Most Dangerous Drugs: Xarelto, Pradaxa and Other Blood Thinners

If asked what the most dangerous prescription drug was, how would you answer? Given the recent opioid crisis, many people would likely answer OxyContin or fentanyl.

Nearly half of anticoagulant adverse events required a hospital stay.ISMP QuarterWatch - July 12, 2017

Contrary to popular belief, the prescription drug most likely to require an emergency room visit is an anticoagulant. This information comes from a report published by the Institute for Safe Medication Practices (ISMP).

Anticoagulants are more commonly referred to as blood thinners. They include drugs such as Xarelto, Pradaxa and warfarin. These medications use different biochemical interactions to prevent blood from clotting.

For the report, the ISMP analyzed data collected by the FDA. In 2016, patients and healthcare workers reported nearly 22,000  severe injuries related to blood thinners. Additionally, there were 3,000 reports of deaths related to blood thinners.

But this only tells part of the story. The FDA only tracks voluntary reports. So the true number of people injured by blood thinners each year may be significantly higher.

The ISMP report also pulled data from a 2016 CDC study. The study found blood thinners to be the cause of more emergency department (ED) visits for outpatient adverse effects than any other class of drugs. The study specifically looked at drugs used for therapeutic use. This includes opioids (non-abuse visits), antibiotics, and diabetes drugs.

According to the CDC data, 48.8% of the injuries from blood thinners required a hospital stay.

Why Are Blood Thinners So Dangerous?

Blood thinners interrupt the blood clotting process. This is useful for treating or preventing certain medical conditions caused by blood clots.

Common Conditions Related To Blood Clots

  • Stroke
  • Pulmonary embolism (blood clot in the lung)
  • Deep vein thrombosis (blood clot in the leg)
  • Atrial fibrillation (abnormal heart rhythm)

The risk of blood clots is also high after certain types of surgery such as knee or joint replacement. Additionally, people with a sedentary lifestyle may be at risk for blood clots.

The problem with blood thinners is that blood clots for a reason. When you cut yourself, you want the blood to clot so that you stop bleeding. If blood didn't clot properly, the smallest scratch could cause someone to fatally bleed out. Thankfully, most people have blood that clots normally to prevent a fatal scenario.

A blood thinner, however, interrupts the natural formation of blood clots. The anti-clotting mechanism varies depending on the specific type of blood thinner you are taking. But the end result is the same. The medication will prevent your blood from clotting.

The good news is that most blood thinners - like warfarin (Coumadin) - have antidotes. These antidotes reverse the effects of the medication. If a person taking warfarin sustains an injury, a medical professional can administer vitamin K to reverse the effects of the drug. This antidote restores the blood's normal clotting behavior.

However, a couple of blood thinners have not always had antidotes. Some blood thinner antidotes were only recently developed. For example, the antidote for Pradaxa was only approved in 2015.  Anyone taking the drug before then was at risk of severe bleeding if they injured themselves. Individuals taking Xarelto were without an antidote until May 2018.

Minimizing the Dangers of Blood Thinners

Given that blood thinners are so dangerous, what can be done to reduce their effects? Here are a few ideas:

Always follow the drug label. This is true with any prescription. But, it's especially important to follow the instructions when dealing with blood thinners. By law, pharmaceutical companies are required to provide details about potential risks. Additionally, they must list individuals who should not take the medication.

Confused by prescription drug labels? Learn how to read them here >>>

Avoid food and drink interactions. When taking blood thinners, avoid any foods or drinks that might interfere with the drug. This includes alcohol. You may also need to avoid foods rich in vitamin K. Vitamin K can counteract the effects of some anticoagulants.

Talk to your doctor or pharmacist. If you don't understand why you were prescribed a blood thinner, talk to your prescribing physician or the pharmacist. Not sure what to ask them? Check out our list of questions to always ask your pharmacist! (The list is good for doctors, too).

Spread awareness! Let others know about the potential dangers of blood thinners. Awareness is another way to prevent serious (and potentially deadly) side effects of the drugs.

Blood thinners are legitimate medications with many beneficial uses for certain patients. However, using them safely is an important part of making sure they remain helpful.

Authored by Katy Moncivais, Ph.D.Medical Editor
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Katy Moncivais holds a Ph.D. in Biomedical Engineering from The University of Texas at Austin. She’s an experienced Regenerative Medicine Consultant with a demonstrated history of working in the hospital & healthcare industry. Skilled in adult stem cells, medical devices, biomechanics, bacterial and mammalian cell culture, and regenerative medicine, she provides guidance on an array of topics affecting consumers. In her role at, Dr. Moncivais works alongside the writing and research staff to help deliver fact-based news stories to consumers. Her unique professional history alongside her rigorous educational background allows her to contribute to a variety of consumer-focused topics with a fresh perspective. In addition, Dr. Moncivais reviews portions of medically driven content to ensure scientific accuracy.
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