Warfarin is an anticoagulant (blood thinner). Warfarin reduces the formation of blood clots.
Warfarin is used to treat or prevent blood clots in veins or arteries, which can reduce the risk of stroke, heart attack, or other serious conditions.
Warfarin may also be used for purposes not listed in this medication guide.
Dosage
Take warfarin exactly as prescribed by your doctor. Follow all directions on your prescription label. Your doctor may occasionally change your dose. Do not take warfarin in larger or smaller amounts or for longer than your doctor tells you to.
Take warfarin at the same time every day, with or without food. Never take a double dose.
Warfarin can make it easier for you to bleed. Seek emergency help if you have any bleeding that will not stop.
You will need frequent "INR" or prothrombin time tests (to measure your blood-clotting time and determine your warfarin dose). You must remain under the care of a doctor while taking this medicine.
Caution/Warning
You should not take warfarin if you are allergic to it, or if:
you have very high blood pressure;
you recently had or will have surgery on your brain, spine, or eye;
you undergo a spinal tap or spinal anesthesia (epidural); or
you cannot take warfarin on time every day.
You also should not take this medicine if you are prone to bleeding because of a medical condition, such as:
a blood cell disorder (such as low red blood cells or low platelets);
ulcers or bleeding in your stomach, intestines, lungs, or urinary tract;
an aneurysm or bleeding in the brain; or
an infection of the lining of your heart.
Do not take warfarin if you are pregnant, unless your doctor tells you to. Warfarin can cause birth defects, but preventing blood clots may outweigh any risks to the baby. If you are not pregnant, use effective birth control to prevent pregnancy while taking warfarin and for at least 1 month after your last dose. Tell your doctor right away if you become pregnant.
Possible major bleeding, sometimes fatal. More likely to occur during initiation of therapy and with higher dosages, resulting in a higher INR.
Monitor INR regularly. Patients at high risk for bleeding may benefit from more frequent INR monitoring, careful dosage adjustment to achieve desired INR, and shorter duration of therapy.
Drugs, dietary changes, and other factors affect INR levels achieved with warfarin sodium therapy.
Instruct patients about preventative measures to minimize risk of bleeding and to immediately report signs and symptoms of bleeding to clinician.
