BMA Concise Guide to Medicine & Drugs

Flutamide

Brand names Chimax, Drogenil

Used in the following combined preparations None

QUICK REFERENCE

Drug group Anticancer drug

Overdose danger rating Medium

Dependence rating Low

Prescription needed Yes

Available as generic Yes

GENERAL INFORMATION

Flutamide is an anti-androgen drug used in the treatment of advanced prostate cancer, often in combination with drugs such as goserelin that control the production of the male sex hormones (androgens). Both drugs are effective because the cancer is dependent on androgens for its continued development. Treatment with goserelin-type drugs causes an initial increase in release of the hormone testosterone, leading to a growth spurt of the cancer (‘tumour flare’), which flutamide is prescribed to stop. In the UK, flutamide treatment is begun three days before the goserelin-type drug. Flutamide is also used to treat prostate cancer when goserelin-type drugs are not prescribed.

Flutamide may discolour the urine amber or yellow-green, but this is harmless. However, you should notify your doctor straight away if your urine becomes dark coloured, because this may be an indication of liver damage.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets.

Frequency and timing of doses 3 x daily, starting 3 days before the goserelin-type drug and continuing for 3 weeks.

Adult dosage range 250mg.

Onset of effect 1 hour.

Duration of action 8 hours.

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children.

Missed dose Take as soon as you remember. If your next dose is due within 2 hours, take a single dose now and skip the next.

Stopping the drug Do not stop taking the drug without consulting your doctor because the condition may worsen rapidly.

Exceeding the dose An occasional unintentional extra dose is unlikely to be a cause for concern. But if you notice any unusual symptoms, or if a large overdose has been taken, notify your doctor.

POSSIBLE ADVERSE EFFECTS

Nausea, vomiting, diarrhoea, insomnia, tiredness, headache, breast swelling or tenderness, decreased libido, and thirst are common adverse effects of flutamide; discuss with your doctor if they are severe. More rarely, dizziness, blurred vision, and stomach or chest pain occur; if so, you should consult your doctor. If you develop a rash or jaundice or your urine becomes dark coloured, you should stop taking the drug and contact your doctor immediately.

INTERACTIONS

Warfarin Flutamide increases the anticoagulant effect of warfarin.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have heart problems.

· You have liver problems.

· You are taking other medicines.

Pregnancy Not prescribed.

Breast-feeding Not prescribed.

Infants and children Not prescribed.

Over 60 No special problems.

Driving and hazardous work Do not undertake such activities until you have learned how flutamide affects you because the drug can cause blurred vision and dizziness.

Alcohol No special problems, but excessive consumption should be avoided.

PROLONGED USE

Prolonged use of flutamide may cause liver damage. Because it is an anti-androgen, the drug also reduces sperm count.

Monitoring Periodic liver-function tests are usually performed.