Highlights for fulvestrant
Fulvestrant is an injected medication used to treat breast cancer in women who have gone through menopause (postmenopausal). It’s used to treat hormone receptor-positive breast cancer that has progressed after other anti-estrogen therapy has been used. It’s also used with the drug palbociclib to treat hormone receptor-negative breast cancer that’s progressed or spread after other endocrine treatment has been used.
This drug is given as an injection into your muscle. It’s given to you by a doctor or nurse in a clinic or hospital. You won’t take this medicine at home.
Fulvestrant should be used with caution if you’re taking blood thinners, are at risk for bleeding, or have low platelet levels in your blood. These factors can increase your risk of bleeding with injections.
Fulvestrant is cleared from your body by your liver. If you have decreased liver function, your doctor may give you a lower dose or not give you the drug. This is to stop too much of the medicine from building up in your blood, which causes side effects.
Common side effects include injection site pain, nausea, muscle, joint, and bone pain, headache, tiredness, hot flashes, vomiting, loss of appetite, weakness, cough, constipation, shortness of breath, and increased liver enzymes.
What is fulvestrant?
This drug is a prescription drug. It’s available as a solution for injection, which is only given by a healthcare provider. You won’t take this drug at home.
This drug may be used as part of a combination therapy. That means you need to take it with other drugs.
Why it's used
This drug is a prescription medicine used to treat hormone receptor-positive breast cancer. It’s only used in women who have gone through menopause and whose cancer has progressed after treatment with an anti-estrogen medicine. It’s also used with the drug palbociclib to treat hormone receptor-negative breast cancer that has progressed or spread after other endocrine treatment has been used.
How it works
This drug belongs to a class of drugs called anti-androgens or estrogen antagonists. A class of drugs refers to medications that work similarly. They have a similar chemical structure and are often used to treat similar conditions.
fulvestrant Side Effects
Most Common Side Effects
The most common side effects that occur with fulvestrant therapy include:
injection site pain
muscle, joint, and bone pain
loss of appetite
shortness of breath
increased liver enzymes
If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.
Serious Side Effects
If you experience any of these serious side effects, call your doctor right away. If your symptoms are potentially life threatening, or if you think you’re experiencing a medical emergency, call 9-1-1.
Injection reactions, such as sciatica, neuralgia, neuropathic pain, and peripheral neuropathy. Symptoms typically occur in the legs and can include:
- numbness or tingling
- muscle weakness
Allergic reaction. Symptoms include:
- swelling of your face, lips, tongue, or throat
- trouble breathing
- skin rash
This drug doesn’t cause drowsiness.
fulvestrant May Interact with Other Medications
Fulvestrant can interact with other medications, herbs, or vitamins you might be taking. Your healthcare provider will look out for interactions with your current medications. Always be sure to tell your doctor about all medications, herbs, or vitamins you’re taking.
How to Take fulvestrant (Dosage)
Your doctor will determine a dose that’s right for you based on your individual needs. Your general health may affect your dose. Tell your doctor about all health conditions you have before your doctor or nurse administers the drug to you.
This drug comes with serious risks if you don’t take it as prescribed.
If you don’t take it at all or skip or miss doses/appointments
Missing a dose could affect your treatment outcome. In order to effectively fight cancer, it’s important to receive your injections on the right day.
If you take too much
If you take too much, you’re at a higher risk for developing side effects, such as nausea, musculoskeletal pain, headache, tiredness, hot flashes, vomiting, loss of appetite, weakness, cough, constipation, and shortness of breath. If you take too much, and experience any of these side effects, call your doctor and go to the emergency room.
What to do if you miss a dose/appointment
If you can’t make your appointment or miss your appointment, contact your doctor right away.
How to tell the drug is working
If this drug is working, the growth of your breast cancer may slow down or stop. Your doctor will do tests and evaluate your symptoms to tell if this drug is working.
This drug is used for long-term treatment.
- Faslodex – fulvestrant injection. (2016, July). Retrieved from <"a href="http://www.accessdata.fda.gov/drugsatfda_docs/label/2016/021344s029lbl.pdf">http://www.accessdata.fda.gov/drugsatfda_docs/label/2016/021344s029lbl.pdf
Content developed in collaboration with University of Illinois-Chicago, Drug Information Group
Medically reviewed by Creighton University, Center for Drug Information and Evidence-Based Practice on September 21, 2016