Taking tamoxifen: what to know

Tamoxifen is a selective oestrogen receptor modulator. It blocks oestrogen signals in breast tissue, so it may be used to treat hormone-sensitive breast cancer or reduce risk in selected people. It can act differently in other tissues, which is why your medical history and regular follow-up matter.

Hot flushes, night sweats, vaginal dryness or discharge, changes in periods, nausea, tiredness and mood changes can occur. Some people have no troublesome effects. Tamoxifen can rarely contribute to blood clots or changes in the womb lining, so unusual symptoms should not be ignored.

Take tamoxifen at the prescribed dose and time each day. Follow your pharmacist's instructions if you miss a dose; do not take extra tablets without advice. Tell every doctor and pharmacist that you take tamoxifen before starting another medicine, supplement or herbal product. Some medicines can alter how tamoxifen works.

Keep appointments for review and mention hot flushes, sexual or vaginal symptoms, mood changes, or troublesome nausea. If you could become pregnant, ask your team about reliable contraception because tamoxifen is not suitable during pregnancy. Discuss pregnancy plans before changing or stopping treatment.

Seek urgent care for sudden breathlessness, chest pain, coughing blood, or a painful swollen leg. Contact your clinician promptly for unexpected vaginal bleeding, pelvic pain, a new vision change, severe headache, or symptoms that are persistent or worsening.

Ask what tamoxifen is intended to do in your care, how long you should take it, and which medicines should be avoided. Ask what bleeding or clot symptoms require urgent help, how side effects can be managed, and who to contact outside clinic hours.