Multivitamin Supplements May Affect Warfarin Anticoagulation in Susceptible Patients

  title={Multivitamin Supplements May Affect Warfarin Anticoagulation in Susceptible Patients},
  author={Daniel Kurnik and Aharon Lubetsky and Ronen Loebstein and Shlomo Almog and Hillel Halkin},
  journal={Annals of Pharmacotherapy},
  pages={1603 - 1606}
OBJECTIVE: To report an interaction of a multivitamin preparation containing small amounts of vitamin K1 (25 μg) with warfarin in a case series and to assess the prevalence of vitamin K1 deficiency in ambulatory anticoagulated patients. CASE SUMMARIES: We describe 3 patients whose anticoagulation was stabilized with warfarin in whom initiation or cessation of a self-prescribed multivitamin supplement delivering 25 μg of vitamin K1 daily was associated with an otherwise unexplained significant… 

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