Efficacy and safety of intravenous phytonadione (vitamin K1) in patients on long-term oral anticoagulant therapy

Raymond C. Shields, Robert D. Mcuane, James D. Kuiper, Hongzhe Li, John A. Heit

Research output: Contribution to journalArticlepeer-review

46 Scopus citations


Objectives: To determine the safety and efficacy of intravenously administered phytonadione (vitamin K1) in patients on routine oral warfarin anticoagulation. Patients and Methods: This retrospective cohort study comprised adults who were taking warfarin, were not bleeding, and received intravenous phytonadione anticoagulation therapy before a diagnostic or therapeutic procedure between September 1, 1994, and March 31, 1996. The main outcome measures were adverse reactions to intravenously administered phytonadione, prothrombin-international normalized ratio time values, the incidence of bleeding and thrombosis after the procedure, and the time between the procedure and return to anticoagulation after resumption of warfarin treatment. Results: Two (1.9%) of the 105 patients studied had suspected adverse reactions to intravenous phytonadione (dyspnea and chest tightness during infusion in both). For the 82 patients who underwent a procedure, the median time from phytonadione to procedure onset was 27 hours (range. 0.7-147 hours), which was significantly less for patients receiving an initial phytonadione dose of more than 1 mg (P=.009). None had thromboembolism after surgery, although 2 (2.4%) of the 82 patients had procedure-associated major bleeding. For the 60 patients resuming warfarin therapy after a procedure, the median time to return to therapeutic anticoagulation was 4.1 days (range, 0.8-31.7 days) and was unaffected by the phytonadione dosage. Conclusions: Intravenous phytonadione appears to be safe and is effective for semiurgent correction of long-term oral anticoagulation therapy before surgery. In small doses, it does not prolong the patient's time to return to therapeutic anticoagulation.

Original languageEnglish (US)
Pages (from-to)260-266
Number of pages7
JournalMayo Clinic proceedings
Issue number3
StatePublished - 2001

ASJC Scopus subject areas

  • General Medicine


Dive into the research topics of 'Efficacy and safety of intravenous phytonadione (vitamin K1) in patients on long-term oral anticoagulant therapy'. Together they form a unique fingerprint.

Cite this