions (3 per 100,000 IV doses). 1, 2
• IV vitamin K should be given by slow infusion over 30 minutes to minimize anaphylaxis risk. 2, 3

Hemorrhagic Disease of the Newborn (Prophylaxis)

All newborns should receive vitamin K prophylaxis at birth to prevent hemorrhagic disease, though the specific dosing is extrapolated from adult reversal protocols in the provided evidence. 5

• Vitamin K deficiency in newborns can lead to serious bleeding complications due to immature hepatic synthesis of clotting factors. 6

Vitamin K Deficiency States

Injectable vitamin K is indicated for patients with malabsorption syndromes, obstructive jaundice, or other conditions causing vitamin K deficiency when oral supplementation is ineffective. 6

• These conditions include fat malabsorption disorders where oral vitamin K cannot be adequately absorbed. 6

Warfarin Overdose Management

For warfarin overdose with minor bleeding progression to major bleeding, administer 5-25 mg (rarely up to 50 mg) parenteral vitamin K. 3

• In emergency situations of severe hemorrhage, combine vitamin K with fresh frozen plasma (200-500 mL) or commercial Factor IX complex to rapidly restore clotting factors. 3

Critical Safety Considerations and Pitfalls

Never exceed 10 mg vitamin K in most clinical situations, as higher doses create a prothrombotic state and cause warfarin resistance lasting up to one week. 1, 2, 4

• High-dose vitamin K may require heparin bridging when warfarin needs to be resumed. 2, 4
• Anaphylactic reactions to IV vitamin K occur via a non-IgE mechanism, possibly due to the polyoxyethylated castor oil solubilizer, and can result in cardiac arrest, severe hypotension, and bronchospasm. 1, 2

In patients with mechanical prosthetic heart valves, use lower doses (1-2 mg oral vitamin K) to avoid difficulty achieving therapeutic INR post-procedure and increased thrombosis risk. 1, 4

PCC use increases risk of venous and arterial thrombosis during the recovery period, requiring consideration of thromboprophylaxis as early as possible after bleeding control. 1, 2

When Injectable Vitamin K is NOT Indicated

For INR 4.5-10 without bleeding, vitamin K is NOT routinely recommended—simply withhold warfarin and monitor serial INR determinations. 1, 4

• Randomized trials show vitamin K accelerates INR normalization but does not reduce major bleeding rates (2% with vitamin K vs 0.8% without). 1
• Add oral vitamin K 1-2.5 mg only if high bleeding risk factors exist: age >65-75 years, history of bleeding, concomitant antiplatelet drugs, renal failure, or alcohol use. 1, 4

Routine pre-operative vitamin K is not advised for patients with elevated INR 1-2 days before elective surgery due to uncertainty about dosing and potential for post-operative warfarin resistance. 1

Vitamin K supplementation is not recommended for routine INR stabilization in patients on chronic warfarin therapy, as evidence shows only modest 3.54% improvement in time in therapeutic range without reduction in bleeding or thrombotic events. 5