Is your blood really thinner with warfarin?

No, warfarin is often referred to as a "blood thinner," but this is a misnomer because warfarin does not actually "thin" the blood. It inhibits a series of clotting factors to keep your blood from forming a blood clot.

• When you cut yourself, there is a series of vitamin K-dependent clotting factors found in your blood that help to form a blood clot to stop the bleeding.
• Warfarin actually blocks (inhibits) these clotting factors and other proteins to keep the blood anti-coagulated, but it does not actually "thin" your blood.

How is bleeding stopped if you take warfarin?

One advantage of using warfarin (Jantoven) is that bleeding events can be reversed with the use of a made-made form of Vitamin K (phytonadione). In fact, it's the vitamin K you were told to be wary of in green, leafy vegetables and other foods -- but in medication form. It can be given as an oral tablet or as an injection, as determine by your healthcare provider.

Your doctor will regularly monitor your warfarin with a blood test called an International normalized ratio, or INR.

• Just like having too much warfarin increases the risk of bleeding, having too little warfarin puts you at risk of forming a blood clot.
• Therefore, the effect of warfarin must be monitored carefully with blood testing. INR tests can help your doctor decide on the best dose of warfarin for you.

Bleeding Risk Precautions with Warfarin

Even though warfarin does not actually "thin" your blood, you might bleed more easily while on treatment, so it's important to take precautions.

• For example, use a soft toothbrush, waxed dental floss, and an electric razor to avoid accidental cuts.
• Avoid sharp objects; use caution in the kitchen.
• Be wary of increased risks for falling, like climbing a ladder or walking on slick sidewalks.
• Tell your doctors, dentist and other healthcare providers if you take anticoagulant medicine or have a bleeding disorder.
• Wear medical alert jewelry, or carry a card with this information. Ask your healthcare provider where you can buy these items.

Many prescription drugs can interact with warfarin. Even common over-the-counter (OTC) drugs may have an effect, such as:

• aspirin
• ibuprofen (Morin, Advil)
• naproxen (Aleve)
• cimetidine (Tagamet)

It's worth your time to have a warfarin drug interaction review performed by your pharmacist with each prescription medicine, over-the-counter product, and herbal or vitamin supplement that you take.

In addition, limit alcohol use which can increase your INR. Speak with your doctor about drinking alcohol if you take warfarin. Also, smoking can affect the way your blood clots. Ask for information if you need help quitting.

This is not all the information you need to know about warfarin for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.

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