If you are prescribed anticoagulants, always follow the instructions of your GP or other healthcare professional. Taking too much of these medicines can result in severe bleeding, especially if you are bruised or injured.

If you are unsure of your instructions, check the patient information leaflet that should come with your medication or call your GP. You can also call NHS 111 for further advice.

Having surgery

If you are taking anticoagulants and you need to have surgery or any kind of invasive procedure, make sure that the healthcare professionals treating you are aware of your medication. This includes procedures used to diagnose other conditions, such as endoscopy, cystoscopy or colonoscopy.

Anticoagulants reduce the ability of your blood to clot, which could be dangerous if any kind of cut (incision) is made during a surgical procedure. It may be necessary to stop taking anticoagulants for a while before and after surgery. This will prevent excessive bleeding during surgery and help the healing process afterwards.

If you are having a dental procedure, such as having a tooth removed, inform your dentist that you take anticoagulants. You do not usually need to stop taking your medication, but you may need to have your international normalisation ratio (INR) tested before the procedure to make sure that it's at a safe level.

Only stop taking your medication on the advice of your GP or another healthcare professional.

Pregnancy

Warfarin is not suitable for pregnant women because it can cross the placenta (the organ that links the mother's blood supply to her unborn baby's) and affect the unborn baby. This can cause birth defects or excessive bleeding from the placenta or foetus.

Warfarin should be avoided in pregnancy if possible, and especially during the first trimester (up to week 13 of the pregnancy) and the third trimester (from week 27 until the birth of the baby).

Heparin may be taken during pregnancy to manage venous thromboembolism (when a blood clot forms in a blood vessel and breaks off, blocking the flow of blood) if the healthcare professional treating you thinks it's necessary.

If you are on anticoagulant medicines and find out you are pregnant or you plan to start trying for a baby, speak to your GP about stopping or changing your prescription.

Breastfeeding

You can usually take warfarin while you are breastfeeding. However, you should first discuss this with your GP or midwife.

Heparin is safe to take while you are breastfeeding.

If you are on anticoagulants and you are breastfeeding or are planning to breastfeed, speak to your GP or midwife to find out if you need to change your prescription.

Avoiding injury

Taking anticoagulant medicines can make you more prone to bleeding if you are injured. Try to avoid minor injuries and cuts and grazes by:

• taking care when brushing your teeth and shaving
• using protection when gardening, sewing or playing contact sports
• using insect repellent to avoid insect bites or stings