RSS Feeds
Correction of Excessive Anticoagulation with Low-Dose Oral Vitamin K1
- Robert T. Weibert, PharmD;
- Dzung The Le, MD, PhD;
- Steven R. Kayser, PharmD; and
- Samuel I. Rapaport, MD
- From the University of California, San Diego, California; and the University of California, San Francisco, California. Grant Support: By grant H27234 from the National Heart, Lung, and Blood Institute, National Institutes of Health. Requests for Reprints: Robert T. Weibert, PharmD, University of California, San Diego, Medical Center, 200 West Arbor Drive, San Diego, CA 92103-8238. Current Author Addresses: Dr. Weibert: University of California, San Diego, Medical Center, 200 West Arbor Drive, San Diego, CA 92103-8238.
Abstract
Background: Despite earlier acceptance of oral vitamin K1 (phytonadione) for the treatment of excessive anticoagulation, some recent guidelines do not recommend its use.
Objective: To reevaluate the efficacy of oral vitamin K1 in correcting excessive anticoagulation.
Design: Case series.
Setting: Anticoagulation clinics at two university medical centers.
Patients: 81 outpatients who had an international normalized ratio (INR) greater than 5.0 but did not have significant bleeding.
Interventions: Withholding 1 or 2 doses of warfarin, administering 2.5 mg of oral vitamin K1, measuring the INR after 24 to 48 hours, and adjusting the warfarin dose.
Measurements: INRs were obtained from a portable capillary fingerstick monitor or from an automated photooptical coagulometer.
Results: In 68 of 71 patients (96%), oral vitamin K1 lowered the INR from between 5.0 and 10.0 to less than 5.0 without inducing resistance to further anticoagulation.
Conclusions: Withholding 1 or 2 doses of warfarin and administering 2.5 mg of oral vitamin K1 is a reliable, safe, and inexpensive way to rapidly correct excessive anticoagulation (INR > 5.0) in patients who do not have serious bleeding episodes and have an INR of less than 10.0.
- Copyright ©2004 by the American College of Physicians
