Anticoagulation Services

Anticoagulation is a word used to describe medicines and other therapies that can “thin” the blood. We offer professional anticoagulation services to assist our patients in managing these therapies. Our services are provided by Registered Nurses upon the advice of your physician. Following are some common questions patients may have about taking warfarin.

What is warfarin?

Warfarin, the generic name for Coumadin®, is given to patients to increase the amount of time it takes to form a clot inside the body or a scab on the skin after a scrape. Some people call this medicine a “blood thinner.”

Why do I take warfarin?

Patients with certain heart problems will take warfarin to decrease the risk of a stroke, blood clot in the lung (pulmonary embolism) or blood clots in the legs. Your doctor will discuss with you the risk and benefit of taking warfarin.

How do I take warfarin?

You should only take warfarin at the schedule recommended by your doctor or his or her nurse. You should take the warfarin at the same time each evening.

Does warfarin have any side effects?

Warfarin is tolerated well by most people. It is rare for a person to have an allergic reaction to warfarin but if you develop a rash, itchy hives or difficulty breathing go to the nearest emergency department or call 9-1-1.

There have been some reports of low blood cell counts or liver problems. If you have any symptoms that worry or bother you, please discuss this with your doctor or nurse.

When will I be able to stop warfarin?

Most people will take warfarin for months or years. How long you take warfarin will be determine by your doctor and discussed with you at your routine follow-up visit.


While taking warfarin you MAY NOT have the following:

  • Aspirin(unless prescribed specifically by a doctor as a prevention for heart disease)
  • Advil, Motrin or Aleve
  • Grapefruit or grapefruit juice
  • Green tea
  • Cranberry juice and salad should be avoided

Do Not:

  • Run out of medicine
  • Miss warfarin doses
  • Double up the day after a missed dose


  • Keep all appointments and go for all blood testing when recommended
  • Wear gardening gloves
  • Avoid activities that could cause serious injury such as sky diving, motorcycle riding, karate, boxing or bungee jumping
  • Wear a medical alert bracelet or necklace
  • Speak with our nurse when you start a new medicine

If ever in doubt or you have a question, call our nursing staff and they will be happy to answer your questions.

What is the INR test?

The INR (international normalized ratio) measures the amount of time it takes for your blood to clot and if the recommended warfarin dose is working. This test is from a finger stick blood sample at the office or a blood sample drawn from your arm at a local laboratory. The INR number may be too high meaning the blood is too “thin” or it may be too low telling us the blood is too “thick.”

The INR will be tested at least once a week in the beginning and will usually be once a month after we find out what is the right dose for you.

What is my INR range?

You will have an assigned target range that we use to determine if you are taking too little, too much or just the right amount of warfarin. The range is usually between 2.0 to 3.5. Your doctor will decide what range is right for you. Your warfarin dose will be determined by what your INR value is on the day of testing.

The INR will be tested at least once a month and more often if you are new to warfarin therapy or the blood is too thick or thin. The nurse will give you the result and instructions on the day of the testing or the next day.

When should I call my doctor or nurse?

If you have any minor bleeding problems such as:

  • Bleeding gums
  • Nose bleeds
  • Blood in your urine
  • Blood in your stool
  • Coughing up blood
  • Vomiting up what looks like coffee grounds
  • Vomiting up blood
  • Unusual bruises all over your body

When should I go to the emergency room?

Any major bleeding or injury.

Why is my diet important?

Many foods and beverages can change how your body uses warfarin on a daily basis. The most common foods that can cause a change include:

  • Foods that are high in vitamin K will lower the INR making the blood thicker
  • Spinach
  • Turnip greens and collard greens
  • Kale
  • Broccoli
  • Brussels sprouts
  • Romaine lettuce
  • Asparagus
  • Red cabbage
  • Beverages
  • Green tea
  • Chamomile tea
  • Dietary supplements

Talk with your nurse if you have questions about any food, beverage, supplement or medicine.

What about vitamins and supplements?

Some vitamins and supplements will interact with warfarin or change how your body uses warfarin.

  • Vitamin C- you may have up to 500mg per day
  • Vitamin E- you may have up to 400IU per day
  • Multivitamins may be taken but must be the same brand each time and taken regularly just like your prescription medicines
  • Herbal supplements to avoid:
  • Alfalfa
  • Black Cohosh
  • Feverfew
  • Garlic supplement
  • Ginger
  • Ginkgo Biloba
  • Licorice
  • Nettle
  • Red Clover
  • St. John’s Wart
  • Sweet clover
  • Ask your nurse about other supplements before taking

What other over-the-counter medicines may I take?
– Cold and Sinus

  • Loratadine (Claratin®)
  • Chlorpheniramine maleate(Coricidin HBP®)
  • Citirizine (Zyertec®)
  • Aches and pains
  • Acetaminophen Tylenol, Tylenol extra strength or Tylenol arthritis
  • DO NOT take BC powders, Goodies or AlkaSeltzer (all of these contain aspirin)

May I drink beer, wine or liquor while taking warfarin?

Some physicians will allow one to two drinks a week but some of our physicians may tell you alcohol with taking warfarin. Be sure to ask your doctor or the nurse.

What if I need surgery?

Speak with your surgeon and ask how many days do you need to be off warfarin before the surgery. Once you have this information contact our nursing staff for further instructions. Please have the surgeon’s name and phone number along with your surgery date available when you call.

Do I stop my warfarin for dental procedures?

For routine cleaning it is not necessary to stop your warfarin. Be sure to tell your dentist you take warfarin.

This web page content was created by the medical staff of the Atlanta Heart Group,PC ©2010 as a teaching aid for current patients and is general information not patient specific medical treatment. Specific instructions should be obtained from your doctor. Not intended for general distribution.