Flutamide (Drogenil ®)
Flutamide is a hormonal therapy drug used to treat prostate cancer. It's also called Drogenil®.This information is best read with our general information about prostate cancer. You will see a doctor or nurse regularly while you have this treatment so they can monitor its effects.
Hormones are substances produced naturally in the body. They act as chemical messengers and help control the activity of cells and organs. Hormonal therapies such as flutamide interfere with 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.
Flutamide blocks testosterone from reaching the cancer cells. Without testosterone, the prostate cancer may shrink or stop growing.
When flutamide is given
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Flutamide may be given short-term (for a few weeks) with other hormonal treatments. It is used to manage a condition called tumour flare that can happen when starting treatments such as goserelin, buserelin, triptorelin, leuprorelin or histrelin. Tumour flare is a temporary increase in testosterone levels, which can lead to an increase in symptoms, such as problems passing urine. Flutamide may be given for the first few weeks of these treatments to prevent this.
Flutamide is also used to treat prostate cancer that has spread to other parts of your body (advanced cancer). It can be given on its own or with other hormonal treatments.
Your doctor or nurse will explain how long you will have flutamide treatment for.
Taking your flutamide tablets
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Flutamide is taken as a tablet three times a day. Doses should be evenly spaced throughout the day. Take the tablets after meals and swallow them whole with a glass of water. Always take your tablets exactly as your nurse or pharmacist explained. This is important to make sure they work as well as possible for you.
It’s important that you do not stop taking any of your tablets unless advised by your doctor. Here are some important things to remember:
If you forget to take your tablet do not take a double dose. Just take your next dose at the right time. The levels of the drug in your blood will not change very much.
Keep tablets in the original package at room temperature and away from heat and direct sunlight.
Keep them safe and out of the reach of children.
Get a new prescription before you run out of tablets and make sure you have plenty for holidays.
Return any remaining tablets to the pharmacist if your treatment is stopped.
Possible side effects of flutamide
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We explain the most common side effects of flutamide here. But we don’t include all the rare ones that are unlikely to affect you. You may get some of the side effects we mention, but you are very unlikely to get all of them. If you are having other drugs as well, you may have some side effects that we don’t list here.
Always tell your cancer doctor or nurse about the side effects you have. They can prescribe drugs to help control some side effects and give you advice about managing side effects.
Breast swelling or tenderness
Many men notice slight breast swelling and tenderness. This is known as gynaecomastia. You may also notice a small amount of liquid leaking from your nipples. Your doctor can talk to you about how this can be treated.
Flutamide can cause diarrhoea. You may also get pain or discomfort in your tummy (abdomen). Drink plenty of fluids (at least 2 litres a day) if you have diarrhoea. Tell your doctor if any pain or discomfort doesn’t improve or gets worse. Your doctor can prescribe anti-diarrhoea tablets if needed. Sometimes you may have to reduce or stop treatment with flutamide and consider other types of hormonal therapy.
This is a common side effect. Your doctor can prescribe anti-sickness drugs if needed.
Most men lose their sex drive and have erection difficulties during hormonal therapy. These can return to normal after you stop taking the drug but some men continue to have difficulties after treatment is over. Your doctor can prescribe treatments to help with erection difficulties, but these don’t affect sex drive.
If you need support coping with sexual difficulties, your nurse or doctor can give you information and refer you for specialist support services.
You might find it helpful to read our information on sexuality and cancer.
Hot flushes and sweats
These are common and can be mild or more severe. During a flush you feel warmth in your neck and face and your skin may redden. Mild flushes last for a few seconds up to about a couple of minutes. More severe flushes can last for 10 minutes or more. You may have sweats and 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, such as cutting down on nicotine, alcohol and hot drinks that contain caffeine such as tea and coffee.
If hot flushes are troublesome your doctor can prescribe drugs to help reduce them.
Hot flushes and sweats may get less as your body adjusts to hormonal treatment. They usually stop completely a few months after treatment finishes.
Tiredness and difficulty sleeping
Tiredness is a common side effect. Flutamide may cause problems with falling or staying asleep. Your doctor or specialist nurse may be able to give you some help and advice with these side effects.
There is evidence that doing exercise can reduce tiredness in men on hormonal therapy. It’s important to get medical advice before starting exercise. Ask your doctor or nurse what it’s safe for you to do.
If tiredness makes you feel sleepy, don’t drive or operate machinery.
Flutamide can sometimes affect the liver. Your doctor will do regular blood tests to check your liver. Tell your doctor if you notice any yellowing of your skin or eyes.
Flutamide may give you a bigger appetite and you might eat more than usual. It’s important to try to eat healthy foods such as fruit and vegetables so you don’t put on too much weight. Ask your doctor or nurse for advice about healthy eating.
Less common side effects of flutamide
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Rarely flutamide may cause an allergic reaction. Signs of a reaction can include a rash, feeling itchy, flushed or short of breath, swelling of your face or lips, or feeling dizzy or unwell. Contact your doctor straight away if you have any of these symptoms.
A rare side effect of flutamide is blurred vision. This may develop a few months after treatment has started. Let your doctor know about any changes to your vision.
Always let your doctor or nurse know about any side effects you have. There are usually ways in which they can be controlled or improved.
Other information about flutamide
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If you need to go into hospital for any reason other than cancer, always tell the doctors and nurses that you are taking flutamide. Explain you are taking hormonal therapy that no one should stop or restart without advice from your cancer doctor. Tell them the name of your cancer doctor so they can ask for advice.
It’s a good idea to know who you should contact if you have any problems or side effects when you’re at home.
Talk to your doctor or nurse about safe levels of alcohol intake while you are taking flutamide. Let them know if you need help or advice on staying within safe levels.
Flutamide can affect how some other medicines work. If you’re taking medicines to thin your blood (such as warfarin) or theophylline to help with your breathing, let your doctor know before beginning treatment.
Tell your doctor about any medicines you are taking, including ones you can buy for yourself, complementary therapies, vitamins and herbal drugs.
Your doctor will advise you not to father a child during treatment. This is because the drugs may harm a developing baby. It’s important to use effective contraception during and for a few months after treatment. You can talk to your doctor or nurse about this.
The information in this section has been produced in accordance with the following sources and guidelines:
British National Formulary. www.bnf.org/bnf/index.htm (accessed August 2014)
electronic Medicines Compendium (eMC). www.medicines.org.uk (accessed August 2014)
NICE clinical guideline 175. Prostate cancer: diagnosis and treatment. 2014.
If you’d like further information on the sources we use, please feel free to contact us.
Thank you to Marilyna Chong, Cancer Services Pharmacist, who reviewed this information.
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