Brand names - Coumadin, Panwarfin, Sofarin, Marevan.
Medication type - Anticoagulant
Common side effects - No common side
Rare side effects - Loss of appetite,
unusual weight loss, nausea, vomiting, skin rash, diarrhea, cramping.
Serious side effects - Allergic reaction
(marked by wheezing, breathing difficulty, hives, or swelling of
lips, tongue, and throat); bleeding into skin and soft tissue; abnormal
bleeding from nose, gastrointestinal tract, urinary tract, or uterus;
severe infection; excessive or unexpected menstrual bleeding; black
vomit; bruises or purple marks on skin. Consult your doctor immediately.
Dosage - Adults: To start, 10 to 15
mg daily, taken once a day. Long-term, usually 2 to 10 mg per day,
taken once a day. Should be taken at the same time every day.
Uses - To prevent blood clot formation,
by blocking the action of vitamin K, a compound necessary for blood
Food interactions - Avoid green, leafy
vegetables and other foods that are rich in vitamin K (liver, broccoli,
cauliflower, kale, spinach, and cabbage). Intake of too much vitamin
K can override the anticlotting effect of warfarin and render the
drug useless. Conversely, certain substances can interfere with
the absorption of vitamin K so much that normal, healthy clotting
(necessary for wounds to heal) is impaired. Megadoses of vitamin
E can do this, as can fish oil supplements and foods high in omega-3
fatty acids. These substances can enhance the effect of anticlotting
drugs so much that a tendency to haemorrhage may result.
Other notes - Regular tests of prothrombin
time (a simple test that measures the time it takes for one stage
of blood coagulation to occur) are needed when taking this drug.
Your doctor may also take stool and urine samples periodically to
check for the presence of blood. Use alcohol with caution, it can
increase or decrease the effect of warfarin. Usually, consume no
more than one drink a day. Warfarin may cause birth defects. Do
not use during pregnancy. Warfarin passes into breast milk. Do not
use while nursing.