Selective Estrogen Receptor Modulator


Selective Estrogen Receptor Modulator, SERM, Droloxifene, Idoxifene, Toremifene, Fulvestrant, Ospemifene, Osphena

  • Indications
  1. Indications vary with specific SERM effects
  2. Hormone Replacement in postmenopausal women
    1. Beyond hot flash stage
    2. Estrogen Replacement contraindicated (Breast Cancer)
    3. Raloxifene
  3. Breast Cancer Prevention in post-menopausal women
    1. Breast Cancer risk >1.66% in 5 years
    2. Raloxifene
    3. Tamoxifen
  4. Breast Cancer Prevention in pre-Menopause
    1. Breast Cancer risk >1.66% in 5 years and age over 35 years old
    2. Tamoxifen
  5. Refractory Atrophic Vaginitis with severe Dyspareunia
    1. Ospemifene (Osphena)
  6. Osteoporosis Prevention in postmenopausal women
    1. HRT is now only recommended for menopausal symptom management
    2. Raloxifene
  • Contraindications
  1. Venous Thromboembolism
  2. Perioperative period
  3. Prolonged immobilization
  4. History of Cerebrovascular Accident (CVA) or Transient Ischemic Attack (TIA)
  • Mechanism
  1. Selective Estrogen Receptor Modulator (SERM)
    1. Diverse group of agents that bind Estrogen receptors with variable activity depending on their target tissue
    2. Most SERMs in use are estrogen Antagonists at Breast and endometrial tissue
  • Medications
  1. Raloxifene
    1. Indicated for breast Cancer Prevention in post-menopausal women and Hormone replacment therapy
    2. Historically used for Osteoporosis Prevention
      1. HRT is now only recommended for menopausal symptom management
  2. Tamoxifen
    1. Indicated for Breast Cancer Prevention in pre-Menopauseal and post-menopausal women
  3. Ospemifene (Osphena)
    1. Indicated for refractory Atrophic Vaginitis with severe Dyspareunia
    2. Avoid in Estrogen-dependent cancer, Venous Thromboembolism, Cardiovascular Risk, pregnancy
    3. Dosing: 60 mg orally daily with food
  4. Bazedoxifene
    1. Combined with Estrogen in Duavee, a Tissue-selective Estrogen Complex (TSEC)
    2. Indicared for Estrogen Replacement Therapy in patients with an intact Uterus
      1. Alternative to combination Estrogen with Progesterone
  5. Fulvestrant
    1. Synthetic Estrogen receptor Antagonist
    2. Competitively binds Estrogen receptors in Breast Cancer cells, decreasing Estrogen receptor binding
    3. May be effective in Tamoxifen-resistant, Estrogen-sensitive, Breast Cancer
  6. Other agents
    1. Droloxifene
    2. Idoxifene
    3. Toremifene
  • Adverse Effects
  1. Hot Flashes
  2. Leg Cramps
  3. Increased Deep Vein Thrombosis and Thromboembolism risk
    1. DVT, PE and Cardiovascular Risk is an FDA black box warning
    2. More likely to occur in first 4 months of treatment
    3. Similar to risk with Estrogen Replacement