Frequently asked questions 

Below are the answers to some common questions about taking warfarin.

What do I do if I have a nosebleed?

If you have a nosebleed, carry out normal first aid:

  • lean your head forward
  • pinch just below the bridge of your nose firmly for at least 10 minutes

If the nosebleed lasts longer than 15 minutes or you have regular nosebleeds, contact your GP surgery or anticoagulant clinic to get your international normalisation ratio (INR) checked. INR is a measure of how long it takes your blood to clot.

What happens if I need an operation or teeth taken out?

Because of the risk of bleeding, your dose of warfarin may have to be lowered or stopped a few days before an operation or removal of teeth.

You must tell the surgeon or dentist you are on warfarin. Also, tell your anticoagulant nurse if you need an operation as soon as possible, so they can make arrangements.

However, if your INR is under four you probably won’t need to have your warfarin dose adjusted.

Can I have normal vaccinations?

Yes, but all injections and vaccinations must:

  • be given under the skin
  • have firm pressure applied to the site for 10 minutes afterwards
  • not be given into the muscle as this may cause bruising

Can I play sports?

Yes, but because of the risk of bleeding:

  • contact sports that could lead to a head injury, such as football, rugby, cricket and hockey, are best avoided if played competitively
  • martial arts and kickboxing must be avoided

Non-contact sports such as running, athletics, cycling and racquet sports can be played. Wear the right protective clothing, such as cycle helmets and knee padding.

Try to lead as normal a life as possible.

Do I need to tell my school?

You must tell your school if you are on warfarin so that they know:

  • that you should avoid contact sports
  • how to care for you if you start bleeding
  • when to contact your parents or guardian

Can I have a body piercing?

It is not a good idea to have a body piercing because of the increased risk of bleeding and the risk of infection.

Can I still go on holiday?

If you are going on holiday, in this country or abroad, tell your anticoagulant nurse and arrange to have your INR checked just before you go.

If you are away for longer than a month, you may need to arrange to have your INR checked locally.

Make sure you have enough warfarin tablets to last your trip.

Will girls have problems with periods and pregnancy?

Because of the risk of bleeding, periods may be heavy and last longer than normal. There are drugs that can help reduce blood loss during these times.

It is important that all girls taking warfarin are told about the importance of contraception as warfarin can be harmful to a baby, especially in the first 12 weeks of pregnancy.

If you are planning a family in the future, you must discuss it with your doctor. Special arrangements will be made for anticoagulant care.

Page last reviewed: 17/06/2014

Next review due: 17/06/2016