Noncontraceptive Uses of the Levonorgestrel Intrauterine System
Although the levonorgestrel-releasing intrauterine system (Mirena) is approved for contraception, it also may have noncontraceptive uses, such as treating idiopathic menorrhagia. The American College of Obstetricians and Gynecologists published a committee opinion in the June 2006 issue of Obstetrics & Gynecology to address the noncontraceptive uses of this system.
The levonorgestrel intrauterine system reduces up to 86 percent of menstrual blood loss after three months in women with idiopathic menorrhagia and up to 97 percent after 12 months. At 12 months after insertion of the system, reported rates of amenorrhea vary from 20 to 80 percent. It is suggested that the levonorgestrel intrauterine system is significantly more effective than oral cyclical norethindrone as a treatment for heavy menstrual bleeding.
However, discontinuing use of the levonorgestrel intrauterine system may result in irregular bleeding, mood swings, acne, breast tenderness, and other hormonal side effects.
Hormone therapy regimens that combine estradiol-delivering methods (i.e., oral, gel, transdermal, or vaginal ring) with the levonorgestrel intrauterine system can effectively reduce climacteric symptoms and induce amenorrhea in 59 to 83 percent of women after one year. However, the long-term effects are unknown.
It is suggested that physicians evaluate women with persistent bleeding in a typical manner regardless of their use of the levonorgestrel intrauterine system.
Oral progestin therapy also is recommended as a treatment option for patients with atypical endometrial hyperplasia, with results consistent with other progestational agents.
Use of the levonorgestrel intrauterine system may be cautiously considered for patients with previous breast cancer who have used tamoxifen (Nolvadex) for more than one year; the system may prevent tamoxifen-induced endometrial changes. However, long-term randomized trials are needed before the levonorgestrel intrauterine system can be recommended as an adjuvant therapy with tamoxifen in women with a history of breast cancer.
It is reasonable to consider use of the levonorgestrel intrauterine system by women with endometriosis who desire effective, long-term contraception.
Physicians are advised to consider the levonorgestrel intrauterine system as an option for the treatment of idiopathic menorrhagia, but additional studies are required to recommend it as a reliable treatment option for endometriosis-associated pelvic pain, endometrial adenocarcinoma, hyperplasia, or as an adjuvant therapy with tamoxifen.