In women who have gone through menopause (a change in life; the end of monthly menstrual cycles), fulvestrant injection is used alone or in combination with ribociclib (Kisqali®) to treat a specific type of hormone receptor positive, advanced breast cancer (breast cancer that depends on hormones like estrogen to grow) or breast cancer has spread to other parts of the body. Fulvestrant injection is also used to treat hormone receptor positive, advanced breast cancer or breast cancer that has spread to other parts of the body in women who have gone through menopause and whose breast cancer has gotten worse after being treated with an anti-estrogen drug like tamoxifen. It can be used alone or in combination with ribociclib (Kisqali®). For women whose hormone receptor-positive, advanced breast cancer has spread to other body parts and gotten worse after being treated with anti-estrogen drugs like tamoxifen, fulvestrant injection is also used in combination with palbociclib (Ibrance®) or abemaciclib (Verzenio®). A group of drugs known as estrogen receptor antagonists includes fulvestrant. It operates by preventing estrogen from having an impact on cancer cells. Some breast cancers that depend on estrogen for growth may be slowed or even prevented by this.

A muscle in the buttocks will be slowly injected with fulvestrant over the course of 1 to 2 minutes. In a medical office, a doctor or nurse administers fulvestrant. For the first three doses (days 1, 15, and 29), it is typically administered once every two weeks, and then once a month after that. Your pharmaceutical dose will be administered to you by two separate injections, one in each buttock.

For a copy of the manufacturer’s information for the patient, ask your doctor or pharmacist.

Ask your doctor or pharmacist for more details if you believe this drug should be used for something else.

Before receiving fulvestrant,

• If you have an allergy to fulvestrant, any other drugs, or any of the ingredients in fulvestrant injection, let your doctor and pharmacist know right once. Request a list of the components from your pharmacist.
• Inform your doctor and pharmacist about all prescription and over-the-counter drugs, vitamins, dietary supplements, and herbal products that you are now taking or intend to use. Make careful to mention blood thinners (anticoagulants) such warfarin (Coumadin, Jantoven). Your physician might need to adjust the dosage of your drugs or keep a close eye on you for side effects.
• Inform your doctor if you now have or ever had liver illness or bleeding issues.
• If you are pregnant or plan to become pregnant, inform your doctor right away.Pregnancy should be avoided both while taking fulvestrant and for at least a year following the last dosage. Consult your physician about birth control options you can take while undergoing therapy. Within seven days of starting treatment, your doctor may also perform a pregnancy test. If you conceive while taking fulvestrant, let your doctor know right away. The fetus may suffer from fulvestrant.
• If you are breastfeeding, let your doctor know. For a year following the last dosage of fulvestrant, you shouldn’t breastfeed while receiving treatment with the drug.
• You should be aware that this medicine may lower both male and female fertility. Discuss the dangers of receiving fulvestrant with your doctor.

Keep eating normally unless your doctor instructs you otherwise.

Call your doctor as soon as you can if you forget to show up for your appointment to receive a dose of fulvestrant.

Fulvestrant could have negative effects. If any of these symptoms are severe or do not go away, let your doctor know right once:

• Nausea
• Vomiting
• Constipation
• Diarrhea
• Abdominal pain
• Reduced appetite
• Unwell throat
• Oral sores
• Weakness
• Flushes or hot flashes
• Headache
• Back, joint, or bone pain
• The area where your drug was injected may experience pain, redness, or edema
• Edema of the lower legs, ankles, feet, or hands
• Dizziness
• Having trouble falling or staying asleep
• Depression
• Anxiety
• Nervousness
• Skin sensations of burning, pricking, tingling, or numbness
• Sweating
• Unexpected vaginal bleeding

Some adverse effects can be very harmful. Call your doctor right away if any of these symptoms occur to you:

• Breathing difficulty
• Chest ache
• Hives
• Rash
• Itching
• Breathing or swallowing challenges
• Swelling of the lips, eyes, tongue, cheeks, or throat
• Discomfort in your legs or lower back
• Tingling, numbness, or weakness in your legs
• Stomach ache in the top right corner
• Eyes or skin that have a yellow tint
• Discomfort or burning when urinating

Other side effects of fulvestrant are possible. If you have any strange side effects while taking this medicine, call your doctor right away.

Call the poison control hotline at 1-800-222-1222 in the event of an overdose. Additionally, information can be found online at https://www.poisonhelp.org/help. Call 911 right once if the person has collapsed, experienced a seizure, is having difficulty breathing, or cannot be roused.

Keep all of your doctor’s appointments.

Inform the lab staff and your doctor that you are taking fulvestrant prior to any laboratory test.

You should keep a written record of every medication you take, including any over-the-counter (OTC) items, prescription drugs, and dietary supplements like vitamins and minerals. This list should be brought with you whenever you see a doctor or are admitted to the hospital. You should always have this information with you in case of emergencies.