Uterine Fibroids and Hysterectomy - Medications

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. Certain approaches may preserve enough estrogen to protect bones and still effectively relieve endometriosis symptoms:

Add-back therapy, which provides doses of estrogen and progestin that are high enough to maintain bone density, but are too low to offset the beneficial effects of the GnRH agonist.
Intermittent leuprolide, which uses repeated six-month courses of GnRH agonists followed by an average of nine months of symptom control only.
Taking GnRH agonists in very low doses is an alternate approach, but is still largely untested.
Adding a bone-protective agent may be helpful. The standard ones are bisphosphonates and include alendronate (Fosamax), risedronate (Actonel), and etidronate (Didronel). Other agents are being tested in combination with a GnRH agonist to preserve bone. They include the parathyroid hormone teriparatide (Forteo) and selective estrogen-receptor modulators (SERMs), such as raloxifene (Evista).

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.

Androgens

Danazol (Danocrine) resembles a male hormone. It suppresses estrogen and is effective for heavy menstrual bleeding caused by fibroids. In some women it produces male characteristics, such as facial hair and voice change. Exercise may help reduce the male-related side effects. Other side effects include weight gain, acne, and dandruff. It may increase the risk for unhealthy cholesterol levels. A few cases of blood clots and strokes have been reported. At present there is no long-term experience using danazol for fibroids.