Taking warfarin (Coumadin)
Warfarin is a medicine that makes your blood less likely to form clots. It is important that you take warfarin exactly as you have been told. Changing how you take your warfarin, taking other medicines, and eating certain foods all can change the way warfarin works in your body. If this happens, you may be more likely to form a clot or have bleeding problems.
Anticoagulant care; Blood-thinner care
What to Expect at Home
Warfarin is a medicine that makes your blood less likely to form clots. This may be important if:
When you are taking warfarin, you may be more likely to bleed, even from activities you have always done.
Changing how you take your warfarin, taking other medicines, and eating certain foods all can change the way warfarin works in your body. If this happens, you may be more likely to form a clot or have bleeding problems.
It is important that you take warfarin exactly as you have been told.
Your provider will test your blood at regular visits. This is called an INR test or sometimes a PT test. The test helps make sure you are taking the right amount of warfarin to help your body.
Alcohol and some medicines can change how warfarin works in your body.
Tell all of your providers that you are taking warfarin. This includes doctors, nurses, and your dentist. Sometimes, you may need to stop or take less warfarin before having a procedure. Always talk to the provider who prescribed the warfarin before stopping or changing your dose.
Ask about wearing a medical alert bracelet or necklace that says you are taking warfarin. This will let providers who take care of you in an emergency know that you are taking this drug.
Some foods can change the way warfarin works in your body. Make sure you check with your provider before making any big changes in your diet.
You do not have to avoid these foods, but try to eat or drink only small amounts of them. In the least, DO NOT change much of these foods and products you eat day-to-day or week-to-week:
Because being on warfarin can make you bleed more than usual:
Prevent falls in your home by having good lighting and removing loose rugs and electric cords from pathways. DO NOT reach or climb for objects in the kitchen. Put things where you can get to them easily. Avoid walking on ice, wet floors, or other slippery or unfamiliar surfaces.
Make sure you look for unusual signs of bleeding or bruising on your body.
When to Call the Doctor
Call your provider if you have:
Jaffer IH, Weitz JI. Anticoagulant drugs. In: Sidawy AN, Perler BA, eds. Rutherford's Vascular Surgery and Endovascular Therapy. 9th ed. Philadelphia, PA: Elsevier; 2019:chap 39.
Kager L, Evans WE. Pharmacogenomics and hematologic diseases. In: Hoffman R, Benz EJ, Silberstein LE, Heslop HE, Weitz JI, Anastasi J, eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2018:chap 8.
Schulman S, Hirsh J. Antithrombotic therapy. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 38.
Review Date: 1/28/2019
Reviewed By: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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