Reversal of warfarin anticoagulant effect

A state in which INR in a patient taking warfarin exceeds the target range, with or without bleeding. Management depends on INR level and bleeding presence: INR 4.5–10 without bleeding – hold dose and monitor; INR above 10 without bleeding – oral vitamin K1 1–2.5 mg; any significant bleeding – intravenous vitamin K1 5–10 mg plus prothrombin complex concentrate (PCC) or fresh frozen plasma.

ICD-10 T45.51 drug

Also known as: Warfarin overdose, Supratherapeutic INR, Warfarin-related bleeding

Drugs used for this condition

APhytomenadioneFirst line · Vitamin K1, haemostatic, antidote for coumarin anticoagulant overdosePhytomenadione is the antidote for warfarin and acenocoumarol overdose. ACC 2020 and SETH 2020 recommend strategy by INR and clinical situation: INR 4.5–10 without bleeding – temporary anticoagulant hold; INR >10 without bleeding – add oral phytomenadione 2.5–5 mg; significant bleeding or emergency surgery – IV phytomenadione 5–10 mg plus prothrombin complex concentrate (PCC) 25–50 IU/kg. Fresh frozen plasma is second-choice if PCC unavailable. K1 effect develops over 6–12 hours, so emergency surgery requires concurrent PCC. After reversal, discussion with a haematologist before restarting anticoagulation.

How to read tiers A–F

Evidence tiers belong to the drug-indication pair, not to the drug as a whole: the same substance can be A for one condition and F for another.

AStrong evidence – first or second line in international guidelines
BRecommended in selected cases
CStudy data contradict each other
DBenefit not proven, no documented harm
FDocumented harm, or risk without benefit