Contain the active ingredient : Tamoxifen which is the main hormone treatment used for breast cancer in women who haven't yet gone through the menopause. It's sometimes also used to treat post-menopausal women.
Tamoxifen can be used in several different ways for breast cancer, depending on the stage of the cancer and what other treatment options are used.
Most women take tamoxifen for five years after having surgery, chemotherapy or radiotherapy (or a combination of these) for their breast cancer. The tamoxifen reduces the risk of the cancer coming back and also reduces the risk of getting cancer in the other breast. Some women may take tamoxifen for two or three years and then switch to a different hormonal therapy.
Sometimes tamoxifen can be used to help shrink a large tumour before having surgery; for some women this can help avoid having a mastectomy.
Tamoxifen may also be used to help control cancers that have come back or spread.
Tamoxifen can also be used to treat infertility in women, when this is caused by problems with ovulation.
Tamoxifen is used to stimulate ovulation in women who can't tolerate the medicine usually used for this, called clomifene. It's taken for a few days during your period to stimulate ovulation later in your cycle.
How does tamoxifen work?
Tamoxifen is a type of medicine called an 'anti-oestrogen'. It works by blocking oestrogen receptors, thereby blocking the effect of oestrogen.
Most breast cancers are sensitive to oestrogen, and their growth is increased in the presence of this hormone. Oestrogen binds to oestrogen receptors on the breast cancer cells and causes changes within the cells that result in faster growth of the cancer. Breast cancers that are sensitive to oestrogen are called oestrogen receptor positive cancers.
By blocking oestrogen receptors, tamoxifen blocks the effect of oestrogen on the breast cancer cells. This stops them from growing.
In the treatment of infertility, tamoxifen stimulates ovulation by blocking oestrogen receptors in a part of the brain called the hypothalamus. This causes more follicle stimulating hormone (FSH) and luteinising hormone (LH) to be released from the pituitary gland. FSH stimulates the ovaries and LH causes the release of an egg from the ovaries (ovulation).
What is it used for?
Treating oestrogen-receptor-positive breast cancer.