Image courtesy of

There is a new $64,000 question in legal circles this summer. It involves a wildly popular form of birth control and an incredibly awful potential side effect. What is that question? Simply put, does Bayer’s Mirena® cause pseudotumor cerebri?

The lawsuits are being filed and, ultimately, this question will find its way into the courtroom. Before we go further, it may be a good idea to explain pseudotumor cerebri (PTC). This condition, while not fatal, is nonetheless extremely painful and can cause permanent damage to those who suffer from it. Another name for PTC is intracranial hypertension (ICH). At its most basic definition, PTC is a build-up of excess cerebrospinal fluid in the skull.

This excess fluid causes a dramatic increase in pressure inside the skull. The results of this increased pressure include severe headaches, as well as migraines. As the pressure also affects the optic nerves, PTC sufferers may also experience vision loss and total blindness. PTC shares so many symptoms with real brain tumors that it is often misdiagnosed at first.

Severe headaches are one possible symptom of PTC. Image courtesy of
Severe headaches are one possible symptom of PTC. Image courtesy of

The is especially easy to do as the only means of diagnosing PTC is via lumbar puncture, also known as a spinal tap. It’s an unpleasant procedure during which a doctor sticks a needle between two vertebrae in the patient’s lower spine. They measure the amount of fluid and also take a sample to determine the extent of the intracranial pressure. Again, PTC is not fatal, but it should be treated as soon as possible after diagnosis because the vision damage can become permanent otherwise.

The treatment options are almost as bad as the condition itself. Sometimes medications will reduce the fluid levels, which relieves the pressure. This works only in mild cases. If the case is more severe, shunts (surgical tubes) must be inserted into the skull to drain the excess fluid.

Now that we’ve covered what PTC is, how does Bayer’s Mirena® (and other company’s birth control products) fit in?

Certain studies dating back as far as the 1990s have linked PTC to certain types of birth control. The New England Journal of Medicine published one such study in 1995. The researchers came to the conclusion that certain products that contained levonorgestrel, a synthetic hormone, also came with a higher risk of PTC. Among these products was the Mirena IUD.

Another study, Risk of intracranial hypertension with intrauterine levonorgestrel, published in June 2015, had as its objective the quantification of “the risk of intracranial hypertension (ICH) with the intrauterine levonorgestrel (IUL) device Mirena®.” The researchers used data obtained from the FDA’s Adverse Events Reporting System (FAERS database) “to quantify a reporting odds ratio (ROR) for ICH and Mirena®. [They also conducted a retrospective cohort study using the IMS LifeLink® database, comparing the risk of two oral contraceptives ethinyl estradiol (EE) with Mirena®.”

Their findings included “a higher than expected number of reports of ICH with Mirena® in the FAERS database. [They] also found a similar risk of ICH with Mirena® compared with the oral contraceptive EE-norgestimate.”

The causal mechanism behind exposure to Mirena® (levonorgestrel) and PTC is currently unknown. The prevailing theory is that somehow the patients’ bodies aren’t able to absorb the excess fluid as they should be able to and PTC results.

What are some things you should look for if you’re concerned about PTC? Experts advise to watch out for the following:

  • Frequent headaches or migraines beginning behind the eyes;
  • Pain that worsens when the patient rotates her eyeballs;
  • Ringing in the ears that matches the patient’s heart beat.

Bayer isn’t alone in facing potential liability for a product that may cause PTC. Pfizer and others are also on the hook for their birth control products. Such products include:

  • Yaz
  • Yasmin
  • Beyaz
  • Ocella
  • Mirena IUD
  • Depo-Provera
  • Safyral
  • Gianvi
  • Implanon
  • Nexplanon
  • NuvaRing
  • Ortho Evra

This list does not cover all such products.

A Closer Look at Mirena Pseudotumor Cerebri

Risk of intracranial hypertension with intrauterine levonorgestrel

Join the Discussion