For many years, warfarin dominated the anticoagulant market in the U.S. However, a new medication, Pradaxa, is now challenging warfarin’s widespread use.

Pradaxa (dabigatran) is now a popular blood thinner medication manufactured by Boehringer Ingelheim Pharmaceuticals and was approved for use by the FDA in October 2010.

The appeal of Pradaxa is that it seems to have fewer side effects and requires less maintenance than warfarin. By August 2012, just two years after Pradaxa was approved by the FDA more than 3.7 million patients in the U.S. had filled prescriptions for the drug.

But in those same two years, Pradaxa was blamed for over 500 deaths.

In fact, in 2011 the Institute of Safe Medical Practices reviewed Pradaxa and other drugs. They found that Pradaxa was linked to more injuries and deaths than any of the other 800 drugs it reviewed.

Does Pradaxa Cause Internal Bleeding?

Pradaxa is normally prescribed to patients who suffer from atrial fibrillation in order to avoid stroke. The hearts of a-fib patients cannot push out blood as quickly as healthy hearts because of irregular beats.

Blood can pool in the heart and if left untreated, that blood can clot. Those blood clots can travel throughout the body and if they reach the brain, cause stroke.

Pradaxa is an anticoagulant which fights against blood clotting and can be beneficial for a patient trying to avoid stroke.

However, a blood thinner also carries with it certain risks. Uncontrollable internal bleeding is one such risk that has been linked to Pradaxa.

The problem is that, unlike warfarin, Pradaxa has not had a bleeding antidote until recently. A doctor could reverse uncontrollable internal bleeding from warfarin by administering Vitamin K, but internal bleeding as a result of Pradaxa was not reversible.

In October 2015, Praxbind, Pradaxa’s antidote, was approved by the FDA.

In one study of healthy volunteers with bleeding events, Praxbind was found to reverse internal bleeding in 89 percent of patients within four hours of receiving the antidote.

Internal Bleeding Risks with Pradaxa

However, there were many uncontrollable internal bleeding events before Praxbind was introduced to the market late last year.

Pradaxa has been linked to increased risk of major stomach or gastrointestinal bleeding and brain hemorrhage in some studies.

In fact, a study published in JAMA in 2013 suggests that treatment with Pradaxa raises the risk of gastrointestinal bleeding as opposed to treatment with warfarin.

Symptoms of Internal Bleeding

Anyone on Pradaxa is at risk for internal bleeding events because of the nature of anticoagulant medications. Pradaxa works as a blood thinner to reduce the risk of stroke, however, it can increase the risk of hemorrhage.

Those on Pradaxa should watch for the following signs of internal bleeding.

These include unusual bleeding from the gums, frequent nose bleeds, pink or brown urine, black or red stools, coughing up or vomiting blood, vomit that looks like coffee grounds and/or heavier than normal vaginal bleeding.

Symptoms of a brain hemorrhage include vision problems, sudden weakness, headache and/or confusion.

Patients should seek immediate help if these symptoms present, the FDA recommends.