What is Mirena?
Mirena is an intrauterine device (IUD) manufactured by Bayer. It is designed to be implanted in a woman’s uterus, where it slowly releases the hormone levonorgestrel (progestin). Mirena can prevent pregnancy for up to three years.
Mirena and Benign Intracranial Hypertension (BIH)
The hormone levonorgestrel, an ingredient in Mirena, has been associated with dozens of cases of Benign Intracranial Hypertension (BIH). One study, published by the New England Journal of Medicine in 1995, described 56 cases in young women on a birth control implant called Norplanon, which contained the hormone levonorgestrel. Many women are concerned because Mirena contains 52-mg of levonorgestrel.
BIH is a severe neurological condition that causes abnormally high levels of cerebrospinal fluid inside the skull. Normally, cerebrospinal fluid cushions the brain. Women with BIH suffer from elevated pressure inside the skull, which can injure the brain. Over time, it can also injure the optic nerves and cause blindness. Another complication, papilledema, causes swelling of the optic disc.
Because BIH is not “benign” (harmless), it is now known as Idiopathic Intracranial Hypertension (IIH) or Secondary Intracranial Hypertension.
What is the problem?
Women who develop severe headaches or blindness may not realize that Mirena could be responsible. The Prescribing Information does not include warnings about neurological side effects, such as BIH. It only recommends seeking medical attention for severe migraine headaches.
The problem is that inadequate risk information could potentially delay diagnosis and treatment. This could increase the risk of long-term complications, such as blindness. Bayer, the manufacturer of Mirena, is facing lawsuits accusing them of downplaying risk information.
Mirena Migraine Headaches
In clinical trials of Mirena, 7.7% of women reported headaches or migraines. According to the Prescribing Information, women with very severe migraine headaches should be evaluated by a doctor. Headaches are also the most common sign of BIH, although it is not clear that the conditions are related. Women who have serious headaches may need to stop using Mirena.
Bayer HealthCare is facing hundreds of lawsuits involving Mirena. The vast majority involve women who were injured by uterine perforations. In 2014, the first nine lawsuits involving Mirena and BIH were filed against Bayer. By 2018, there were hundreds of Mirena lawsuits for victims of intracranial hypertension. Attorneys asked judges to centralize the litigation in federal court, but they were denied. Instead, cases will proceed individually in the state court where they were originally filed.