Menstrual Disorders - Medications

GnRH Agonists

Gonadotropin releasing hormone (GnRH) agonists are sometimes used to treat menorrhagia. GnRH agonists block 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 a nasal spray, Nafarelin (Synarel). Such drugs may be used alone or in preparation for procedures used to destroy the uterine lining. They are not generally suitable for long-term use.

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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 these drugs 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 called a bisphosphonate (alendronate or etidronate) may also be helpful.
Other agents are being tested in combination with a GnRH agonist to preserve bone. They include parathyroid hormone or tibolone (available in Europe). Tibolone is known as a selective estrogen-receptor modulator (SERM), which means it has some, but not all, effects of estrogen.

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.

Danazol

Danazol (Danocrine) is a synthetic substance that resembles a male hormone. It suppresses estrogen, and therefore menstruation, and is used (sometimes in combination with an oral contraceptive), to help prevent heavy bleeding. It may also improve operative success rates in women with menorrhagia when used before ablation or resection to destroy the uterine lining. It is not suitable for long-term use.

Adverse side effects include facial hair, deepening of the voice, weight gain, acne, and dandruff. It may also increase the risk for unhealthy cholesterol levels. Pregnant women or those trying to become pregnant should not take this drug because it may cause birth defects. [For more information on this drug, see In-Depth Report #74: Endometriosis or In-Depth Report #63: Fibroids.]