Faslodex Injection: Uses, Dosage, Side Effects, Precautions and Alternates

Quick overview

Faslodex Injection (fulvestrant) is a prescription estrogen receptor antagonist given by injection to treat certain types of hormone receptor-positive breast cancer in postmenopausal women. It is used for metastatic breast cancer that has progressed after other hormone treatments, as well as for certain advanced HER2-negative breast cancers, sometimes combined with other targeted therapies. It works by blocking and reducing estrogen receptors on cancer cells, helping to slow or stop their growth.

What is Faslodex Injection

Faslodex is a prescription injection medicine used to treat certain types of hormone receptor-positive breast cancer in women who have gone through menopause, including cancer that has spread or gotten worse after other hormone treatments.

Faslodex Injection uses

• Treatment of hormone receptor positive metastatic breast cancer in postmenopausal women with disease progression following antiestrogen therapy.
• In postmenopausal females with HER2-negative advanced breast cancer who've never had hormone therapy before.
• Along with ribociclib (Kisqali), in postmenopausal females with HER2-negative advanced or metastatic breast cancer who've never tried hormone therapy or whose breast cancer got worse after previous hormone therapy.
• Along with palbociclib (Ibrance) or abemaciclib (Verzenio), in females with HER2-negative advanced or metastatic breast cancer whose breast cancer got worse after hormone therapy.

Benefits of Faslodex Injection

• May slow the growth of tumors that are stimulated by estrogen.
• Can help stop the spread of hormone receptor-positive cancer or get rid of it completely.
• Treats certain hormone receptor-positive breast cancers.
• Blocks and degrades estrogen receptors.
• Helps slow growth of estrogen-dependent cancer cells.
• Used in certain advanced or metastatic breast cancers.
• Can be combined with targeted therapies in selected patients.

How Faslodex Injection works

Faslodex blocks the hormone estrogen from attaching to receptors on breast cancer cells, which stops estrogen from signaling the cancer cells to grow and multiply. It also lowers the amount of the estrogen receptor protein in the cancer cells.

Faslodex Injection dosage

This medicine is given as an injection into the muscle of the buttocks by a healthcare provider; you do not give it to yourself. Each treatment is given as two separate injections, one into each buttock, given slowly over one to two minutes per injection. Injections are usually given on days 1, 15, and 29 of the first month of treatment, and then once a month after that. If you have severe liver problems, you may receive only one injection at each visit instead of two. You can ask your nurse to warm up the injection in their hands before giving it to you, which may help lessen pain.

Available forms and strengths

Faslodex is available as a solution in a prefilled syringe for intramuscular injection.

Side effects of Faslodex Injection

Common

• Injection site pain
• Nausea
• Bone pain
• Joint pain
• Headache
• Back pain
• Fatigue
• Pain in the arms or legs
• Hot flashes
• Vomiting
• Loss of appetite
• Weakness
• Cough
• Constipation
• Shortness of breath
• Increased liver enzymes
• Hair loss (when combined with other breast cancer medicines)

Serious

• Increased liver enzymes, which can cause stomach pain, yellowing of the skin or eyes, or dark urine
• Bleeding problems, such as bruising easily or bleeding that doesn't stop after a cut
• Allergic reactions, including rash, itching, swelling of the face, lips, tongue or throat, or trouble breathing

Warnings and precautions

• This medicine should be used with caution in people who have bleeding disorders, low platelet counts, or who take blood-thinning medicines, because the injection into the muscle could cause increased bleeding.
• Do not take this medicine if you have ever had an allergic reaction to it or any of its ingredients.
• You should not become pregnant while taking this medicine, since it can cause harm to an unborn baby.
• Faslodex can harm an unborn baby and should not be used during pregnancy. Women who can become pregnant should use effective non-hormonal birth control while taking this medicine and for one year after the last dose.
• It isn't known if this medicine passes into human breast milk. Because of the chance of harm to a nursing baby, you and your doctor should decide whether you will take this medicine or breastfeed, not both.
• No routine dose adjustment is usually required for mild-to-moderate renal impairment.
• People with moderate liver problems are usually given a lower dose, since the drug builds up more in the body. The medicine has not been studied in people with severe liver problems.
• There are no known interactions between this medicine and alcohol, but people with liver disease (including alcohol-related liver disease) may need a lower dose. Ask your doctor how much alcohol, if any, is safe for you while taking this medicine.
• Fatigue or dizziness may affect driving.

Storage

• Refrigerate, 2°-8°C (36°-46°F).
• To protect from light, store in the original carton until time of use.

When to see a doctor

• Get medical help right away if you have signs of a serious allergic reaction, such as swelling of the face, lips, tongue, or throat, or trouble breathing.
• Call your doctor right away if you notice signs of liver problems, such as stomach pain, yellowing of the skin (jaundice), or dark urine.
• Tell your doctor right away if you have signs of a bleeding problem, such as bruising easily or a cut that doesn't stop bleeding.
• Tell your healthcare provider right away if you become pregnant or think you might be pregnant while receiving this medicine.

Alternatives

• Anastrozole
• Letrozole
• Exemestane