Enzalutamide (Xtandi)

Enzalutamide is a type of hormone therapy known as an anti androgen . It's a treatment for prostate cancer that has spread to other parts of the body (metastatic cancer). 

You pronounce enzalutamide as en-za-loo-ta-mide. It is also known as Xandi.

You might have enzalutamide:

• if other hormone treatments have stopped working (hormone resistant prostate cancer). But you have no or mild symptoms and do not need chemotherapy

• if you have already had docetaxel chemotherapy, and your cancer has grown during chemotherapy. Or come back after treatment

• with other hormone treatments for prostate cancer that are working (hormone sensitive prostate cancer)

How does enzalutamide work?

Prostate cancer needs the hormone testosterone to grow. Enzalutamide is a hormone treatment that blocks testosterone from reaching prostate cancer cells. This can slow the growth of the cancer and may shrink it. You might hear it called an androgen receptor blocker or inhibitor. 

How do you have enzalutamide?

You have enzalutamide as tablets once a day. 

You swallow them whole with a glass of water. You can have the tablets with or without food.

Taking your tablets

You should take the right dose, not more or less.

Talk to your healthcare team before you stop taking a cancer drug, or if you miss a dose.

You might have enzalutamide with other hormone drugs.

How often do you have enzalutamide?

You usually carry on taking enzalutamide for as long as it is working, and the side effects aren’t too bad.

Tests

You might have blood tests before starting treatment and during your treatment. They check your general health and might check your levels of blood cells and other substances in the blood.

What are the side effects of enzalutamide?

Side effects can vary from person to person. They also depend on what other treatment you are having. 

When to contact your team

Your doctor, nurse, or pharmacist will go through the possible side effects. They will monitor you closely during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:

• you have severe side effects 

• your side effects aren’t getting any better

• your side effects are getting worse

We haven't listed all the side effects here. Remember it is very unlikely that you will have all of these side effects, but you might have some of them at the same time.

Common side effects

These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:

Tiredness and weakness (fatigue)

Tiredness and weakness (fatigue) can happen during and after treatment. Doing gentle exercises each day can keep your energy up. Don't push yourself, rest when you start to feel tired and ask others for help.

Hot flushes and sweats

We have some tips for coping with hot flushes in men. This information also includes some of the possible treatments. Talk to your doctor if your hot flushes are hard to cope with.

High blood pressure

Tell your doctor or nurse if you have headaches, nose bleeds, blurred or double vision or shortness of breath. Your nurse will check your blood pressure regularly.

Falls

You are at risk of falls. Talk to your healthcare team if you are concerned about this.

Broken bones (fractures)

Enzalutamide lowers the levels of testosterone. This can cause thinning and weakening of the bones and can increase your risk of fractures.

Occasional side effects

These side effects happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have one or more of them. They include:

• memory problems such as forgetfulness

• difficulty concentrating

• headaches

• breast swelling that may also feel tender

• dry or itchy skin

• an uncontrollable urge to move a part of the body, usually your legs (restless legs syndrome)

• heart problems – this is due to a build up of fatty substances in the arteries, causing a blockage

• taste changes

Rare side effects

These side effects happen in fewer than 1 in 100 people (less than 1%). You might have one or more of them. They include:

• seizures (fits)

• increased risk of getting an infection

• seeing things that are not there (visual hallucination)

• changes in your liver, you have blood tests to check this

Other side effects

There isn't enough information to work out how often these side effects might happen. You might have one or more of them. They include:

• bruising, bleeding gums or nosebleeds. Or you may see blood in your wee or have dark poo. Contact your healthcare team if you have these symptoms or any unusual bleeding

• feeling or being sick

• diarrhoea

• fluid build up in different parts of the body such as the face, lips, and tongue - due to a reaction to the treatment

• muscle pain, spasms or weakness

• changes in your heart rhythm

• posterior reversible encephalopathy syndrome (PRES) - a rare disorder of the nerves causing headache, fits, confusion and changes in vision - contact your healthcare team straight away if you have these symptoms. This condition is reversible

• back pain

• a rash with blisters or spots that can be all over the body, these can be painful. Other symptoms include a high temperature, headaches and feeling generally unwell. This is rare, there isn’t enough information to say how often this might happen

• second cancers. Talk to your doctor if you are concerned about this

Coping with side effects

We have more information about side effects and tips on how to cope with them.

What else do you need to know?

Other medicines, food and drink

Cancer drugs can interact with medicines, herbal products, and some food and drinks. We are unable to list all the possible interactions that may happen. An example is grapefruit or grapefruit juice which can increase the side effects of certain drugs.

Tell your healthcare team about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies. Also let them know about any other medical conditions or allergies you may have.

Contraception and pregnancy

It is important not to get someone pregnant while you are having treatment. You need to use 2 effective methods of contraception during treatment and for 3 months afterwards.

Talk to your doctor or nurse about effective contraception before starting treatment.

Loss of fertility

Enzalutamide might affect fertility in people. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Treatment for other conditions 

If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.

More information about this treatment

For further information about this treatment and possible side effects go to the electronic Medicines Compendium (eMC) website. You can find the patient information leaflet on this website.

You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.