How can fibroids be treated medically?

There are no medicines currently available that will permanently shrink fibroids.

Because fibroid growth tends to stop and regress after menopause, the important reproductive hormones--estrogen, progesterone, or both--most likely play a critical role in their survival.

Some agents that block either of these hormones are used to treat severe fibroids with some success.

Contraceptives

Some studies conducted more recently on the newer low-dose OC combinations suggest they may be protective and may even reduce the risk of fibroids. It is not clear, however, how or if they should be used in women with fibroids.

A new form of IUD called the Levonorgestrel Intrauterine System (LNG IUS) is an excellent contraceptive that helps reduce uterine bleeding, even in women with fibroids, although it seems to have minimal effects on fibroids themselves.

Progestins (either natural progesterone or synthetic progestogen) are useful for women who clearly have heavy uterine bleeding caused by unopposed production of estrogen. Some may be useful for women with bleeding due to fibroids, although it is not yet clear which ones will be beneficial.

GnRH Agonists

Gonadotropin releasing hormone (GnRH) blocks the release of the reproductive hormones LH (luteinizing hormone) and FSH (follicular-stimulating hormone). As a result, the ovaries stop ovulating and no longer produce estrogen. GnRH agonists include goserelin (Zoladex), buserelin, a monthly injection of leuprolide (depot Lupron), and nafarelin (Synarel), a nasal spray.) Such agents may be used to alone or in preparation for procedures used to destroy the uterine lining.

These agents may be used in the following situations:

• As preoperative treatment three to four months before uterine surgery. The use of GnRH agonists in such cases reduced fibroid size and uterus volume, helped correct any existing anemia due to blood loss, reduced blood loss during surgery, and reduced the duration of hospital stay.
  
• For women with fibroids nearing menopause. Such women only need them for a short period.
  
• Possibly helpful in improving subsequent fertility. It is important to note, however, that women should not try to become pregnant while taking these drugs. They pose a risk for birth defects.

While GnRH agonists can reduce fibroids by between 30% and 90% of original size, they have certain limitations:

• They are not permanent cures and fibroids regrow after the drugs are discontinued.
  
• They can't be taken orally.
  
• They are expensive.
  
• Long-term use of GnRh agonists has an adverse effect on bone density.

Before using these drugs, the physician should be certain that no other complicating conditions are present, particularly leiomyosarcoma (cancer). The use of these drugs can delay treatment of the malignancy and cause severe complications.

Commonly reported side effects (which can be severe in some women) include menopausal-like symptoms that include hot flashes, night sweats, changes in the vagina, weight change, and depression. The side effects vary in intensity depending on the GnRH agonist. They may be more intense with leuprolide and persist after the drug has been stopped.

The most important concern is possible osteoporosis from estrogen loss. Women ordinarily should not take them for more than six months.

GnRH treatments used alone do not prevent pregnancy. Furthermore, if a woman becomes pregnant during their use, there is some risk for birth defects. Women who are taking GnRH agonists should use non-hormonal birth control methods, such as the diaphragm, cervical cap, or condoms while on the treatments.

Antiprogestins

Gestrinone.
Antiprogestins are promising agents for fibroids. Gestrinone has been shown to reduce uterine volume and stop bleeding. In addition, benefits appear to persist.

Adverse effects of gestrinone include male hormone symptoms, such as acne, and possibly the development of unhealthy cholesterol levels.

Mifepristone.

This agent is an anti-progestin that has reduced fibroid size in some studies.