Patient Medication Guide
Coumadin
What is warfarin (Coumadin), and how does it work?
Warfarin is a prescription medicine that helps stop abnormal blood clots from forming or growing larger in blood vessels. Because clots can block blood flow, they can cause a heart attack, brain attack (stroke), and other serious problems.
Understanding Warfarin
Safe treatment depends on consistent monitoring
Your dose and testing schedule are individualized by your healthcare provider.
Blood testing is essential
While taking warfarin, you must have regular blood tests to make sure you are receiving enough warfarin to stop harmful clots—but not so much that your blood cannot clot when it should, such as after a cut.
How do I take warfarin?
Because warfarin increases your risk for bleeding, take it exactly as your healthcare provider tells you.
PT/INR blood tests
PT/INR stands for prothrombin time and international normalized ratio. Your healthcare provider will decide how often you need testing—commonly every one to four weeks—and may change your warfarin dose based on the results.
Balance clotting and bleeding risk
An INR below your personal target may increase the risk of a harmful clot, while an INR above your target may increase the risk of bleeding. Follow the target range given by your healthcare provider.
Daily Guidelines
Follow these instructions while taking warfarin
Consistency and communication with every member of your healthcare team are essential.
Important Safety Information
Know when to seek immediate help
Call your healthcare provider immediately—or call 911 when symptoms are severe, sudden or life-threatening—if you have a severe headache, worsening fever or illness, dizziness or weakness, chest pain, trouble breathing, or new pain or changes in color or temperature in any part of your body, such as your toes.
If you hit your head, seek emergency medical evaluation right away to make sure there is no bleeding in the brain, even if you initially feel well.
For bleeding that will not stop or another medical emergency, call 911.
Living Safely With Warfarin
Diet and bleeding precautions
Small, consistent habits can help your treatment work safely.
Do I have to change my diet?
Eat a normal, balanced diet. Do not make dietary changes without first talking to your healthcare provider.
Foods rich in vitamin K—especially dark green or leafy vegetables such as broccoli and spinach—can change warfarin’s effect. You do not have to avoid these foods, but try to keep the amount you eat consistent from week to week.
Do not drink alcohol. Avoid cranberry juice and cranberry products because they can affect how warfarin works in your body.
How can I reduce bleeding risk?
Because you may bleed more easily, take these precautions:
- Clean your teeth gently with a soft-bristle toothbrush and waxed floss.
- Use an electric razor or hair-removal cream instead of a razor blade.
- Take care not to cut yourself when using knives and other sharp objects.
- Do not walk barefoot, and avoid activities with a risk of injury, such as contact sports.