Overview: Fulvestrant is an injection used to treat certain types of breast cancer. It blocks growth of breast tissue that needs estrogen to grow. The most common side effects are pain at the injection site, nausea, bone pain, and joint or muscle pain.
Uses
What is fulvestrant used for?
Fulvestrant is commonly used to treat certain types of breast cancer.
Fulvestrant may also be used for other conditions as determined by your healthcare provider.
How does fulvestrant work (mechanism of action)?
Fulvestrant blocks estrogen activity in some tissue. It binds to estrogen receptors blocking growth of breast tissue that needs estrogen to grow.
How is fulvestrant supplied (dosage forms)?
Brands and other names
- Faslodex
Dosage forms and strengths
- 250 mg/5 mL solution for injection, prefilled syringes
How should I store fulvestrant?
Fulvestrant is usually given by a healthcare provider in a hospital or clinic. If you will store fulvestrant at home, follow the instructions given by your healthcare provider.
Side Effects
What are the most common side effects of fulvestrant?
The most common side effects of fulvestrant are listed below. Tell your healthcare provider if you have any of these side effects that bother you.
- Pain at the injection site
- Nausea, vomiting, constipation, or diarrhea
- Bone pain
- Joint pain, muscle pain, back pain, or pain in your arms, legs, hands, or feet
- Headache
- Feeling tired or weak
- Hot flashes
- Loss of appetite
- Cough or shortness of breath
- Increased liver enzymes
There may be other side effects of fulvestrant that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
What are the serious side effects of fulvestrant?
While less common, the most serious side effects of fulvestrant are described below, along with what to do if they happen.
Severe Allergic Reactions. Fulvestrant may cause allergic reactions, which can be serious. Stop using fulvestrant and get help right away if you have any of the following symptoms of a serious allergic reaction.
- Breathing problems or wheezing
- Racing heart
- Fever or general ill feeling
- Swollen lymph nodes
- Swelling of the face, lips, mouth, tongue, or throat
- Trouble swallowing or throat tightness
- Itching, skin rash, or pale red bumps on the skin called hives
- Nausea or vomiting
- Dizziness, feeling lightheaded, or fainting
- Stomach cramps
- Joint pain
Nerve Damage. It is possible for your sciatic nerve to be damaged when receiving fulvestrant injections. Call your healthcare provider right away if you have any of the following symptoms in your legs.
- Numbness or a tingly feeling
- Weakness
Warnings & Precautions
Who should not use fulvestrant?
Allergies to Ingredients. People who are allergic to any of the following should not use fulvestrant.
- Fulvestrant
- Faslodex
- Any of the ingredients in the specific product dispensed
Your pharmacist can tell you all of the ingredients in the specific fulvestrant products they stock.
What should I know about fulvestrant before using it?
Blood tests measuring your estradiol (a hormone) levels while you are using fulvestrant may not be accurate. Tell all of your healthcare providers that you are using fulvestrant, so they can accurately interpret your lab work.
It may be difficult for you or your partner to get pregnant while you are using fulvestrant. Talk to your healthcare provider if you have concerns about this.
What should I tell my healthcare provider before using fulvestrant?
Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if fulvestrant is right for you.
In particular, make sure that you discuss any of the following.
Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.
- Low blood platelet levels or you bleed easily
- Liver problems
Blood Thinners. Tell your healthcare provider if you use a blood thinner. Medicines that thin your blood may increase your risk of bleeding when you receive fulvestrant injections.
Pregnancy. You should use an effective method of birth control while using fulvestrant. Your healthcare provider may check to be sure you are not pregnant before you start using it. Fulvestrant may cause harm to an unborn baby. Tell your healthcare provider if you are, think you are, or plan to become pregnant.
Breastfeeding. It is not known if fulvestrant passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should stop breastfeeding or stop fulvestrant.
Interactions
Does fulvestrant interact with foods or drinks?
There are no known interactions between fulvestrant and foods or drinks.
It is unknown if drinking alcohol will affect fulvestrant. However, the risk of hot flashes may be increased if you drink alcohol while using fulvestrant because alcohol can trigger hot flashes.
Does fulvestrant interact with other medicines (drug interactions)?
There are no known interactions between fulvestrant and other medicines. Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.
Overdose/Missed Dose
What should I do if I accidentally use too much fulvestrant?
If you or someone else has used too much fulvestrant, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.
What should I do if I miss a dose of fulvestrant?
If you miss an appointment to get your fulvestrant dose, call to make another appointment as soon as possible.