Key Points To Remember When Taking Warfarin

• Keep all medical and blood testing appointments.
  
• Report any signs and symptoms of bleeding, or if you experience new chest pain, shortness of breath or weakness on one side of the body.
  
• Ask about drug interactions whenever you start, stop or change a medication.
  
• Be consistent with your diet.

Contents:

• What is warfarin?
• Why am I taking warfarin?
• How do I take warfarin?
• Why is warfarin use monitored so carefully?
• What is INR?
• What are the possible side effects of warfarin?
• What do I need to know about drug interactions with warfarin?
• What role does my diet play?
• What about alcohol?
• Safety Tips
• Questions or Concerns?

What is warfarin?

• Warfarin is the generic name for Coumadin® (brand or trade name).
  
• Warfarin belongs to a class of medications called anticoagulants, which help prevent clots from forming in your blood.

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Why am I taking warfarin?

You are taking warfarin because you have a medical condition that puts you at risk for forming dangerous blood clots, or you already have a blood clot that requires treatment. Dangerous blood clots can lead to stroke or death if untreated.
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How do I take warfarin?

• Warfarin is taken once daily at the same time every day, preferably in the evening, with or without food.
  
• If you miss a dose of warfarin, take the missed dose as soon as possible on the same day. If you forget, do not double up the next day! Write the day of your missed dose on your calendar and let your health care provider know at your next visit.

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Why is warfarin use monitored so carefully?

Warfarin is a medication that requires careful and frequent monitoring to make sure that you are being adequately treated, but not over- or under-treated. If you have too much warfarin in your body, you may be at risk for bleeding. If you have too little warfarin in your body, you may be at risk for forming dangerous blood clots. Medications, food and alcohol can also interfere with warfarin, making close monitoring even more important.
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What is INR?

• International Normalized Ratio (INR) is a blood test that helps determine the right warfarin dose for you.
  
• The INR tells us how much warfarin is in your bloodstream and is a measure of how fast your blood clots.
  
• A high INR means you are more likely to bleed (your blood does not clot very fast).
  
• A low INR means you are more likely to form a clot (your blood clots very fast).
  
• All patients will have an INR goal depending on their medical condition(s).

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What are the possible side effects of warfarin?

The major side effect of warfarin is bleeding (especially when your INR is too high). Here are some symptoms of bleeding to look for and to report to your health care provider:

• Unusual bruising or bruises that won't heal
  
• Bleeding from your nose or gums
  
• Unusual color of urine or stool (including dark brown urine, or red or black/tarry stools)

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What do I need to know about drug interactions with warfarin?

Many drugs can potentially interfere with warfarin and may cause your INR to change, putting you at risk for bleeding or a clot. These drugs include prescription medications, over-the-counter medications (like aspirin, ibuprofen, naproxen), and dietary and herbal supplements. They should be avoided unless otherwise directed by health provider.
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What role does my diet play?

The amount of vitamin K in your diet may affect your response to warfarin. Certain foods (like green, leafy vegetables) have high amounts of vitamin K and can decrease your INR. You do not have to avoid foods high in vitamin K, but it is very important to try to maintain a consistent diet every week.
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What about alcohol?

Alcohol use also may affect your response to warfarin. Excessive use can lead to a sharp rise in your INR. It is best to avoid alcohol while you are taking warfarin.
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Safety Tips

• Carry a wallet ID card and/or wear an emergency alert bracelet
  
• Tell all health care providers (physicians, nurses, pharmacists, dentists, etc.) that you are taking warfarin, especially if you have any planned surgeries or procedures.
  
• Alert your health care provider if you are pregnant or become pregnant while taking warfarin.
  
• Plan ahead when traveling by having enough warfarin and arrange for follow-up blood tests. It is also important to keep your diet consistent.
  
• Avoid any sport or activity that may result in a serious fall or injury.
  
• Use a soft-bristled toothbrush to protect your gums.
  
• Use an electric razor if you are prone to cut yourself when shaving.

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Questions or Concerns?

If you have any questions, please contact your physician, nurse or pharmacist.

For more information, please visit the following PAMF Web sites and pages:

• Anticoagulation Clinic
• Urgent Care
• List of PAMF departments and services

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