Flutamide (Drogenil)

Flutamide is a type of hormone therapy drug called an anti androgen. Prostate cancer depends on the male sex hormone, testosterone, to grow. Testosterone is an androgen. Prostate cancer cells have special proteins known as receptors that take up testosterone. Anti androgens such as flutamide attach to the receptors and stop testosterone reaching the cancer cell. This can slow down the growth of the cancer or shrink it.

You take flutamide either alone, or with another type of drug for prostate cancer called a luteinising hormone (LH) blocker. LH blockers include goserelin (Zoladex), leuprorelin (Prostap) and triptorelin. If you are having flutamide with one of these drugs, it is to stop what is called a flare reaction. When you first start on LH blockers you actually make more testosterone for the first few days or weeks. This soon settles down, and after a few weeks you stop making testosterone. Flutamide helps to reduce any cancer symptoms caused by the temporary increase in testosterone.

You take flutamide as a tablet, 3 times a day. Try to take it at evenly spaced times during the day. If you are having it to stop a flare reaction, you take it for a few days before starting the LH blocker, and stay on it for about 4 to 6 weeks.

It is very important that you take tablets according to the instructions your doctor or pharmacist gives you. For example, whether you have a full or empty stomach can affect how much of a drug gets into your bloodstream. You should take the right dose, not more or less. And never stop taking a cancer drug without talking to your specialist first.

We've listed the side effects associated with flutamide 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. Or look in the cancer drug side effects section.

More than 10 in every 100 people have one or more of these.

• Hot flushes – these are similar to those that women have during the menopause. They affect 3 out of 5 men treated (60%) and are caused by the fall in testosterone levels. Unfortunately some men have them for as long as they stay on the treatment. Tell your doctor or nurse if they are difficult for you to cope with
• Lowered interest in having sex (libido) and problems getting an erection (impotence) – this affects about 3 out of 10 (30%) men but stops after you finish treatment
• Flutamide may have a harmful effect on a developing baby. You are advised not to father a child while you are on treatment. If you are sexually active, you should discuss contraception with your doctor before you start your treatment
• You may not be able to father a child immediately after treatment with this drug, but this effect is usually temporary. It is important to talk to your doctor about your fertility before starting treatment

Between 1 and 10 in every 100 people have one or more of these.

• Tiredness or fatigue usually improves within a few weeks of starting treatment
• Sadness usually improves within a few weeks of treatment – if it goes on for longer, talk to your doctor or nurse about getting some help
• Breast tenderness and swelling – this can affect about 1 out of 10 (10%) men treated, and can be distressing. Rarely, you may have some fluid leaking from your breast (galactorrhoea) with the swelling
• Feeling or being sick affects 1 in 10 men treated (10%) – it is usually mild and can be controlled by anti sickness medicines
• Diarrhoea affects about 1 in 10 men (10%) – it is usually mild but if you have diarrhoea you need to make sure you drink plenty of fluids
• A reduced number of red blood cells (anaemia) – about 1 in 20 men (5%) will become anaemic

Fewer than 1 in 100 people have these.

• Temporary changes in the way your liver works – this affects only 1 in 100 men (1%). You will have blood tests to check for this. If you become itchy, your urine gets darker, or your skin and eyes look yellow, contact your doctor
• Blurred vision – your vision may become blurred a few months after you start treatment
• A skin rash and, very rarely, increased sensitivity to the sun (photosensitivity)

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

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.

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and over the counter remedies – some drugs can react together. Flutamide can react with the drug warfarin. If you are taking warfarin you will need to have regular blood tests and your warfarin dose may need adjusting.