Enzalutamide (Xtandi®)

Enzalutamide (Xtandi®) is a hormonal therapy drug used to treat prostate cancer that has spread to other parts of the body. It’s best to read this with our general information about advanced (metastatic) prostate cancer.

You have enzalutamide as capsules. Your cancer doctor or nurse will tell you how long to take it for.

Like all hormonal therapy drugs, enzalutamide can cause side effects. Some of these can be serious so it’s important to read the detailed information below. How hormonal therapy affects people varies from person to person. It’s important to read about the side effects so that you know what to expect. Your doctor or nurse can talk to you more about this and give you advice on how to manage side effects.

Tell your doctor or nurse straight away if you feel unwell or have severe side effects, including any we don’t mention here. If you need to see a health professional for any reason other than cancer, always tell them that you are having this treatment.

How enzalutamide works

Hormones are substances produced naturally in the body. They act as chemical messengers and help control the activity of cells and organs. Hormonal therapies interfere with the way hormones are made or how they work in the body.

Most prostate cancers need the hormone testosterone to grow. Almost all testosterone in men is made by the testicles. A very small amount is made by the adrenal glands, which sit above the kidneys.

Enzalutamide blocks testosterone from reaching the prostate cancer cells. This may stop or slow down the growth of the cancer cells.

When enzalutamide is given

Enzalutamide is used to treat prostate cancer that has spread to other parts of the body. This is known as advanced (metastatic) prostate cancer. It is used when other hormonal treatments are no longer helping to control prostate cancer.

It may be given:

  • after you have had treatment with a chemotherapy drug called docetaxel
  • if you have no or few symptoms of prostate cancer and chemotherapy is not yet recommended.

Taking your enzalutamide capsules

You take enzalutamide as capsules once a day. Swallow the capsules whole and don’t open or chew them, as this can affect how they work. Take them at the same time each day. They can be taken with or without food, and before or after food.

Always take your capsules exactly as your nurse or pharmacist has explained. This is to make sure they work as well as possible for you. For most people, enzalutamide is taken as four capsules in a single daily dose.

Do not stop taking any of your capsules unless your doctor tells you to. Here are some important things to remember:

  • If you forget to take your capsules, just take them as soon as you remember unless it is nearly time for your next one. Don’t take a double dose.
  • Keep capsules in the original package and at room temperature, away from heat and direct sunlight.
  • Keep them safe and out of the sight and reach of children.
  • Get a new prescription before you run out of capsules and make sure you have plenty for holidays.
  • Return any remaining capsules to the pharmacist if your treatment is stopped.

You can usually carry on having enzalutamide for as long as it is controlling the cancer.

Possible side effects of enzalutamide

We explain the most common side effects of enzalutamide here. We also include some rarer side effects. You may get some of the side effects we mention, but you are very unlikely to get all of them. If you are having other drugs as well, you may have some side effects that we don’t list here.

You will see a doctor or nurse regularly while you have this treatment. Always tell your doctor or nurse about the side effects you have. They can prescribe drugs to help control them and give you advice about managing them. Don’t stop taking enzalutamide without talking to your doctor first.

More information about this drug

We’re not able to list every side effect for this treatment here, particularly the rarer ones. For more detailed information you can visit the electronic Medicines Compendium (eMC).

Hot flushes and sweats

These are common and can be mild or more severe. During a flush, you feel warmth in your neck and face and your skin may redden. Mild flushes last for a few seconds up to about a couple of minutes. More severe flushes can last for 10 minutes or more. You may have sweats and then feel cold and clammy. Some people feel anxious or irritable during a hot flush.

There are things you can do to try to reduce flushes, such as cutting down on nicotine, alcohol and hot drinks that contain caffeine, such as tea and coffee.

If hot flushes are worrying you, your doctor can prescribe drugs to help reduce them. You may have fewer hot flushes and sweats as your body adjusts to hormonal treatment. They usually stop completely a few months after treatment finishes.

We have more information about hot flushes.


Feeling very tired is a common side effect of many cancer treatments. If this happens to you, it is important to try to pace yourself and get as much rest as you need. Try to balance this with some gentle exercise, such as short walks, which will help. If tiredness is making you feel sleepy, don’t drive or operate machinery.


