Safety and effectiveness of low-dose, oral vitamin K1 administration in asymptomatic out-patients on warfarin or acenocoumarol with excessive anticoagulation

Daniela Poli, Emilia Antonucci, Alessandra Lombardi, Gian Franco Gensini, Rosanna Abbate, Domenico Prisco

Research output: Contribution to journalArticle


The management of asymptomatic overanticoagulation with low dose vitamin K1 is recommended in patients taking oral anticoagulants, independently of the type of coumarin being administered. To evaluate the safety and effectiveness of this practice we observed 127 patients on warfarin and 14 on acenocoumarol, who received 2 mg oral vitamin K1 on at least one occasion. At the first measurement, international normalized ratio (INR) mean values were significantly lower in patients on acenocoumarol than in patients on warfarin (p=0.0001) and all patients on acenocoumarol showed INR values below the therapeutic range. Vitamin K1 should be used cautiously in patients being anticoagulated with acenocoumarol.

Original languageEnglish
Pages (from-to)237-238
Number of pages2
Issue number2
Publication statusPublished - Feb 1 2003



  • Oral anticoagulation
  • Overcoagulation
  • Vitamin K1

ASJC Scopus subject areas

  • Hematology

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