Dabigatran is a type of medicine known as an anticoagulant, or blood thinner.

It makes your blood flow through your veins more easily. This means your blood will be less likely to make a dangerous blood clot.

It's used to treat people who have had a health problem caused by a blood clot, such as:

• a stroke
• a heart attack
• a blood clot in the leg (deep vein thrombosis, or DVT)
• a blood clot in the lungs (pulmonary embolism)

It's also used to prevent blood clots if you're at high risk of having them in the future.

People who are at high risk include those who have:

• an abnormal heartbeat (atrial fibrillation)
• recently had surgery to replace a hip or knee joint

Dabigatran is only available on prescription. It comes as capsules.

• It's usual to take dabigatran twice a day.
• You can take dabigatran with or without food.
• The most common side effect of dabigatran is bleeding more easily than normal, such as having nosebleeds, bleeding gums and bruising. It tends to happen in the first few weeks of treatment or if you're unwell.
• Always carry your anticoagulant alert card with you. Show it to your doctor or dentist before you have surgery or dental treatment. It's important they know you're taking dabigatran, as it may put you at risk of bleeding.
• Dabigatran is also called by the brand name Pradaxa.

Dabigatran can be taken by adults aged 18 and over.

Dabigatran is not suitable for some people. Tell your doctor if you:

• have had an allergic reaction to dabigatran or any other medicines in the past
• are trying to get pregnant or you're already pregnant - dabigatran can be harmful to your baby
• have liver problems
• are taking any other medicines that affect blood clotting, such as warfarin
• have any injuries that are currently bleeding a lot (such as a wound)
• have a stomach ulcer
• have had a recent spinal injury or surgery
• have ever had surgery to replace a heart valve
• are taking the herbal remedy St John's wort (often taken for depression)
• have antiphospholipid syndrome, a condition that affects the immune system and makes you more likely to get blood clots

It's very important to take dabigatran as your doctor advises.

It's usual to take it twice a day. You can take it with or without food, but try to take it at the same time every day.

If you have trouble swallowing pills, speak to your doctor or pharmacist.

Avoid opening up dabigatran capsules as this increases the risk of side effects.

How much to take

Your dose of dabigatran depends on why you're taking it.

• For a heart problem called atrial fibrillation or a blood clot (DVT or pulmonary embolism) - the usual dose is 150mg twice a day.
• For a hip or knee joint replacement - the usual dose is 110mg twice a day.

Your doctor may give you a lower dose if you're at increased risk of bleeding.

This includes if you:

• are aged 75 years or older
• take verapamil (a medicine for high blood pressure)
• have problems with your kidneys, stomach or throat

If you're unsure what dose you need to take, check with your pharmacist or doctor.

What if I forget to take it?

What you need to do depends on why you're taking dabigatran.

• For atrial fibrillation or a blood clot - take the forgotten dose as soon as you remember. If it's due in less than 6 hours, skip the forgotten dose.
• For a hip or knee joint replacement - skip the forgotten dose completely and then take your next dose when it's due.

Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.

If you often forget doses, it may help to set an alarm to remind you.

You could ask your pharmacist for advice on other ways to remember your medicines.

What if I take too much?

Ask your pharmacist or doctor for advice straight away, as taking too much dabigatran puts you at risk of bleeding.

How long will I take it for?

How long you need to take dabigatran for will depend on why you're taking it.

If you're taking it for:

• a knee joint replacement - you'll probably take dabigatran for 10 days
• a hip joint replacement - it's usual to take dabigatran for 4 to 5 weeks
• a blood clot - depending on what caused the blood clot, you'll normally take dabigatran for at least 3 months
• atrial fibrillation - you might need to take dabigatran long term or even for the rest of your life

Anticoagulant alert card

Your doctor or pharmacist will give you an anticoagulant alert card.

Carry this with you all the time. It tells healthcare professionals that you're taking an anticoagulant. This can be useful for them to know in case of a medical emergency.

If you need any medical or dental treatment, show your anticoagulant alert card to the nurse, doctor or dentist.

This includes before you have vaccinations and routine sessions with the dental hygienist.

Your doctor may advise you to stop taking dabigatran or reduce your dose for a short time.

Switching from warfarin to dabigatran

If you need to switch from warfarin to dabigatran, your doctor will advise you when to stop taking warfarin.

This will probably be a few days before you start dabigatran.

Your doctor or anticoagulant clinic will do a blood test called the international normalised ratio (INR) to check how quickly your blood's clotting.

This is to help decide exactly when you should start taking dabigatran.

Switching from dabigatran to warfarin

If you need to switch from dabigatran to warfarin, you may need to take both medicines together for a few days.

Your doctor or anticoagulant clinic will do a blood test called the international normalised ratio (INR) to check how quickly your blood's clotting.

This is to help decide exactly when you should stop taking dabigatran.

While dabigatran has enormous benefits, the downside is that it can make you bleed more than normal.

