Dabigatran (Pradaxa) for preventing stroke in people with atrial fibrillation

Published in Medicine Update

Date published: About this date

Health and medicines information in this article may have changed since the date published. This information does not replace advice from a health professional.

This Medicine Update is for people with atrial fibrillation who are taking, or thinking about taking, dabigatran.

Summary

Dabigatran is a medicine that is used to help prevent a stroke in people with a condition called atrial fibrillation.

People with atrial fibrillation are more likely to develop a blood clot in their heart. The blood clot can then move to the brain and cause a stroke.

Dabigatran can help to lower the risk of forming harmful blood clots and, in turn, the risk of having a stroke. It belongs to a group of medicines called anticoagulants.

Dabigatran is an alternative to warfarin for preventing strokes. As with other anticoagulant medicines, there is a risk of serious bleeding. Some serious bleeds may be life-threatening.

Dabigatran is a capsule that you take twice a day. For most people taking dabigatran to prevent stroke, there is a standard dose.

Unlike the INR blood tests for warfarin, there is currently no blood test to monitor how well dabigatran is working or to adjust your dose.

Because dabigatran is a fairly new medicine, the full range of potential side effects is not yet known.

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What is dabigatran?

The active ingredient of this medicine is dabigatran (pronounced da-BIG-a-tran).

It is also known by the brand name Pradaxa.

The active ingredient is the chemical in the medicine that makes themedicine work.

Many medicines are known by their brand names as well as by the name of the active ingredient. Some medicines are available under several different brand names.

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What is dabigatran for?

People with atrial fibrillation are at greater risk of having a stroke than other people.

Dabigatran can be prescribed through the Pharmaceutical Benefits Scheme (PBS) to help prevent a stroke in people with atrial fibrillation.

How does atrial fibrillation contribute to your risk of stroke?

Atrial fibrillation is an irregular heartbeat that can lead to a blood clot forming in the heart. If the blood clot moves from the heart to the brain, it can block small blood vessels and cause a stroke.

Dabigatran can also be used after hip or knee surgery. Read more about taking dabigatran after hip or knee replacement surgery.

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Who can take dabigatran?

You can be prescribed dabigatran for preventing stroke if:

  • you have an irregular heartbeat called atrial fibrillation, and
  • your atrial fibrillation is not due to heart valve disease or heart valve replacement surgery, and
  • your doctor finds that you have one or more of the other risk factors for stroke.

Other factors that can increase your risk of stroke include:

  • heart failure
  • high blood pressure
  • being over 75 years of age diabetes
  • a previous stroke or blood clot.

But dabigatran may not be suitable for you if you have:

  • a medical condition that increases your likelihood of bleeding
  • reduced kidney function
  • liver problems.

Your doctor will need to take these into consideration before prescribing dabigatran.

Talk with your health professional about all the treatment options for preventing stroke.

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How to take dabigatran

It is important that you take dabigatran twice every day — one capsule in the morning and one at night, at the same times each day.

Swallow the dabigatran capsule whole with a full glass of water. It can be taken with or without food.

Do not chew the dabigatran capsule or break it open, as this may increase the effect of the medicine.

Talk to your doctor or pharmacist if you forget to take your dabigatran capsule. Do not take a double dose as this will increase your chance of bleeding.

What is the dose?

Unlike warfarin, there is a standard dose for most people.

The standard strength capsule contains 150 milligrams (mg) of dabigatran.

A lower-strength 110 mg capsule may be prescribed for people:

  • aged over 75 years who have a higher chance of side effects
  • with kidney problems
  • with a high risk of bleeding.

What do I do if I forget a dose?

It’s important to take your dabigatran every day, at the same times — once in the morning and once in the evening.

However, if you forget to take it, only take the missed dose if you remember within 6 hours of the time you usually take it.

Don’t take the missed dose if you remember more than 6 hours after the time you normally take it. Take your next dose the next morning or evening at the usual time.

Don’t take a double dose at any time. If you miss a dose, ask a doctor or pharmacist for advice.

How long will I need to take dabigatran for?

Dabigatran for preventing stroke is likely to be a long-term treatment.

