Vitamin K Administration and Reversal of Anticoagulation

Route of Administration and Duration of Effect

Intravenous vitamin K has a maximum effect lasting 6-12 hours, making it suitable for rapid correction of coagulopathy 1
Oral vitamin K takes longer to work, with maximum effect occurring at approximately 24 hours after administration 1
For patients requiring immediate reversal of vitamin K antagonists, the missing coagulation factors are typically replaced with prothrombin complex concentrate, as the half-life of administered coagulation factors is only about six hours 2

When administering prothrombin complex concentrate for vitamin K antagonist reversal, vitamin K should be co-administered to stimulate production of vitamin K-dependent coagulation factors after the initial effect of prothrombin complex concentrate wears off 2
For patients with mechanical valves and uncontrollable bleeding who have received prothrombin concentrate complex, adjunctive use of intravenous vitamin K is reasonable if resumption of vitamin K antagonist therapy is not anticipated for 7 days 3, 4
After reversal with vitamin K, international normalized ratio should be monitored regularly over the next week, as a minority of patients take over a week to clear anticoagulants from their blood and require additional vitamin K 2

For immediate reversal of anticoagulation in life-threatening bleeding, a 10-mg intravenous dose of vitamin K is recommended 3, 4
A 5–10 mg dose of vitamin K is generally recommended for vitamin K antagonist reversal, as lower doses may not fully correct the international normalized ratio 2
More than 10 mg of vitamin K can prevent re-anticoagulation for days and may create a prothrombotic state, which could lead to further thromboembolism 2

Rare anaphylactoid reactions with bronchospasm and cardiac arrest can occur after intravenous vitamin K administration, with an incidence of 3 per 100,000 doses 1
The use of prothrombin complex concentrate with vitamin K is associated with an increased risk of venous and arterial thrombosis during the recovery period 2
Alterations in vitamin K intake can affect the response to anticoagulant agents, requiring careful monitoring of blood clotting tests in patients using anti-vitamin K drugs 1