Tamoxifen

Summary

Tamoxifen and raloxifene are medications used to treat breast cancer. An important side effect of tamoxifen is an increased risk for developing endometrial cancer. Other side effects seen with both tamoxifen and raloxifene are increased risk of blood clots or thromboembolisms, as well as menopause symptoms.

Key Points

• Tamoxifen, Raloxifene
  • Mechanism
    • Selective estrogen receptor modulators (SERMs)
      • Inhibit estrogen-receptive breast cancer cells
      • But may stimulate estrogen receptors in other tissues (e.g. uterus)
  • Clinical Use
    • Breast Cancer
      • Tamoxifen is continued for years after breast cancer to prevent recurrence
  • Side Effects and Adverse Reactions
    • Endometrial cancer
      • Irregular or excessive menstrual bleeding should be reported
      • Although tamoxifen inhibits estrogen-receptive cells in the breast tissue, it has the opposite effect in the uterus, meaning it stimulates the estrogen-receptive cells. This can lead to excessive proliferation and the growth of cancerous cells.
    • Thromboembolic events
      • Stroke
      • Pulmonary embolism
      • DVT
    • Symptoms of menopause
      • Blockade of estrogen receptors in vaginal tissue
      • Common, expected side effects
        • Hot flashes
        • Vaginal dryness
        • Decreased libido
    • Ocular toxicity
      • Retinopathy
      • Cataracts
      • Report any vision changes or eye problems