0
Sign In  | Subscribe
20 August 2002, Vol 137, No. 4>
Summaries for Patients | 20 August 2002

Vitamin K Reverses Overanticoagulation with Warfarin More Quickly When Given by Mouth Than by Injection FREE

[+] Article and Author Information

The summary below is from the full report titled “Oral Vitamin K Lowers the International Normalized Ratio More Rapidly Than Subcutaneous Vitamin K in the Treatment of Warfarin-Associated Coagulopathy. A Randomized, Controlled Trial.” It is in the 20 August 2002 issue of Annals of Internal Medicine (volume 137, pages 251-254). The authors are MA Crowther, JD Douketis, T Schnurr, L Steidl, V Mera, C Ultori, A Venco, and W Ageno.


Ann Intern Med. 2002;137(4):I-39. doi:10.7326/0003-4819-137-4-200208200-00004
Text Size: A A A

What is the problem and what is known about it so far?

Warfarin is a medicine that “thins” the blood, making it take longer to coagulate. Doctors prescribe warfarin to treat or prevent several common medical conditions, including blood clots and stroke. Patients taking warfarin need to have blood tests called international normalized ratios (INRs) to check that the amount of warfarin they are taking is thinning their blood an appropriate amount. When the INR is too low (underanticoagulation), clots can occur; when it is too high (overanticoagulation), serious bleeding can occur. When patients become overanticoagulated while taking warfarin, doctors temporarily stop the warfarin. They also sometimes start treatment with vitamin K to speed the reversal of warfarin's effects. It is not known whether giving vitamin K by mouth or by injection brings the INR into the desired range more quickly.

Why did the researchers do this particular study?

To find out whether vitamin K reverses overanticoagulation due to warfarin more quickly if it is given by mouth or if it is given by injection.

Who was studied?

51 patients who were taking warfarin and became overanticoagulated.

How was the study done?

The researchers assigned patients at random to get 1 milligram of vitamin K either by mouth or by injection and measured each patient's INR the next day. They also followed patients for 1 month to see whether they developed any blood clots or bleeding.

What did the researchers find?

Of the 26 patients who got vitamin K by mouth, 15 had INR values in the desired range the next day compared with only 6 of 25 patients who got vitamin K by injection. During the 1-month follow-up period, no patient developed blood clots or serious bleeding.

What were the limitations of the study?

First, this study did not include a group of patients who stopped warfarin without taking vitamin K, so it does not tell us whether giving vitamin K in addition to stopping warfarin is a better way to reverse overanticoagulation than simply stopping warfarin. Second, these results may not apply to overanticoagulated patients who are having active bleeding complications. Third, vitamin K pills are not currently available in North America, so vitamin K can be given by mouth only in liquid form.

What are the implications of the study?

Doctors should consider oral administration when prescribing vitamin K for patients on warfarin who become overanticoagulated.

Figures

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).
Compression-Only CPR: Pushing the Science Forward
Cone
AAM 2010;304:1493-1495.
All you need to read in the other general jounals
BMJ 2010;341:c5893-c1494.

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 This Article

to gain full access to the content and tools.

Want to Subscribe?

Learn more about subscription options

Register Now for a free account
Advertisement

Related Content

Customize your page view by dragging & repositioning the boxes below.

Topic Collections
PubMed Articles
[Sublingual haematoma as a result of dysregulated peroral anticoagulant therapy].
Ugeskrift for laeger Issue date: 2012 Mar 5
Warfarin-induced sublingual hematoma mimicking Ludwig angina: Conservative management of a potentially life-threatening condition.
Ear, nose, & throat journal Issue date: 2011 Feb

Annals of Internal Medicine

Other Resources

Copyright © 2013 The American College of Physicians. All Rights Reserved.
Print ISSN: 0003-4819 | Online ISSN: 1539-3704

Buy This Article

to gain full access to the content and tools.

Want to Subscribe?

Learn more about subscription options

Register Now for a free account
Forgot your password?
Enter your username and email address. We'll send you a reminder to the email address on record.
(Required)
(Required)