Fulvestrant Side Effects

Medically reviewed by Philip Thornton, DipPharm. Last updated on Jul 29, 2024.

Applies to fulvestrant: intramuscular solution.

Precautions

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Receiving this medicine while you are pregnant can harm your unborn baby. If you are a woman who can bear children, your doctor may give you a pregnancy test 7 days before you start receiving this medicine to make sure you are not pregnant. Use a highly effective form of birth control to keep from getting pregnant during treatment and for 1 year after your last dose. If you think you have become pregnant while receiving the medicine, tell your doctor right away.

Talk with your doctor before receiving this medicine if you plan to have children. Some men and women who receive this medicine have become infertile (unable to have children).

This medicine may increase your risk of bleeding. This is more likely to occur if you have bleeding problems or if you are taking a blood thinner (eg, warfarin). Tell your doctor right away if you have unusual bleeding or bruising after receiving this medicine.

This medicine may cause you to have bleeding from the vagina, especially when you first start receiving it. If the bleeding continues or is bothersome, check with your doctor right away.

Tell your doctor if you have numbness, tingling, or weakness in your legs after receiving this medicine.

Before you have any medical tests, tell the medical doctor in charge that you are using this medicine. The results of some tests (eg, serum estradiol) may be affected by this medicine.

Serious side effects of fulvestrant

Along with its needed effects, fulvestrant may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking fulvestrant:

Other side effects of fulvestrant

Some side effects of fulvestrant may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to fulvestrant: intramuscular solution.

Gastrointestinal adverse events

• Very common (10% or more): Nausea (up to 34%), stomatitis (up to 28%), diarrhea (up to 24%), vomiting (up to 19%), abdominal pain (up to 12%)
• Common (1% to 10%): Constipation^[Ref]

Hematologic

• Very common (10% or more): Neutropenia (up to 83%), leukopenia (up to 53%), anemia (up to 30%), thrombocytopenia (up to 23%)
• Common (1% to 10%): Reduced platelet count
• Uncommon (0.1% to 1%): Leukorrhea, febrile neutropenia^[Ref]

Cardiovascular

• Very common (10% or more): Vasodilation(up to 18%), hot flushes
• Common (1% to 10%): Venous thromboembolism^[Ref]

Musculoskeletal

• Very common (10% or more): Bone pain (up to 16%), muscle pain, joint pain
• Common (1% to 10%): Back pain, pain in extremity^[Ref]

Nervous system

• Very common (10% or more): Headache (up to 15%)
• Common (1% to 10%): Sciatica, peripheral neuropathy, dysgeusia, dizziness, paresthesia
• Uncommon (0.1% to 1%): Neuralgia^[Ref]

Respiratory

• Very common (10% or more): Pharyngitis (up to 16%), dyspnea (up to 15%)
• Common (1% to 10%): Epistaxis, cough, chest pain^[Ref]

Genitourinary

• Very common (10% or more): Pelvic Pain (up to 10%)
• Common (1% to 10%): Urinary tract infection, vaginal hemorrhage
• Uncommon (0.1% to 1%): Vaginal moniliasis^[Ref]

Dermatologic

• Very common (10% or more): Alopecia (up to 18%), rash (up to 17%)
• Common (1% to 10%): Dry skin, sweating, pruritus^[Ref]

Hypersensitivity

• Very common (10% or more): Hypersensitivity reactions
• Uncommon (0.1% to 1%): Anaphylaxis^[Ref]

Hepatic

• Very common (10% or more): Elevated hepatic enzymes (ALT, AST, ALP)
• Common (1% to 10%): Elevated bilirubin
• Uncommon (0.1% to 1%): Hepatic failure, hepatitis, elevated gamma-GT^[Ref]

Immunologic

• Very common (10% or more): Infections (up to 47%)
• Common (1% to 10%): Influenza syndrome^[Ref]

Local

• Very common (10% or more): Injection site pain (up to 12%), injection site reaction

Common (1% to 10%):

• Uncommon (0.1% to 1%): Injection site hemorrhage, injection site hematoma^[Ref]

Ocular

• Common (1% to 10%): Increased lacrimation, blurred vision, dry eye^[Ref]

Metabolic

• Very common (10% or more): Anorexia (up to 16%)
• Common (1% to 10%): Peripheral edema^[Ref]

Psychiatric

• Common (1% to 10%): Insomnia, depression, anxiety^[Ref]

Other

• Very common (10% or more): Fatigue (up to 41%), pain (up to 19%), pyrexia (up to 13%)
• Common (1% to 10%): Asthenia^[Ref]

See also:

Frequently asked questions

• How long can you take Faslodex?
• How long does it take for Faslodex to start working?
• Is Faslodex a form of chemotherapy?

Further information

Fulvestrant side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer