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Direct oral anticoagulants for AF and VTE


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Anticoagulants (blood thinning medicines) might be prescribed for you if you are diagnosed with atrial fibrilation (AF, irregular heart rhythm) or venous thromboembolism (VTE, a blood clot).

Why you need an anticoagulant

Anticoagulants stop the blood from clotting as quickly as it usually does.

If you have AF you are at a bigger risk of having blood clots in the brain, causing stroke. Taking an anticoagulant will reduce this risk.

If you have been diagnosed with a blood clot in a blood vessel in your lungs (pulmonary embolism, PE) or in the deep vein in your leg (deep vein thrombosis, DVT), you will need an anticoagulant to stop the clot getting larger, or new clots from forming.

Why have you been prescribed a direct oral anticoagulant (DOAC)?

DOACs, such as apixaban, edoxaban rivaroxaban and dabigatran, are suitable alternatives to warfarin for treating AF, DVT or PE. Unlike warfarin, they are used at a fixed dose, and they do not need close monitoring of blood levels.

How long will you need to take the DOAC for?

This will depend on the condition you are being treated for. If you have AF, anticoagulation with a DOAC will usually continue long-term.

If this is your first DVT or PE, you will usually take a DOAC for 3-6 months.

For recurrent blood clots, you might need to have DOAC treatment long-term. Your doctor will discuss this with you and confirm how long you need to continue your treatment for.

How do you take the medicine?

This will depend on the particular DOAC you have been prescribed. Each medicine comes in various strengths and doses. Please follow the dosage instructions given by your doctor, nurse or pharmacist. Your medication box will be labelled with the correct dosage for you. You should take your medicine at the same time every day, with or after food if advised.

Always read the leaflet that comes with your medicine and speak to your doctor or pharmacist if you have any questions or concerns.

What if you miss a dose?

If you miss a dose, take it as soon as you remember, but do not double up on the total daily dose. Please refer to the information leaflet supplied with your medicine for specific information, or call our Pharmacy services team (number below) for advice.

Are there any side effects?

Bleeding is the most common side effect of DOACs, as they increase the time it takes for your blood to clot.

Seek medical advice immediately if you:

  • suffer a head injury
  • have prolonged nosebleeds
  • have blood in your urine, stools (including black, tar-like stools) or vomit (sick)
  • have unexplained or severe bruising or bleeding.

If you have bleeding from a wound, apply pressure to the wound, and if the bleeding does not stop within 10 minutes, go to the Emergency Department (A&E).

Your other medicines

Your medicines will be reviewed when you are first prescribed a DOAC, and any necessary changes will be made.

Medicines including vitamin supplements, herbal remedies and over-the-counter medicines may interact with DOACs, so it is important that you:

  • check with a pharmacist before starting or stopping any medicines
  • avoid taking any other medicines that may increase your risk of bleeding (such as aspirin or ibuprofen), unless your doctor has specifically prescribed them for you.

If you need a painkiller, paracetamol and codeine are okay.

Remember to tell other healthcare professionals looking after you that you are taking a DOAC. This includes anyone who prescribes you medication, reviews your medication or carries out a procedure, for example a dentist.

Do you need to change your diet or alcohol intake?

You do not need to change what you eat when taking a DOAC. You should maintain a healthy and balanced diet. DOACs are not directly affected by alcohol. We recommend that you do not exceed the safe limits of alcohol (14 units each week), as this can increase your risk of bleeding.

Are DOACs safe in pregnancy?

It is not advisable to become pregnant if you have a DVT or PE, or while taking a DOAC. Tell your doctor straight away if you become pregnant, as you will need to change to a different medication.

Will you have a follow-up?

Soon after starting treatment, you may have an appointment at the hospital. This is to make sure that you are not experiencing any problems with your new medicine. Your GP will order routine tests at least once a year to check your kidneys, and for side effects.

Useful sources of information?

The MedTap app allows patient and carers to access short videos giving similar information to that discussed during consultations.

We recommend that you always carry an anticoagulant card with you in case of emergency. If you do not already have the card, please ask your pharmacist for one.

Always speak to a doctor before you stop taking your medicine.



Ref number: 5106/VER1

Date published: November 2020 | Review date: November 2023

© 2021 Guy’s and St Thomas’ NHS Foundation Trust

A list of sources is available on request


Where next?

Contact us

Our medicines helpline is open Monday to Friday, 9am to 5pm.

Phone: 020 7188 8748

Please call this helpline if you have a question about medicines prescribed by us.

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