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Brand name: Coumadin
Generic Name: Warfarin

This medicine is a "blood thinner" or an anticoagulant.

What does this medicine do?

  • Decreases the clotting ability of the blood
  • Helps prevent harmful clots from forming in the blood vessels or on mechanical heart valves
  • Is commonly given to patients who have mechanical heart valves, stents in the pulmonary artery or chronic atrial flutter 

How should I give my child this medicine?

  • Give this medicine only in the amount your doctor orders
  • There are 8 different strengths of Coumadin tablets. Each tablet has a number on it and is a different color. Each tablet is scored & breaks in half easily.
  • You may not give the same dose each day. For instance, on Monday, Wednesday and Friday you may give 2 mg, and on Sunday, Tuesday, Thursday and Saturday you may give 1 mg.
  • A helpful guide for remembering the dosing is the use of a calendar with the dose written underneath each day. Some people find the use of a weekly pillbox helpful.
  • Give at the same time every day
  • Coumadin dissolves in liquid and may be mixed with a small amount and given with an oral syringe. Coumadin may also be sprinkled on a spoon with food such as applesauce or ice cream. If you change the way Coumadin is given (dissolving, crushing, chewing or swallowing) notify your nurse or doctor.  

What should I do if my child vomits after a dose?

If the vomiting occurs within 15 minutes after the medicine is given, give the entire dose again. If more than 15 minutes have passed, do not give it again until the next scheduled dose.  

What should I do if my child misses a dose?

  • If you miss a dose, give it as soon as possible, if you remember the same day. Then go back to the regular schedule.
  • Do not give more than one dose on the same day
  • If you can't remember if you gave the dose, do not give it. It is safer to miss one dose than to take an extra dose.  

What precautions or special instructions should I know about?

  • Taking too much may cause bleeding, taking too little, may allow a clot to form where it could be dangerous
  • Your child will need to have regular blood tests to check the level of Coumadin in the blood. The test/number that is used is known as PT/INR. This number is watched closely so that your child will receive the right dose.
  • Tell all doctors and dentists that your child is taking this medication
  • Do not give any other medication, such as aspirin, antihistamines or antibiotics, unless you check with your doctor first. Occasional (once or twice) use of ibuprofen should be safe, but if this medication is used consistently, it will alter the level of Coumadin in your child's blood. Therefore, check with your doctor about the more frequent use of it.
  • Acetaminophen/Tylenol is safe to use
  • Avoid contact sports
  • Normal childhood play such as recess and gym are safe
  • Wear a helmet when riding bikes, roller blading or skate boarding
  • Always use a seat belt in the car
  • If you fall or are injured, and have bleeding, pain, swelling, excessive bruising or change in your level of consciousness, call your doctor or emergency room

Possible side effects that should be reported to your doctor:

  • Heavy bleeding from a small cut
  • Bleeding from gums when brushing teeth.
  • Unexplained bruising or purplish areas on skin
  • Unexplained nosebleeds
  • Red or black stools
  • Bloody or tea colored urine
  • Vomiting or coughing up of blood or coffee ground material
  • Stomach pain
  • Blurred vision
  • Severe headaches
  • Unusually heavy or unexpected menstrual bleeding
  • Joint pain

Never ignore signs of bleeding. If you have questions or concerns, contact your doctor or call the Pediatric Cardiology Clinic at (734) 764-5176. At night or on weekends call the paging operator at (734) 936-6267 and ask for the Pediatric Cardiology Fellow on call.

Interactions of Coumadin with food:

  • Vitamin K affects how Coumadin works on the clotting factors and is found in many foods and multi-vitamin supplements. Vitamin K rich foods do not need to be avoided, but should be eaten in the same amounts. For instance if your child eats broccoli 3 times a week, then stops eating it, the Coumadin level could rise. The opposite will happen if your child does not eat broccoli, and then decides to eat it 3 times a week; the Coumadin level may drop.
  • Foods rich in vitamin K:
    • Broccoli
    • Brussel sprouts
    • Cauliflower
    • Chick peas
    • Cucumber peels
    • Green Tea
    • Greens
    • Lettuce
    • Liver (beef or pork)
    • Spinach
  • Excessive use or abuse of alcohol is to be avoided as this will lead to a major fluctuation in the PT/INR and may lead to excessive bleeding or clot formation. An occasional drink (1-2) may be consumed without problems.

Other things that may affect how Coumadin works:

  • Fever (greater than 101 for 24 hours)
  • Diarrhea, vomiting
  • Use of antibiotics

Notify your doctor if these occur. They may cause your child's Coumadin level to be too high.


This information does not cover all the uses, precautions, side effects or interactions of this medicine. If you have any further questions, please contact your doctor.

2006: Information reviewed by Lynda Dettling BSN, RN


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