Bicalutamide (Casodex)

Bicalutamide is also known as Casodex. You pronounce bicalutamide as bye-ka-loo-ta-mide.

It is a type of hormone therapy Open a glossary item known as an anti androgen Open a glossary item

It is a treatment for prostate cancer.

How does bicalutamide work?

Prostate cancer needs the male hormone testosterone Open a glossary item to grow. Testosterone is also called an androgen. 

Bicalutamide stops testosterone from reaching the cancer cells. This can slow the growth of your cancer and may shrink it.

How do you take bicalutamide?

Bicalutamide is a tablet.

You should swallow the tablet whole with a glass of water. 

You must take tablets according to the instructions your doctor or pharmacist gives you.

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.

How often do you have bicalutamide?

You take bicalutamide once a day. You usually take it for at least 2 years or until you need a different type of therapy to treat your cancer. 

You might have bicalutamide:

Reducing tumour flare

You need to take bicalutamide before you start some other types of hormone treatment because they take a few weeks to lower your testosterone. During this time they can make your symptoms worse. This is called tumour flare. 

If you are having bicalutamide to stop tumour flare, you take it for a few days before starting the luteinising hormone blocker, and stay on it for about 4 weeks. 


You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.

What are the side effects of bicalutamide?

Side effects can vary from person to person. They also depend on what other treatments you're having. 

When to contact your team

Your doctor, nurse or pharmacist will go through the possible side effects. They will monitor you 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

Early treatment can help manage side effects better. 

Contact your advice line immediately if you have signs of infection, including a temperature above 37.5C or below 36C.

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:

Breast swelling and tenderness (gynaecomastia)

This treatment can cause swelling and tenderness in the breast tissue. Talk to the team looking after you about this.

Feeling weak

You might feel weak or lack strength in your body while having this treatment. 

Skin rash

Skin problems include a skin rash, dry skin and itching. This usually goes back to normal when your treatment finishes. Your healthcare team can tell you what products you can use on your skin to help.

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:

  • hot flushes
  • lowered interest in sex
  • erection problems
  • feeling sick
  • constipation
  • being very sleepy or dizzy
  • lowered appetite
  • indigestion
  • liver changes such as yellowing of the skin or whites of the eyes (jaundice)
  • changes to body hair (hair loss on the head but increased hair growth on the body)
  • weight gain
  • blood in urine
  • depression
  • fluid build up (oedema)
  • breathlessness and looking pale (due to lower levels of red blood cells)
  • tummy (abdominal pain)
  • passing wind
  • chest pain

Rare side effects

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

  • a severe allergic reaction that can cause a rash, shortness of breath, redness or swelling of the face and dizziness - some allergic reactions can be life-threatening. Tell your nurse or doctor if you notice any of these symptoms
  • breathlessness and cough caused by changes to the lung tissue making it less flexible

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, foods or 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.


This treatment might harm a baby developing in the womb. It is important not to get someone pregnant while you are having treatment and for a few months afterwards.

Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if your partner becomes pregnant while you're having treatment.

Loss of fertility

It is not known whether his treatment might affect your 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.

Some men might be able to store sperm before starting treatment.

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.

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