East Atlanta Cardiology - Warfarin (Coumadin) Therapy

Warfarin (Coumadin) Therapy

What is Warfarin?

Warfarin is a blood thinner taken orally that increases the time for a person’s blood to clot (coagulate). There are several factors that affect the blood’s ability to clot and Warfarin specifically acts on the Vitamin K dependent coagulation factors. Warfarin should be taken every day at the same time, preferably in the evenings. Its effect lasts for 2 to 5 days and it may take several weeks to reach therapeutic levels. This varies from person to person. Because of its long acting effect, your Warfarin dose may differ day to day. An example would be take 1 tablet every day except ½ tablets on Mondays and Fridays.

Warfarin is used as a prophylactic treatment to keep future clots from forming. It cannot dissolve existing clots.

How is it monitored?

Warfarin is monitored by a blood test called a Protime or INR. This is measured by a simple blood test that can be performed through the lab or by a finger stick. At East Atlanta Cardiology we have the equipment to monitor your INR by a finger stick. At first, you will need to come in every week until your adequate blood level is reached. For someone with Atrial Fibrillation, Stroke or history of a blood clot, the INR should be between 2.0 and 3.0. For someone with an artificial heart valve replacement, the INR should be between 2.5 and 3.5. Sometimes these levels are varied due to each person’s risk factors and history. Once a therapeutic level is reached, the INR can be checked once every 2 to 4 weeks. This level is affected by many things that will be discussed further. Because of this, a person’s dose of Warfarin can vary greatly patient to patient.

What are the side effects?

Side effects may include hypersensitivity/allergic reactions, elevated liver enzymes, nausea, vomiting, headache, dizziness, and more commonly, cold intolerance. Please ask your pharmacist for a complete list of side effects. The side effect that causes the greatest concern is the risk of bleeding. If your INR goes to high, it can cause major or fatal bleeding. For this reason, it is imperative that you follow your Doctor’s guidelines closely and come in regularly for your INR check. If you think you are having an allergic reaction or are experiencing unusual bleeding, call your Doctor immediately.

What foods should I avoid?

Foods high in vitamin K can lower your INR. These include green, leafy vegetables including spinach, collard greens, lettuce, turnip greens, brussel sprouts, broccoli, cabbage and kale. If you continue to eat these foods, you must be consistent every week and spread out the days you eat them. If you are taking Warfarin for only a short time, it might be best to avoid these foods for the time being.

Examples of Vitamin K foods:

Kale, 1 cup	1,147mcg
Collards, 1 cup	1,059mcg
Spinach, 1 cup	1,027 mcg
Turnip Greens, 1 cup	851 mcg
Mustard Greens, 1 cup	419 mcg
Brussels Sprouts, 1 cup	300 mcg
Broccoli, 1 cup	220 mcg
Onions (spring or scallion), 1 cup	207 mcg
Lettuce, 1 cup	97 mcg
Okra, 1 cup	64 mcg

What drug interactions should I be aware of?

It seems that almost every drug has some sort of affect on a person’s INR. Some medications that have a greater interaction include any antibiotic, Amiodarone, and steroids. If a different Doctor starts you on any of these, notify your Doctor immediately. This includes any steroid shots you may receive such as a Cortisone shot. It is best that you notify your Doctor anytime a new medication is added. NSAID (anti-inflammatory agents) should be taken minimally such as aspirin or ibuprofen. If you have a history of a heart attack, you may be asked to take an 81 mg Aspirin in conjunction with your Warfarin.

What happens if my INR goes to high?

Most of the time, elevations in your INR level are realized before they become dangerously high and you will be asked to stop your Coumadin for a few days and eat extra food with Vitamin K in them. If you are having bleeding problems and your INR is moderately high, you may be given a Vitamin K shot. In extreme situations, you will be admitted and monitored in the hospital.

Are there any alternatives?

For now, there are no substitutions that match the therapeutic effect of Warfarin for Atrial Fibrillation or Artificial Heart Valve Replacements. However, if you choose not to take Warfarin or you are allergic to it, aspirin can be taken as it does offer some protection.

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