Estramustine (Estracyt) | Cancer Research UK
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What estramustine is

Estramustine is made from two types of drugs combined

  • A hormone called oestrogen
  • A chemotherapy drug called nitrogen mustard

Estramustine is a treatment for advanced prostate cancer. Your doctor may suggest it if your prostate cancer is no longer responding to hormone treatment.


How estramustine works

Estramustine stops cancer cells from separating into 2 new cells, so it stops tumours from growing. It may also block hormones in the body from encouraging the cancer cells to grow.


How you have estramustine

Estramustine comes as capsules. You should take the capsules on an empty stomach – more than 1 hour before meals or at least 2 hours afterwards. You need to take them with plenty of water. It is best to take them at the same time each day.

Do not take estramustine with milk, drinks containing milk, anti acid medicines, or foods high in calcium.  All these can interfere with absorbing the drug into your body. Some heart medicines called ACE inhibitors can interact with estramustine. Tell your doctor if you are taking heart medicines. 

It is very important that you take the capsules according to the instructions your doctor or pharmacist gives you. You should take the right dose, not more or less. And never stop taking a cancer drug without talking to your specialist first.

It is also important to store your tablets in a safe place away from children. Take unused tablets back to the pharmacy.

You usually have estramustine as a course of several cycles of treatment. You take the capsules in 3 or 4 doses daily. A typical plan is to take the capsules daily for 6 weeks, followed by a 2 week break.

The side effects associated with estramustine are listed below. You can use the links (underlined) to find out more about each side effect. Where there is no link, please see our cancer drugs side effect section or click on search at the top of the page.


Common side effects

More than 10 in every 100 people have one or more of these effects.

  • Feeling or being sick can happen within 2 hours of taking the drug – it is usually mild and easily controlled with anti sickness injections and tablets. Some people can have severe vomiting for 6 to 8 weeks after starting this drug that is difficult to control. Let your doctor or nurse know if it happens. If you are sick within 2 hours of taking estramustine, don't take another dose but tell your doctor or nurse when you next see them
  • Breast tenderness or enlargement (gynaecomastia) happens in roughly half the people treated – men may have 1 or 2 radiotherapy treatments to the breast area to help prevent this
  • Lowered interest in having sex (libido)
  • Difficulty in getting an erection (impotence)
  • Diarrhoea happens in about 2 out of 10 (20%) people – drink plenty of fluids and if it becomes severe or lasts more than a day or two, tell your doctor or nurse
  • Fluid build up, leading to swollen hands or feet

Occasional side effects

Between 1 and 10 in every 100 people have one or more of these.

  • Loss of fertility – you may not be able to father a child after treatment with this drug. Talk to your doctor before starting treatment if you think you may want to have a baby in the future. You may be able to store sperm before starting treatment
  • Dry, itching skin or a rash
  • A raised blood pressure – your nurse will check your blood pressure regularly
  • Liver changes that are very mild and unlikely to cause symptoms – they will almost certainly go back to normal when treatment is finished. You will have regular blood tests to check how well your liver is working
  • Muscle weakness
  • Sadness and depression
  • Headaches
  • Confusion

Rare side effects

Fewer than 1 in 100 people have these effects.

  • An increased risk of getting an infection from a drop in white blood cells – it is harder to fight infections and you can become very ill. You may have headaches, aching muscles, a cough, a sore throat, pain passing urine, or you may feel cold and shivery. If you have a severe infection this can be life threatening. Contact your treatment centre straight away if you have any of these effects or if your temperature goes above 38°C. You will have regular blood tests to check your blood cell levels
  • Tiredness and breathlessness due to a drop in red blood cells (anaemia) – you may need a blood transfusion
  • Bruising more easily due to a drop in platelets – you may have nosebleeds, bleeding gums after brushing your teeth, or lots of tiny red spots or bruises on your arms or legs (known as petechia)
  • Heart problemslet your nurse or doctor know if you have any sudden chest pain or breathlessness
  • Difficulty sleeping (insomnia)
  • Increased risk of blood clots (thrombosis) – let your nurse or doctor know if you have a sore, painful, red area on your leg or sudden chest pain and breathlessness
  • An allergic reaction to the drug – let your doctor or nurse know straight away if you have a skin rash, itching, sudden wheeziness, breathlessness, or swelling of the eyes, face or lips
  • Other medical conditions such as diabetes and kidney problems can be made worse by taking estramustine – tell your doctor if you have any other health problems

Important points to remember

The side effects above may be mild or more severe. A side effect may get better or worse through your course of treatment, or more side effects may develop as the course goes on. This depends on

  • How many times you've had the drug before
  • Your general health
  • The amount of the drug you have (the dose)
  • Other drugs you are having

Coping with side effects

Talk to your doctor, pharmacist or nurse about all your side effects so they can help you manage them. They can give you advice or reassure you. Your nurse will give you a contact number to ring if you have any questions or problems. If in doubt, call them.

Other medicines

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and over the counter remedies. Some drugs can react together.

Pregnancy and contraception

This drug may harm a baby developing in the womb. It is important not to father a child while you are having treatment and for a few months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.


If your partner is breastfeeding during your treatment you need to use a reliable form of barrier contraception. Ask your doctor or nurse about suitable types of contraception.


Immunisations and chemotherapy

You should not have immunisations with live vaccines while you are having chemotherapy or for at least 6 months afterwards. In the UK, these include rubella, mumps, measles (usually given together as MMR), BCG, yellow fever and Zostavax (shingles vaccine).

You can have other vaccines, but they may not give you as much protection as usual until your immune system has fully recovered from your chemotherapy. It is safe to have the flu vaccine.

It is safe for you to be in contact with other people who've had live vaccines as injections. There can be problems with vaccines you take by mouth (oral vaccines), but not many people in the UK have these now. So there is usually no problem in being with any baby or child who has recently had any vaccination in the UK. You might need to make sure that you aren't in contact with anyone who has had oral polio, cholera or typhoid vaccination recently, particularly if you live abroad.


More information about estramustine

This page does not list all the very rare side effects of this treatment that are very unlikely to affect you. For further information look at the Electronic Medicines Compendium website at

If you have a side effect not mentioned here that you think may be due to this treatment you can report it to the Medicines Health and Regulatory Authority (MHRA) at

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Updated: 26 August 2014