An anti-androgen tablet used in prostate cancer
Flutamide
An anti-androgen tablet that blocks the action of testosterone, used in prostate cancer, with regular liver checks.
What is Flutamide?
Flutamide is an anti-androgen, a medicine that blocks the effect of male hormones such as testosterone on the body. It is used in prostate cancer, which often grows in response to testosterone, so blocking it can help slow the cancer. It is taken as tablets by mouth, usually spread through the day. It is sometimes used together with a hormone-lowering injection, including to cover the brief hormone surge when that injection is first started. An important safety point is that it can affect the liver, so liver blood tests are needed before and during treatment, and any signs of liver trouble must be reported promptly.
Education and reference only. This is a plain-language guide to Flutamide — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Flutamide is an anti-androgen medicine used mainly in the treatment of prostate cancer. The prostate and many prostate cancers rely on male hormones (androgens), chiefly testosterone, to grow. Flutamide works by blocking the receptors that testosterone acts on, so the hormone cannot drive the cancer. It is taken by mouth as tablets. It may be used on its own or, commonly, alongside a hormone-lowering injection such as a GnRH analogue, including at the start of that injection to cover the temporary hormone surge it causes. It is prescribed and supervised by a specialist team, with attention to liver safety.
How it works
Testosterone normally attaches to receptors inside prostate and prostate cancer cells and tells them to grow. Flutamide blocks these receptors so testosterone cannot deliver that signal, which helps slow or hold back cancer that depends on the hormone. Because it blocks the hormone's effect rather than lowering the hormone itself, it is often combined with a medicine that lowers testosterone production, giving a fuller block. At the start of a hormone-lowering injection there is a brief testosterone surge, and flutamide can be used to stop this surge causing a temporary flare of the cancer.
Company & origin
Originated / developed by: Various manufacturers.
An anti-androgen medicine used in the UK to block the effect of testosterone in prostate cancer, taken as tablets and needing liver monitoring.
Practical use
How to take Flutamide
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take the tablets by mouth as prescribed, usually spread evenly through the day to keep a steady level.
- Have your liver blood tests before starting and during treatment as arranged, and do not skip them.
- Report straight away any yellowing of the skin or eyes, dark urine, pale stools, severe tiredness or tummy pain.
- If you are using it with a hormone-lowering injection, take both as your specialist team advises.
- Tell your team about all your other medicines, as some interact with flutamide.
Weighing it up
Advantages & disadvantages of Flutamide
Advantages
- Blocks the male hormone that drives many prostate cancers, helping to slow the disease.
- Taken conveniently by mouth as tablets.
- Useful alongside a hormone-lowering injection, including to cover the surge when that injection is started.
Disadvantages
- Can affect the liver, so it needs regular liver blood tests and prompt reporting of warning signs.
- Commonly causes breast tenderness or swelling, hot flushes and reduced sex drive.
- Needs to be taken regularly through the day and interacts with some other medicines.
Practical use
Good to know
The most important safety point with flutamide is its effect on the liver: it can occasionally cause liver problems, so liver blood tests are done before starting and regularly during treatment, and you should report straight away any yellowing of the skin or eyes, dark urine, pale stools, severe tiredness, nausea or tummy pain. It is taken regularly through the day to keep a steady level. Because it blocks male hormones, it commonly causes breast tenderness or swelling, hot flushes and reduced sex drive. A harmless effect in some people is a change in urine colour. It is often used alongside a hormone-lowering injection, particularly to cover the surge when that injection is first started. Always give your team a full list of your other medicines.
Who should not take it / use with caution
- People who have had a serious allergic reaction to flutamide or its ingredients should not take it.
- It is not used in people with serious existing liver problems, and is used cautiously where liver function is borderline.
- It is a medicine for prostate cancer and is not suitable for women or children for this purpose.
Monitoring
- Liver blood tests before starting and regularly during treatment.
- Watching for warning signs of liver trouble, such as yellowing of the skin or eyes.
- Reviewing how well the prostate cancer responds, including PSA blood tests.
Side effects
- Breast tenderness or swelling, hot flushes and reduced sex drive from blocking male hormones.
- Diarrhoea, nausea or stomach upset in some people.
- A harmless change in urine colour in some people.
- Liver problems, sometimes serious, which is why liver tests and prompt reporting of warning signs are essential.
Key interactions
- It can interact with blood-thinning medicines such as warfarin, increasing the risk of bleeding, so clotting may need checking.
- Other medicines that can affect the liver may add to the strain, so tell your team everything you take.
- Alcohol may add to liver stress, so discuss sensible limits with your team.
Available as: Tablets taken by mouth.
Answers
Flutamide: frequently asked questions
What is flutamide used for?
It is an anti-androgen used in prostate cancer; it blocks the effect of testosterone, the male hormone that often drives the cancer to grow.
Why do I need liver blood tests?
Flutamide can occasionally affect the liver, so liver tests are done before and during treatment, and any warning signs must be reported promptly.
What warning signs should I look out for?
Report straight away any yellowing of the skin or eyes, dark urine, pale stools, severe tiredness, nausea or tummy pain, as these can signal liver trouble.
Why is it sometimes used with an injection?
It is often combined with a hormone-lowering injection for a fuller block, and to cover the brief testosterone surge when that injection is first started.
Why might my urine change colour?
A change in urine colour is a harmless effect of flutamide in some people and is not usually a cause for concern, but mention it to your team if unsure.
Authoritative sources
- BNF
- NICE CKS
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