Goserelin (Zoladex) for prostate cancer

• What goserelin is
• How you have the treatment
• Common side effects
• Occasional side effects
• Rare side effects
• Important things to remember

Goserelin is a type of hormone therapy drug called a pituitary down regulator or ‘leuteinising hormone releasing hormone agonist’ (LHRH agonist). It is also called Zoladex. It interrupts the cycle of hormone production in the body. It does this by stopping the release of leuteinising hormone from the pituitary gland. In men, this stops the testicles producing the male sex hormone, testosterone. In women, it stops the ovaries from producing oestrogen.

Prostate cancer depends on testosterone, to grow. The aim of hormone therapy for prostate cancer is to reduce or stop the body making testosterone, to slow down the growth of cancer or shrink it.

You have goserelin as an injection just under the skin of your tummy (abdomen). It is called a ‘depot injection’, which means that the drug is absorbed slowly into your body over a period of time. You might have the injection

• Every 4 weeks (after 28 days you will need another injection)
• Every 12 weeks

You should try to make sure you have the injection on time. A few days won’t make a big difference but the aim is to stop you producing testosterone and the injections are made to last for either 4 or 12 weeks. If you are late having the injection you may start making testosterone again.

We have general information about hormone therapies in the cancer treatment section.

We've listed the side effects associated with goserelin below. You can use the links to find out more about each side effect. Where there is no link, please click on search at the top of the page.

Many men will have one or more of the following side effects

• Problems getting an erection (impotence) occur because you are not producing testosterone while you have treatment - this usually gets better within 3 and 12 months after finishing treatment
• Skin rashes are usually mild - let your doctor know
• Painful joints
• Hot flushes and sweats in 3 out of 5 men (60%), caused by the fall in testosterone levels and lasting as long as treatment continues for some men - tell your doctor or nurse if they are difficult to cope with
• Decreased interest in having sex (low libido)
• Breast tenderness and swelling in about 3 out of 10 (30%) of men - this can be distressing so your doctor may suggest a small dose of radiotherapy before treatment to try and prevent it
• Tumour flare causing pain to increase for the first few weeks - your doctor may give you another hormone drug to start with, to try and prevent this
• Goserelin may have a harmful effect on a developing baby so you should not father a child while you are on treatment - discuss contraception with your doctor before you start your treatment if this is a possibility

• Bruising of the skin where you have the injection
• Headache
• Feeling or being sick is usually mild and can be controlled by anti sickness medicines
• Weight gain - you may find you put on weight easily. You should be able to control this with diet and exercise, but it is sometimes a struggle to keep weight down when you are having hormone treatment

• Changes in blood pressure - during treatment, your blood pressure may be lower or higher than usual. Your nurse or doctor should check this regularly. Most men can continue taking goserelin, and their blood pressure usually goes back to normal either during treatment or when their treatment has finished
• Bone thinning can happen with long term treatment
• Men taking goserelin may find that the levels of sugar in their blood can change. These will be checked by regular blood tests. If you are diabetic, you will have to take extra care in checking your blood sugar.

The side effects above may be mild or more severe. A side effect may get better or worse through your course of treatment, or more side effects may develop as the course goes on. This depends on

• How many times you've had the drug before
• Your general health
• The amount of the drug you have (the dose)
• Other drugs you are having

Some side effects are inconvenient or upsetting but not damaging to your health.

Some side effects are serious medical conditions and need treating. Where we have urged you to contact your doctor, this is because

• Your side effect may need treating
• Your drug dose may need reducing to try to prevent the side effect

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and other over the counter remedies - some drugs can react together.

Talk to your doctor, pharmacist or nurse about all your side effects so that they can help you manage them. You should have a contact number for your specialist nurse. You can ring if you have any questions or problems. They can give you advice or reassure you. If in doubt, call them.