Navigation Links
Genetic Test Predicts Response to Warfarin
Date:3/5/2008

Using it could save money and lives, expert says

WEDNESDAY, March 5 (HealthDay News) -- Variations of a gene that determines a person's sensitivity to warfarin are important in determining the initial doses of the anti-clotting drug, researchers report.

That information already is being put to medical use. Last August, the U.S. Food and Drug Administration changed the labeling to say that doctors should consider a genetic test when first prescribing warfarin, better known by its brand name, Coumadin.

"This test can save $1.1 billion in health-care costs and 18,000 lives a year," said Dr. Raymond Woosley, president of the Critical Path Institute, a private organization that is working with the FDA and the biotechnology industry on the subject.

The FDA estimates that 2 million Americans take warfarin to prevent potentially dangerous blood clots. Reasons range from implantation of an artificial heart valve to the abnormal heartbeat called atrial fibrillation.

But warfarin is a notoriously difficult drug to manage, especially at the start. Too much can lead to hemorrhages; too little can allow clots to form. One individual may do well on 1.5 milligrams a day, while another may require 20 milligrams daily.

Some medical centers run elaborate tests to determine the starting dose, but "the standard way is to start with 5 milligrams, then titrate the doses according to blood tests that show the response to warfarin," said Dr. C. Michael Stein, a professor of medicine and pharmacology at Vanderbilt University. He was the leader of the group reporting the finding in the March 6 issue of the New England Journal of Medicine.

Two genes are known to affect the response to warfarin. One, designated CYP2C9, governs the metabolism of the medication, or how fast it is eliminated from the body. The other, designated VKORC1, governs sensitivity, or how the body reacts to a given dose of warfarin. The new study of 297 people starting warfarin therapy showed that variants of the sensitivity gene should be considered in the first prescription, Stein said.

Stein is a leader in the new field of pharmacogenomics, which hopes to tailor medical treatment to each individual's genetic makeup. The field has been made possible by the Human Genome Project, which has mapped the full human genetic makeup. That information has led the U.S. government to sponsor programs on specific applications of pharmacogenomics and to a small but growing industry of companies developing and marketing genetic tests, such as one for warfarin sensitivity.

"The Critical Path Institute is a nonprofit organization that creates neutral ground where the FDA and industry can work together," Woosley said. "We get no funding from companies, so we can invite them to sit down with the FDA. We have brought all the companies together to develop genetic tests and asked them to share their data."

Several warfarin sensitivity tests now are available, costing perhaps $500 or $600, Woosley said.

"This is not something that changes the way doctors practice tomorrow," Stein said of the new study. "It is additional information on the relative importance of these two genes early in therapy which will refine the way that physicians use warfarin."

And the tests are useful only when warfarin treatment starts, Woosley said. They do not eliminate the need for periodic blood tests to make precise adjustments to warfarin dosage.

Nevertheless, said Dina Paltoo, the National Heart, Lung, and Blood Institute program director who oversaw the agency's funding of the study, "this can help physicians clarify what dose a patient should get, so it could reduce adverse drug effects, toxicity and bleeding."

Testing should be done because "these genetic variations are critically important in how warfarin affects each individual," Paltoo said.

More information

You can learn more about pharmacogenomics from the U.S. National Library of Medicine.



SOURCES: Raymond Woosley, M.D., Ph.D., president, Critical Path Institute, Tucson, Ariz.; C. Michael Stein, M.D., professor, medicine and pharmacology, Vanderbilt University, Nashville, Tenn.; Dina Paltoo, Ph.D., M.P.H., Health Scientist Administrator, Division of Heart and Vascular Diseases, National Heart, Lung, and Blood Institute, Bethesda, Md.; March 6, 2008, New England Journal of Medicine


'/>"/>
Copyright©2008 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. Many Parents Share Genetic Test Findings With Kids
2. Genetic predisposition increases childhood asthma risk
3. New Alzheimers findings: High stress and genetic risk factor lead to increased memory decline
4. Test Spots Genetic Damage Done by Smoking
5. Scientists demonstate link between genetic variant and effectiveness of smoking cessation meds
6. Scientists highlight benefits of genetic research in sport, but warn of ethical concerns
7. Genetics Hold Promise, Challenges for Cancer Care
8. Researchers genetically engineer micro-organisms into tiny factories
9. Study Questions Genetic Screening for Treatable Diseases
10. Researchers provide genetic associations from a genome-wide scan for cardiovascular disease traits
11. Genetic variation affects smoking cessation treatment
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Genetic Test Predicts Response to Warfarin
(Date:5/28/2016)... ... ... city where’s it’s easy to spot the neon lights of chains serving fast food, one ... a taste for real food. , On May 13, the Best Western Plus ... restaurant focusing on dishes made by hand with wholesome, organic ingredients that are sourced locally ...
(Date:5/27/2016)... , ... May 27, 2016 , ... Two director-level employees ... YWCA Tribute to Women and Industry (TWIN) 2016 honorees. The award recognizes businesswomen ... For this year, Geri Boone, Director of the MLTSS (Managed Long-Term Services and Supports) ...
(Date:5/27/2016)... (PRWEB) , ... May 27, 2016 , ... With over ... to walk, the demand for a sustainable product to aid in the rehabilitation process ... aid in the recovery of individuals with hemiplegia due to stroke. , Ekso Bionics ...
(Date:5/27/2016)... , ... May 27, 2016 , ... ... to help educate the many who are unaware of the plight of aphasia. ... will run within the “Stroke Awareness” campaign. , The link between stroke and ...
(Date:5/27/2016)... ... 27, 2016 , ... Aimed at nurses and employees in the health care ... leaders in the nursing and health care industry. It also provides insight to the ... University. , As the nursing industry is coming out of one of the ...
Breaking Medicine News(10 mins):
(Date:5/24/2016)... 2016 The innovator of ... , s first dual therapy stent, introduces catheters ... OrbusNeich, a global company specializing in the provision ... include products to treat peripheral artery disease. The JADE™ ... devices for lower limb and arteriovenous (AV) fistula intervention. ...
(Date:5/24/2016)... , May 24, 2016 ... ™ , la première endoprothèse à ... destinés à l,intervention portant sur les membres ... OrbusNeich, entreprise mondiale spécialisée dans ... changer la vie, a élargi son portefeuille ...
(Date:5/24/2016)... Dutch surgeons have launched a ground-breaking medical app to help doctors ... a global scale. Medical professionals from Europe , ... the US have already signed up for the app, which combines ... environment. Education  "Imagine a doctor for Medicines ... at Harvard to treat a bomb victim via live streaming - ...
Breaking Medicine Technology: