Navigation Links
Warfarin May Need Less Monitoring for Some
Date:11/14/2011

By Serena Gordon
HealthDay Reporter

MONDAY, Nov. 14 (HealthDay News) -- Most people taking the blood-thinner warfarin need blood tests every four weeks to make sure they're receiving the right dose of medication, but new research suggests that some people could safely have those tests done just once every 12 weeks.

Longer intervals between monitoring isn't an option for everyone on warfarin, just those who have received the same dose of medication for six months or longer, noted the study, published in the Nov. 15 issue of the Annals of Internal Medicine.

"Sometimes it's difficult to go every four weeks, and we found that for patients who are very stable who have been monitored every four weeks, going every 12 weeks was not different in dosing," said the study's lead author, Dr. Sam Schulman, a professor of medicine and director of the clinical thromboembolism program at McMaster University in Hamilton, Ontario.

"Since there are 2 million patients in North America on warfarin, it could add quite a bit of cost savings if they could go longer [between tests]," said Schulman.

Warfarin (brand names Coumadin, Jantoven) thins the blood, and it's prescribed to help prevent blood clots. Blood clots can cause heart attacks and strokes. If too little warfarin is given, the blood isn't thinned enough and blood clots can form. But too much warfarin can thin the blood excessively, making internal bleeding a risk.

Once the right dose is found, some people remain stable on that dose indefinitely. For others, constant changes are needed to their warfarin dose. Schulman said that about one-third of his patients have stable doses.

The test that's done every four weeks to monitor a patient's warfarin dose is called international normalized ratio (INR) monitoring.

The current study included 250 people who were receiving unchanged warfarin doses for at least six months. They were randomly assigned to one of two groups: one that received INR monitoring every four weeks or one that was monitored every 12 weeks.

The researchers found that people who were monitored every four weeks had an optimal dose of warfarin 74.1 percent of the time, compared with 71.6 percent for the group monitored every 12 weeks.

"Assessment of warfarin dose every 12 weeks seems to be safe and non-inferior to assessment every four weeks," wrote the study's authors.

"This study contributes a bit to answering the question of how often you have to test, but there was no information on [blood clots] and bleeding events," noted Dr. Jeffrey Berger, an assistant professor and director of cardiovascular thrombosis at New York University Langone Medical Center in New York City. But he added that complications such as blood clots and bleeding are rare events, and to properly assess the risk of these complications with longer monitoring, a much larger trial would be necessary.

He also said, "I think this is a very important study in the current horizon where we have an increasing number of potential alternatives to Coumadin. It's important to understand the tradeoffs between drugs."

The U.S. Food and Drug Administration has approved two alternatives to warfarin: dabigatran etexilate (Pradaxa) and rivaroxaban (Xarelto). And Berger said that another drug, apixaban (Eliquis), will likely be approved soon.

The newer medications don't require monitoring of the dosage, but they are significantly more expensive than warfarin. In Canada and the United States, warfarin costs about 10 cents per day, while Schulman said that a newer medication can be as much as $3.60 a day.

Still, Berger pointed out that without the cost of monthly monitoring, the newer drugs may end up being more cost-effective.

More information

Learn more about warfarin from the U.S. National Library of Medicine.

SOURCES: Sam Schulman, M.D., professor, medicine, and director, clinical thromboembolism program, McMaster University, Hamilton, Ontario, Canada; Jeffrey S. Berger, M.D., assistant professor and director, cardiovascular thrombosis, New York University Langone Medical Center, New York City; Nov. 15, 2011, Annals of Internal Medicine


'/>"/>
Copyright©2010 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. Herbal Supplements, Warfarin Can Be Hazardous Mix
2. New Blood Thinner a Promising Alternative to Warfarin
3. Warfarin Patients Often Unaware of Risks from Herbs, Supplement Use
4. Warfarin Use May Raise Risk of Death From Traumatic Injuries
5. Study Pits New Blood Thinner Against Warfarin For Irregular Heartbeat
6. Apixaban superior to warfarin for preventing stroke, reducing bleeding and saving lives
7. New Blood Thinner May Outperform Warfarin for Irregular Heartbeat
8. Almac Launches New STEMS System to Transform Temperature Controlled Shipment Monitoring in Clinical Trials
9. ANT+ and iTMP Announce the Digifit™ Ecosystem - The First iPhone™ Apps to Integrate Running, Cycling and Heart Rate Monitoring
10. The Results Are In: Users of BodyMedia's Wearable Body-Monitoring Technology Lose 3 Times More Weight
11. Improved patient care with telemonitoring
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Warfarin May Need Less Monitoring for Some
(Date:7/25/2017)... OK (PRWEB) , ... July 25, 2017 , ... ... proud to announce the launch of their partnership to provide the Pharmacist ... the first pharmacy-focused platform in the country with the ability to develop the ...
(Date:7/25/2017)... ... July 25, 2017 , ... Therachat ... will be exhibiting and providing demos of its smart journaling platform at the ... Center in Washington D.C. from August 3-6, 2017. , The APA Annual Convention ...
(Date:7/25/2017)... , ... July 25, 2017 , ... ... ATM provider in the United States, today announced its partnership with financial technology ... , The foundation of the solution lies within Hyosung’s superior ATMs, assisted ...
(Date:7/25/2017)... Jacksonville, Fla. (PRWEB) , ... July 25, 2017 , ... ... employee and father Ezra Clark is taking advantage of a new benefit for employees ... “It really means a lot that the company supports me and other employees as ...
(Date:7/25/2017)... TX (PRWEB) , ... July 25, 2017 , ... SignatureCare ... emergencies in the Austin, TX area 24 Hours a day. , The ... Austin, TX. , “We’ve been open four months now and things are running ...
Breaking Medicine News(10 mins):
(Date:7/25/2017)... and CAMBRIDGE, Massachusetts , July 25, 2017 ... repurposing drugs to treat rare nervous system diseases, has concluded ... develop and market the drug SOM0226 against transthyretin amyloidosis (ATTR). ... very promising results in a Phase 2 study conducted in ... office in the United States ...
(Date:7/24/2017)... July 24, 2017 IBM (NYSE: IBM ) ... Quadrant for Solid-State Arrays (SSA) for the fourth year in ... According to Gartner, "Vendors in the Leaders quadrant have the ... Vision. A vendor in the Leaders quadrant has the market ... the acceptance of new technologies. These vendors demonstrate a clear ...
(Date:7/21/2017)... EDMONTON, Alberta , July 21, 2017 /PRNewswire/ ... University of Alberta in Edmonton, Canada ... partner journal, Schizophrenia 1 , demonstrating that AI ... schizophrenia with 74% accuracy. This retrospective analysis also ... symptoms in schizophrenia patients with significant correlation, based ...
Breaking Medicine Technology: