prolonged INR (whilst on warfarin)

Last reviewed 01/2018

• the 1998 BJH guidelines stated (1):
  • if 3.0 < INR < 6.0 (target INR 2.5) then:
    • reduce warfarin dose/stop warfarin
    • restart warfarin when INR < 5.0
  • if 4.0 < INR < 6.0 (target INR 3.5)
    • reduce warfarin/stop warfarin
    • restart warfarin when INR < 5.0
  • if 6.0 < INR < 8.0 and no bleeding or minor bleeding then:
    • stop warfarin
    • restart when INR < 5.0
  • if INR > 8.0 and no bleeding or minor bleeding then:
    • stop warfarin
    • restart warfarin when INR < 5.0
    • if other risk factors for bleeding then give 0.5-2.5mg of oral vitamin K
  • if major bleeding then:
    • stop warfarin
    • give prothrombin concentrate 50 units per kg or FFP 15 ml/kg
    • give 5 mg of vitamin K (oral or iv)

Reference:

1. Guidelines on oral anticoagulation: third edition . British Journal of Haematology 1998;101 (2): 374-387.