If you have or are at risk of having blood clots, your doctor might suggest Pradaxa as a treatment option. It’s a prescription blood thinner used to:

Pradaxa may be used short or long term, depending on the condition it’s prescribed to treat. Your doctor will provide more information on how long you’ll take this drug.

The active ingredient in Pradaxa is dabigatran. (An active ingredient is what makes a drug work.)

Pradaxa comes as a capsule you swallow. It’s also available as pellets that you can mix with soft foods (such as applesauce) or apple juice and swallow immediately.

For more information about Pradaxa, including details about its uses, see this in-depth article on the drug.

Like other drugs, Pradaxa can cause mild to serious side effects (also known as adverse effects). Keep reading to learn more.

Some people may experience mild to serious side effects during their Pradaxa treatment. Examples of the drug’s commonly reported side effects include:

* To learn more about this side effect, see the “Side effects explained” section below.

These are just a few of the side effects Pradaxa can cause. They won’t happen to everyone who takes this drug. Additional mild and serious side effects that are possible with Pradaxa are listed below.

Like most drugs, taking Pradaxa may cause mild side effects. Examples that have been reported with Pradaxa include:

* To learn more about this side effect, see the “Side effects explained” section below.

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bother you, talk with your doctor or pharmacist. And do not stop taking Pradaxa unless your doctor recommends it.

Pradaxa may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Pradaxa, visit MedWatch.

While rare, serious side effects are possible from Pradaxa treatment. Serious side effects that have been reported with this drug include:

If you develop serious side effects while taking Pradaxa, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* Pradaxa has a boxed warning for this side effect. This is the most serious warning from the Food and Drug Administration (FDA). To learn more, see the “Side effects explained” section below.
† To learn more about this side effect, see the “Side effects explained” section below.

Get answers to some frequently asked questions about Pradaxa’s side effects.

Do older adults have a higher risk of side effects from Pradaxa?

Yes, adults ages 65 years and older have an increased risk of certain side effects from Pradaxa. Specifically, older adults who took this drug in studies had higher rates of bleeding, including serious bleeds.

To learn more about Pradaxa and serious bleeding, see the “Side effects explained” section below. Talk with your doctor or pharmacist to learn more about the risks and benefits of taking this drug as an older adult.

Do Pradaxa’s side effects vary depending on the strength I take (such as 110 mg or 150 mg)?

No. In the drug’s studies, there were no differences in side effects based on the strength of the Pradaxa capsules that were taken.

Is hair loss a side effect of Pradaxa?

Hair loss wasn’t reported by people taking Pradaxa in studies. It’s been reported in rare cases by people who have used Pradaxa since the drug came on the market. But it’s not known for sure whether the hair loss was caused by Pradaxa or some other factor.

If you’re concerned about hair loss and your medications, talk with your pharmacist or doctor.

Does Pradaxa cause weight gain?

No, weight gain wasn’t a side effect reported among people taking Pradaxa in studies.

This drug is prescribed to treat or prevent certain blood clots. If you’re taking Pradaxa to prevent blood clots after surgery, such as a hip replacement, your doctor will likely want you to avoid exercise and moving around for some time. You may gain weight during this time due to decreased physical activity.

Talk with your doctor if you have unexpected weight gain or other weight-related issues while taking Pradaxa.

Learn more about some of the side effects Pradaxa may cause.

Increased risk of blood clots when stopping Pradaxa

Pradaxa has boxed warnings regarding the increased risk of blood clots when you stop taking the drug. Boxed warnings are the most serious warnings from the Food and Drug Administration (FDA). They alert doctors and patients about drug effects that may be dangerous.

Pradaxa is a blood thinner. Your risk of blood clots increases when you stop taking any blood thinner, including Pradaxa. In certain situations, such as before a surgery, your doctor may have you temporarily stop treatment with this drug. They’ll tell you exactly when you should stop taking Pradaxa and when to start taking it again after your surgery.

What might help

Due to the risk of blood clots, it’s important that you do not stop taking Pradaxa unless your doctor specifically recommends it.

If you’re interested in stopping Pradaxa, talk with your doctor first. If they agree you’ll stop taking it, they can talk with you about other blood thinners that may be used for your condition.

Risk of blood clots in or around your spine

Pradaxa has boxed warnings for increased risk of blood clots in or around your spine. Boxed warnings are the most serious warnings from the FDA.

Blood thinners such as Pradaxa increase your risk of blood clots, called hematomas, in or around your spine. These can occur if you receive an injection, such as an epidural, into or around your spine. These blood clots can be dangerous and even cause paralysis in extreme cases.

Your risk of spinal hematoma is higher if:

What might help

Your doctor will carefully monitor you if you need to have a spinal procedure while you’re taking Pradaxa. You should let them know right away if you have symptoms such as back pain, numbness or tingling, or muscle weakness.

Serious bleeding

Treatment with Pradaxa can result in serious bleeding, including internal bleeding.

Pradaxa can cause bleeding because of how it works. It’s a blood thinner used to treat or prevent blood clots. It works by making your blood less likely to clot. This can make your body more likely to bleed. It can mean that minor cuts turn into bleeds that go on for a long time. But it can also cause serious bleeds that may be life threatening in extreme cases.

