Pradaxa Side Effects
Pradaxa is an anticoagulant, or blood thinner, that is prescribed to prevent blood clots and reduce the risk of stroke in patients with non-valvular atrial fibrillation (abnormal heart rhythm), deep vein thrombosis (DVT), or pulmonary embolism (PE). Pradaxa was one of the first FDA approved alternative therapies to warfarin, a commonly prescribed anticoagulant, and gained popularity quickly because it requires less monitoring through regular blood tests and has fewer drug and food interactions than warfarin.
Dabigatran, the active ingredient in Pradaxa, is known as a direct thrombin inhibitor. Thrombin is an enzyme that is found in blood plasma and helps facilitate blood clotting. By directly inhibiting this enzyme, the coagulation, or clotting, process cannot fully activate.
However, this anticoagulation process is also a cause for severe side effects. Pradaxa has been shown to reduce incidences of stroke, but also carry a greater risk for gastrointestinal bleeding over warfarin.
Common Pradaxa Side Effects
Taking Pradaxa can cause some side effects. If you experience any of the side effects listed below, contact your doctor or seek medical help immediately:
Most Common Side Effects of Pradaxa
Allergic Reactions to Pradaxa
Some Pradaxa users may experience symptoms of an allergic reaction. Contact your doctor if you experience:
- Hives, rashes, and itching
- Chest pain or tightness
- Trouble breathing
- Dizziness or feeling faint
- Swelling of your face or tongue
Severe Side Effects of Pradaxa
In addition to the more common mild side effects and adverse reactions listed above, Pradaxa can cause a number of severe side effects. These can lead to severe pain and suffering, long-term health problems, and even death.
Pradaxa and Bleeding
When taking the blood thinner Pradaxa, patients may experience more severe symptoms, like coughing up or vomiting blood or blood-like material, bloody or black stools, and bruising and bleeding that takes longer to go away or stop. These symptoms may be a clue that other damaging bleeding episodes could occur within the body.
Pradaxa, like other anticoagulant therapies, runs an increased risk of bleeding in the brain, major gastrointestinal bleeding, myocardial infarction (heart attack), which all can lead to death. In a study performed by the FDA, Pradaxa was found to have an increased risk of major gastrointestinal bleeding over other anticoagulants, like warfarin.
Discontinuing Use of Pradaxa
Despite the potential side effects of Pradaxa, the FDA still considers the benefits of the drug to outweigh the potential adverse events for many patients. However, if a patient wants to discontinue the use of Pradaxa, they should do so with the supervision of their healthcare provider. Discontinuing the use of Pradaxa or other blood thinning medications can greatly increase the risk of stroke or other blood clotting complication.
Pradaxa’s Prescribing Information and Medication Guide provides information and warnings for patients about discontinuing the medication without the guidance of a healthcare professional and without understanding the increased risk for strokes. However, in April 2013, Boehringer Ingelheim announced that it was adding an FDA black box warning, the most serious warning the FDA uses on prescribing information, to alert patients to the risk of stroke when a patient discontinues the use of Pradaxa.
Pradaxa Black Box Warning
WARNING: (A) PREMATURE DISCONTINUATION OF PRADAXA INCREASES THE RISK OF THROMBOTIC EVENTS, and (B) SPINAL/EPIDURAL HEMATOMA
See full prescribing information for complete boxed warning
(A) PREMATURE DISCONTINUATION OF PRADAXA INCREASES THE RISK OF THROMBOTIC EVENTS: Premature discontinuation of any oral anticoagulant, including PRADAXA, increases the risk of thrombotic events. To reduce this risk, consider coverage with another anticoagulant if PRADAXA is discontinued for a reason other than pathological bleeding or completion of a course of therapy (2.4, 2.5, 2.6, 5.1).
(B) SPINAL/EPIDURAL HEMATOMA: Epidural or spinal hematomas may occur in patients treated with PRADAXA who are receiving neuraxial anesthesia or undergoing spinal puncture. These hematomas may result in long-term or permanent paralysis (5.3). Monitor patients frequently for signs and symptoms of neurological impairment and if observed, treat urgently. Consider the benefits and risks before neuraxial intervention in patients who are or who need to be anticoagulated (5.3).
Sometimes Pradaxa will need to be stopped before any medical or dental procedure or surgery. If you need to stop taking Pradaxa for another medical event, speak to the doctor who prescribed Pradaxa to you and ask when you should stop taking it leading up to your procedure and when you can start taking it again.
Pradaxa and Blood Clots
Anticoagulants like Pradaxa are prescribed to help patients reduce their incidence of blood clots. However, using Pradaxa can also increase the risk of blood clots in certain situations. For example, patients who receive an epidural or spinal tap may develop a blood clot in their spinal cord that can lead to paralysis.
Patients are more likely to develop a spinal blood clot if:
- an epidural catheter is placed in your spine used to give certain medicines
- you are currently taking NSAIDs or other blood thinning medicines
- you have a history of spinal issues and surgeries
- you have a history of repeated or difficult spinal punctures
If you receive a spinal anesthetic or spinal puncture while you are taking Pradaxa, your doctor should monitor you closely for signs and symptoms of a spinal blood clot. Additionally, tell your doctor immediately if you experience any of the symptoms below:
- Back pain
- Tingling and numbness
- Muscle weakness, especially in your legs and feet
Pradaxa and Heart Attacks
While gastrointestinal bleeding is the most frequent adverse event reported for Pradaxa use, other events including stroke, acute kidney failure, liver failure, and heart attacks have been reported too.
Two separate studies published concurrently showed an increased risk of heart attacks for Pradaxa users over user of other blood thinning agents like warfarin.
