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Generic Name: fulvestrant (ful VES trant)
Brand Names: Faslodex

Medically reviewed by P. Thornton, DipPharm. Last updated on Dec 11, 2018.

What is Faslodex?

See also: Kisqali

Faslodex (fulvestrant) is an anti-estrogen medication. It works by blocking the actions of estrogen in the body. Certain types of breast cancer use estrogen to grow and multiply in the body.

Faslodex is used to treat advanced hormone-related breast cancer in women. It is sometimes used if your cancer tests negative for a protein called human epidermal growth factor receptor 2 (HER2). HER2 protein can speed the growth of cancer cells.

Faslodex may also be used when the cancer has progressed or has spread to other parts of the body after treatment with anti-estrogen medication.

Faslodex may also be given together with another medicine (either abemaciclib or palbociclib) to treat advanced HER2-negative breast cancer that has progressed or spread.

Important information

You should not receive Faslodex if you are pregnant.

Avoid getting pregnant or breast-feeding a baby for at least 1 year after you stop using this medicine.

Before you receive Faslodex, tell your doctor if you have liver disease, a bleeding or blood-clotting disorder, or thrombocytopenia (a low level of platelets in the blood). Also tell your doctor if you are taking a blood thinner such as warfarin (Coumadin, Jantoven).

Call your doctor for instructions if you miss an appointment for your injection.

Before taking this medicine

You should not receive Faslodex if you are allergic to fulvestrant, or if you are pregnant.

To make sure Faslodex is safe for you, tell your doctor if you have ever had:

  • liver disease;

  • a bleeding or blood clotting disorder; or

  • thrombocytopenia (a low level of platelets in the blood).

Using Faslodex during pregnancy could harm the unborn baby. Use effective birth control to prevent pregnancy while you are using this medicine and for at least 1 year after your treatment ends. Tell your doctor right away if you become pregnant during this time.

It is not known whether fulvestrant passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using fulvestrant.

How is Faslodex given?

Faslodex is given as two injections into a muscle of your buttock. Your doctor, nurse, or other healthcare provider will give you this injection. Each injection must be given slowly, and can take up to 2 minutes to complete.

Faslodex is usually given once every 2 weeks at first, and then once a month. Do not miss any scheduled appointments.

When treatment also includes taking abemaciclib or palbociclib, these medicines are taken by mouth and have different dosing schedules. Palbociclib is also taken with food while abemaciclib may be taken with or without food. Follow your doctor's dosing instructions very carefully.

If you are a woman using Faslodex together with Ibrance, tell your doctor if you are going through menopause (you have symptoms such as irregular menstrual periods, hot flashes, night sweats, or vaginal dryness). You may need to be treated with an additional hormone medication.

Use all medications as directed and read all medication guides you receive. Do not change your dose or dosing schedule without your doctor's advice.

This medicine can cause unusual results with certain medical tests. Tell any doctor who treats you that you are using this medicine.

Read all patient information, medication guides, and instruction sheets provided to you. Ask your doctor or pharmacist if you have any questions.

Faslodex dosing information

Usual Adult Dose for Breast Cancer:

Initial dose: 500 mg IM on days 1, 15, and 29, then once a month thereafter.

What happens if I miss a dose?

Call your doctor for instructions if you miss an appointment for your Faslodex injection.

What happens if I overdose?

Since this medication is given by a healthcare professional in a medical setting, an overdose is unlikely to occur.

What should I avoid while receiving Faslodex?

Fulvestrant can pass into body fluids (urine, feces, vomit). For at least 48 hours after you receive a dose, avoid allowing your body fluids to come into contact with your hands or other surfaces. Caregivers should wear rubber gloves while cleaning up a patient's body fluids, handling contaminated trash or laundry or changing diapers. Wash hands before and after removing gloves. Wash soiled clothing and linens separately from other laundry.

Faslodex side effects

Get emergency medical help if you have signs of an allergic reaction to Faslodex: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • signs of nerve damage - numbness, tingling, weakness, or burning pain.

Common Faslodex side effects may include:

  • headache;

  • bone pain, joint pain, muscle pain;

  • nausea, vomiting, loss of appetite, constipation;

  • weakness, feeling tired;

  • cough, sore throat, sinus problems, trouble breathing;

  • abnormal liver function tests;

  • hot flashes; or

  • pain where the medicine was injected.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Faslodex?

Tell your doctor about all your current medicines and any you start or stop using, especially:

  • a blood thinner - warfarin, Coumadin, Jantoven.

This list is not complete. Other drugs may interact with fulvestrant, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Faslodex only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.