Warfarin

Warfarin is an anticoagulant (blood thinner). It reduces the formation of blood clots by blocking the formation of certain clotting factors.

Warfarin is used to prevent heart attacks, strokes, and blood clots in veins, arteries and lungs. It treats or prevents clots that may occur because of a type of abnormal heartbeat (atrial fibrillation) or heart valve replacement. Warfarin is also used to reduce the risk of death or blood clotting events (eg, stroke) after a heart attack.

Warfarin may also be used for purposes other than those listed here.

This medication can cause birth defects in an unborn baby. Do not use if you are pregnant. Use an effective form of birth control, and tell your doctor if you become pregnant during treatment. Never take a double dose of warfarin.

If you need to have a lumbar puncture (spinal tap) or any type of surgery, you may need to temporarily stop using warfarin. Be sure the surgeon knows ahead of time that you are using this medication.

Carry an ID card or wear a medical alert bracelet stating that you are taking warfarin, in case of emergency. Any doctor, dentist, or emergency medical care provider who treats you should know that you are taking this medication. Warfarin interacts with many other drugs, and these interactions can be dangerous, even fatal. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor. You should not take acetaminophen (Tylenol), aspirin, or NSAIDs (non-steroidal anti-inflammatory drugs) unless your doctor has told you to. NSAIDs include celecoxib (Celebrex), diclofenac (Voltaren), ibuprofen (Motrin, Advil), indomethacin, naproxen (Aleve, Naprosyn), piroxicam (Feldene), and others. These medicines may affect blood clotting and could cause serious bleeding in your stomach or intestines.

Avoid sudden changes in your diet. Vitamin K decreases the effects of warfarin. Large amounts of vitamin K are found in foods such as liver, broccoli, brussels sprouts, spinach, Swiss chard, coriander, collards, cabbage, and other green leafy vegetables. Do not change the amount of these foods in your diet without first talking to your doctor.

Avoid eating cranberries, drinking cranberry juice, or taking cranberry herbal products.

Avoid drinking alcohol, which can increase some of the side effects of warfarin.

Take warfarin exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Your doctor may occasionally change your dose to make sure you get the best results from warfarin. Follow the directions on your prescription label.

Take each dose with a full glass of water. Take warfarin at the same time every day. Warfarin can be taken with or without food.

Your body's response to warfarin can be affected by your diet, environment, physical well-being, and other medicines or herbal (botanical) products you use.

Avoid dieting to lose weight while taking warfarin. Tell your doctor if your body weight changes for any reason.

It is important to take warfarin regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.

To be sure this medication is helping your condition, your blood will need to be tested on a regular basis. Do not miss any scheduled visits to your doctor.

If you need to have a lumbar puncture (spinal tap) or any type of dental work or surgery, you may need to temporarily stop using warfarin. Be sure your doctors know ahead of time that you are using warfarin.

Carry an ID card or wear a medical alert bracelet stating that you are taking warfarin, in case of emergency. Any doctor, dentist, or emergency medical care provider who treats you should know that you are taking warfarin. Store this medication at room temperature away from heat, moisture, and light.

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include bruising, broken blood vessels under the skin, excessive bleeding from cuts or wounds, blood in the urine or stools, and heavy menstrual periods in women.

You should not take acetaminophen (Tylenol), aspirin, or NSAIDs (non-steroidal anti-inflammatory drugs) unless your doctor has told you to. NSAIDs include celecoxib (Celebrex), diclofenac (Voltaren), ibuprofen (Motrin, Advil), indomethacin, naproxen (Aleve, Naprosyn), piroxicam (Feldene), and others. These medicines may affect blood clotting and could cause serious bleeding in your stomach or intestines.

Avoid sudden changes in your diet. Vitamin K decreases the effects of warfarin. Large amounts of vitamin K are found in foods such as liver, broccoli, brussels sprouts, spinach, Swiss chard, coriander, collards, cabbage, and other green leafy vegetables. Do not change the amount of these foods in your diet without first talking to your doctor.

Avoid eating cranberries, drinking cranberry juice, or taking cranberry herbal products.

Avoid drinking alcohol, which can increase some of the side effects of this medication.

Avoid sports or activities that could result in a bruising or bleeding injury. Use extra caution to avoid cuts when brushing your teeth or shaving.