How Does the Medication Work?
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 clot formation in check, allowing the body's natural processes to break down the clot.
Warfarin Uses in Children
Although warfarin has not been thoroughly and adequately studied in children, enough evidence is available to suggest that it is effective for preventing and treating blood clots in children. However, dosing may be more difficult for children, and monitoring may need to be more frequent.
Off-Label Uses for Warfarin
On occasion, your healthcare provider may recommend warfarin for something other than the conditions discussed in this article (this would be known as an "
off-label" use). At this time, using warfarin to prevent recurrent
transient ischemic attacks (
TIAs or "
mini strokes") is an off-label use.