What is bicalutamide?
Bicalutamide is a man-made drug that is used in the treatment of prostate cancer. It is a type of hormonal therapy. Hormonal therapies interfere with the production or action of particular hormones in the body. Hormones are substances produced naturally in the body. They act as chemical messengers and help to control the activity of cells and organs.
How it works
Most prostate cancers need supplies of the male hormone testosterone to grow. This is produced by the testes and adrenal glands. On the surface of the prostate cancer cells are proteins called receptors. Bicalutamide has a structure similar to the male sex hormone testosterone. It works by blocking and preventing testosterone from attaching (binding) to the receptors on the surface of the prostate cancer cells. Without testosterone, the cancer cells either grow more slowly,or stop growing altogether. The cancer may shrink in size.
Bicalutamide may be used on its own to treat prostate cancer that is contained within the prostate gland, or in the tissues around the prostate gland. In prostate cancer which has spread to other parts of the body, bicalutamide may be given on its own or together with injections of another type of hormonal therapy drug such as goserelin, buserelin, triptorelin or leuprorelin. These drugs block the production of a hormone produced by the pituitary gland (leuteinising hormone), which stimulates the production of testosterone.
How it is given
Bicalutamide is a tablet, which is taken once a day.
Possible side effects
Each person’s reaction to any medication is unique. Many people have very few side effects with bicalutamide while others may experience more. The side effects described in this section will not affect everyone and may be different if you are having more than one drug. We have outlined the most common side effects. However, we have not included those which are very rare and therefore extremely unlikely to affect you. If you notice any effects that you think may be due to the drug but which are not listed here, please discuss them with your doctor or nurse.
You will see your doctor regularly while you have this treatment so that he or she can monitor the effects. This section should help you to discuss any queries about your treatment and its side effects with your doctor or nurse, as they are in the best position to help and advise you.
Some people may have some of the following side effects.
Breast tenderness or fullness Some men may notice slight breast swelling and tenderness known as gynaecomastia. Your doctor can prescribe medicines to reduce any discomfort.
Hot flushes These are usually mild and may wear off after a period of time. There are a number of ways to help reduce hot flushes and sweats. It can be useful to avoid or cut down on tea, coffee, nicotine and alcohol. Let your doctor know if hot flushes are causing you any problems as recent research suggests that progesterone or some anti-depressants may be helpful in controlling this side effect.
Some people find that complementary therapies help, and your GP may be able to give you details about obtaining these on the NHS.
Itching and dryness of the skin This is usually mild. Let your doctor know if it is a problem for you. Sometimes creams or medications can reduce this effect.
Nausea (feeling sick), vomiting and mild diarrhoea These effects are usually mild and easily controlled. Nausea can sometimes be relieved by taking the tablet with food. Let your doctor know if you have any of these side effects as medicines can be prescribed to help.
CancerBACUP’s section on diet and the cancer patient discusses ways of coping with these effects and CancerBACUP also has a section on managing nausea and vomiting.
Lowering of libido (sex drive), and impotence (loss of ability to have an erection) If these effects occur, sexual function will return to normal after stopping the drug. Your doctor or nurse can discuss this with you.
Drowsiness and weakness Occasionally bicalutamide may cause feelings of weakness and drowsiness.
Blood in the urine A rare side effect of bicalutamide is blood in the urine (haematuria). Let your doctor know if you have this.
Length of treatment
Your doctor will discuss the length of treatment that they feel is appropriate for your situation. Cyproterone acetate is given for as long as it is being effective in controlling your cancer. This may be for several months or years.
Things to remember about bicalutamide tablets
- Keep the tablets in a safe place where children cannot reach them, as cyproterone acetate could harm them.
- If your doctor decides to stop the treatment, return any remaining tablets to the pharmacist. Do not flush them down the toilet or throw them away.
- If you are sick just after taking the tablet tell your doctor as you may need to take another one.
- If you forget to take your tablet, do not take a double dose. Don’t worry, the levels of the drug in your blood will not change very much – but try not to miss more than one or two tablets in a row.
- Remember to get a new prescription a few weeks before you run out of tablets and make sure you that have plenty for holidays etc.
This section has been compiled using information from a number of reliable sources including;
- Martindale: The Complete Drug Reference (33rd edition). Sweetman et al. Pharmaceutical Press, 2002.
- British National Formulary (46th edition). British Medical Association and Royal Pharmaceutical Society of Great Britain, September 2003.
For further references, please see the general bibliography.