Taking warfarin

It's very important that you take warfarin exactly as directed. Don't increase your prescribed dose unless the doctor in charge of your care advises you to.

Warfarin is taken once a day, usually in the evening. It's important to take your dose at the same time each day, before, during or after a meal.

The aim of warfarin therapy is to decrease the blood's tendency to clot, but not stop it clotting completely.This meansthe dose of warfarin you're taking must be carefully monitored and, if necessary, adjusted.

You'll have regular blood tests at your GP surgery or local anticoagulant clinic to make sure your dose is correct.

The international normalised ratio (INR) is a measure of how long it takes your blood to clot. The longer it takes your blood to clot, the higher your INR.Your INR will be used to determine the dose of warfarin you need to take.

Although there are now three new anticoagulants that don't require regular monitoring rivaroxaban, apixaban and dabigatran most people who need an anticoagulant will be prescribed warfarin.

When you start taking warfarin, you may be given a yellow booklet about anticoagulants, which explains your treatment.

How long you'll need to take warfarin for will depend on the condition for which it's been prescribed. Ask the healthcare professional responsible for your care if you're not sure.

Missed doses

If you usually take warfarin in the morning and forget to take it at your normal time,take it as soon as you remember and continue as normal.

However, if it's time to take your next dose,don'ttake a double dose to catch up, unless your GPhas specifically advised you to.

If you forget to take your dose of warfarin in the evening but remember before midnight on the same day, take the missed dose.

If midnight has passed, leave that dose and take your normal dose the next day at the usual time.

Ask your GP or staff at your local anticoagulant clinic if you're not sure what to do about a missed dose of warfarin.You can also call NHS111 for advice.

Who shouldn't take warfarin

The following people shouldn't take warfarin:

  • pregnant women it can affect the development of the baby
  • people with uncontrolled high blood pressure (severe hypertension)
  • people with a high risk of internal bleeding for example, those with a stomach ulcer
  • people with a bleeding disordersuch as haemophilia
Content supplied by the NHS Website

Medically Reviewed by a doctor on 21 Dez 2018