Tamoxifen is an antioestrogen medication used as a tablet to treat and prevent breast cancer. Antiestrogens are used to block the action of the oestrogen hormone.
Tamoxifen must not be used in pregnancy unless the mother’s life is at risk. Adequate contraception must be used by all fertile women who use tamoxifen. Breastfeeding must be ceased before use and it is not for use in children. Use tamoxifen with caution if suffering from bleeding disorders and blood cell abnormalities. Regular gynaecological checks are essential.
Common side effects include hot flushes, abnormal vaginal bleeding, itchy vulva, fluid retention, lightheadedness, nausea, vomiting and diarrhoea. less commonly a vaginal discharge, headache, blood clots (thrombosis), bone pain and vision changes may occur. Rarely there may be damage to the uterus and ovary, and blood cell changes.
Tamoxifen interacts with anticoagulants (eg. warfarin) and the herb dong quai.
This medication has saved the lives of thousands of women with breast cancer and has prevented recurrences in thousands more. It was introduced in the late 1980s.