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Fulvestrant

Brand names: Faslodex

What is fulvestrant used for?

  • Fulvestrant is used to treat breast cancer.
  • This medicine may be used with other drugs to treat your health condition. If you are also taking other drugs, talk with your doctor about the risks and side effects that may happen.

Before taking fulvestrant, tell your doctor:

  • If you are allergic to fulvestrant; any part of this medicine; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
  • If you are breast-feeding. Do not breast-feed while you take fulvestrant and for 12 months after your last dose.

This medicine may interact with other drugs or health problems.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take fulvestrant with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take fulvestrant?

  • Tell all of your health care providers that you take fulvestrant. This includes your doctors, nurses, pharmacists, and dentists.
  • Be sure to have regular breast exams and gynecology check-ups. You will also need to do breast self-exams as you have been told.
  • This medicine may affect certain lab tests. Tell all of your health care providers and lab workers that you take fulvestrant.
  • This medicine may affect fertility. Fertility problems may lead to not being able to get pregnant or father a child.
  • This medicine may cause harm to an unborn baby. A pregnancy test will be done before you start fulvestrant to show that you are NOT pregnant.
  • Women must use birth control while taking fulvestrant and for some time after the last dose. Ask your doctor how long to use birth control. If you get pregnant, call your doctor right away.

How is fulvestrant best taken?

Use fulvestrant as ordered by your doctor. Read all information given to you. Follow all instructions closely.

  • It is given as a shot into a muscle.

What do I do if I miss a dose?

  • Call your doctor to find out what to do.

What are the side effects of fulvestrant that I need to call my doctor about immediately?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • Signs of infection like fever, chills, very bad sore throat, ear or sinus pain, cough, more sputum or change in color of sputum, pain with passing urine, mouth sores, or wound that will not heal.
  • Signs of a urinary tract infection (UTI) like blood in the urine, burning or pain when passing urine, feeling the need to pass urine often or right away, fever, lower stomach pain, or pelvic pain.
  • Low mood (depression).
  • Anxiety.
  • Chest pain or pressure.
  • Shortness of breath.
  • Swelling in the arms or legs.
  • Any unexplained bruising or bleeding.
  • This medicine may cause nerve damage in the area where the injection is given. Call your doctor right away if you have any leg numbness, tingling, or weakness.

What are some other side effects of fulvestrant?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

  • Hot flashes.
  • Headache.
  • Feeling dizzy, tired, or weak.
  • Back, bone, joint, or muscle pain.
  • Constipation.
  • Cough.
  • Throat irritation.
  • Stomach pain.
  • Pelvic pain.
  • Trouble sleeping.
  • Sweating a lot.
  • Flu-like signs.
  • Pain in arms or legs.
  • Pain where the shot was given.
  • Diarrhea, throwing up, upset stomach, and feeling less hungry are common with fulvestrant. If these happen, talk with your doctor about ways to lower these side effects. Call your doctor right away if any of these effects bother you, do not get better, or get very bad.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

If overdose is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out fulvestrant?

  • If you need to store fulvestrant at home, talk with your doctor, nurse, or pharmacist about how to store it.

Consumer information use and disclaimer

  • If your symptoms or health problems do not get better or if they become worse, call your doctor.
  • Do not share your drugs with others and do not take anyone else's drugs.
  • Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
  • Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
  • Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about fulvestrant, please talk with your doctor, nurse, pharmacist, or other health care provider.
  • If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

This information should not be used to decide whether or not to take fulvestrant or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to fulvestrant. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.

Source: Wolters Kluwer Health. Last updated August 20, 2020.