Uterine Fibroids and Hysterectomy - Medications

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. In one study, 89% of the women maintained a smaller uterine for at least 18 months after stopping the treatment. In another study, bone density even increased slightly. Adverse effects of gestrinone include male hormone symptoms, such as acne, and possibly the development of unhealthy cholesterol levels. Adverse effects of gestrinone include male hormone symptoms, such as acne, and possibly the development of unhealthy cholesterol levels.

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Mifepristone. Mifepristone (Mifeprex) is used for emergency contraception, but is controversial because of its name: the abortion pill. This agent is an anti-progestin that has reduced fibroid size in some studies. In one study, it reduced fibroids as significantly as GnRH agonists and the fibroids were less likely to recur.

Asoprisnil. A promising new antiprogestin called Asoprisnil has been shown to reduce fibroids. The drug is in the final stages of evaluation by the FDA and is expected to be approved in 2004.

Investigative Agents

A number of agents are under investigation for treating fibroids.

Selective estrogen-receptor modulators (SERMs) are agents that have some of the effects of estrogen but do not produce some of its complications, such as a higher risk for uterine cancer. Raloxifene (Evista) is proving to be beneficial in preventing bone loss in patients taking GnRH agonists for uterine fibroids, and may also be helpful as a single agent for preventing fibroid growth.
Agents that block growth factors believed to play a role in fibroids are also under investigation. Pirfenidone is one such agent, which blocks fibroid cell reproduction. Another is interferon alpha, substance that inhibits angiogenesis (the growth of new blood vessels).
Agents derived from retinoids (vitamin A compounds) may inhibit cell proliferation in fibroid tissue. One such agent LGD1069 (Targretin) is showing promise in animal studies.
Fulvetrant (Faslodex) blocks estrogen and has been studied for uterine fibroids and endometriosis, although progress in these areas has stalled in favor of research for its use in breast cancer.