Coumadin
® (
warfarin sodium) is a prescription anticoagulant, often described as a "blood thinner" (although it does not actually thin the blood). It is used to prevent and treat blood clots due to various causes.
Who Makes This Medication?
Brand-name Coumadin is manufactured by Bristol-Myers Squibb Company.
Blood clotting is a complex process that involves many different substances in the body, known as clotting factors, and several different steps.
Coumadin works to inhibit blood clotting by decreasing the formation of active forms of certain clotting factors.
Some clotting factors require vitamin K to be converted into their active forms. Although this reaction changes vitamin K into an unusable form, the body can recycle it back using an enzyme known as vitamin K epoxide reductase. Coumadin blocks this enzyme, inhibiting the recycling of vitamin K and, thereby, decreasing the formation of the active clotting factors.
It is important to understand that Coumadin does not "dissolve" or break down blood clots (only special "clot buster" medications that must be given in the hospital can do this). Rather, the medication prevents them from forming. When used to treat a blood clot, Coumadin keeps the clot formation in check, allowing the body's natural processes to break down the clot.
When and How to Take the Drug
General considerations for those taking Coumadin include the following:
- This medication comes in tablet form. It is also available as an injection, although this form is rarely used.
- Coumadin is usually taken by mouth once a day.
- Although it does not matter what time of day you take this medication, be sure to take it at the same time each day.
- If necessary, the tablets can be broken in half. However, it is best if this can be avoided, since even tiny variations in the dosage can cause problems.
- You can take Coumadin with food or on an empty stomach.
- For the medication to work properly, it must be taken as directed.
The recommended dose of Coumadin will vary, depending on how you respond to the medication (this is monitored using regular blood tests). As is always the case, do not adjust your dose unless your healthcare provider specifically instructs you to do
Just like any medicine, Coumadin can cause side effects. The side effects of this medication can be dangerous. The risk of most dangerous side effects can be reduced by careful monitoring.
Possible side effects of Coumadin include but are not limited to:
- Bleeding, including dangerous internal bleeding
- Easy bruising
- "Purple toe syndrome"
- Hair loss.
(Click Coumadin Side Effects to learn more, including potentially serious side effects you should report immediately to your healthcare provider.)
Food Interactions With Coumadin
People who take Coumadin must follow certain dietary restrictions, as some foods interact with this medication
(see Coumadin Diet for more information).
What Should I Tell My Healthcare Provider?
You should talk with your healthcare provider prior to taking Coumadin if you have:
- A bleeding disorder
- Intestinal or stomach ulcers or bleeding
- Bleeding in the brain
- An aneurysm
- Inflammation of the sac the surrounds the heart (the pericardium)
- A bacterial infection of the endocardium (the inner layer of the heart)
- A condition (such as a mental illness) that limits the ability to follow instructions carefully
- Had a negative reaction to heparin
- Liver disease, such as liver failure, cirrhosis, or hepatitis
- Kidney disease, such as kidney failure
- High blood pressure
- A clotting disorder known as protein C deficiency
- Polycythemia vera (a condition involving excess red blood cells)
- Vasculitis (a blood vessel disorder)
- Diabetes
- An indwelling bladder catheter
- Any allergies, including allergies to food, dyes, or preservatives.
Also, let your healthcare provider know if you:
Make sure to tell your healthcare provider about any other medications you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
What If I Take an Overdose?
An overdose with Coumadin could potentially cause life-threatening problems as the result of dangerous internal bleeding. If you happen to take too much of this drug, seek immediate medical attention.
How Should Coumadin Be Stored?
Coumadin should be stored at room temperature, away from moisture and heat. Keep this and all other medications out of the reach of children.
What Should I Do If I Miss a Dose?
If you do not take your Coumadin as scheduled, take your missed dose as soon as possible on the same day. However, do not take two doses on the same day or take a double dose. Be sure to keep track of any missed doses (perhaps on a calendar), as your healthcare provider will use this information when monitoring your response to the medication.
If you miss one or more doses, be sure to contact your healthcare provider for further instructions.
- Coumadin 1 mg (pink)
- Coumadin 2 mg (lavender)
- Coumadin 2.5 mg (green)
- Coumadin 3 mg (tan)
- Coumadin 4 mg (blue)
- Coumadin 5 mg (peach)
- Coumadin 6 mg (teal)
- Coumadin 7.5 mg (yellow)
- Coumadin 10 mg (white).
An injectable version of Coumadin is also available.
Each tablet is a different color. The colors of the tablets are important, as it is essential to make sure you have the correct strength (taking too little or too much can be dangerous). Every time you refill your prescription, make sure the tablets are the correct color.
