Taking Warfarin (Coumadin)

Warfarin (Coumadin) helps keep your blood from clotting. It is used to reduce the risk for stroke, heart attack, or a blood clot passing to your lung. Warfarin also increases your risk of bleeding. Because of this, it must be taken exactly as directed by your doctor or the clinic that manages your warfarin doses. You also need to protect yourself from injury. 

Follow these safety tips

• Take this medicine at the same time each day. Take it with a full glass of water, with or without food. If you miss a dose, contact your doctor or the clinic that manages your warfarin doses immediately to find out how much to take.

• Protect yourself from injury. Warfarin makes your blood less likely to form clots. If you take too much, it can cause bleeding.

• Have regular blood tests to measure the effect of warfarin.

• Tell all of your doctors that you take warfarin.

• If you will be taking warfarin for quite a while, carry an ID card or get Medical Alert jewelry. This will alert others in case you are not able to do so yourself. 

• Carry with you the name and number of the person to contact in case of an emergency.

Monitoring your PT/INR blood levels after discharge

It is important to monitor your correct warfarin dose with regular PT/INR blood tests after discharge. PT is the time in seconds it takes your blood to clot. The PT is used to calculate the INR. In order for your warfarin to work well, your INR must be in a certain range. If it is too low, you are not protected from having a stroke or blood clot. If it is too high, you are at a higher risk of bleeding.

• Go for your blood (PT/INR) tests as often as directed. Diet and medication can affect your PT/INR level.

• Your last INR was ___________ .

• Ask your doctor what your goal INR is. My goal INR is between ___________ and ___________.

• My next PT/INR blood draw is due on _________________ (date) at ____________________________ (name of doctor or clinic).

• The name of the doctor or clinic who is monitoring my anticoagulation therapy is ______________________ and the phone number is ___________________.

• You should be called with your INR results within one business day of having the blood test. If you have not heard from the doctor or clinic in one business day, please call the doctor or clinic that manages your warfarin.

• If your labs (PT/INR) are drawn at a location other than your doctor's office, please remember to tell your doctor as soon as you get your lab results. 

What to do at home

• Adjust your warfarin dose as directed by your doctor, ____________________ (name of doctor).

• Have another PT/INR test done as instructed.

• Do not go barefoot. Always wear shoes.

• Do not trim corns or calluses yourself.

• Always talk with your doctor before taking any herbs, vitamins, prescription or over-the-counter (OTC) medications, especially aspirin and non-steroidal anti-inflammatory drugs (such as ibuprofen, Motrin, Naproxen, Aleve).

• Always talk with your doctor before stopping any medication or changing the dose of any of your medications.

• Use an electric razor instead of a manual one.

• Use a soft-bristled toothbrush and waxed floss.

• Avoid major changes in your diet. 

When to call your health care provider

Warfarin increases your risk of bleeding. Call your health care provider right away before you take your next dose if you have any of these problems:

• Bleeding that does not stop in 10 minutes

• A heavier-than-normal period or bleeding between periods

• Coughing or throwing up blood or something that looks like coffee grounds

• Nausea, bloating, diarrhea, or bleeding hemorrhoids

• Bleeding hemorrhoids

• Dark red or brown urine

• Red or black tarry stools

• Red or black-and-blue marks on your skin that get larger

• A fever or an illness that gets worse

• Dizziness, headache, weakness, or fatigue

• Chest pain or trouble breathing

• A serious fall or a blow to the head

• Swelling or pain after an injury or at an injection site

• Bleeding gums after brushing your teeth

Keep your diet the same

Keep your diet pretty much the same each day. That is because many foods contain vitamin K which helps your blood clot.  Eating foods that contain vitamin K can affect the way warfarin works. You do not need to avoid foods that have vitamin K. But, you do need to keep the amount of them you eat about the same day to day. If you change your diet for any reason, such as due to illness or to lose weight, be sure to tell your doctor or the clinic that manages your warfarin.

• Foods high in vitamin K are asparagus, avocado, broccoli, cabbage, kale, spinach, and some other leafy green vegetables. Oils, such as soybean, canola, and olive oils, are also high in vitamin K.
• Food products that may affect blood clotting include cranberries and cranberry juice, fish oil supplements, garlic, ginger, licorice, and  turmeric.
• Herbs used in herbal teas or supplements can also affect blood clotting. Keep the amount of herbal teas and supplements you use the same. 
• Alcohol can increase the effect of warfarin in your body.

Talk with your health care provider or dietician if you have concerns about these or other food products and their effects on warfarin.

What to watch for

If you have any of these signs or reactions, call your doctor right away or go to the hospital.

Signs of too much bleeding:

• More bruising than normal

• Prolonged bleeding from cuts

• Bleeding from the nose or gums

• Blood in your urine, vomit, or stools (red or black color)

• Coughing up blood

• Unusually heavy menstrual bleeding

• Sudden change to a dark or purplish color in your toes or any other area of your body

Allergic Reactions:

• Rash

• Itching

• Swelling

• Trouble swallowing or breathing

Important Information for You to Know

Medical Conditions

Before starting this medicine, be sure your doctor knows if you have any of these conditions:

• Stomach ulcer now or in the past

• Vomited blood or had bloody stools (black or red color)

• Aneurysm, pericarditis, or pericardial effusion

• Blood disorder

• Recent surgery, stroke, mini-stroke, or spinal puncture

• Kidney or liver disease, uncontrolled high blood pressure, diabetes, vasculitis, congestive heart failure, lupus or other collagen-vascular disease, or high cholesterol

• Pregnancy or breastfeeding

• Younger than 18 years old

• Recent or planned dental procedure

Drug Interactions

Many medicines interfere with the effect of warfarin. Before starting this medicine, be sure your doctor knows about any prescription, OTC, or herbal drugs you are taking. This is especially true if you are taking:

• Antibiotics

• Heart medicines

• Cimetidine (Tagamet)

• Aspirin or other anti-inflammatory drugs such as ibuprofen (Advil, Motrin, or Nuprin), naproxen (Aleve, Naprosyn, Anaprox), ketoprofen (Orudis, Oruvail), or other arthritis medicines

• Drugs for depression, cancer, HIV (protease inhibitors), diabetes, seizures, gout, high cholesterol, or thyroid replacement

• Vitamins containing Vitamin K or herbal products such as ginkgo, Q10, garlic, or St. John's Wort

NOTE: This information topic may not include all directions, precautions, medical conditions, drug/food interactions, and warnings for this drug. Check with your doctor, nurse, or pharmacist for any questions that you may have. 

06/2021