Health Library Atrial Fibrillation: Taking Anticoagulants SafelyFrom Healthwise

Key points

• When taken properly, anticoagulants can reduce your risk of stroke from atrial fibrillation.
• Certain precautions should be followed when taking anticoagulants.
• Regular blood monitoring is needed while taking anticoagulants.
• You will need to take anticoagulants as long as you have atrial fibrillation.

 What are anticoagulants?
 Why are anticoagulants used for atrial fibrillation?
 How do I take anticoagulants safely?
 Where to go from here

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Anticoagulants, such as warfarin (Coumadin, for example), are medicines that help prevent blood clots. Anticoagulants are often called blood thinners, but they do not actually thin the blood. Instead, they work by increasing the time it takes a blood clot to form.

Anticoagulants are used to treat atrial fibrillation because irregularly beating heart chambers cause blood to pool. Pooled blood is more likely to develop blood clots, which can travel from the heart to the brain and cause a stroke. Anticoagulants help prevent the blood clots from forming and reduce the risk of stroke caused by atrial fibrillation.

Normally, blood needs to clot quickly to prevent wounds from bleeding too much. Because you have atrial fibrillation, you need to take an anticoagulant to help prevent a stroke. The anticoagulant slows the amount of time it takes for your blood to clot. This increases your risk of developing problems with bleeding. The following precautions will help make taking anticoagulants safe.

Safety tips when taking anticoagulants

• Take your medicine at the same time each day. Usually, anticoagulants are taken in the evening. This allows your doctor to adjust your dosage based on the blood test taken earlier that day.
• Check with your doctor before using any over-the-counter medicines (especially ones that contain aspirin), supplements, or natural remedies. To help keep track of all of your medicines, use a medication planner (What is a PDF document?).
• Wear a medical alert ID bracelet, pendant, or charm to let others know you take an anticoagulant. Ask your pharmacist for information about ordering one.
• Tell any new doctor you consult that you are taking anticoagulant medicine.
• Be on the alert for signs of bleeding, and call your doctor immediately if any of these signs occur.
• Get regular blood tests to check your clotting time. When you are taking an anticoagulant, you will have blood drawn regularly so that your doctor can monitor the level of the anticoagulant in your blood. The test that measures how long it takes your blood to clot is called prothrombin time, or pro-time. Your clotting time is usually reported in INR (which stands for international normalized ratio). Most people should have an INR between 2 to 3 for protection against stroke.
• Eat a balanced diet. Don't suddenly change your intake of vitamin K–rich foods, such as broccoli, cabbage, asparagus, lettuce, and spinach. Vitamin K can interfere with the action of anticoagulants, making it more likely that your blood will clot.
• Tell your doctor if you are not able to eat for several days or have stomach upset, diarrhea, or fever or if you have a major change in your diet for other reasons. It is important not to have sudden changes in your diet.
• Avoid excessive use of alcohol. If you drink, do so only in moderation. Alcohol decreases the effect of anticoagulants. Alcohol also affects your balance and coordination and increases your risk of injury from a fall.
• Don't smoke. Smoking affects how the body uses medicine and increases the blood's clotting effects.
• Avoid activities that have a high risk for injury, such as skiing, football, or other contact sports. An injury could result in excessive bleeding if you are taking anticoagulants.
• Modify your environment to help prevent falls.

Use the following items to lower the risk of bleeding:

• An electric razor
• A soft-bristled toothbrush and waxed floss
• Protective clothing, such as gloves and shoes
• Nonslip mats in the tub and shower

Other precautions when taking anticoagulants

What to do if you miss a dose

Now that you have read this information, you can feel confident that you can take anticoagulants safely.

Talk with your doctor

If you have questions about this information, take it with you when you visit your doctor. You may want to use a highlighter to mark areas or make notes in the margins of the pages where you have questions.

Author:	Robin Parks, MS	Last Updated: December 18, 2008
Medical Review:	Caroline S. Rhoads, MD - Internal Medicine John M. Miller, MD - Electrophysiology
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