What is the recommended adult dose of vitamin K (phylloquinone) for reversal of anticoagulation or treatment of deficiency?

Recommended Adult Dosage of Vitamin K (Phylloquinone) for Anticoagulation Reversal and Deficiency Treatment

For anticoagulation reversal due to warfarin/VKA therapy, the recommended adult dose of vitamin K (phylloquinone) is 2.5-10 mg orally, with doses up to 25 mg initially for severe cases, while vitamin K deficiency treatment typically requires 2.5-25 mg orally. 1

Dosing for Anticoagulation Reversal

Oral Administration (Preferred Route)

• Mild to moderate over-anticoagulation (INR 5.0-9.0): 1-2.5 mg oral phylloquinone 2
• Severe over-anticoagulation (INR >10.0): 5 mg oral phylloquinone 2
• Life-threatening bleeding: 10 mg intravenous dose 3

Parenteral Administration (For Emergency Situations)

• For patients with mechanical valves and uncontrollable bleeding requiring immediate reversal:
  • Four-factor prothrombin complex concentrate is reasonable 3
  • Adjunctive use of intravenous vitamin K (10 mg) is reasonable if resumption of VKA therapy is not anticipated for 7 days 3

Dosing for Vitamin K Deficiency

• Standard adult dose: 2.5-25 mg orally, sometimes up to 50 mg 1
• Maintenance therapy: Evaluate INR after 6-8 hours and repeat dose if INR remains prolonged 1
• Parenteral nutrition supplementation: 150 μg per day in addition to what's present in lipid emulsion 4

Important Clinical Considerations

Monitoring Response

• Check prothrombin time/INR 12-48 hours after oral administration 1
• If response is inadequate, repeat the dose 1
• Improvement in INR may take 1-8 hours after administration 1

Cautions and Contraindications

• Vitamin K will not counteract the anticoagulant action of heparin 1
• Overzealous therapy may restore conditions that originally permitted thromboembolic events 1
• Keep dosage as low as possible to achieve therapeutic goals 1
• Repeated large doses are not warranted in liver disease if initial response is unsatisfactory 1

Route of Administration Considerations

• Oral route is preferred when possible due to:
  • Lower risk of adverse reactions compared to intravenous administration 1, 2
  • Intravenous administration may cause anaphylactoid reactions 1
  • Subcutaneous administration may cause cutaneous reactions 2

Special Situations

• For patients with fat malabsorption disorders:
  • Bile salts must be given with oral tablets when endogenous bile supply is deficient 1
  • Consider parenteral administration if absorption is severely compromised 1

Factors Affecting Dosing Decisions

• Severity of coagulation disorder
• Presence and severity of active bleeding
• Current INR level
• Indication for anticoagulation
• Patient-specific factors (liver function, malabsorption)
• Concomitant medications that may interfere with vitamin K metabolism

Remember that vitamin K is not a clotting agent but rather supports the body's natural clotting factor synthesis. The goal is to restore adequate coagulation without overcorrecting and increasing thrombotic risk.