You should not stop taking dabigatran unless your doctor advises you to.

How to store dabigatran

Exposing dabigatran capsules to the air may reduce how well the medicine works.

You should keep dabigatran capsules in their sealed blister segments or in the bottle with the lid properly closed, and only remove each capsule immediately before taking it. Any dabigatran capsules that are accidently exposed to air should not be used and should be discarded.

For the same reason, don’t remove dabigatran capsules from the foil blister pack or bottle for repackaging in tablet organisers or weekly medication packs (dose administration aids or dosette boxes).

Once a bottle of dabigatran has been opened, the contents must be used within 4 months and any remaining capsules should be discarded after this time.

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What does dabigatran do?

Dabigatran helps to lower the risk of forming harmful blood clots that could cause a stroke, or a blockage in a vein or the lungs.

Dabigatran is a type of medicine called an anticoagulant. Anticoagulants are sometimes incorrectly referred to as 'blood thinners' — although this is not how they actually

work. Anticoagulants (including dabigatran) work by increasing the time it takes for the blood to clot.

It’s important to note that dabigatran doesn’t treat the fast, irregular heartbeat of atrial fibrillation. Your doctor will prescribe other medicines or treatments for this.

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Important side effects to consider

Bleeding is a serious side effect

The most significant side effect of dabigatran and other anticoagulant medicines is bleeding. Serious bleeding is a risk with dabigatran and warfarin). Some serious bleeds may be life-threatening.

You should seek urgent medical attention if you have:

  • bleeding that won’t stop
  • a nosebleed lasting for more than 10 minutes
  • unexplained or severe bruising.

Internal bleeding is harder to detect. Contact your doctor immediately or go to the emergency department at your nearest hospital if you experience any of the following:

  • blood in your urine
  • red or black faeces
  • feeling light-headed or dizzy
  • headaches that are unusual for you.

If you experience any serious injury, you are at greater risk of internal bleeding. You must get immediate medical attention, particularly if you hit your head.

Indigestion is very common

Dabigatran can cause indigestion. Speak to your health professional about ways to manage indigestion if it affects you. For example, taking dabigatran with food may help.

Dabigatran is a relatively new medicine, so not all side effects are known

Dabigatran has been tested in clinical trials, but the full range of potential side effects is not yet known. See your doctor straight away if you have any changes in your health or unusual symptoms after starting dabigatran.

For a list of all possible side effects, see the consumer medicine information (CMI) for Pradaxa (dabigatran).

Ask your health professional about the possible side effects of dabigatran before you take it. Always tell them about any changes to your condition if you're taking a new medicine.

To report possible side effects call the NPS Adverse Medicine Events (AME) Line on 1300 134 237.

People with questions about their medicines or seeking general information about side effects can call NPS Medicines Line on 1300 633 424.

Both these services are available Monday to Friday, 9am to 5pm AEST.

A clinical trial is a research study conducted with patients, which compares one treatment with one or more other treatments, to assess its effectiveness and safety.

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What else you should know about dabigatran

Do not stop taking dabigatran without talking to your doctor. This puts you at greater risk of developing a blood clot and having a stroke.

Check before starting or stopping any other medicine

Dabigatran interacts with some medicines, but it doesn’t appear to interact with foods.

If you are taking dabigatran, you should talk to your doctor or pharmacist before taking any other medicine, including over-the-counter and complementary medicines as well as those bought from a supermarket, health food store or the internet.

Medicines that can interact with dabigatran and increase your risk of bleeding include:

  • clopidogrel (e.g. Iscover, Plavix) — which also affects blood clotting
  • itraconazole (Sporanox) and ketoconazole tablets (e.g. Nizoral) for fungal infections
  • some antidepressants (e.g. Cipramil, Citalopram, Efexor-XR, Cymbalta)
  • St. John’s wort
  • aspirin (e.g. Dispirin, Aspro, Solprin)
  • ibuprofen (e.g. Advil, Brufen, Nurofen), diclofenac (e.g. Fenac, Voltaren), naproxen (e.g. Naprogesic, Naproleve) and celecoxib (Celebrex) for pain and inflammation.

