Heart Disease: Warfarin and Other Blood Thinners

Warfarin, which goes by the brand name Coumadin, is an anticoagulant medication. This means that it helps prevent clots from forming in the blood. Blood thinners are used to treat some types of heart disease.

You have been prescribed warfarin because your body may be making blood clots or you may have a medical condition known to promote unwanted blood clots. It is often prescribed for patients with atrial fibrillation (an irregular heart rhythm), pulmonary embolism, and after artificial heart valve surgery or orthopedic procedures.

Blood clots can move to other parts of your body and cause serious medical problems, such as a heart attack. Warfarin will not dissolve a blood clot; however, over time, the blood clot may dissolve on its own. Warfarin may also prevent other clots from forming or prevent clots from becoming larger. Warfarin will not dissolve a blood clot, but it may prevent other clots from forming and keep existing clots from getting larger. There are other blood thinners that you may be given in the hospital or even at home for a short amount of time: Heparin, Lovenox, or Fragmin. These drugs are administered either by vein (intravenous) or just under the skin into the subcutaneous fat.

Blood Testing

In order for your health care provider to determine the correct dose of warfarin, it will be necessary for you to have blood tests. The tests are performed in a laboratory, usually once a week to once a month, as directed by your doctor.

The prothrombin time (PT or protime) test is used to calculate your International Normalized Ratio (INR). Your INR will help your health care provider determine how fast your blood is clotting and whether your medication dose needs to be changed. Illness, diet, medication changes and physical activities may affect your INR. Tell your health care provider about changes in your health, medications (prescription and over-the-counter), or lifestyle so that appropriate dosage adjustments can be made in your warfarin therapy.

What Does Warfarin Look Like?

Coumadin brand tablets are round and scored, which means they can be broken in half. Each tablet color represents a different strength. The strength of the tablet is measured in milligrams (mg) as follows:

• 1 mg (pink)
• 2 mg (lavender)
• 2.5 mg (green)
• 3 mg (tan)
• 4 mg (blue)
• 5 mg (peach)
• 6 mg (teal or blue-green)
• 7.5 mg (yellow)
• 10 mg (white)

Other brands of warfarin should have the same colors and strengths as the Coumadin brand tablets. However, other brands of warfarin tablets may have a different shape or appearance. For example, they may be oval or square.

How Should I Take Warfarin?

Take your warfarin dose as instructed once a day. Try to take it at the same time every day. A good time to take your warfarin is early in the evening (such as between 5 and 6 p.m.). Warfarin can be taken with or without food.

Do not take a double dose to make up for a missed dose. Also, never change your dose without first discussing the change with your doctor.