Xarelto is an anticoagulant manufactured by Bayer and Janssen Pharmaceuticals, Inc. Since its FDA approval in 2011, Xarelto has been very successful for both Bayer and Janssen with $1.3B in sales in 2013 and over 13 million prescriptions written for the drug in the U.S. alone.

Xarelto was approved by the FDA for the treatment of atrial fibrillation, deep vein thrombosis, pulmonary embolism, and to reduce the clotting risk following a hip or knee replacement surgery. One of the key benefits touted by the makers of Xarelto has been that it does not require blood monitoring or dietary changes, making the drug very appealing for patients who must take a blood thinner regularly.

Although Xarelto was marketed as being better than warfarin because of less maintenance, if a serious bleed occurs, there is no antidote to stop the bleeding with Xarelto like there is for patients taking warfarin. Bayer and Janssen’s marketing of Xarelto caused the FDA to issue the companies a warning letter about misbranding Xarelto (due to the companies minimizing the risks of Xarelto in advertisements).

As a result of there being no antidote for Xarelto, more than a few patients taking the drug have had serious bleeding events. The frequency of the bleeding events with Xarelto have led to the drug being labeled as the most dangerous blood thinner on the market and has led to doctors being nervous to prescribe it to their patients.

The serious bleeding events that have occurred as a result of taking Xarelto have led to many lawsuits against Bayer and Janssen. The pending lawsuits against the companies have been consolidated into a multidistrict litigation in Louisiana, and as of October 2015, there were over 2,000 pending lawsuits. If Bayer and Janssen choose not to settle the cases against them by 2016, the first Xarelto trials will be heard in February of 2017.