Tamoxifen, a triphenylethylene-derivative, nonsteroidal estrogen agonist-antagonist, is an antineoplastic agent. Tamoxifen blocks the actions of estrogen in breast tissue and is used to treat estrogen receptor-positive breast cancer in adults and to lower the risk of breast cancer in women with DCIS or at high risk. Learn about side effects, interactions, and indications. Nolvadex (Tamoxifen Citrate) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources. Tamoxifen reference guide for safe and effective use from the American Society of Health-System Pharmacists (AHFS DI). What Is Tamoxifen and How Does It Work? Tamoxifen is used to treat breast cancer that has spread to other parts of the body (metastatic breast cancer), to treat breast cancer in certain patients after surgery and radiation therapy, and to reduce the chances of breast cancer in high-risk patients. Tamoxifen citrate is a type of hormone therapy called a selective estrogen receptor modulator (or SERM). It works by binding to estrogen receptors, blocking estrogen’s effects in some tissues while mimicking its effects in others. Overview: Tamoxifen is commonly used to treat certain types of breast cancer. It is also used to lower your risk of invasive breast cancer and keep some breast cancers from coming back. It blocks. Each 10 mL of SOLTAMOX oral solution contains 20 mg tamoxifen, equivalent to 30.4 mg tamoxifen citrate. The oral solution is a sugar-free, clear colorless liquid, with licorice and aniseed. Tamoxifen prescription and dosage information for physicians and health care professionals. Pharmacology, adverse reactions, warnings, and Tamoxifenside effects. Tamoxifen is an antiestrogen drug used in the treatment of breast cancer. It blocks the activity of estrogen, helping to stop the growth of some tumors.