How does this medicine work?

Warfarin (war-far-in) is an anticoagulant. An anticoagulant helps prevent blood clots in the blood vessels. It does not dissolve clots or thin the blood, although you may hear people call it a “blood thinner.” In order for this medicine to safely help your child, it must be given correctly.

How is the medicine given?

The most common brand of warfarin is Coumadin®. Do not switch brands of warfarin because different brands may not produce the same effect in your child’s body.

How should I give it?

Warfarin comes in tablet form. There are many strengths of warfarin tablets. Read the label and check to be sure that you are giving the correct dose.

For children who cannot swallow pills, ask the doctor how to give it.

Give the exact dose of warfarin that the doctor has prescribed, at the same time each day. It is helpful to keep a warfarin calendar with the doses marked on each day, and check them off when they are given.

Are there any precautions about food or other medicines?

This medicine can be given with or without food. Avoid alcohol or foods containing alcohol. Vitamin K decreases the effect of warfarin. Foods high in vitamin K include green leafy vegetables, egg yolks, liver, and soybean products. If your child eats these foods more than 3 times a week, let the doctor know.

Do not make major changes in your child’s eating habits or give vitamins, herbal products, or nutrition supplements without checking with the doctor.

Do not use any medicine (prescription or non-prescription) while taking warfarin

without checking with the pharmacist or doctor. Many medicines, such as antibiotics, birth control pills, aspirin, vitamins, antacids, laxatives, and nutrition supplements, can change the effect of warfarin in the body.

What should I do if a dose is missed?

If a dose is missed, give it as soon as you remember that day. If you do not remember if you have given a dose, do not give it. Go back to the regular schedule tomorrow. If you do not remember until the next day, continue with the regular schedule and do not give the missed dose. If in doubt, it is generally safer to take too little than too much warfarin.

If your child throws up within 30 minutes after receiving a dose, give it again. If your child vomits after 30 minutes, do not repeat the dose.

If more than one dose is missed or vomited, please call the clinic.

What are the side effects?

The main side effect of warfarin is bleeding. That is why it must be monitored carefully. Ways to prevent bleeding are:

    • give warfarin as directed
    • have your child’s blood tests done
      regularly, as directed by the doctor
    • be sure your child sees a dentist regularly
    • brush teeth gently with a soft toothbrush
    • floss teeth gently after brushing (for children younger than 9 years, parents should help with the brushing and flossing)
    • if the gums are red and puffy, brush teeth gently but do not floss until the nflammation has gone away
    • cut fingernails and toenails carefully
    • prevent constipation by drinking extra fluids and eating high-fiber foods
    • avoid sports or activities that are likely to cause injury
    • when using a knife or any sharp item or tool, point it away from you
    • use an electric razor rather than a razor blade

When should I call the clinic?

Call hematology helpline 982403210 if:

  • if two or more doses are missed
  • any new medical problems
  • any unexplained changes in urinating or stooling
  • a major change in diet is planned
  • unable to eat for several days
  • temperature higher than 101° F for more than 2 days
  • diarrhea
  • vision changes
  • pregnancy
  • bleeding from a cut that will not stop after 5 minutes of pressure
  • bleeding from the mouth or nose
  • coughing up blood
  • other signs of bleeding:
    • swelling, tenderness, or redness in a joint, especially after an injury
    • increased menstrual flow
    • increased bruising
    • black stools
    • stools with red streaks
    • severe, prolonged headache
    • unusual stomach or back pain
    • weakness, dizziness, feeling faint

What else do I need to know?

Your child should carry an ID card or wear a medical alert bracelet or necklace to let emergency caregivers know that he or she is taking warfarin.

While your child is taking warfarin, tests called prothrombin time (PT) or International Normalized Ratio (INR) must be done on a regular basis to check your child’s blood clotting. The tests are done more often at first, and less often after your child’s dose has been established.

It is very important to keep appointments with the lab for these tests so the doctor can adjust the warfarin dose as needed.

If your pharmacist changes the warfarin brand, notify the clinic of the change.

You and your child should know the names of all the medicines he or she is taking. Be sure to tell anyone involved in your child’s care that he or she is taking warfarin. Please remember to bring the medicine container when your child comes to the clinic or emergency department.

Always make sure you have enough warfarin on hand.

Check the label for the expiration date. Flush outdated medicines down the toilet instead of putting them in the garbage.

Store all medicines in their original containers and away from direct sunlight or heat. Do not store in humid places such as the bathroom. Keep all medicines out of children’s reach, locked up if possible

If too much or the wrong kind of medicine is taken, call the clinic immediately


This sheet is not specific to your child but provides general information. If you have any questions, please call:

Hematology Clinic
3rd floor, Kedar
Opp.Krupa Petrol Pump,
Parimal Garden, Ambawadi
Clinic: 07926463219
Whattsapp: 8238065890