Enzalutamide (Xtandi®) is a hormonal therapy drug used to treat prostate cancer that has spread to other parts of the body.
Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.
Hormones are chemicals that our bodies make. Hormones act as messengers and help control how cells and organs work. Hormonal therapies are drugs that change the way hormones are made or how they work in the body.
Prostate cancer needs 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 slow down the growth of the cancer cells and help control advanced prostate cancer.
Enzalutamide is used to treat prostate cancer that has spread to other parts of the body. This is known as advanced (metastatic) prostate cancer.
Taking enzalutamide tablets
Enzalutamide comes as tablets you can take at home. Your nurse or pharmacist will tell you how many to take. You take enzalutamide every day.
You may have enzalutamide on its own, or with other drugs. Your nurse or doctor will talk to you about your treatment plan. You usually take enzalutamide for as long as it is controlling the cancer.
Always take the tablets exactly as explained. This is important to make sure they work as well as possible for you. Make sure you:
- swallow them whole with a glass of water.
- do not chew, cut, crush or dissolve the tablets.
- take them at the same time every day.
If you forget to take the tablets, you should take the missed dose as soon as possible within the same day. If a full day has passed, let your doctor or nurse know. Do not take a double dose unless your doctor tells you to.
Other things to remember about your tablets:
- Keep them in the original package and at room temperature, away from heat and direct sunlight.
- Keep them safe and out of sight and reach of children.
- If you are sick just after taking the tablets, contact your healthcare team. Do not take another dose.
- Get a new prescription before you run out of tablets, and make sure you have plenty for holidays.
- If your treatment is stopped, return any unused tablets to the pharmacist.
Your nurse or pharmacist may also give you other medicines to take home. Take all your medicines exactly as they have been explained to you. Do not stop taking any of your medicines unless your doctor tells you to.
We explain the most common side effects of this treatment here. We also include some less common side effects.
You may get some of the side effects we mention, but you are unlikely to get all of them. If you are also having treatment with other cancer drugs, you may have some side effects that we have not listed here.
You will see a doctor, nurse or pharmacist regularly while you are having this treatment. Always tell them about any side effects you have. They can give you drugs to help control most side effects. They can also offer advice to help you cope.
Most side effects can be managed. But sometimes side effects are harder to control. It is important not to stop taking hormonal therapy without telling your doctor. If side effects cannot be managed, your doctor may suggest you take a different type of hormonal therapy.
Serious and life-threatening side effects
Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.
Contact the hospital
Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.
We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.
Hot flushes and sweats
Hot flushes are a common side effect of this treatment. During a flush, your neck and face may feel warm and look red. Flushes may last from a few seconds up to 10 minutes. 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:
- Wear clothes made from natural fabrics, such as cotton.
- Wear layers of clothes that you can remove if you feel hot.
- Use cotton bed sheets and have layers of bedding that you can remove if you feel hot.
- Keep room temperatures cool or use a fan.
- Have cold drinks rather than hot ones. Try to avoid drinks with caffeine in them.
You may have fewer hot flushes and sweats as your body adjusts to hormonal treatment. Or your doctor can prescribe drugs to help. Flushes and sweats usually stop a few months after treatment finishes, but some people continue to have them.
You can read more about coping with hot flushes.
Feeling tired is a common side effect. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can give you more energy. If you feel sleepy, do not drive or operate machinery.
This treatment may cause headaches. If this happens, tell your doctor or nurse. They can give you painkillers.
High blood pressure (hypertension)
Enzalutamide may cause your blood pressure to increase. Your doctor or nurse may check your blood pressure before you start taking enzalutamide and during your treatment.
Muscle or bone pain
If you have pain in your muscles or bones, tell your doctor. They can prescribe painkillers to ease this.
You may find you get restless legs while taking this treatment. This is when you feel you need to move your legs regularly. It is more common at night time. Talk to your doctor or nurse if you get this. They can check that it is caused by the tablets and not any other reasons. They can also give you ways to help manage it.
This treatment may affect your skin. It may cause a rash, which might be itchy. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using an unperfumed moisturising cream every day.
Always tell your doctor or nurse about any changes to your skin. They can give you advice and may prescribe creams or medicines to help. Skin changes usually improve when treatment finishes.
You may have some mood changes during this treatment. You may feel low or depressed. Let your doctor or nurse know if you notice any changes.
Memory and concentration
You may notice changes in your memory. You may also find it harder to concentrate. To help you remember things, try using:
- a notebook
- notes on your phone
- a calendar.
Dizziness, drowsiness and falls
Enzalutamide may cause:
- blurred vision
Let your doctor know if you have any of these side effects. Do not drive or operate machinery if you have them.
These side effects 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 clear to reduce the risk of tripping. Make sure rooms are well lit and always put a light on if you get up during the night.
Breast swelling or tenderness
This treatment may cause swelling and tenderness of your breast tissue. This is called gynaecomastia. Your doctor can give you advice on preventing and treating this.
Most men lose their sex drive and have erection problems during hormonal therapy. Things often return to normal after you stop taking the drug. But some men continue to have problems after treatment is over. Your doctor can prescribe treatments to help with erection problems. But these treatments will not increase your sex drive.
Bone thinning (osteoporosis)
If you take this treatment for several months or more, you may get bone thinning. This is called osteoporosis. This can increase your risk of a broken bone (fracture). You may have bone density scans to check your bone health before and during treatment.
Doing regular exercise, such as walking, can improve your bone health. Eating a healthy diet can help too. Your doctor may prescribe drugs called bisphosphonates to help protect your bones. They may also advise you to take calcium and vitamin D supplements.
Risk of infection
This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is called neutropenia.
If you have an infection, it is important to treat it as soon as possible. Contact the hospital straight away on the 24-hour contact number you have 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
- needing to pass urine often.
It is important to follow any specific advice your cancer treatment team gives you.
You will have regular blood tests during treatment. If your white blood cell count is low, your doctor may reduce or delay your treatment for a short 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.
Contact the hospital straight away if you suddenly feel unwell, or have symptoms such as:
- a worsening headache
- feeling confused
- problems with your sight.
Rarely, enzalutamide can cause an allergic reaction. Signs of a reaction include:
- swelling of the lips, tongue, or throat
- feeling breathless.
If you feel unwell or have any of these signs, contact the hospital straight away. Do not take any more of this treatment until you have spoken to them.
Blood clot risk
Cancer and some cancer treatments can increase the risk of a blood clot. Symptoms of a blood clot include:
- pain, redness or swelling in a leg or arm
- chest pain.
If you have any of these symptoms, contact a doctor straight away.
A blood clot is serious, but can be treated with drugs that thin the blood. Your doctor or nurse can give you more information.
Some medicines can affect how this treatment works or be harmful when you are having it. Always tell your cancer doctor about any drugs you are taking or planning to take, such as:
- medicines you have been prescribed
- medicines you buy in a shop or chemist
- vitamins, herbal drugs and complementary therapies.
Tell other doctors, pharmacists or dentists who prescribe or give you medicines that you are having this cancer treatment.
You can visit the electronic Medicines Compendium (eMC) for more detailed information about your treatment.
Some drugs can affect whether you can make someone pregnant.
There may be ways to preserve your fertility. If you are worried about this, it is important to talk with your doctor before you start treatment.
Medical and dental treatment
If you need medical treatment for any reason other than cancer, always tell the doctors and nurses that you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.
If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.