What is buserelin?
Buserelin is a man-made drug which is used in the treatment of advanced prostate cancer, when it has spread to other parts of the body or come back after initial treatment. It is a type of hormonal therapy.
Hormonal therapies change the production or activity 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 the adrenal glands. The testes will only make testosterone if told to do so by leuteinising hormone, which is produced from a part of the brain known as the pituitary gland.
Buserelin reduces the production of leuteinising hormone, and so the levels of testosterone fall. This may shrink or slow down the cancer growth. There may be a brief increase in testosterone levels in the first few days or weeks of starting treatment with buserelin.
How it is given
Buserelin is given as an injection under the skin (subcutaneously) three times a day for the first week, and is then continued as a nasal spray six times per day in each nostril. Sometimes people may find the injection slightly uncomfortable, and may notice an area of redness at the injection site afterwards.
You should avoid using a nasal decongestant for at least 30 minutes after using buserelin nasal spray.
Possible side effects
Each person’s reaction to any medication is unique. Many people have very few side effects with buserelin, while others may experience more. 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 which 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 side effects listed here.
Nasal irritation The nasal spray may cause temporary irritation to the lining of the nose. Nasal decongestants should be avoided before and for 30 minutes after using the nasal spray.
Tumour flare There may be a temporary increase in testosterone levels in the first few days or weeks of starting buserelin. Some men may have an increase in symptoms such as bone pain, or may have problems passing urine. Rarely, other problems may occur due to a temporary increase in the size of the tumour. This is known as tumour flare. If you have any problems, you will need to let your doctor know. Other types of hormonal therapy such as cyproterone acetate, flutamide or bicalutamide, may be given for the first few weeks of starting buserelin to prevent tumour flare.
Hot flushes These can be quite common, but many men find that the hot flushes 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.
Decreased libido (sex drive) Men usually experience a decreased sex drive and a loss of the ability to have an erection. If this occurs sexual function will return to normal after stopping the drug. Your doctor or nurse can discuss this with you.
Breast tenderness or fullness Men may sometimes notice slight breast swelling and tenderness known as gynaecomastia. Your doctor can prescribe medicines to reduce any discomfort.
Weight gain and tiredness You may notice that you gain a few pounds in weight and may feel less energetic than usual. This usually subsides when the buserelin treatment is stopped.
Nausea (feeling sick), vomiting and mild diarrhoea These are uncommon but may occasionally happen. If they occur they can usually be effectively controlled. Tell your doctor if you have nausea, vomiting or diarrhoea. It is important to drink plenty of fluids if you have diarrhoea.
Length of treatment
Your doctor will discuss the length of treatment that they feel is appropriate for your situation. Buserelin is often given for several months or years.
Things to remember about buserelin injections and nasal spray
- Keep the medications in a safe place where children cannot reach them, as buserelin could harm them.
- If your doctor decides to stop the treatment, return any remaining medications to the pharmacist. Do not flush them down the toilet or throw them away.
- If you forget to take the buserelin, 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 doses in a row. Let your doctor or nurse know.
- Remember to get a new prescription a few weeks before you run out of tablets and make sure that you have plenty for holidays etc.
For more information contact CancerBACUP’s Cancer Support Service.
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.