Fulvestrant injection is used alone or in combination with ribociclib (Kisqali^®) to treat a certain type of hormone receptor positive, advanced breast cancer (breast cancer that depends on hormones such as estrogen to grow) or breast cancer has spread to other parts of the body 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 alone or in combination with ribociclib (Kisqali^®) to treat hormone receptor positive, advanced breast cancer or breast cancer that has spread to other parts of the body 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^®) or abemaciclib (Verzenio^®) to treat hormone receptor positive, advanced breast cancer in women whose breast cancer has spread to other parts of the body and 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.

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.

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.

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

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

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

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.

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

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.