Tamoxifen powder blocks the actions of estrogen, a female hormone. Certain types of breast cancer require estrogen to grow. Tamoxifen is used to treat some types of breast cancer in men and women. It is also used to lower a woman's chance of developing breast cancer if she has a high risk (such as a family history of breast cancer). Tamoxifen powder may also be used for purposes not listed in this medication guide.
02 Tamoxifen powder (10540-29-1) video
03 Tamoxifen powder Base Information
|Melting Point||>92°C (dec.)|
|Appearance||White to Off-White|
|Half Life||5 to 7 days|
|Solubility||Chloroform (Sparingly), Methanol (Slightly)|
|Application||It’s applied to the treatment of advanced, recurrent breast cancer and ovarian cancer.|
04 Tamoxifen powder General Description
Tamoxifen powder is an antagonist of the estrogen receptor in breast tissue via its active metabolite, 4-hydroxytamoxifen. In other tissues such as the endometrium, it behaves as an agonist, and thus may be characterized as a selective estrogen-receptor modulator. Tamoxifen is the usual endocrine (anti-estrogen) therapy for hormone receptor-positive breast cancer in pre-menopausal women, and is also a standard in post-menopausal women although aromatase inhibitors are also frequently used in that setting.
Some breast cancer cells require estrogen to grow. Estrogen binds to and activates the estrogen receptor in these cells. Tamoxifen is metabolized into compounds that also bind to the estrogen receptor but do not activate it. Because of this competitive antagonism, tamoxifen acts like a key broken off in the lock that prevents any other key from being inserted, preventing estrogen from binding to its receptor, blocking cancer cell growth.
Tamoxifen powder was discovered by pharmaceutical company Imperial Chemical Industries(now AstraZeneca) and is sold under the trade names Nolvadex, Istubal, Valodex, and Genox. However, the drug has been widely referred to by its generic name “tamoxifen”, even before its patent expiration.
It is on the World Health Organization’s List of Essential Medicines, a list of the most important medication needed in a basic health system.
05 Tamoxifen powder (10540-29-1) History
Tamoxifen powder was initially made in 1962 by chemist Dora Richardson. It is on the World Health Organization’s List of Essential Medicines, the most effective and safe medicines needed in a health system. Tamoxifen powder is available as a generic medication. Tamoxifen is one of three drugs in an anti-angiogenetic protocol developed by Dr. Judah Folkman, a researcher at Children’s Hospital at Harvard Medical School in Boston. Folkman discovered in the 1970s that angiogenesis – the growth of new blood vessels – plays a significant role in the development of cancer. Since his discovery, an entirely new field of cancer research has developed. Clinical trials on angiogenesis inhibitors have been underway since 1992 using many different drugs. The Harvard researchers developed a specific protocol for a golden retriever named Navy who was cancer-free after receiving the prescribed cocktail of celecoxib, doxycycline, and tamoxifen – the treatment subsequently became known as the Navy Protocol. Furthermore, tamoxifen treatment alone has been shown to have anti-angiogenetic effects in animal models of cancer which appear to be, at least in part, independent of tamoxifen’s ER antagonist properties.
06 Tamoxifen (10540-29-1) Mechanism Of Action
Tamoxifen powder is a nonsteroidal agent that binds to estrogen receptors (ER), inducing a conformational change in the receptor. This results in a blockage or change in the expression of estrogen dependent genes. The prolonged binding of tamoxifen to the nuclear chromatin of these results in reduced DNA polymerase activity, impaired thymidine utilization, blockade of estradiol uptake, and decreased estrogen response. It is likely that tamoxifen interacts with other coactivators or corepressors in the tissue and binds with different estrogen receptors, ER-alpha or ER-beta, producing both estrogenic and antiestrogenic effects.
07 Tamoxifen (10540-29-1) Application
Tamoxifen is a selective estrogen response modifier (SERM), protein kinase C inhibitor and anti-angiogenetic factor. Tamoxifen is a prodrug that is metabolized to active metabolites 4-hydroxytamoxifen (4-OHT) and endoxifen by cytochrome P450 isoforms CYP2D6 and CYP3A4. In breast cancer, the gene repressor activity of tamoxifen against ERBB2 is dependent upon PAX2. Blocks estradiol-stimulated VEGF production in breast tumor cells.
Protein kinase C inhibitor. Induces apoptosis in human malignant glioma cell lines. Tamoxifen and its metabolite 4-hydroxytamoxifen are selective estrogen response modifiers (SERMs) that act as estrogen antagonists in mammary gland. Blocks estradiol-stimulated VEGF production in breast tumor cells.
08 Tamoxifen (10540-29-1) More research
Tamoxifen for Medical uses
Tamoxifen is currently used for the treatment of both early and advanced estrogen receptor-positive (ER-positive or ER+) breast cancer in pre- and post-menopausal women. Additionally, it is the most common hormone treatment for male breast cancer. It is also approved by the FDA for the prevention of breast cancer in women at high risk of developing the disease. It has been further approved for the reduction of contralateral (in the opposite breast) cancer. The use of tamoxifen is recommended for 10 years.
In 2006, the large STAR clinical study concluded that raloxifene is equally effective in reducing the incidence of breast cancer, but after an average 4-year follow-up, although the difference was not statistically significant, there were 36% fewer uterine cancers and 29% fewer blood clots in women taking raloxifene than in women taking tamoxifen
09 Tamoxifen (10540-29-1) Document Download
10 Tamoxifen (10540-29-1) Reference
- Sutherland, R., et al.: Nature, 267, 434 (1977), Lerner, L., et al.: Cancer Res., 50, 4177 (1990), Love, R., et al.: J. Clin. Oncol., 20 2559 (2002),
- Jordan VC: Fourteenth Gaddum Memorial Lecture. A current view of tamoxifen for the treatment and prevention of breast cancer. Br J Pharmacol. 1993 Oct;110(2):507-17. [PubMed:8242225]
- Steiner AZ, Terplan M, Paulson RJ: Comparison of tamoxifen and clomiphene citrate for ovulation induction: a meta-analysis. Hum Reprod. 2005 Jun;20(6):1511-5. Epub 2005 Apr 21. [PubMed:15845599]
- 01. Overview
- 02. Tamoxifen powder (10540-29-1) video
- 03. Tamoxifen powder Base Information
- 04. Tamoxifen powder General Description
- 05. Tamoxifen powder (10540-29-1) History
- 06. Tamoxifen (10540-29-1) Mechanism Of Action
- 07. Tamoxifen (10540-29-1) Application
- 08. Tamoxifen (10540-29-1) More research
- 09. Tamoxifen (10540-29-1) Document Download
- 10. Tamoxifen (10540-29-1) Reference