Some men have headaches while taking enzalutamide. It is important to drink plenty of fluids to help with this. Try to drink around two litres (three and a half pints) per day. Let your doctor know if you have headaches as they can prescribe medicines to help.

High blood pressure (hypertension)

Enzalutamide may cause a rise in blood pressure. Your blood pressure may be checked before you start taking enzalutamide and during the course of your treatment.

Muscle and bone pain

If you have pain in your muscles or bones, tell your doctor. They can prescribe painkillers to ease this.

Skin changes

You may find that your skin gets dry. Some men develop a skin rash, but this is usually mild and often gets better without treatment. Tell your doctor if you notice any skin changes.

Breast tenderness or fullness

You may sometimes notice breast swelling and tenderness, known as gynaecomastia. Your doctor can advise you on how this can be prevented or treated.

Mood changes

You may experience mood swings or feel nervous, which you can talk to your doctor about. Some men may get hallucinations but this isn’t common. Let your doctor know if this happens.

Memory and concentration

You may notice changes in your memory or ability to concentrate. Try using a notebook, Post-it notes and a calendar to help you keep track of things.

Dizziness, blurred vision and drowsiness

Enzalutamide may cause dizziness, blurred vision and drowsiness. Let your doctor know if you have any of these side effects. Don’t drive or operate machinery if you have them.

Dizziness and blurred vision can also increase your risk of falls and broken bones (fractures). If you feel dizzy when walking, you should sit down straight away until it passes. Try to keep areas that you walk through free of clutter and make sure there aren’t things that you could trip over, such as loose rugs.

Make sure rooms are well lit and always put a light on if you get up during the night.

Sexual effects

Most men lose their sex drive and have erection difficulties (impotence) during hormonal therapy. Things often return to normal after you stop taking the drug, but some men continue to have difficulties after treatment is over. Your doctor can prescribe treatments to help with erection difficulties but these don’t affect sex drive.

If you need support coping with sexual difficulties, your nurse or doctor can give you information and refer you for specialist support services.

Possible side effects of long-term enzalutamide treatment

Bone thinning (osteoporosis)

Taking enzalutamide will, over time, increase your risk of bone thinning (osteoporosis). In some men this can increase the risk of a broken bone (fracture). Your doctor can give you advice on how your bone health can be monitored. They can also tell you about treatments for bone thinning. Regular walking and resistance exercises, such as lifting weights, can help to keep your bones strong. Eating a healthy diet, not smoking and sticking to sensible drinking guidelines will also help to protect your bones. Let your doctor know if you have any discomfort in your bones or joints.

We have more information on our website about bone health.

It is important to tell your doctor or nurse straight away if you feel ill or have severe side effects. This includes any we don’t mention here.

Less common side effects of enzalutamide

Risk of infection

Enzalutamide may reduce the number of white blood cells in your blood. This will make you more likely to get an infection. When the number of white blood cells is low it’s called neutropenia.

Contact the hospital or your doctor straight away if:

  • your temperature goes over 37.5°C (99.5°F)
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection.

Symptoms of an infection include:

  • feeling shivery
  • a sore throat
  • a cough
  • diarrhoea
  • needing to pass urine.

You will have blood tests while taking enzalutamide to check the number of white blood cells. If they get too low, your doctor may ask you to stop taking enzalutamide or reduce the dose for a time.


Very rarely, enzalutamide can cause seizures (fits). If you have a seizure, stop taking enzalutamide and see a doctor straight away. Let your doctor know if you are already taking medication for seizures.

Other information about enzalutamide

Other medicines

Enzalutamide can interact with several other drugs. This includes medicines you can buy in a shop or chemist. Tell your doctor about any medicines you are taking, including ones you can buy for yourself, complementary therapies, vitamins and herbal drugs.


It is not advisable to father a child while taking enzalutamide, as it may harm the developing baby. If your partner is pregnant or of child-bearing age, it is important to use effective contraception, such as condoms and another form of birth control, while taking this drug and for three months after finishing treatment. You can discuss this with your doctor or nurse.

Medical and dental treatment

If you need to go to hospital for a reason not related to the cancer, it is 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.

Always tell your dentist you are taking enzalutamide.