This is because while you're taking dabigatran, your blood will not clot as easily.

Less serious bleeding

It's usual to bleed more easily than normal while you're taking dabigatran.

The kind of bleeding you might have includes:

• periods that are heavier and last longer than normal
• bleeding for a little longer than usual if you cut yourself
• occasional nosebleeds (that last for less than 10 minutes)
• bleeding from your gums when you brush your teeth
• bruises that come up more easily and take longer to fade than usual

This type of bleeding is not dangerous and should stop by itself.

If it happens, keep taking dabigatran, but tell your doctor if the bleeding bothers you or does not stop.

Things you can do to help yourself

• Cuts - press on the cut for 10 minutes with a clean cloth.
• Nosebleeds - find out how to stop a nosebleed or watch this video on stopping nosebleeds.
• Bleeding gums - if your gums are bleeding, try using a soft toothbrush and waxed dental floss to clean your teeth.
• Bruises - these are harmless, but can be unsightly. It might help to make them fade more quickly if you put an ice pack wrapped in a towel over the bruise for 10 minutes at a time several times a day.

What you can do to prevent bleeding

While you're taking dabigatran, be careful when you do activities that might cause an injury or a cut or bruising.

It can help to:

• avoid playing contact sports or other activities than can cause an injury, such as football, rugby, hockey and horse riding
• wear gloves when you use sharp objects like scissors, knives and gardening tools
• stop wet shaving or removing hair with wax - use an electric razor or hair-removing cream instead
• take dentures (false teeth) or retainers out for a few hours a day, if you wear them, to give your gums a rest - do not wear dentures or retainers that do not fit properly
• tell your doctor, dentist or nurse that you take dabigatran before you have any medical or dental procedures or surgery - this includes vaccinations and routine appointments with the dental hygienist

Serious bleeding

Occasionally, you can have serious bleeding from taking dabigatran.

This can be dangerous and needs urgent medical attention.

Like all medicines, dabigatran can cause side effects, although not everyone gets them.

Very rarely, dabigatran can lead to bleeding in the brain.

This can cause a very severe headache, fits (seizures), changes to your eyesight, numbness or tingling in your arms or legs, and make you feel very tired, weak or sick.

If you suddenly get any of these symptoms, contact your doctor immediately. This is an emergency.

Common side effects

These common side effects happen in more than 1 in 100 people.

They're usually mild and do not last long, but talk to your doctor or pharmacist if these side effects bother you or do not go away:

• tiredness and lack of energy, shortness of breath, noticeable heartbeats (heart palpitations) and pale skin - these can be signs of anaemia
• feeling dizzy or lightheaded
• feeling or being sick (nausea or vomiting)
• stomach pain or indigestion

Serious allergic reaction

In rare cases, dabigatran can cause a serious allergic reaction (anaphylaxis).

These are not all the side effects of dabigatran. For a full list, see the leaflet inside your medicines packet.

What to do about:

• signs of anaemia - speak to your doctor, who may arrange a blood test.
• feeling dizzy or lightheaded - if dabigatran makes you feel dizzy when you stand up, try getting up very slowly or stay sitting down until you feel better. If you begin to feel dizzy, lie down so you do not faint, then sit until you feel better. If the dizziness does not go away or keeps happening, speak to your doctor. They may arrange a blood test to see if you have anaemia.
• feeling or being sick (nausea or vomiting) - it may help to avoid rich or spicy food while you're taking dabigatran. If you're being sick, drink plenty of water by having small and frequent sips to prevent dehydration.
• stomach pain or indigestion - try to rest and relax. Putting a heat pad or covered hot water bottle on your stomach may also help. If you're in a lot of pain, speak to your pharmacist or doctor. If you need something to ease discomfort from indigestion, try taking an antacid. But do not put off seeing a pharmacist or doctor.

Dabigatran is not normally recommended during pregnancy or while breastfeeding.

Some medicines and supplements can interfere with dabigatran. This can lead to serious side effects.

If you're taking dabigatran, tell your doctor before starting to take these medicines:

• any other anticoagulant, such as warfarin or enoxaparin
• any other drugs that affect blood clotting, such as clopidogrel, ticagrelor or prasugrel
• drugs to treat heart problems, such as verapamil, amiodarone or dronedarone
• drugs to treat fungal or bacterial infections, such as fluconazole, ketoconazole or clarithromycin
• certain drugs used to treat depression, such as fluoxetine, sertraline or citalopram
• drugs to treat HIV, such as ritonavir
• drugs to treat epilepsy, such as carbamazepine or phenytoin
• non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or aspirin

Taking dabigatran with everyday painkillers

You can take paracetamol while you're taking dabigatran.

Do not take aspirin or ibuprofen while you're taking dabigatran unless a doctor has said it's OK to. They increase the chance of bleeding.

Mixing dabigatran with herbal remedies and supplements

Do not take St John's wort, the herbal remedy for depression, while you're taking dabigatran.

It can increase your risk of side effects.