Fulvestrant Brand Name– FASLODEX

What is Fulvestrant

Fulvestrant is an intramuscular estrogen-receptor antagonist without any known estrogen agonist effects. It was the first in a class of antiestrogens that works by downregulating the estrogen receptor as opposed to blocking it as with tamoxifen.

Fulvestrant has demonstrated potent inhibition of breast cancer cells in vitro and in vivo.

In clinical trials, fulvestrant was as effective as anastrozole, an aromatase inhibitor, in postmenopausal women who had received previous hormonal therapy.

Fulvestrant is FDA approved in postmenopausal women as monotherapy or in combination with ribociclib for the first-line treatment of hormone receptor (HR)-positive, HER2-negative advanced breast cancer and as monotherapy or in combination with ribociclib for the treatment of HR-positive advanced breast cancer after disease progression following endocrine therapy.

It is FDA approved in combination with palbociclib or abemaciclib for the treatment of HR-positive, HER2-negative advanced or metastatic breast cancer in women after disease progression on endocrine-based therapy.

Pregnancy should be avoided during treatment and for 1 year after the last dose of fulvestrant. Fulvestrant can also interfere with estradiol measurement by immunoassay, resulting in falsely elevated estradiol levels.


  • breast cancer

For the treatment of breast cancer

for the treatment of hormone receptor (HR)-positive, HER2-negative advanced breast cancer in postmenopausal women who have not previously been treated with endocrine therapy, as monotherapy

Side Effects

  1. abdominal pain
  2. acneiform rash
  3. alopecia
  4. anemia
  5. angioedema
  6. anorexia
  7. anxiety
  8. arthralgia
  9. asthenia
  10. back pain
  11. bone pain
  12. cheilitis
  13. chest pain (unspecified)
  14. conjunctivitis
  15. constipation
  16. cough
  17. cystitis
  18. depression
  19. diaphoresis
  20. diarrhea
  21. dizziness
  22. dysgeusia
  23. dyspnea
  24. elevated hepatic enzymes
  25. fatigue
  26. fever
  27. glossitis
  28. headache
  29. hepatic failure
  30. hepatitis
  31. hot flashes
  32. hyperbilirubinemia
  33. hypoalbuminemia
  34. hypoglycemia
  35. hypophosphatemia
  36. infection
  37. influenza
  38. injection site reaction
  39. insomnia
  40. leukopenia
  41. maculopapular rash
  42. musculoskeletal pain
  43. myalgia
  44. nausea
  45. neuropathic pain
  46. neutropenia
  47. ocular infection
  48. oral ulceration
  49. paresthesias
  50. pelvic pain
  51. peripheral edema
  52. peripheral neuropathy
  53. pharyngitis
  54. pruritus
  55. pulmonary embolism
  56. rash
  57. rhinitis
  58. stomatitis
  59. thrombocytopenia
  60. thromboembolism
  61. thrombosis
  62. urticaria
  63. vaginal bleeding
  64. vertigo
  65. vomiting
  66. weight loss

Monitoring Parameters

  • pregnancy testing


  • anticoagulant therapy
  • breast-feeding
  • children
  • coagulopathy
  • contraception requirements
  • hepatic disease
  • infants
  • infertility
  • laboratory test interference
  • neonates
  • neurologic events
  • peripheral neuropathy
  • pregnancy
  • pregnancy testing
  • reproductive risk
  • thrombocytopenia


  • Fluoroestradiol F 18

Fluoroestradiol F 18: (Major) Administer fluoroestradiol F 18 before starting fulvestrant; however, do not delay indicated therapy to administer fluoroestradiol F 18. Fulvestrant may block estrogen receptors (ER) for up to 28 weeks and reduce the uptake of fluoroestradiol F 18 and detection of ER-positive lesions.