Warfarin is sold under the brand names Coumadin and Jantoven by prescription only. As an anticoagulant, Warfarin is sometimes incorrectly referred to as a blood thinner. Rather than thinning the blood, Warfarin simply makes it more difficult for blood to clot by blocking clotting agents. While some ability for blood to clot is necessary in cases of cut and injuries, harmful clots can lead to stroke, embolism, or heart attack. [caption id="attachment_2580" align="alignright" width="300"] Guide to Taking Warfarin[/caption] Patients who are taking Warfarin should