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Hormone drug: Cyproterone acetate (Brand name: Cyprostat®)

The information on this page comes from our Tool Kit fact sheet on Cyproterone. To order your own tailored copy of the Tool Kit, visit our publications page. You can also download and print a PDF version of this fact sheet.

This page is for men who are about to start, or are already taking, cyproterone acetate to control their prostate cancer. It explains how the drug is taken, why it is used and what side effects it may cause. This page should be used together with the information that comes with your medicine and the advice of your specialist team or pharmacist.

What is cyproterone?

Cyproterone is a form of hormone therapy called an anti-androgen. It comes as 50mg and 100mg tablets. The brand name of the drug is Cyprostat.

Cyproterone slows down the growth of prostate cancer cells by reducing the amount of testosterone that reaches the cells. Most prostate cancer cells need testosterone to grow and spread.

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How do I take cyproterone?

Cyproterone tablets are taken by mouth after meals. The amount you take will depend on why you need the drug. There are three main reasons for taking cyproterone:

Tumour flare

If you are about to start treatment with an LHRH agonist, you may take cyproterone to prevent a temporary rise in testosterone, called tumour flare. This is the body’s natural response to the first injection. It can cause an increase in pain for men whose cancer has spread to the bone and some men may have problems passing urine. Tumour flare is temporary and lasts for up to three weeks.

To prevent tumour flare, you may take a total of 300mg of cyproterone each day for up to three weeks after your first LHRH agonist injection. If you have problems with side effects after taking cyproterone, this dose may be reduced to 200mg a day. You will take the tablets two or three times a day after meals.

Treatment of prostate cancer

You may take cyproterone on its own to slow down the growth of the cancer. It may also be used if an LHRH agonist or orchidectomy is no longer controlling the cancer. You will need to take a total of between 200mg and 300mg each day, divided into two or three doses after meals.

Hot flushes

Cyproterone may be used to treat hot flushes caused by other hormone treatments (LHRH agonists or orchidectomy). You will start off with a total of 50mg of cyproterone a day, taken two or three times during the day after meals. The dose can be increased to 150mg if needed.

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What are the side effects?

Like all drugs, cyproterone may cause side effects in some men. We have listed the most common ones here but you should tell your doctor if you feel any change within yourself while you are having treatment.

Some men get very few side effects and others get more. Many side effects will only last for as long as you are taking the drug. However, if you take cyproterone for a long period of time, it may take several months after you finish treatment for the side effects to stop. If you have any questions or worries about any side effects, speak to your doctor or specialist nurse. You can also call our confidential Helpline.

Liver problems

Higher doses of cyproterone (200mg to 300mg) can affect how well your liver works after several months of treatment. You will have regular blood tests to check your liver for as long as you are taking the drug.

Breast swelling and tenderness

Some men get swelling (gynaecomastia) and tenderness in one or both breasts. Your doctor can give you advice on how this can be prevented or treated.

Loss of sex drive

Cyproterone may cause you to lose your sex drive (libido) for as long as you are taking the drug. You are likely to become infertile but you should take extra steps to avoid fathering children because cyproterone may harm a developing baby.

Anxiety and depression

Cyproterone affects your hormone levels and this can cause mood swings. If you have been diagnosed with depression, cyproterone can make your symptoms worse. Your doctor or specialist team can offer support. Talking to family and friends about how you feel can also help.

Tiredness

You may feel tired when you start to take cyproterone. This usually improves within a couple of months. If you are affected, do not drive or use heavy machinery.

Breathlessness

Some men sometimes feel short of breath while they are taking cyproterone. This does not cause any harm and does not need treatment.

Blood sugar

Cyproterone can cause a rise in blood sugar levels. If you have diabetes you may need to test your blood sugar more often and you may need to adapt your diabetes medication.

Weight changes

You may either put on or lose weight if you take cyproterone for a long period of time.

Hair loss and growth

You may notice the hair on your body becomes patchy whereas the hair on your head may become thicker.

Blood clots

Some men have developed blood clots but we do not know whether this was caused by cyproterone or by something else. Your risk may be increased if you have a history of blood clots, sickle cell anaemia or diabetes which has affected the blood vessels.

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How long will I need to take cyproterone?

The length of time you take cyproterone for depends on why you are taking it and how well it is working. Due to its effects on the liver, cyproterone is unlikely to be used for more than a few months. Read our section on what happens afterwards for information on other treatments that can be used after hormone therapy.

Links

Medicines.org.uk
http://www.medicines.org.uk
This page contains links to information about medicines, including copies of the leaflets supplied by pharmaceutical companies and information in large print, audio and Braille.

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Reviewed by:

  • Dr John Graham, Lead Consultant Oncologist, Taunton & Somerset NHS Trust
  • Nicola James, Macmillan Nurse Consultant; Uro-oncology, Chesterfield NHS Foundation Trust
  • Dr Chris Parker, Senior Lecturer and Honorary Consultant in Clinical Oncology, Institute of Cancer Research and Royal Marsden Hospital
  • Lucy Powell, Urology Cancer Nurse Specialist, Essex Rivers NHS Trus
  • The Prostate Cancer Charity Information Volunteers
  • The Prostate Cancer Charity Support & Information Specialist Nurses/li>

Written and edited by:

The Prostate Cancer Charity Information Team

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Page last updated: March 28th 2008