Heart Home > Clinical Effects and Treatment Guidelines for Warfarin
Blood clotting is a complex process that involves many different substances in the body, known as clotting factors, and several different steps. Warfarin works to inhibit blood clotting by decreasing the formation of active forms of certain clotting factors.
Some clotting factors require vitamin K to be converted into their active forms. Although this reaction changes vitamin K into an unusable form, the body can recycle it back using an enzyme known as vitamin K epoxide reductase. Warfarin blocks this enzyme, inhibiting the recycling of vitamin K and, thereby, decreasing the formation of the active clotting factors.
It is important to understand that warfarin does not "dissolve" or break down blood clots (only special "clot buster" medications that must be given in the hospital can do this). Rather, it prevents them from forming. When used to treat a blood clot, warfarin keeps the clot formation in check, allowing the body's natural processes to break down the clot.
When and How to Take This Drug
General considerations for those taking warfarin include the following:
- This medication comes in tablet form. It is also available as an injection, although this form is rarely used.
- Warfarin is usually taken by mouth once a day.
- Although it does not matter what time of day you take warfarin, be sure to take it at the same time each day.
- If necessary, the tablets can be broken in half. However, it is best to avoid this, since even tiny variations in the dosage can cause problems.
- You can take this medication with food or on an empty stomach.
- For warfarin to work properly, it must be taken as directed.