Antiestrogen

An antiestrogen is a substance that blocks the production or utilization of estrogens, or inhibits their effects. Estrogens are the family of hormones that promote the development and maintenance of female sex characteristics.

Although aromatase inhibitors could be considered antiestrogens by some definitions, they are often considered to be a distinct class. Aromatase inhibitors reduce the production of estrogen, while the term "antiestrogen" is usually reserved for agents reducing the response to estrogen.

Hot flashes, osteoporosis, breast atrophy, and vaginal dryness can be side effects of antiestrogens.

Antiestrogens like tamoxifen can promote an invasive phenotype in estrogen receptor (ER)-positive breast cancer cells with deficient intercellular adhesion.

Ethamoxytriphetol (MER-25) was the first antiestrogen to be discovered, followed by clomifene citrate and tamoxifen. Fulvestrant is another antiestrogen, and is the only pure antiestrogen, or silent antagonist of the estrogen receptor, to have been introduced clinically.

See also

• Selective estrogen receptor modulator
• Antiandrogen
• Antiprogestin

External links

 This article incorporates public domain material from the U.S. National Cancer Institute document "Dictionary of Cancer Terms".