Generic Name: tamoxifen
Other Market Name: Nolvadex, Soltamox
Drug Class: Hormone Therapy Medications
Approval Status: Approved
Generic Version Available: Yes
Tamoxifen is a selective estrogen receptor modulator approved for adjuvant (post-surgery) treatment to prevent recurrence or spread of early breast cancer and for treatment of women and men with advanced or metastatic breast cancer. It is also used to prevent breast cancer in high-risk women. It is sometimes used to treat ovarian cancer, though it is not FDA-approved for this indication.
The female hormone estrogen promotes the growth of hormone receptor-positive breast cancer. Tamoxifen works blocking these receptors and preventing estrogen from binding to cancer cells. It has selective activity against breast cancer while having estrogen-like activity elsewhere in the body. It also inhibits some kinases and cytokines that promote cancer growth.
Tamoxifen reduces the risk of breast cancer recurrence or spread (metastasis) after initial treatment with surgery, radiation and chemotherapy. Studies show that it also lowers the chances of developing breast cancer in high-risk women (such as those with a family history) and reduces the likelihood that very early breast cancer known as ductal carcinoma in situ (DCIS) will progress to invasive cancer. It works best in people with estrogen receptor-positive breast cancer. Premenopausal women with advanced breast cancer may be able to use tamoxifen as an alternative to ovary removal.
Dosing Info: Tamoxifen is taken as a pill once or twice daily. The brand-name Nolvadex pill was discontinued and has been replaced by generic versions. Soltamox is an oral liquid formulation of tamoxifen.
Common side effects include hot flashes, muscle and joint pain, swelling, headache, nausea, mood changes and vaginal dryness. Premenopausal women may have irregular periods or stop menstruating. Potential serious side effects may include strokes, blood clots, pulmonary embolism, cataracts and increased risk of uterine cancer. Tamoxifen should not be used during pregnancy.
Last Reviewed: December 13, 2018