A petition requesting that the Judicial Panel on Multidistrict Litigation centralize more than 100 lawsuits from women claiming Bayer’s Mirena contraceptive device caused them to develop intracranial hypertension was filed Dec. 29.

In their petition, the women seek to transfer all “substantially similar” cases pending against Bayer to a federal judge in the Southern District of Mississippi for convenience, judicial economy and consistency in rulings. The court in Mississippi was selected based on the fact that it is not currently overtaxed and has an efficient civil docket.

The 116 pending cases against Bayer allege that the Mirena intrauterine system caused them to develop conditions like increased intracranial pressure or intracranial hypertension (IH), which is sometimes referred to as pseudotumor cerebri. IH occurs when there is a high amount of pressure in the space that surrounds the brain and spinal cord.

“Symptoms of IH include severe headache, nausea, ringing in the ears, blurred or dimmed vision, double vision, and neck, shoulder or back pain,” said the plaintiffs in the petition. “This condition can also cause swelling of the optic nerves, leading to temporary or permanent blindness. There is currently no treatment to reverse permanent injury to the optic nerves caused by increased intracranial pressure.”

Plaintiffs contend that a potent hormone called levonorgestrel released by Mirena is the cause of intracranial hypertension. According to the petition, Bayer has ignored years of research linking the hormone and intracranial hypertension and continues to fail to warn consumers and physicians about the risk.

Link Between Mirena Hormone and Intracranial Hypertension Dates Back Years

The association between intracranial hypertension and the levonorgestrel hormone released by Mirena has been known for years.

A similar device that also released levonorgestrel called the Norplant was approved by the U.S. Food and Drug Administration (FDA) in 1990. Norplant, which was made and sold by companies that were later bought by Bayer, eventually included a warning that intracranial hypertension had been reported by some users of the Norplant device.

“In light of the pharmaceutical industry’s experience with the Norplant System, as well as Bayer’s specific involvement as the manufacturer of the Norplant System, Bayer knew or should have known of the association between levonorgestrel and IH at the time it put Mirena on the market,” plaintiffs said in the petition. “However, the product label for the Mirena LNG-IUS has never contained any warning relating to the risk of IH.”

Despite the fact that Bayer carries a warning of a link between IH and levonorgestrel in Jadelle, another one of its levonorgestrel-releasing contraceptive implants, Bayer has yet to make any changes to the labeling of Mirena.

More recently, a group of researchers reported in June 2015 that their epidemiological study found exposure to a levonorgestrel-releasing contraceptive was significantly associated with the development of intracranial hypertension. A woman exposed to such a device is 7.7 times more likely to develop IH than a woman who was not exposed to the device, according to the study.

While there are currently 116 pending cases in 17 different jurisdictions making virtually identical claims, hundreds of more related lawsuits are expected to be filed against Bayer because Mirena has been used by more than 15 million women around the world.

In fact, since Mirena was first approved 2000, the FDA has received more than 70,000 complaints from consumers on all types of issues, including perforation, breast cancer and ovarian cysts. Hundreds of lawsuits unrelated to the current issue of IH have been filed against Bayer’s Mirena in the past.

The law firm handling some of the cases requesting consolidation expects to file more than a hundred lawsuits on behalf of women who developed IH and is aware of significantly more unfiled cases.