The first lawsuits have been filed against Bayer for the manufacture of its blood thinner, Xarelto. According to Reuters, an anonymous company insider has confirmed this information and said that, as of June 2014, up to 10 separate suits have been launched against the company. Legal action against Bayer was considered inevitable by many industry experts, as safety concerns continue to mount regarding Xarelto. A Bayer spokesperson did not comment on the insider’s statement. Instead, the spokesperson said that the drug’s risks are known and affirm clinical studies used to review the medication prior to launch.

There are major safety concerns regarding Xarelto, including hundreds of fatal reports. Xarelto’s side effect profile includes several severe complications, including rectal, brain or intestinal hemorrhaging. This hemorrhaging typically persists for up to 24 hours after it starts, and there is no clinically safe way to halt it once it presents.

Even when it was approved for use in 2011 by the Food and Drug Administration (FDA), Xarelto’s safety beyond two years of use was unknown. Initial safety reports, however, suggest it is among the most dangerous medications on the market. In 2011, doctors reported 151 fatal events to the FDA associated with Xarelto use. In Germany, 72 deaths and 968 injury reports were filed from January to August 2013. Some physicians in Germany no longer administer Xarelto as a front line treatment to their patients.

When the drug was initially approved, it was only recommended for use in patients who were receiving a knee or hip replacement. In November 2011, it was also approved for use in patients with atrial fibrillation that was not heart valve related. A year later, the FDA approved Xarelto for use in patients with pulmonary embolism or deep vein thrombosis. It is considered chemically similar to other popular blood thinners like Pradaxa and has quickly become one of the most prescribed anticoagulant drugs in the world. In 2013, Xarelto garnered approximately $1.3 billion in sales in the U.S., and the company expects to top that figure in 2014.

Another popular blood thinner medication, Pradaxa, was approved a year earlier and has been the subject of more than 4,000 lawsuits totaling about $650 million. Some industry watchdogs believe that Bayer will face a similar number of lawsuits as the risks of Xarelto become better known.