What is tamoxifen (Soltamox)?

Tamoxifen is an anti-estrogen that prevents the effects of estrogens on tissues.

What brand names are available for tamoxifen (Soltamox)?

Soltamox is currently the only brand available for tamoxifen. Nolvadex brand has been discontinued.

Is tamoxifen (Soltamox) available as a generic drug?


Do I need a prescription for tamoxifen (Soltamox)?


Why is tamoxifen (Soltamox) prescribed to patients?

  • Tamoxifen is used for the treatment of invasive breast cancer in men and women, the most common type of breast cancer, following surgery and/or radiation and for preventing invasive breast cancer in women at high risk for developing it.
  • Tamoxifen also is used for the treatment of women following surgery and radiation for a less common type of breast cancer called ductal carcinoma in situ (DCIS or intraductal carcinoma). Women who have had DCIS are at high risk for developing invasive breast cancer at a later date, and tamoxifen prevents development of the invasive cancer in almost half of the women during the first five years of treatment.
  • Occasionally, tamoxifen is used to stimulate ovulation.

What are the side effects of tamoxifen (Soltamox)?


  • Uterine malignancies, stroke, and pulmonary embolism were reported when tamoxifen was used for risk-reduction in women with ductal carcinoma in situ and women at high risk for breast cancer.

The most common side effects associated with tamoxifen are:

Serious side effects include:

  • Tamoxifen is associated with blood clots leading to deep vein thrombosis and pulmonary embolism.
  • Tamoxifen can cause abnormalities of liver tests, reduced white blood cells, red blood cells, and platelets. Reduced platelets can lead to bleeding. Patients should keep appointments for blood work to monitor for these side effects. Patients should report any suspected side effects immediately, especially bleeding and yellowing of the skin.

What is the dosage for tamoxifen (Soltamox)?

  • The dose for metastatic breast cancer treatment, DCIS, and prevention of breast cancer is 10 mg twice daily or 20 mg once daily for 5 years.
  • The dose for stimulation of ovulation is 5-40 mg twice daily for 4 days.
  • Tamoxifen can be taken with food.

Which drugs or supplements interact with tamoxifen (Soltamox)?

  • Tamoxifen increases the blood thinning effect of warfarin (Coumadin, Jantoven) and reduces blood levels of letrozole (Femara) and anastrozole (Arimidex).
  • Phenobarbital and rifampin may reduce blood levels of tamoxifen by increasing the breakdown of tamoxifen.

Is tamoxifen (Soltamox) safe to use during pregnancy or while breastfeeding?

  • Tamoxifen should not be used during pregnancy because it can harm the fetus.
  • It is not known whether tamoxifen is excreted in breast milk. Tamoxifen causes a reduction in milk production. Women taking tamoxifen should not breastfeeding.

What else should I know about tamoxifen (Soltamox)?

What preparations of tamoxifen (Soltamox) are available?
  • Tablets: 10 and 20 mg. Solution: 10 mg/5 ml
How should I keep tamoxifen (Soltamox) stored?
  • Tamoxifen should be stored in a dry place at 15 C – 30 C (59 F – 86 F).
How does tamoxifen (Soltamox) work?
  • The precise mechanism of its action is unknown, but one possibility is that it binds and blocks estrogen receptors on the surface of cells, preventing estrogens from binding and activating the cell. It is used in patients for treating and preventing breast cancer.
When was tamoxifen (Soltamox) approved by the FDA?
  • Tamoxifen was approved by the FDA in December 1997.

From WebMD Logo

Cancer Resources
Featured Centers
Health Solutions From Our Sponsors

Medically Reviewed on 3/18/2019


Medically reviewed by John P. Cunha, DO, FACOEP; Board Certified Emergency Medicine


FDA Prescribing Information