Fulvestrant (Faslodex ®)
Fulvestrant is a type of hormonal therapy used to treat breast cancer. On this page we refer to it by its more commonly used name, Faslodex.
This section describes Faslodex, how it is given and some of its possible side effects. It should ideally be read with our information on breast cancer or secondary (metastatic) breast cancer.
You will see your doctor regularly while you have this treatment so they can monitor its effects. This information should help you to discuss any queries about your treatment and its side effects with your doctor or specialist nurse.
Faslodex is a type of hormonal therapy used to treat breast cancer that has spread in women who have had their menopause. Faslodex is usually used when other hormonal therapies are no longer controlling the cancer.
Hormones are substances produced naturally in the body. They act as chemical messengers and help control the activity of cells and organs. Hormonal therapies work by interfering with the production or action of particular hormones.
Many breast cancers rely on the female sex hormone oestrogen to grow. Hormone-positive breast cancers have proteins called receptors on the breast cancer cells. They are known as oestrogen-receptor positive or ER-positive breast cancers. When oestrogen comes into contact with the receptors, it fits into them and stimulates the cancer cells to divide so that the tumour grows.
Faslodex works in two ways. It’s an anti-oestrogen drug. It fits into the oestrogen receptor and blocks oestrogen from reaching the cancer cells. This means the cancer either grows more slowly or stops growing altogether. It also works by reducing the number of receptors on breast cancer cells.
Faslodex is given as two injections, one into the muscle of each buttock. It’s given every two weeks for the first three doses, and is then given once a month.
It can be given by your GP or practice nurse at the surgery. If you're not able to visit the surgery, a district nurse can give you the injection at home.
You may find the injection slightly uncomfortable and may notice an area of redness at the injection site afterwards.
When Faslodex is given
Back to top
Faslodex is used to treat women with ER-positive secondary (metastatic) breast cancer. It can be given to postmenopausal women who have been treated with another hormonal therapy but whose cancer has progressed.
Length of treatment with Faslodex
Back to top
Your doctor will discuss with you the length of treatment they feel is appropriate for your situation. Faslodex may be given for months or longer.
Possible side effects of Faslodex
Back to top
Each person's reaction to any medicine is different. Many people have very few side effects with Faslodex, while others may experience more. The side effects described here won't affect everyone and may be different if you are having more than one drug.
We have outlined the most common side effects but haven't included those that are rare and therefore unlikely to affect you. If you notice any effects that aren't listed here, discuss them with your doctor or nurse.
You may have some of the following side effects, to varying degrees:
Feeling sick (nausea), being sick (vomiting) and diarrhoea
Let your doctor know if you experience nausea, vomiting or diarrhoea, as they can usually be treated. If you get diarrhoea, it's important to drink plenty of fluids.
Hot flushes and sweats
Hot flushes and sweats are usually mild and may wear off after a period of time. Some women find that avoiding or cutting down on tea, coffee, nicotine and alcohol can reduce sweats. Research suggests that hormones called progestogens or some types of antidepressants may help to control this side effect. Your doctor or nurse can discuss this with you. We have information on managing menopausal symptoms such as hot flushes and sweats, which might be useful.
Diane talks about how she coped with menopausal symptoms after treatment for breast cancer.
Some people find complementary therapies such as acupuncture helpful. Your GP may be able to give you details about having these on the NHS.
Let your doctor know if you are getting headaches, as they can prescribe medication to help.
Some women experience pain and stiffness in their joints. Let your doctor know if this is a problem. You may find it helpful to take mild painkillers.
Faslodex may cause changes in the way your liver works. You're very unlikely to notice any problems but your doctor will take regular blood samples to check your liver is working properly.
Some people have mild skin rashes.
Some women may experience vaginal bleeding, usually in the first few weeks of treatment. This is rare and usually occurs after changing from treatment with another hormonal therapy to treatment with Faslodex. If bleeding continues, tell your doctor or breast care nurse.
You may have some pain and inflammation at the injection site. Let your doctor know if this becomes troublesome.
Blood clots (thrombosis)
Faslodex can slightly increase the risk of getting a blood clot. Tell your doctor immediately if you have pain, warmth, swelling or tenderness in an arm or leg, or any chest pain.
Because Faslodex is given by injection into the muscle, it shouldn't be used by people with certain blood disorders or who are receiving blood thinners (anticoagulants), such as warfarin.
Always let your doctor or nurse know about any side effects you have, as there are usually ways in which they can be controlled or improved.
Back to top
Delaying an injection
Delaying an injection by two days or so shouldn't make a great difference. However, it’s important to remember that the injections are designed to last for four weeks, so you should have them as regularly as possible.
If you’re admitted to hospital for a reason not related to the cancer, it’s important to tell the doctors and nurses looking after you that you are having hormonal treatment. You should tell them the name of your cancer specialist so that they can ask for advice.
It’s a good idea to know who you should contact if you have any problems or troublesome side effects when you’re at home. During office hours you can contact the clinic or ward where you had your treatment. Your specialist nurse or doctor will tell you who to contact during the evening or at weekends.
This information has been compiled using information from a number of reliable sources, including:
British National Formulary. 63rd edition. British Medical Association and Royal Pharmaceutical Society of Great Britain. 2012.
electronic Medicines Compendium (eMC). www.medicines.org.uk (accessed November 2012).
Sweetman, et al. Martindale: The Complete Drug Reference. 37th edition. Pharmaceutical Press. 2011.
With thanks to Bruce Burnett, Teacher Practitioner in Clinical Pharmacy Practice, and the people affected by cancer who reviewed this edition. Reviewing information is just one of the ways you could help when you join our Cancer Voices network.