Intravenous versus subcutaneous vitamin K1 in reversing excessive oral anticoagulation.

Our data suggest that compared with the subcutaneous route of administration, intravenous vitamin K1 results in a more prompt reduction in the international normalized ration. However, for most patients, subcutaneous vitamin K1 is an effective and safe alternative when used in conjunction with modification of subsequent warfarin dosing, because virtually all patients achieved a safe level of anticoagulation within 72 hours with this route of administration.