noun \tə-ˈmäk-sə-ˌfen\

Definition of TAMOXIFEN

:  an estrogen antagonist C26H29NO used in the form of its citrate especially to treat postmenopausal breast cancer


probably by recombination & alteration of trans-, oxy, and clomiphene
First Known Use: 1972


noun \ta-ˈmäk-si-ˌfen\   (Medical Dictionary)

Medical Definition of TAMOXIFEN

: a selective estrogen receptor modulator that acts as an estrogen antagonist in breast tissue and is administered orally in the form of its citrate C26H29NO·C6H8O7 especially to treat breast cancer or reduce the risk of its development or reoccurrence—see nolvadex


noun    (Concise Encyclopedia)

Synthetic hormone, marketed as Nolvadex, that prevents the binding of estrogen to estrogen-sensitive breast cancer cells. Initially used to prevent recurrences of breast cancer after successful treatment, it was later found to prevent first occurrences in women at high risk. The most serious side effect is an increased risk of thrombosis, which may require patients to take an anticoagulant as well. Studies on its effectiveness against breast and other cancers continue.


Next Word in the Dictionary: tamp (transitive verb)
Previous Word in the Dictionary: Tam o' Shanter
All Words Near: tamoxifen

Seen & Heard

What made you want to look up tamoxifen? Please tell us where you read or heard it (including the quote, if possible).