The makers of the blood thinning medication Eliquis (apixaban) may be facing an equal number of product liability lawsuits like those filed against competitors Xarelto and Pradaxa, which are facing mounting litigation for bleed outs – irreversible internal bleeding that can result in death.

All three anticoagulants (blood thinners) have been widely prescribed to prevent blood clots in patients suffering from atrial fibrillation (arrhythmia of the heart); deep vein thrombosis (blood clots deep within the body); pulmonary embolism (blood clots in the lungs) and stroke.

The drugs were the first alternative to Warfarin (Coumadin), a blood thinner that has been on the market in the United States since the 1950s.

Pradaxa (dabigatran) received FDA approval in 2010 and is made by Boehringer Ingelheim. Xarelto was developed by Bayer and Johnson & Johnson subsidiary Janssen Pharmaceuticals, and was approved by the FDA in 2011, while Eliquis, a Bristol Myers Squibb and Pfizer product, followed with FDA approval the next year.

A study published in the New England Journal of Medicine showed that patients with atrial fibrillation did better on Eliquis compared with warfarin in preventing strokes while also reducing the risk of bleeding by 31 percent. Eliquis also reduced the risk of death from any cause by 11 percent.

“Eliquis’ efficacy in preventing strokes proved about as good as Pradaxa’s and slightly better than Xarelto’s,” according to a 2011 article published in Medical Marketing & Media. “Pradaxa, which like Eliquis is dosed twice daily, demonstrated superior efficacy but not safety vs. warfarin, and Xarelto was non-inferior to warfarin on efficacy and safety, with once-daily dosing.”

Unlike warfarin (Coumadin), however, Eliquis, Xarelto and Pradaxa do not have an approved antidote which would reverse the blood thinning effects of the medication in the event of an internal bleed. Warfarin users are able to reverse a bleeding event with a dose of vitamin K and fresh frozen plasma to reverse the drug’s anticoagulant effects.

Coincidentally, the most common adverse events reported by the new generation of blood thinners include uncontrollable internal bleeding and hemorrhage.

Thousands of product liability lawsuits have been filed against the manufacturers of all three drugs — Pradaxa, Xarelto and Eliquis — as the result of the lack of a bleeding antidote. Patients accuse the drug makers of manufacturing and selling a dangerous drug while failing to warn users or the medical community that a reversal agent does not exist.

While Eliquis is the newest of the three next-generation anticoagulants, it is also the one medical professionals know the least about when it comes to reversing bleeding, according to a study published in the Journal of Neurosurgery.

“To date, there are no human studies of reversal agents in patients who require rapid (Eliquis) reversal,” according to the study’s researchers.

Boehringer Ingelheim has reportedly made gains in an antidote to its blood-thinner Pradaxa and is trying to expedite FDA approval process. Bayer and Johnson & Johnson are also working on developing an antidote for Xarelto.