How does warfarin work?
- Vitamin K is found naturally in foods.
- Your body needs vitamin K to make clotting factors in your liver. These clotting factors help blood to clot and stop bleeding under normal conditions.
- Warfarin blocks vitamin K from making these clotting factors. This lowers the number of clotting factors in your blood. This makes your blood:
o Less likely to form dangerous clots.
o Keeps clots you have from getting bigger. - Warfarin does not break up a clot that has already formed.
How do I take warfarin?
Warfarin is a pill. You take it by mouth. Your care team will prescribe the amount (how much) you need to take based on your blood test results.
When taking warfarin:
- Take it at the same time each day. Most people take it in the evening
- Write down your current dose and when a change is made by your care team.
- Use a pill box so you do not miss a dose.
- If you miss a dose, take the dose as soon as you can on the same day.
- If you do not remember until more than 12 hours after you missed a dose, do not take the dose you missed. Instead, take your usual dose the next day.
- Do not take 2 doses at the same time to make up for a missed dose, unless told to do so.
- Missing a dose of warfarin can change your blood test results. Write down the date you missed the dose. Tell your care team at your next visit.
- Call your care team right away if you miss warfarin doses for 2 or more days.
How long do I have to take warfarin?
The length of time you need to take warfarin will depend on the medical reason you take it. Some people must take warfarin their whole life. Others need it for a few months.
Never stop taking your warfarin without talking to your care team.
How should I store warfarin?
- Keep this medicine away from children.
- Store it at room temperature. Keep it away from too much heat and moisture. Do not keep it in the bathroom.
- Get rid of any medicine that is expired or no longer needed.