Brand names for warfarin are Warfant, Jantoven, Coumadin, Lawarin, Marevan, and Waran.
Contents of this article:
Who uses warfarin?
Warfarin prevents blood clots from forming.
Warfarin is useful for people who are at risk of forming blood clots. This includes people with deep vein thrombosis (DVT), where clots form in the legs, and pulmonary embolism, where there is a clot in the lung.
If a clot forms and breaks loose, it can travel through the bloodstream and block a vessel in another part of the body, such as the lungs, the leg, the kidneys, or the gut. In the brain, a clot can cause a stroke. The consequences of a clot can be fatal.
Warfarin can help to prevent stroke in older patients with atrial fibrillation, or irregular heartbeat. People with an artificial heart valve may also use warfarin.
In the 1920s, farmers in the northern United States and Canada were troubled by a hemorrhagic disease that was killing their cattle. It was traced to moldy hay, and the disease became known as sweet clover disease.
When one of the farmers presented an agricultural scientist named Wilhelm Schoeffel with a can of unclotted blood 10 years later, to see what he could suggest, Schoeffel experimented with it that same day. From there, warfarin was discovered.
Warfarin was first used in 1948 as a pesticide to kill mice and rats. It is still used in pest control today. In high doses, it can cause multiple hemorrhages.
In the 1950s, researchers found that it helped prevent thrombosis and embolism in people with a range of conditions. In 1954, it was approved in the U.S. for clinical use in humans.
Warfarin remains the most commonly prescribed anticoagulant in the U.S., although other drugs, such dabigatran, are becoming more widespread.
The name "warfarin" refers to the organization that funded key research, the Wisconsin Alumni Research Foundation (WARF), and coumarin.
Coumarin is commonly used as a precursor molecule for producing many synthetic anticoagulants, including warfarin.
How does warfarin work?
Vitamin K enables blood to clot. Warfarin slows down vitamin K production in the body. In this way, it slows down the blood clotting process.
This helps the blood to flow more freely around the body, and it reduces the risk of clots forming in the heart or blood vessels.
What are the disadvantages associated with Warfarin?
Warfarin is an effective medication, but it has several disadvantages. Many prescription drugs and foods interact with it.
A number of common foodstuffs and supplements can interact with warfarin.
Foods with high levels of vitamin K interact with warfarin.
These include liver, broccoli, Brussels sprouts, and green leafy vegetables, such as coriander, cabbage, collards, spinach, and Swiss chard. Anyone using warfarin should check with their doctor before making a radical change in their diet.
Researchers from the Intermountain Medical Center Heart Institute have found that over two thirds of the 100 most popular over-the-counter herbal or dietary supplements interfere with how Warfarin works. Out of 100 people who were using warfarin for atrial fibrillation, 35 were using supplements, and over half were unaware that they could interact.
The supplements compete with the anticoagulant medication in the liver, causing warfarin to become either under- or over-active. The blood can either become too thin, increasing the risk of bleeding, or too thick, leading to a higher chance of stroke.
Health Canada 9.3 percent (resource no longer available at www.hc-sc.gc.ca) of warfarin users died from their injuries after a traumatic event, compared with 4.8 percent of people of the same age who were not using Warfarin.
Warfarin use was found to increase the mortality from severe head injuries by 50 percent in patients younger than 65 years.
Patients using warfarin were also more likely to have blunt mechanism injuries and to sustain their injuries at home or in a residential institution. They also experienced more severe injuries overall.
The researchers caution that warfarin should not be used for longer than it is needed.
The AHA warn against purchasing drugs, including warfarin or Coumadin, online, because the ingredients of drugs with similar names in other countries may be slightly different from those in the U.S.