Degarelix (Firmagon®) is a hormonal therapy drug used to treat prostate cancer. It is best to read this information with our general information about hormonal therapies and the type of cancer you have.
Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.
Hormones are chemicals that our bodies make. Hormones act as messengers and help control how cells and organs work. Hormonal therapies are drugs that change the way hormones are made or how they work in the body.
Most prostate cancers need the hormone testosterone to grow. Almost all testosterone in men is made by the testicles. A very small amount is made by the adrenal glands, which sit above the kidneys. Degarelix stops the testicles from making testosterone. This reduces testosterone levels and may shrink the prostate cancer or stop it growing.
Degarelix is given as an injection under the skin (subcutaneously). It is usually given in your tummy.
The first time you have it, the nurse will give you 2 injections of the drug. After this, you have 1 injection a month.
You usually have the first injection at your hospital clinic appointment. After this they can be given by your GP or practice nurse at the surgery. If you are not able to visit the surgery, a district nurse may give you the injection at home.
If an injection is delayed by 2 to 3 days this should not affect how well the treatment works. But you should try to have your injections as regularly as possible.
Your nurse or doctor will talk to you about your treatment plan.
You may have some pain, swelling, redness, or a darker colour around the area that was injected. Let your doctor know if this happens. Painkillers may help.
We explain the most common side effects of this treatment here. We also include some less common side effects.
You may get some of the side effects we mention, but you are unlikely to get all of them. If you are also having treatment with other cancer drugs, you may have some side effects that we have not listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.
Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.
Serious and life-threatening side effects
Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.
Contact the hospital
Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.
We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.
Hot flushes and sweats
These are common. During a flush, your neck and face may feel warm and look red. Flushes can last for a few seconds or for up to 10 minutes. You may have sweats then feel cold and clammy. Some people feel anxious or irritable during a hot flush.
There are things you can do to try to reduce flushes:
- Wear clothes made from natural fabrics, such as cotton.
- Dress in layers of clothes that you can remove as needed.
- Use cotton sheets and have layers of bedding.
- Keep the room temperature cool or use a fan.
- Have cold drinks rather than hot ones. Try to avoid drinks with caffeine in them.
You may have fewer hot flushes and sweats as your body adjusts to hormonal treatment. Or your doctor can prescribe drugs to help. Some people continue to have flushes and sweats, but they usually stop a few months after treatment finishes.
You can read more about coping with hot flushes and managing hormonal symptoms in our information on prostate cancer.
Chills, fever or flu-like symptoms after the injection
Some men have these symptoms a few hours after having the injection. They usually settle within a few hours. Contact your cancer nurse or doctor if you have them.
This treatment may cause headaches. If this happens, tell your doctor or nurse. They can give you painkillers.
Feeling tired is a common side effect. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can give you more energy. If you feel sleepy, do not drive or operate machinery.
Muscle or bone pain
You may get pain in your muscles or bones. If this happens, tell your doctor so they can give you painkillers. Let your doctor or nurse know if it does not get better.
Weight gain and loss of muscle strength
You may gain weight, particularly around your waist, and you may lose some muscle strength. Eating a healthy diet and exercising regularly can help control your weight. Resistance exercises, such as lifting weights, may help you to reduce the loss of muscle strength. Ask your doctor or nurse for advice.
Sickness is usually mild. If you feel sick, your doctor can give you tablets to help.
This treatment may cause diarrhoea. Diarrhoea means passing more stools (poo) than is usual for you, or having watery or loose stools. If you have a stoma, it will be more active than usual.
If you have diarrhoea:
- try to drink at least 2 litres (3½ pints) of fluids each day
- avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods
- contact the hospital for advice.
Breast swelling or tenderness
This treatment can cause swelling and tenderness of your breast tissue. This is called gynaecomastia. Your doctor can give you advice on how this can be prevented or treated.
Most men lose their sex drive and have erection problems during hormonal therapy. Things often return to normal after you stop taking the drug. But some men continue to have problems after treatment is over. Your doctor can prescribe treatments to help with erection problems. But these treatments will not increase your sex drive.
Effects on the liver
Treatment may affect how your liver works. This is usually mild. You will have blood tests to check how well your liver is working. Tell your doctor if you notice any yellowing of your skin or eyes.
Dizziness or blurred vision
Occasionally, degarelix can cause these side effects. Don’t drive or operate machinery if you have them. Talk to your doctor if you are worried about this.
Anaemia (low number of red blood cells)
This treatment can reduce the number of red blood cells in your blood. These cells carry oxygen around the body. If the number of red blood cells is low, you may be tired and breathless. Tell your doctor or nurse if you feel like this. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.
Some people have an allergic reaction while having this treatment. Signs of a reaction can include:
- feeling hot or flushed
- a skin rash
- feeling dizzy
- a headache
- feeling breathless.
If you feel unwell or have any of these signs, tell a doctor or nurse straight away. Do not take any more of this treatment until you have spoken to them.
You may have some mood changes during this treatment. You may feel low or depressed. Let your doctor or nurse know if you notice any changes.
Memory or concentration
You may notice changes in your memory. You may also find it harder to concentrate. To help you remember things, try using:
- a notebook
- notes on your phone
- a calendar.
This treatment may affect your skin. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using an unperfumed moisturising cream every day. The treatment may cause a rash, which may be itchy.
Always tell your doctor or nurse about any skin changes. They can give you advice and may give you creams or medicines to help. Any changes to your skin are usually temporary and improve when treatment finishes.
Bone thinning (osteoporosis)
If you take this treatment for several months or more, you may get bone thinning. This is called osteoporosis. This can increase your risk of a broken bone (fracture). You may have bone density scans to check your bone health before and during treatment.
Doing regular exercise, such as walking, can improve your bone health. Eating a healthy diet can help too. Your doctor may prescribe drugs called bisphosphonates to help protect your bones. They may also advise you to take calcium and vitamin D supplements.
Effects on the heart
Chemotherapy can affect the way the heart works. You may have tests to see how well your heart is working. These may be done before, during and sometimes after treatment. If the treatment is causing heart problems, your doctor can change the type of chemotherapy you are having.
Contact a doctor straight away if you:
- have pain or tightness in your chest
- feel breathless or dizzy
- feel your heart is beating too fast or too slowly.
Other conditions can cause these symptoms, but it is important to get them checked by a doctor.
Raised blood sugar levels
This treatment can raise your blood sugar levels. If you have a raised blood sugar level, you may:
- feel thirsty
- need to pee (pass urine) more often
- feel tired.
Tell your doctor or nurse if you have these symptoms.
If you have diabetes, your blood sugar levels may be higher than usual. Your doctor will talk to you about how to manage this. You may need to adjust your insulin or tablet dose.
Blood clot risk
Cancer and some cancer treatments can increase the risk of a blood clot. Symptoms of a blood clot include:
- pain, redness or swelling in a leg or arm
- chest pain.
If you have any of these symptoms, contact a doctor straight away.
A blood clot is serious, but can be treated with drugs that thin the blood. Your doctor or nurse can give you more information.
Some drugs can affect whether you can make someone pregnant.
There may be ways to preserve your fertility. If you are worried about this, it is important to talk with your doctor before you start treatment.
Some medicines can affect the hormonal treatment or be harmful when you are having it. This includes medicines you can buy in a shop or chemist. Tell your cancer doctor about any drugs you are taking, including vitamins, herbal drugs and complementary therapies.
Medical and dental treatment
If you need medical treatment for any reason other than cancer, always tell the doctors and nurses that you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.
If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.