Warfarin (Coumadin®) is an anticoagulant medicine. Anticoagulants, like warfarin, help keep blood clots from forming. If blood clots do form, warfarin can keep them from getting bigger. Warfarin is often called a "blood thinner" but it does not really thin your blood. Warfarin makes it take longer for your blood to clot.
How does warfarin work?
Warfarin makes your blood take longer to clot. Your liver makes clotting factors that help your blood clot and keep you from bleeding. Vitamin K is needed to make these clotting factors. Warfarin stops your liver from using vitamin K, so you don't make as many clotting factors. With fewer clotting factors, your blood takes longer to clot.
Why was I prescribed warfarin?
You may have a blood clot or be at risk to get a clot. Blood clots can be harmful if they block blood vessels or cut off blood supply and oxygen to parts of your body. Clots can form in your veins, arteries, heart valves, or in your heart. Warfarin may be used for any of these problems:
Atrial fibrillation (irregular heart beat)
Blood clot in the leg (deep vein thrombosis, DVT)
Blood clot in the lungs (pulmonary embolism, PE)
Heart valve disease or artificial heart valve
Other harmful clots
To keep you from forming harmful clots
What should I think about before I start warfarin therapy?
Your health care provider has decided that you need warfarin. However, some people should not take warfarin. Call your provider immediately if:
You are allergic to warfarin or anything in warfarin pills, such as dyes or colorings.
You are pregnant or plan to become pregnant. Warfarin can cause death or birth defects in an unborn baby. You should use effective birth control while taking warfarin.
What information do I need to keep track of when I am on warfarin?
Warfarin can cause serious problems. For this reason, it is important that you keep track of some information while you are taking this medicine. This will help your health care provider take better care of you.
When you are on warfarin, you will need to do two things:
Keep a log about your warfarin therapy. When you click on the word "log" anywhere in this section, it will take you to a chart you can print out and use as your log. This log has places for you to write down these things:
Your warfarin dose
Your blood test result. The blood test result is called an INR.
Important things about your warfarin therapy like changes in your diet, medicines, or health.
Notes about any changes in your warfarin doses and lab results.
Keep a list of all your medicines. This includes all your prescription medicines, any over-the-counter medicine, herbal products, supplements, and vitamins. Visit Med Card for more information about keeping track of your medicines and to print a card you can use to track them.
Do I need to let my health care provider know I am on warfarin?
Yes. It is very important that you let all your health care providers know you are on warfarin. This includes your physician, pharmacist, nurse and dentist. Warfarin increases your chance of bleeding. Warfarin can interact with many medicines as well. This is important information for your health care team to know.
Wear medical alert jewelry to let others know you are on warfarin. This is especially important in an emergency when you may not be able to tell your care providers. You can purchase a medical alert bracelet from most pharmacies. You can also order medical alert jewelry, such as a bracelet or necklace, from companies such as MedicAlert at www.MedicAlert.com.