Paracetamol (Panadol, Panamax) does not interact with dabigatran and can be used to treat headache, pain or fever.

An interaction is when another medicine, food or drink (including alcohol) changes how strongly a medicine works, or changes its side effects in some way. The interaction may be with a food or food supplement, another prescription or over-the-counter medicine, or a natural or herbal remedy.

Let your health professional know that you take dabigatran

Tell your doctor, pharmacist, dentist and other health professionals that you’re taking dabigatran. They may need to talk to the doctor who prescribed dabigatran for you, particularly if you need to have surgery.Back to Contents


Other medicines for preventing stroke caused by atrial fibrillation

Warfarin has been used for over 50 years to prevent stroke. It is very effective, but it may take some time to get the dose right.

If you take warfarin, you need to have a regular INR (International Normalised Ratio) blood test to monitor its effect.

If your INR is too high, your blood is taking too long to clot and your risk of bleeding increases. If it is too low, your blood is clotting too quickly. Your warfarin dose may need to be adjusted based on your INR results.

Your INR can be affected by many other medicines as well as certain foods. If you have started taking warfarin, you need to be careful not to make big changes to your diet or to the medicines you are taking and, if a big change does occur, report this to your doctor promptly.

Rivaroxaban (Xarelto) is another newer anticoagulant medicine that can be used for preventing stroke caused by atrial fibrillation. Long-term evidence about the risks and benefits is not yet available.

Apixaban (Eliquis) is another newer anticoagulant medicine available in Australia. It belongs to the same class of drugs as rivaroxaban and is also used to prevent blood clots forming in people who undergo knee and hip replacement surgery. Long-term evidence about the risks and benefits is not yet available.

In clinical trials, rivaroxaban and apixaban prevented a similar number of strokes overall compared with warfarin.

Aspirin is less effective than warfarin or other anticoagulants such as dabigatran. It may be an option for some people with atrial fibrillation, but usually only for those at a low risk of stroke or who can’t take warfarin.

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How to decide between dabigatran and warfarin

Your doctor will help you weigh-up the potential benefits and risks of dabigatran and warfarin.

Remember that benefits and side effects differ between medicines and from person to person.

Warfarin’s effect can sometimes vary, so it’s important to have regular (INR) blood tests to make sure that it’s working well. There is currently no equivalent test available that measures the effect of dabigatran.

Dabigatran is effective for preventing strokes

In clinical trials, dabigatran prevented more strokes overall than warfarin. However, because warfarin is very effective, the improvement with dabigatran was small.

There are people who should keep taking warfarin

People who took their warfarin regularly in clinical trials — and had stable blood test (INR) results — were less likely to benefit from switching to dabigatran. So bear this in mind if you are doing well on warfarin treatment.

Some people may find dabigatran more convenient

People taking dabigatran do not have regular blood tests, whereas people taking warfarin do. This is because there is no equivalent of the INR blood test for dabigatran.

Some people find these tests bothersome. But others like the opportunity to discuss their progress with their health professional and check that the warfarin is working. People taking dabigatran will still need to visit their doctor as often as recommended.

Fewer medicines are known to interact with dabigatran compared with warfarin. However, as dabigatran is a newer medicine, its full range of interactions with other medicines may not yet be known. Unlike warfarin, there are no specific dietary considerations with dabigatran.

Serious bleeding is a risk with dabigatran and warfarin

Serious bleeding needs urgent hospital treatment because it may be life-threatening.

In a clinical trial comparing dabigatran with warfarin, the number of people who had a serious bleed each year was similar with both medicines — about 3 or 4 out of every 100 people (3% to 4%).

But remember — you will only be prescribed dabigatran or warfarin if the benefit is thought to outweigh the risk of serious bleeding.

Unlike warfarin, there is currently no specific antidote for dabigatran if serious bleeding occurs. This means that, if you do have a bleed when you are taking dabigatran, it will be more difficult to stop than if you were taking warfarin.

