Tamoxifen citrate is the chemical name of active ingredient in Nolvadex. 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.
You may be given tamoxifen for five years. Some women are given tamoxifen for a few years and are then changed to a different type of hormonal therapy known as an aromatase inhibitor. Daily dosages greater than 20 milligrams are usually divided in half and taken twice a day, in the morning and evening, or as directed by your doctor. If you are using the liquid, measure the dose carefully using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose.
Most breast cancers need supplies of the female hormone oestrogen to grow. Cancer cells have proteins called receptors on their surface that the sex hormones attach to. Tamoxifen fits into the oestrogen receptor but does not activate the cells to divide. The tamoxifen stays in place and stops oestrogen from reaching the cancer cells so that they either grow more slowly or stop growing altogether. Tamoxifen can greatly reduce the chance of oestrogen-receptor-positive cancers coming back after surgery. It can also be used to shrink large tumours before surgery so that they can be removed.
Side effects are more common in premenopausal women, who may develop menopausal side effects as a result of a lowered level of oestrogen. The most common side effects, apart from feeling sick (nausea), are hot flushes and sweats, particularly at night. Some women feel depressed while taking tamoxifen, but this may be due to other causes.