Dabigatran (Pradaxa) for stroke prevention in 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 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 reduces the tendency of blood to clot 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 there is a standard dose. There is no need for a blood test to monitor how well it’s working or to adjust the dabigatran dose as there is with the standard anticoagulant treatment, warfarin.

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

Contents


What dabigatran is

The active ingredient of this medicine is dabigatran (pronounced da-BIG-a-tran). It is also known by the brand name Pradaxa.


What dabigatran is for

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

Dabigatran is used to help prevent a stroke in people with atrial fibrillation.

How does atrial fibrillation contribute to your risk of stroke?

Atrial fibrillation is a fast, 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. A separate Medicine Update is available for dabigatran following hip or knee surgery.


Who can take dabigatran

You can be prescribed dabigatran for stroke prevention 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 are:

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

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.


How to take dabigatran

It is important that you take dabigatran twice a day — one capsule in the morning and one at night.

Swallow the dabigatran capsule with water. It can be taken with or without food.

Do not chew the dabigatran capsule or break it open.

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 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
  • people with kidney problems
  • those with a high risk of bleeding.

How long will I need to take dabigatran for?

Dabigatran for the prevention of stroke is likely to be a long-term treatment.

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


What does dabigatran do?

Dabigatran helps to prevent a stroke in people with atrial fibrillation by reducing the chances of a blood clot forming.

Dabigatran is a type of medicine called an anticoagulant. Anticoagulants reduce the tendency of blood to clot. Anticoagulants are sometimes called blood thinners.

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.


Important side effects of dabigatran to consider

For a more complete list of possible side effects for Pradaxa (dabigatran), see the consumer medicine information (CMI) available on our Medicines Finder page.

Bleeding is a serious side effect

The most significant risk for dabigatran and other anticoagulant medicines is bleeding (see 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:

Ask your health professional about the possible side effects of this medicine 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 from anywhere in Australia (Monday–Friday, 9am–5pm AEST).

People with questions about their medicines or seeking general information about side effects can call the NPS Medicines Line on 1300 633 424 (Monday–Friday, 9am–5pm AEST).

  • 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

It is very common for dabigatran to 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 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. You should be aware of this and see your doctor straight away if you have any changes in your health or unusual symptoms after starting dabigatran.

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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 taking any other medicine

Dabigatran interacts with some other 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 those from a supermarket or health food store.

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

  • clopidogrel (Iscover, Plavix) — which is also used to thin the blood
  • itraconazole (Sporanox) and ketoconazole tablets (Nizoral) for fungal infections
  • aspirin
  • ibuprofen (Advil, Brufen, Nurofen), diclofenac (Fenac, Voltaren), naproxen (Naprogesic, Naproleve) and celecoxib (Celebrex) for pain and inflammation
  • St. John’s wort.

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

Let your health professional know that you take dabigatran

Tell your doctor, pharmacist and dentist 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.


Other medicines for preventing stroke caused by atrial fibrillation

Warfarin has been used to prevent stroke for over 50 years. 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 blood test (called an INR 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 results.

Your INR is affected by many other medicines as well as certain foods. If you start taking warfarin, you need to be careful not to make big changes to your diet.

Rivaroxaban (Xarelto) is another newer anticoagulant medicine that can be used for preventing stroke caused by atrial fibrillation. As it is a new medicine, long-term evidence about the risks and benefits is not available. Read more about rivaroxaban for stroke prevention.

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

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

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

Warfarin’s effect can sometimes vary, so it’s important to have regular blood tests to make sure that it’s working well. Studies have shown that dabigatran’s effect is more predictable, so regular blood tests aren’t needed.

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.

But there are people who should probably stay on warfarin

In clinical trials, people who took their warfarin regularly, and had good blood test (INR) results, appeared to be less likely to benefit from switching to dabigatran.

So bear this in mind if you are doing well on warfarin therapy.

Some may find dabigatran more convenient

People taking dabigatran do not need regular blood tests, whereas people taking warfarin do.

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.

Fewer medicines interact with dabigatran than with warfarin. And, unlike warfarin, there are no dietary restrictions 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.

Doctors are familiar with using warfarin

Warfarin has been used for many years so its benefits and side effects are well known. Dabigatran is a very new medicine, and less is known about its long-term safety.


Dabigatran availability

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. For more information see pbs.gov.au.

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 currently covered by the PBS when it is prescribed for short-term use to prevent blood clots forming after hip or knee replacement surgery.


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.

Keep to a healthy diet

Fresh rather than processed foods are much better for you. A healthy diet has lots of different vegetables, fruit and whole grains and limits the amount of sugary, salty and fatty foods.

Limit alcohol consumption

People who drink heavily are three times more likely to have a stroke. Limit your alcohol intake to two 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 recognize 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.

The Stroke Foundation has more information about the risk factors for stroke and how it can be prevented.

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Where to find more information

You can find more information in the consumer medicine information (CMI). This will tell you:

  • who should not use the medicine
  • which other medicines should be avoided
  • how to take the medicine
  • most of the possible side effects
  • the ingredients.

You can get the CMI leaflet for Pradaxa from:

  • your doctor or pharmacist
  • our Medicines Finder page
  • Boehringer Ingelheim, the makers of Pradaxa (dabigatran), on 1800 226 315.

Information over the phone

NPS works with healthdirect Australia to provide the Medicines Line phone service for consumers.

To get more information about any medicine call 1300 MEDICINE (1300 633 424). This service is available from anywhere in Australia, Monday to Friday, 9am to 5pm AEST excluding NSW public holidays.

To report a side effect

Call the NPS Adverse Medicine Events (AME) Line on 1300 134 237, Monday to Friday, 9am to 5pm AEST excluding public holidays.

The AME Line is a service where you can report possible side effects of your medicine and contribute to national medicine safety efforts. Information on medicine-related side effects is passed on to the Therapeutic Goods Administration (TGA) for assessment, but your personal details will remain confidential and your privacy maintained.

Acknowledgment

NPS acknowledges the contribution of the Heart Foundation and the Stroke Foundation in the production of this article.

Logo of the National Heart FoundationLogo of the National Stroke Foundation

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