Clinical information
Common uses
- metastatic breast cancer (women and men)
- adjuvant treatment after breast cancer surgery
- ductal carcinoma in situ, after surgery and radiation
- reducing breast cancer risk in high-risk women
Common side effects
- hot flashes (most frequent)
- vaginal discharge
- irregular periods
Cautions
- increased risk of blood clots (DVT, pulmonary embolism)
- for risk reduction: not with prior blood clots
- not with warfarin-type anticoagulants in risk-reduction use
- high blood calcium can occur with bone metastases
Interactions
- warfarin-type anticoagulants — anticoagulant effect increased
- anastrozole — do not combine
- letrozole — its levels reduced by tamoxifen
- rifampin — lowers tamoxifen levels
- aminoglutethimide — lowers tamoxifen levels
- cytotoxic chemotherapy — higher blood clot risk
Pregnancy: avoid — can harm the baby; use non-hormonal contraception
Reference information, not medical advice — always follow your doctor or pharmacist. Source: DailyMed, dailymed.nlm.nih.gov, tamoxifen citrate tablet label, setid 509f8ba3-214d-aec8-e063-6294a90af498 (accessed 2026-08-16)