The US Food and Drug Administration approved Mirena (levonorgestrel intrauterine system) to treat heavy menstrual bleeding in women who use intrauterine contraception as their method of pregnancy prevention. This is the first intrauterine device approved by the FDA for this additional indication.

Mirena was approved as a contraceptive by the FDA in 2000. It is a small, flexible hormone-releasing device inserted into the uterus to prevent pregnancy. The device should be inserted by a trained health care professional.

"Women who suffer heavy, prolonged menstrual periods find the condition unpleasant, disabling, and frightening," said Kathleen Uhl, director of the FDA's Office of Women's Health. "Bleeding can be so heavy that women must miss work, school, or social activities."

"In the primary clinical trial, women using Mirena showed a statistically significant reduction in menstrual blood loss," said Scott Monroe, director of the Division of Reproductive and Urologic Products in the FDA's Center for Drug Evaluation and Research.

Participants in the clinical trial had excessive menstrual blood loss prior to treatment and did not have any medical conditions that are known to cause heavy menstrual bleeding, except for small uterine fibroids in some cases.

Mirena is recommended for women who have had a child. Clinical studies to support both the contraception and heavy menstrual bleeding indications have excluded women who have never been pregnant.

Since its approval in 2000, the most serious adverse reactions reported in patients using Mirena for any indication include: ectopic pregnancy (a pregnancy in which the fertilized egg grows outside the uterus); intrauterine pregnancy (a pregnancy with Mirena in place); group A streptococcal sepsis; an infection called pelvic inflammatory disease; embedment of the device in the uterine wall; and perforation of the uterine wall or cervix.

The most common adverse events reported by patients in the primary clinical trial using Mirena to treat heavy menstrual bleeding included uterine bleeding/spotting at irregular intervals, headache, ovarian cysts, vaginitis, pain during menstruation (dysmenorrhoea), pelvic pain, and breast tenderness.

Mirena is made by Bayer HealthCare Pharmaceuticals, Wayne, New Jersey.