Symptoms of a serious bleed can include:

Certain people have a higher risk of serious bleeding if they take Pradaxa. This includes people who:

  • are ages 65 years or older
  • have kidney problems
  • have a stomach ulcer or existing stomach bleed
  • take other drugs that increase the risk of bleeding

What might help

Immediately contact your doctor if you think you have symptoms of a serious bleed. But if your symptoms feel life threatening, go to the closest emergency room or dial 911 right away.

Indigestion

You may experience indigestion (upset stomach) as a side effect of Pradaxa. This was among the most common side effects reported by people taking the drug in studies.

Symptoms of indigestion can include:

What might help

Contact your doctor if you think you’re having indigestion from Pradaxa. They’ll likely want to make sure your symptoms aren’t due to a bleed (see “Serious bleeding” just above).

If they rule out other causes, they can suggest a treatment for your symptoms, such as:

But if your symptoms still persist, your doctor may suggest switching you from Pradaxa to another blood thinner.

Allergic reaction

Like most drugs, Pradaxa can cause an allergic reaction in some people, although this isn’t common. Symptoms can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin, usually in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

  • an antihistamine you swallow, such as Benadryl (diphenhydramine)
  • a product you apply to your skin, such as hydrocortisone cream

If your doctor confirms you’ve had a mild allergic reaction to Pradaxa, they’ll decide whether you should continue using it.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Pradaxa, they may have you switch to a different treatment.

Keeping track of side effects

During your Pradaxa treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking a new drug or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how it affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Pradaxa affects you. They can then use this information to adjust your treatment plan if needed.

Pradaxa may not be right for you if you have certain medical conditions. (This is known as a drug-condition interaction.) Other factors may also affect whether this drug is a good treatment option for you.

Talk with your doctor about your health history before starting Pradaxa. Factors to consider include those described below.

Boxed warnings

Pradaxa has boxed warnings about the increased risk of blood clots when you stop taking it, and blood clots in or around your spine. Boxed warnings are the most serious warnings from the Food and Drug Administration (FDA). They alert doctors and patients about drug effects that may be dangerous.

To learn more, see the “Side effects explained” section above.

Other warnings

Active bleed or bleeding problem. Doctors usually won’t prescribe Pradaxa if you have an active bleed. This drug can make it harder to treat a bleed that’s already happening. You should let your doctor know if you have a bleeding problem such as hemophilia before starting Pradaxa. Existing bleeding problems can increase your risk of bleeding as a side effect from this drug. Your doctor can review the risks and benefits of different treatments for your condition.

Antiphospholipid syndrome. People with a rare condition called triple-positive antiphospholipid syndrome may have a higher risk of blood clots from Pradaxa. Due to this risk, doctors typically won’t prescribe Pradaxa if you have this condition. They can review other treatments that may be safer options for you.

Kidney problem. Be sure to let your doctor know if you have a kidney problem such as chronic kidney disease (CKD) before starting Pradaxa. Having a kidney problem such as CKD can cause the level of the drug to build up in your body. This can increase your risk of bleeding and other side effects Pradaxa may cause. If you have a kidney problem, your doctor may prescribe a lower dosage of this drug for you.

Mechanical heart valve. Doctors usually won’t prescribe Pradaxa if you have a mechanical heart valve. Studies found the drug increases the risk of blood clots in people with this kind of heart valve. In this situation, your doctor can review other treatments for your condition with you.

Stomach ulcer. It’s important to let your doctor know if you have a stomach ulcer before you start taking Pradaxa. This drug may cause your ulcer to bleed more. Your doctor can review the risks and benefits of different treatments for your condition if you have a bleeding problem.

Allergic reaction. If you’ve had an allergic reaction to Pradaxa or any of its ingredients, your doctor will likely not prescribe it for you. Ask them about other medications that might be better options.

Alcohol and Pradaxa

Drinking alcohol while taking Pradaxa can increase your risk of bleeding. Due to this risk, if you drink alcohol, it’s important to talk with your doctor about your alcohol consumption before starting this drug. They can discuss with you how much alcohol, if any, is safe for you to drink during treatment.

Pregnancy and breastfeeding while taking Pradaxa

It’s not known whether it’s safe to take Pradaxa while pregnant. If you’re pregnant or planning to become pregnant, talk with your doctor about the best treatment plan for your condition.

Pradaxa’s drugmaker recommends that you do not breastfeed a child while you’re taking this drug. Talk with your doctor about your treatment options and the healthiest way to feed your child.

Mild and serious side effects aren’t common with Pradaxa but they can occur. To learn more about side effects reported by people taking the drug in studies, talk with your doctor. Some examples of questions to ask them include:

  • How do Pradaxa’s side effects compare with similar drugs for treating my condition?
  • Is it safe to have surgery while I’m taking Pradaxa?
  • Will my risk of side effects from Pradaxa decrease over time?

Call your doctor right away if you experience side effects while taking Pradaxa, especially symptoms of bleeding or digestive side effects.

To learn more about Pradaxa, see these articles:

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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.