Seek medical help immediately if you are taking Pradaxa and experience the following severe symptoms of heart disease:
- Chest pain
- Shortness of breath
- Dizziness and loss of consciousness
Investigation of Pradaxa Side Effects
Pradaxa was approved by the FDA and released to the public in 2010 as an alternative option to warfarin. However, it became clear in the first year after numerous reports of severe bleeding events, that the approved and stated side effects of the medication needed further investigation from the FDA.
Timeline of Pradaxa Side Effect Studies
October 2010: The U.S. Food and Drug Administration (FDA) approves Pradaxa as an anticoagulant for prevention of blood clots and stroke in patients who experience non-valvular atrial fibrillation (abnormal heart rhythm).
February 2011: After reports of a chronic kidney patient who experienced severe gastrointestinal bleeding while using Pradaxa, the Institute for Safe Medication Practices (ISMP), a U.S. non-profit organization, releases a safety alert advising physicians to appropriately adjust prescriptions of Pradaxa in patients who have a history of kidney or renal problems.
December 2011: The FDA releases a statement stating they are conducting a safety review of post-marketing reports of serious bleeding events in patients using Pradaxa.
January 2012: The ISMP releases report of over 500 cases of fatal and other severe bleeding events linked to Pradaxa use in the elderly.
March 2012: The Journal of Neurosurgery publishes a report that discusses the case of an 83-year old patient using Pradaxa who died of a cerebral hemorrhage after a fall. The reports was published to highlight the risk of severe bleeding in Pradaxa patients and urge the development of an antidote.
May 2012: A presentation at the Thrombosis & Hemostasis Summit of North America in 2012 revealed results from a real-world study comparing Pradaxa and warfarin and claimed that warfarin was safer than Pradaxa. The results showed that complications arose more often when a patient discontinued Pradaxa compared to patients who discontinued warfarin. Additionally, complications caused by Pradaxa appeared very early in treatment, after less than four months on average.
June 2012: The ISMP QuarterWatch report states that Pradaxa was the leading drug responsible for fatalities than with any other drug in 2011. According to the report Pradaxa use lead to a total of 3,781 reports with 542 patient deaths. The other reports consisted of hemorrhaging, acute renal failure, and stroke.
September 2012: A study published in The Archives of Internal Medicine suggests that oral anticoagulants, like Pradaxa and Xarelto, may pose risks that outweigh any benefits when used in patients who experienced acute coronary syndrome (ACS) and are receiving antiplatelet therapy.
September 2012: A study published in The Circulation: Cardiovascular Quality and Outcomes journal suggests that Pradaxa did not increase the effects on the treatment of atrial fibrillation. The study suggests that Pradaxa’s off-label uses are on the rise.
September 2012: A report is published in The Journal of the American Medical Association (JAMA) highlighting the dangers of expedited FDA approval of medication without fully understanding the side effects and safety of the drug. The report used Pradaxa as one of the three medications used as examples.
October 2012: Boehringer Ingelheim halts part of the RE-ALIGN clinical trial, where patients were randomized to warfarin or Pradaxa after a mechanical valve surgery. The patients using Pradaxa in this trial had an increased risk for blood clots. The FDA released a safety alert soon after to healthcare providers and patients setting the standard that Pradaxa not be used in patients with mechanical prosthetic heart valves.
May 2014: The FDA completed a study in Medicare patients using either Pradaxa or warfarin to understand the risks for stroke, bleeding in the brain, gastrointestinal bleeding, heart attack and death. The study reported that Pradaxa has lower risks for stroke and death, but a higher risk of gastrointestinal bleeding compared to warfarin.
Pradaxa Antidote & Reversal Agent
When Pradaxa was first sold in the U.S., there was no antidote or reversal agent developed to reverse the blood thinning properties during a bleeding event. For the first five years of it’s use, Pradaxa quickly outpaced another warfarin in reported adverse events, causing thousands of patients to suffer sometimes fatal uncontrollable bleeding. This had led to thousands of patients and families to file lawsuits against its manufacturer, Boehringer Ingelheim, stating that patients weren’t properly warned about the severe side effects of the drug.
In October 2015, the FDA granted accelerated approval to an antidote called Praxbind (idarucizumab), which can reverse Pradaxa’s blood thinning effects in a patient experiencing uncontrollable bleeding. Currently, Pradaxa is the only blood thinning medication with an FDA approved antidote.
Because the Pradaxa antidote Praxbind received accelerated approval, many healthcare providers are wary of the safety of the antidote and advise patients to consider all of the benefits and drawbacks when considering relatively new blood thinners like Pradaxa and Xarelto.
Pradaxa Drug Interactions
Before taking Pradaxa, it is important that you tell your doctor and pharmacist if you are allergic to Pradaxa, any of the ingredients of Pradaxa, or any other medications. Pradaxa should not be taken with any other medications or supplements that also have blood thinning mechanisms, like aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs).
The list below are the medications and supplements most commonly interact with Pradaxa and is not all-inclusive. There are more than 379 drugs may interact with Pradaxa. Be sure to speak to your doctor about any medications and supplements you may be taking:
Drugs That Interact with Pradaxa
Lawsuits Over Pradaxa Side Effects
Because the side effects of Pradaxa can be so severe, thousands of individuals have filed Pradaxa lawsuits against Boehringer Ingelheim, making claims of negligence and product liability against the pharmaceutical manufacturer. Many of the legal claims revolve around the fact that Boehringer knew about studies showing the potentially severe adverse effects of the blood thinner, but they did not properly communicate the risks of taking the drug to patients and doctors. Also, since no antidote was available until late October 2015, those who took the drug before that date argue that the drug company should have informed them about potentially safer or equally safe alternatives.