Atrial fibrillation patients face an increased risk of blood clots that can lead to stroke. Anticoagulants like Pradaxa can reduce that risk, but they do so at the cost of an increased risk of Pradaxa bleeding.

By disrupting the flow of blood through the heart, atrial fibrillation causes blood to pool. The pooling increases the chance that blood clots will form, increasing the risk of stroke. To reduce this risk of stroke, physicians may prescribe blood-thinning medications, also known as anticoagulants.

These medications reduce the risk of stroke by inhibiting the blood’s ability to clot. However, the same effect reduces the body’s ability to stop any bleeding once it starts.

Pros and Cons of Pradaxa Treatment

To determine whether Pradaxa treatment is appropriate, physicians apply formulas that predict the likelihood an atrial fibrillation patient will develop blood clots or have bleeding problems. These formulas account for several factors such as the patient’s age, sex, and history of certain cardiovascular problems.

Based on the results from these formulas, physicians determine whether or not to prescribe anticoagulants, and if so, which anticoagulants, such as Pradaxa, to prescribe.

For several decades, the most widely prescribed anticoagulant medication was warfarin, also sold under the trade name Coumadin. It was first approved by the FDA in 1954 to reduce the risk of blood clots that can cause stroke. However, in warfarin treatment, getting the dosage right is tricky, as it requires regular blood testing and dosage adjustment.

Warfarin patients also must control their intake of vitamin K, which reduces warfarin’s anticoagulant effect. That means limiting their intake of otherwise healthy leafy green vegetables that happen to be high in vitamin K.

Pradaxa is one of three new anticoagulants introduced between 2010 and 2013 (the other two being Xarelto and Eliquis) that do not require the same blood monitoring, dosage adjustment, or dietary restrictions. Studies have also shown that these three medications are at as effective as warfarin at preventing stroke.

However, all three new anticoagulants have a significant drawback in that they have no antidote, or reversal agent, that counteracts their anticoagulant effect in case of excessive bleeding. Sometimes the anticoagulant effect needs to be stopped on short notice, such as when an accident causes unexpected bleeding or when the patient needs emergency surgery.

For patients taking warfarin, the effect can be controlled simply by administering Vitamin K. But there is no such reversal agent available for Pradaxa yet. So far, the only way to counter the effect of Pradaxa is to give the body time to process and eliminate the drug.

Pradaxa Antidote Under FDA Review

There may soon be a new Pradaxa antidote on the market. Boehringer Ingelheim Pharmaceuticals, the maker of Pradaxa, has developed a new drug called idarucizumab specifically for use as a Pradaxa antidote. The company has been developing idarucizumab since before Pradaxa was on the market.

In April 2015, Boehringer Ingelheim Pharmaceuticals announced the FDA had granted priority review status for idarucizumab. Priority review status is an accelerated FDA approval process for drugs that show exceptional potential for clinical usefulness.

The approval process is still pending, however, and whether idarucizumab is safe and effective has not been conclusively established. Until the FDA issues a final decision, Pradaxa patients must continue to live with the risk of Pradaxa bleeding.