Common reasons for coumadin use are in atrial fibrillation to reduce the risk of stroke, in persons with clotting disorders, in persons with mechanical heart valves, and
sometimes in people with severe heart failure. The usual dosage is somewhere between 1 and
15 mg a day. Potential side effects include bleeding, hair loss, nausea, vomiting, stomach cramps
, diarrhea and leukopenia (low blood cell count).