Doctors are familiar with using warfarin

Warfarin has been used for many decades so its benefits and side effects are well known. Dabigatran is a relatively new medicine, and less is known about its long-term safety.
Warfarin’s effect can sometimes vary, so it’s important to have regular INR blood tests to make sure that it’s working well. There is no blood test for the effect of dabigatran.

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Dabigatran availability

Dabigatran is used in two different ways:

  • to prevent stroke in people with atrial fibrillation, and
  • to prevent blood clots forming in the leg veins after hip or knee replacement surgery.

Dabigatran is PBS subsidised for preventing stroke in people with atrial fibrillation who also have one or more risk factors for stroke including people who:

  • have had a previous stroke, transient ischemic attack (TIA) or VTE
  • are 75 years or older
  • have high blood pressure
  • have diabetes
  • have heart failure.

Dabigatran is currently subsidised by the Pharmaceutical Benefits Scheme (PBS) when it is prescribed for short-term use to prevent blood clots forming after hip or knee replacement surgery.

Most medicines prescribed by your doctor are covered by the Pharmaceutical Benefits Scheme (PBS). This means that the Australian Government pays part of the cost of your medicine. You will need to pay the full price if the medicine is not available on the PBS, or is not available on the PBS for your specific condition.

More information is available on the Pharmaceutical Benefits Scheme (PBS) from the Australian Government Department of Health.

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Other ways to prevent stroke

Some of the risk factors for stroke, like age, gender and medical conditions (such as atrial fibrillation), are things you can’t change. However, there are several lifestyle-related risk factors that you can control.

Know your personal risk factors

Your doctor can help you monitor and manage medical conditions that increase your risk of having a stroke. These include high blood pressure, diabetes and high blood cholesterol.

Be physically active and exercise regularly

Keeping fit is important for so many aspects of your health. You don’t need to take part in organised sport or exercise classes to do this. Just walking or generally being more active will be of benefit.

Remember that if you are taking dabigatran or warfarin you need to be careful to avoid activities that increase your risk of injury.

Eat a healthy diet

Fresh rather than processed foods are much better for you. Eat a healthy diet consisting of different vegetables, fruit and whole grains and limit the amount of sugar, salt and fat.

Limit alcohol consumption

People who drink heavily are three times more likely to have a stroke. Limit your alcohol intake to two standard drinks a day and have at least two alcohol-free days every week.

Stop smoking

Smoking is a major risk factor for stroke. If you smoke, get help to stop now. Talk to your doctor or call Quitline on 137 848.

Second-hand smoke from other people’s cigarettes is also harmful and you should try to avoid it.

Learn to recognise the warning signs of a stroke and how to take action

The FAST test is an easy way to remember and recognise the signs of stroke. FAST stands for Face, Arms, Speech and Time to act.

  • Face — Check their face. Has their mouth drooped?
  • Arms — Can they lift both arms?
  • Speech — Is their speech slurred? Do you understand them?
  • Time — Is critical.

If you see any of these signs, call 000 straight away.

The signs of stroke may occur alone or in combination and they can last a few seconds or up to 24 hours and then disappear.

More information

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Where to find more information about dabigatran

Read the consumer medicine information (CMI)

The CMI for Pradaxa (dabigatran) will tell you:

  • who should not use the medicine
  • how to take the medicine
  • most of the possible side effects
  • the ingredients.

You can get the CMI leaflet for Pradaxa (dabigatran) from:

  • your doctor or pharmacist
  • the NPS MedicineWise Medicine Finder
  • Boehringer Ingelheim, the makers of Pradaxa (dabigatran), on 1800 226 315.

Find out more about dabigatran.

Information over the phone

Call Medicines Line on 1300 MEDICINE (1300 633 424) from anywhere in Australia. This service is available Monday to Friday, 9am–5pm EST, with the exception of NSW public holidays.

To report a side effect with dabigatran

Call the Adverse Medicines Event (AME) Line on 1300 134 237 (Monday to Friday, 9am–5pm EST).

The AME Line lets you report and discuss side effects that might be related to your medicine. The side effects of your medicine — but not your personal details — are reported to the Australian medicines regulatory agency (the Therapeutic Goods Administration or TGA for short). The information helps to improve the safe use of medicines.

More about using medicines wisely

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