Mephyton (phytonadione 5mg tablets)

Prescribing Information

Managing international normalized ratios (INRs)

According to the American College of Chest Physicians (ACCP), vitamin K antagonists (VKAs) reduces the risk of1:

  • Systemic embolism in patients with prosthetic heart valves or atrial fibrillation
  • Primary and secondary venous thromboembolism
  • Acute myocardial infarction (AMI) in patients with peripheral arterial disease
  • Death in patients with AMI

To reduce the risk of hemorrhage during VKA therapy, the INR should not be allowed to rise above a desired therapeutic range2

  • For most conditions target range is 2.0 to 3.0
  • For some specific conditions target range is 2.5 to 3.5

ACCP guidelines for managing elevated INRs and bleeding1

Plan a strategy based on:
  • Current INR
  • Presence of bleeding
  • Time frame for required reversal
Reverse INR to desired range by*:
  • Changing warfarin dosage
  • Administering vitamin K or blood products
* For complete information about INR reversal by condition, please see ACCP Guidelines available in Reference 1 cited below.

ACCP Guidelines recommend oral vitamin K tablets to reverse elevated INR1

  • Oral vitamin K is well tolerated, effective, and convenient
  • Oral vitamin K has a low risk of overcorrecting an elevated INR
  • IV vitamin K is recommended when rapid reversal of INR is required

References:

  1. Ansell J, Hirsh J, Poller L, et al. The pharmacology and management of the vitamin antagonist: the seventh ACCP conference on antithrombotic and thrombolytic therapy. Chest. 2004;126 (suppl 3):204S-233S [erratum in: Chest. 2005;127:415-416.]
  2. Wilson SE, Watson HG, Crowther MA. Low-dose oral vitamin K therapy for the management of asymptomatic patients with elevated international normalized rations: a brief review. Can Med Assoc J. 2004;170:821-824.