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Faslodex

Generic name: fulvestrantful-VES-trant ]
Drug classes: Estrogen receptor antagonists, Hormones / antineoplastics

Medically reviewed by Philip Thornton, DipPharm. Last updated on Apr 21, 2023.

What is Faslodex?

Faslodex 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 in postmenopausal women with hormone-related breast cancer that is advanced or has spread to other parts of the body (metastatic).

Faslodex is used alone or in combination with another medicine called ribociclib (Kisqali) to treat HR-positive, HER2-negative breast cancer in:

Faslodex is used in combination with palbociclib (Ibrance) or abemaciclib (Verzenio) when the cancer has progressed after treatment with anti-estrogen medication.

Warnings

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 be treated with Faslodex if you are allergic to fulvestrant, or if you are pregnant.

Tell your doctor if you have ever had:

You may need to have a negative pregnancy test 7 days before starting this treatment.

Fulvestrant may harm an unborn baby. Use effective birth control to prevent pregnancy while using this medicine and for at least 1 year after your last dose. Tell your doctor right away if you become pregnant during this time.

Faslodex may affect fertility (ability to have children) in both men and women. However, it is important for women to use birth control to prevent pregnancy because fulvestrant can harm an unborn baby.

Do not breastfeed while using Faslodex, and for at least 1 year after your last dose.

How is Faslodex given?

Faslodex is given as two injections into a muscle of your buttock. A healthcare professional 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.

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

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.

If you are a woman using Faslodex with abemaciclib or palbociclib, tell your doctor if you are still 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.

Dosing information

Usual Adult Dose of Faslodex for Breast Cancer:

Monotherapy:
500 mg IM into the buttocks (gluteal area) slowly (1 to 2 minutes per injection) as two 5 mL injections, one in each buttock, on days 1, 15, 29 and once monthly thereafter

Combination Therapy:
In combination with palbociclib or abemaciclib: 500 mg IM into the buttocks (gluteal area) slowly (1 to 2 minutes per injection) as two 5 mL injections, one in each buttock, on days 1, 15, 29 and once monthly thereafter

Comments:
-This drug is not recommended for use in men.
-When this drug is used in combination with palbociclib, the recommended dose of palbociclib is 125 mg orally once daily for 21 consecutive days followed by 7 days off therapy for a complete cycle of 28 days. Palbociclib should be taken with food. Refer to the prescribing information for palbociclib.
-When this drug is used in combination with abemaciclib, the recommended dose of abemaciclib is 150 mg orally 2 times a day. Abemaciclib may be taken with or without food. Refer to the prescribing information for abemaciclib.
-Pre- or peri-menopausal women treated with the combination of this drug plus palbociclib or abemaciclib should be treated with luteinizing hormone-releasing hormone (LHRH) agonists according to current guidelines.

Uses:
-As monotherapy for hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer in postmenopausal women not previously treated with endocrine therapy or HR-positive advanced breast cancer in postmenopausal women with disease progression following endocrine therapy
-For HR-positive, HER2-negative advanced or metastatic breast cancer in combination with palbociclib or abemaciclib in women with disease progression after endocrine therapy

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:

Common Faslodex side effects may include:

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 other medicines, especially:

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 drug interactions are listed here.

Frequently asked questions

View more FAQ

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.