Faslodex (fulvestrant) is a brand-name drug prescribed for adults with certain types of breast cancer. Faslodex comes as a solution for intramuscular injection. It’s given by a healthcare professional, typically once per month.
Faslodex is approved by the Food and Drug Administration (FDA) to treat hormone receptor-positive breast cancer. Faslodex is a type of hormone therapy. Doctors prescribe it alone or in combination with other breast cancer drugs.
Faslodex is prescribed by itself for:
- Hormone receptor-positive, HER2-negative advanced breast cancer in postmenopausal females* who haven’t received hormone therapy before. (With advanced breast cancer, the cancer has spread to nearby tissues or lymph nodes.)
- Hormone receptor-positive advanced breast cancer in postmenopausal females whose cancer has worsened after receiving a different hormone therapy in the past.
Faslodex is prescribed with other drugs for:
- Hormone receptor-positive, HER2-negative advanced or metastatic breast cancer in postmenopausal females who haven’t received hormone therapy before, or whose cancer worsened after receiving a different hormone therapy in the past. For this purpose, doctors prescribe Faslodex with ribociclib (Kisqali). (With metastatic breast cancer, the cancer has spread to distant areas of the body.)
- Hormone receptor-positive, HER2-negative advanced or metastatic breast cancer in females whose cancer worsened after receiving a different hormone therapy in the past. For this purpose, doctors prescribe Faslodex with palbociclib (Ibrance) or abemaciclib (Verzenio).
Faslodex belongs to a drug class called estrogen receptor antagonists. Faslodex is available in a generic version.
Keep reading for specific information about the dosage of Faslodex, including its strength and how the medication is given. For a comprehensive look at Faslodex, including more details about its uses, see this article.
Note: This article describes typical dosages for Faslodex provided by the drug’s manufacturer. However, your doctor will prescribe the Faslodex dosage that’s right for you.
Keep reading below for more information on Faslodex dosing.
Faslodex comes as a solution in a prefilled syringe for intramuscular injection. Your doctor or another healthcare professional will give your injections. To learn more, see the “How Faslodex is given” section below.
Faslodex comes in one strength of 250 milligrams (mg) in 5 milliliters (mL) of solution.
The following information describes dosages that are commonly prescribed or recommended. However, your doctor will determine the best dosage to fit your needs.
Dosage for breast cancer
Faslodex may be prescribed for hormone receptor-positive breast cancer in certain situations. Doctors prescribe Faslodex alone or in combination with other breast cancer drugs. (For details, see the top of this article.)
If your doctor prescribes Faslodex, your dose will likely be 500 mg (given as two injections of 250 mg each). To start, you’ll receive three doses of Faslodex during the first month, on days 1, 15, and 29. After these three doses, you’ll receive monthly injections. The typically recommended maintenance dosage is 500 mg once per month.
Talk with your doctor if you’d like more information about your Faslodex dosing schedule.
Faslodex is meant to be a long-term treatment. If you and your doctor determine that Faslodex is safe and effective for you, you’ll likely take it long term.
Before you start Faslodex, talk with your doctor about what to expect.
The Faslodex dosage your doctor prescribes will depend on certain factors. These include:
- your age
- your liver function
If you have liver damage, your doctor may lower your Faslodex dosage. This includes lower starting doses at the beginning of treatment and lower maintenance doses.
Talk with your doctor if you have questions about Faslodex dosage adjustments.
Your doctor or another healthcare professional will give you Faslodex as an intramuscular injection in your buttocks area. Typically, you’ll go to your doctor’s office or a clinic for your injections.
Faslodex comes in syringes prefilled with a solution containing 250 milligrams (mg) of the drug. A typical dose is 500 mg, so you’ll receive two 250-mg injections. Your doctor will inject one syringe into each buttock slowly, over 1–2 minutes.
If you have questions about how Faslodex is given, talk with your doctor for more information.
You’ll receive Faslodex doses at your doctor’s office or at a hospital or clinic. If you miss a scheduled appointment for your dose, call your doctor’s office right away to reschedule.
To help make sure that you don’t miss an appointment, try using a reminder system. This can include setting an alarm or putting an appointment note where you’ll see it, such as on your bathroom mirror or bedside table. You could also use the calendar app on your phone.
The dosages in this article are typical dosages provided by the drug’s manufacturer. If your doctor recommends Faslodex for you, they’ll prescribe the dosage that’s right for you.
If you have questions about the dosage of Faslodex that’s best for you, talk with your doctor.
Besides learning about dosage, you may want other information about Faslodex. These additional articles might be helpful:
- More about Faslodex. For information about other aspects of Faslodex, refer to this article.
- Side effects. To learn about side effects of Faslodex, see this article. You can also look at the Faslodex prescribing information.
- Details about your condition. For details about your condition, see our breast cancer hub.
Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.