Fulvestrant
- Medical Review: Jennifer Winn, MD, MS
Fulvestrant (Faslodex) is an estrogen receptor antagonist, or ERA, a class of medicine that stops the activity of estrogen on cancer cells to keep them from growing.
How fulvestrant works
Fulvestrant blocks the effect of estrogen that drives cancer growth in hormone receptor-positive breast cancer.
Who gets fulvestrant
Fulvestrant is FDA approved for use in postmenopausal women with metastatic hormone receptor-positive breast cancer. It may be given to:
- postmenopausal women, if the cancer is HER2-negative and they have not received hormonal therapy
- postmenopausal women, if the cancer grew while taking a different hormonal therapy
- anyone with palbociclib (Ibrance) or abemaciclib (Verzenio) whose cancer grew despite treatment with a different hormonal therapy for early or metastatic breast cancer
How fulvestrant is given
Fulvestrant is given by injection into the buttocks. For the first month, you will receive two shots every 2 weeks. Afterward, it is given as two injections every 4 weeks.
Side effects and things to remember
Common side effects of fulvestrant are:
- pain at the site you receive the injection
- hot flashes
- nausea and vomiting
- fatigue
- muscle, joint and bone pain
- headache
- loss of appetite
- weakness
- cough
- constipation
- shortness of breath
- higher liver enzymes, which means damage or inflammation of the liver
You should not take fulvestrant if you are pregnant, and you should not become pregnant while taking it or for a year after treatment ends as fulvestrant can harm the fetus. You also should not breastfeed while taking fulvestrant.
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