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Drug Information

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  • Common uses
  • How to take the medication
  • Common side effects
  • Precautions & interactions

How Fulvestrant Injection works, side effects, interactions and precautions.

Fulvestrant Injection

Fulvestrant Injection

(ful ves' trant)

Brand Name(s): , Faslodex®


WHY is this medicine prescribed?

Fulvestrant injection is used to treat a certain type of hormone receptor positive, advanced breast cancer (breast cancer that depends on hormones such as estrogen to grow) in women who have experienced menopause (change of life; end of monthly menstrual periods) and have not previously been treated with an anti-estrogen medication such as tamoxifen (Nolvadex). Fulvestrant injection is also used to treat hormone receptor positive, advanced breast cancer in women who have experienced menopause and whose breast cancer has worsened after they were treated with an anti-estrogen medication such as tamoxifen. Fulvestrant injection is also used in combination with palbociclib (Ibrance®) to treat hormone receptor positive, advanced breast cancer in women whose breast cancer has worsened after they were treated with anti-estrogen medication such as tamoxifen. Fulvestrant is in a class of medications called estrogen receptor antagonists. It works by blocking the action of estrogen on cancer cells. This can slow or stop the growth of some breast tumors that need estrogen to grow.

Are there OTHER USES for this medicine?

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

HOW should this medicine be used?

Fulvestrant comes as a solution (liquid) to be injected slowly over 1 to 2 minutes into a muscle in the buttocks. Fulvestrant is administered by a doctor or nurse in a medical office. It is usually given once every 2 weeks for the first 3 doses (days 1, 15, and 29) and then once a month thereafter. You will receive your dose of medication as two separate injections (one in each buttock).

Ask your doctor or pharmacist for a copy of the manufacturer's information for the patient.

What SPECIAL PRECAUTIONS should I follow?

Before receiving fulvestrant,

  • tell your doctor and pharmacist if you are allergic to fulvestrant, any other medications , or any of the ingredients in fulvestrant injection. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention anticoagulants (blood thinners) such as warfarin (Coumadin, Jantoven). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have or have ever had any bleeding problems or liver disease.
  • tell your doctor if you are pregnant, or plan to become pregnant.You should not become pregnant while you are receiving fulvestrant and for at least 1 year after receiving the final dose. Talk to your doctor about birth control methods that you can use during your treatment. Your doctor may also check to see if you are pregnant within 7 days before you begin treatment. Tell your doctor if you become pregnant during your treatment with fulvestrant. Fulvestrant may harm the fetus.
  • tell your doctor if you are breastfeeding. You should not breastfeed during your treatment with fulvestrant and for 1 year after receiving the final dose.
  • you should know that this medication may decrease fertility in men and women. Talk to your doctor about the risks of receiving fulvestrant.

What SPECIAL DIETARY instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do IF I FORGET to take a dose?

If you miss an appointment to receive a dose of fulvestrant, call your doctor as soon as possible.

What SIDE EFFECTS can this medicine cause?

Fulvestrant may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • nausea
  • vomiting
  • constipation
  • diarrhea
  • stomach pain
  • loss of appetite
  • sore throat
  • mouth sores
  • weakness
  • hot flashes or flushing
  • headache
  • pain in bones, joints, or back
  • pain, redness, or swelling in the place where your medication was injected
  • swelling of the hands, feet, ankles, or lower legs
  • dizziness
  • difficulty falling asleep or staying asleep
  • depression
  • anxiety
  • nervousness
  • feelings of numbness, tingling, pricking, or burning on the skin
  • sweating
  • abnormal vaginal bleeding

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:

  • shortness of breath
  • chest pain
  • hives
  • rash
  • itching
  • difficulty breathing or swallowing
  • swelling of the face, throat, tongue, lips, or eyes
  • pain in your lower back or legs
  • numbness, tingling, or weakness in your legs
  • pain in the upper right part of the stomach
  • yellowing of the skin or eyes
  • pain or burning while urinating

Fulvestrant may cause other side effects. Call your doctor if you have any unusual problems while receiving this medication.

What should I do in case of OVERDOSE?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at [WEB]. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

What OTHER INFORMATION should I know?

Keep all appointments with your doctor.

Before having any laboratory test, tell your doctor and the laboratory personnel that you are receiving fulvestrant.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.



This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS® Patient Medication Information. © Copyright, 2018. The American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Selected Revisions: November 15, 2017.

Fulvestrant Injection is commonly used to treat:

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