0

The full content of Annals is available to subscribers

Subscribe/Learn More  >
Brief Communications |

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
[+] Article and Author Information

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.


Copyright ©2004 by the American College of Physicians


Ann Intern Med. 1997;126(12):959-962. doi:10.7326/0003-4819-126-12-199706150-00005
Text Size: A A A

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.

Figures

Grahic Jump Location
Figure 1.
The effect on the international normalized ratio (INR) 24 hours after patients received 2.111

5 mg of oral vitamin K and had 1 dose of warfarin withheld. Data are grouped according to the initial INR for each patient. Open symbols (B columns) are INRs before patients received vitamin K ; closed symbols (A columns) are INRs 24 hours after patients received vitamin K . The dashed lines delineate the target range for correcting excessive anticoagulation (an INR between 2.0 and 5.0). The solid lines delineate geometric mean INRs.

Grahic Jump Location
Grahic Jump Location
Figure 2.
The effect on the international normalized ratio (INR) 48 hours after patients received 2.111

5 mg of oral vitamin K and had 2 doses of warfarin withheld. Data are grouped according to the initial INR for each patient. Open symbols (B columns) are INRs before patients received vitamin K ; closed symbols (A columns) are INRs 48 hours after patients received vitamin K . The dashed lines delineate the target range for correcting excessive anticoagulation (an INR between 2.0 and 5.0). The solid lines delineate geometric mean INRs.

Grahic Jump Location

Tables

References

Letters

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Comments

Submit a Comment
Submit a Comment

Summary for Patients

Clinical Slide Sets

Terms of Use

The In the Clinic® slide sets are owned and copyrighted by the American College of Physicians (ACP). All text, graphics, trademarks, and other intellectual property incorporated into the slide sets remain the sole and exclusive property of the ACP. The slide sets may be used only by the person who downloads or purchases them and only for the purpose of presenting them during not-for-profit educational activities. Users may incorporate the entire slide set or selected individual slides into their own teaching presentations but may not alter the content of the slides in any way or remove the ACP copyright notice. Users may make print copies for use as hand-outs for the audience the user is personally addressing but may not otherwise reproduce or distribute the slides by any means or media, including but not limited to sending them as e-mail attachments, posting them on Internet or Intranet sites, publishing them in meeting proceedings, or making them available for sale or distribution in any unauthorized form, without the express written permission of the ACP. Unauthorized use of the In the Clinic slide sets will constitute copyright infringement.

Toolkit

Buy Now

to gain full access to the content and tools.

Want to Subscribe?

Learn more about subscription options

Advertisement
Related Articles
Related Point of Care
Topic Collections
PubMed Articles
Forgot your password?
Enter your username and email address. We'll send you a reminder to the email address on record.
(Required)
(Required)