Chemistry:Antiestrogen

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Short description: Class of drugs
Antiestrogen
Drug class
Fulvestrant.svg
Fulvestrant, a steroidal antiestrogen and a drug used in the treatment of breast cancer.
Class identifiers
SynonymsEstrogen antagonists; Estrogen blockers; Estradiol antagonists
UseBreast cancer; Infertility; Male hypogonadism; Gynecomastia; transgender men
ATC codeL02BA
Biological targetEstrogen receptor
Chemical classSteroidal; Nonsteroidal (triphenylethylene, others)
External links
MeSHD020847

Antiestrogens, also known as estrogen antagonists or estrogen blockers, are a class of drugs which prevent estrogens like estradiol from mediating their biological effects in the body. They act by blocking the estrogen receptor (ER) and/or inhibiting or suppressing estrogen production.[1][2] Antiestrogens are one of three types of sex hormone antagonists, the others being antiandrogens and antiprogestogens.[3] Antiestrogens are commonly used to stop steroid hormones, estrogen, from binding to the estrogen receptors leading to the decrease of estrogen levels.[4] Decreased levels of estrogen can lead to complications in sexual development.[5] Antiandrogens are sex hormone antagonists which are able to lower the production and the effects that testosterone can have on female bodies.[6]

Types and examples

Antiestrogens include selective estrogen receptor modulators (SERMs) like tamoxifen, clomifene, and raloxifene, the ER silent antagonist and selective estrogen receptor degrader (SERD) fulvestrant,[7][8] aromatase inhibitors (AIs) like anastrozole, and antigonadotropins including androgens/anabolic steroids, progestogens, and GnRH analogues.

Estrogen receptors (ER) like ERα and ERβ include activation function 1 (AF1) domain and activation function 2 (AF2) domain in which SERMS act as antagonists for the AF2 domain, while “pure” antiestrogens like ICI 182,780 and ICI 164,384 are antagonists for the AF1 and AF2 domains.[9]

Although aromatase inhibitors and antigonadotropins can be considered antiestrogens by some definitions, they are often treated as distinct classes.[10] Aromatase inhibitors and antigonadotropins reduce the production of estrogen, while the term "antiestrogen" is often reserved for agents reducing the response to estrogen.[11]

Medical uses

Antiestrogens are used for:

Side effects

In women, the side effects of antiestrogens include hot flashes, osteoporosis, breast atrophy, vaginal dryness, and vaginal atrophy. In addition, they may cause depression and reduced libido.

Pharmacology

Antiestrogens act as antagonists of the estrogen receptors, ERα and ERβ.


History

The first nonsteroidal antiestrogen was discovered by Lerner and coworkers in 1958.[12] Ethamoxytriphetol (MER-25) was the first antagonist of the ER to be discovered,[13] followed by clomifene and tamoxifen.[14][15]

See also

References

  1. "Definition of antiestrogen - NCI Dictionary of Cancer Terms, Definition of antiestrogen - NCI Dictionary of Cancer Terms". http://www.cancer.gov/dictionary/?CdrID=44813. ,
  2. "antiestrogen" at Dorland's Medical Dictionary
  3. Using Medical Terminology: A Practical Approach. Lippincott Williams & Wilkins. 2006. pp. 977–. ISBN 978-0-7817-4868-1. https://archive.org/details/usingmedicalterm0000nath. 
  4. "Fulvestrant: a review of its use in hormone receptor-positive metastatic breast cancer in postmenopausal women with disease progression following antiestrogen therapy". Drugs 64 (6): 633–48. 2004-03-01. doi:10.2165/00003495-200464060-00009. PMID 15018596. 
  5. "A Review on Sex Steroid Hormone Estrogen Receptors in Mammals and Fish". International Journal of Endocrinology 2020: 5386193. 2020-02-07. doi:10.1155/2020/5386193. PMID 32089683. 
  6. "A systematic review of antiandrogens and feminization in transgender women". Clinical Endocrinology 94 (5): 743–752. September 2020. doi:10.1111/cen.14329. PMID 32926454. 
  7. Nuclear Receptors as Drug Targets. John Wiley & Sons. 8 September 2008. pp. 164–165. ISBN 978-3-527-62330-3. https://books.google.com/books?id=iATfLbPgRugC&pg=PA164. 
  8. Cancer Chemotherapy and Biotherapy: Principles and Practice. Lippincott Williams & Wilkins. 8 November 2010. pp. 660–. ISBN 978-1-60547-431-1. https://books.google.com/books?id=WL4arNFsQa8C&pg=PA660. 
  9. Pike, Ashley C.W.; Brzozowski, A.Marek; Walton, Julia; Hubbard, Roderick E.; Thorsell, Ann-Gerd; Li, Yi-Lin; Gustafsson, Jan-Åke; Carlquist, Mats (2001-02-01). "Structural Insights into the Mode of Action of a Pure Antiestrogen" (in en). Structure 9 (2): 145–153. doi:10.1016/S0969-2126(01)00568-8. ISSN 0969-2126. PMID 11250199. 
  10. Antiestrogens, aromatase inhibitors, and apoptosis in breast cancer. Vitamins & Hormones. 71. 2005. pp. 201–37. doi:10.1016/S0083-6729(05)71007-4. ISBN 9780127098715. 
  11. "Signaling pathways of apoptosis activated by aromatase inhibitors and antiestrogens". Cancer Research 63 (22): 8037–50. November 2003. PMID 14633737. https://cancerres.aacrjournals.org/content/63/22/8037.short. 
  12. "Basic guide to the mechanisms of antiestrogen action". Pharmacological Reviews 50 (2): 151–96. June 1998. PMID 9647865. https://pubmed.ncbi.nlm.nih.gov/9647865/. 
  13. Tamoxifen: Pioneering Medicine in Breast Cancer. Springer Science & Business Media. 23 July 2013. pp. 7–. ISBN 978-3-0348-0664-0. https://books.google.com/books?id=p-W5BAAAQBAJ&pg=PA7. 
  14. Estrogen Action, Selective Estrogen Receptor Modulators and Women's Health: Progress and Promise. World Scientific. 27 May 2013. pp. 7,112. ISBN 978-1-84816-959-3. https://books.google.com/books?id=ZM26CgAAQBAJ&pg=PA7. 
  15. Drug Discovery: A History. John Wiley & Sons. 23 June 2005. pp. 198–199. ISBN 978-0-471-89979-2. https://books.google.com/books?id=Cb6BOkj9fK4C&pg=PA198. 

External links

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