Health Guide
Drug Guide

Antiandrogen (Oral route)

Brand Names:

Dosage Forms:

Uses of This Medicine:

Nonsteroidal antiandrogens are used to treat cancer of the prostate gland. The prostate gland is present only in males; therefore, females do not get prostate cancer.

Nonsteroidal antiandrogens block the effect of the male hormone testosterone in the body. Giving a nonsteroidal antiandrogen together with another treatment that decreases the amount of testosterone produced in the body is one way of treating this type of cancer.

These medicines are available only with your doctor's prescription.

Before Using This Medicine:


Tell your doctor if you have ever had any unusual or allergic reaction to medicines in this group or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Studies with the nonsteroidal antiandrogens have been done only in adults, and there is no specific information comparing the use of these medicines in children with use in other age groups. There is a chance that a nonsteroidal antiandrogen could interfere with the development of boys. However, cancer of the prostate gland usually occurs in middle-aged or older men, so it is very unlikely that a child would need these medicines.

Older adults

Nonsteroidal antiandrogens have been tested in elderly people and have not been shown to cause different side effects or problems than they do in younger adults.


Nonsteroidal antiandrogens, and other treatments for prostate cancer that are used together with these medicines, may cause low sperm counts or otherwise decrease a man's ability to father a child. In some cases, these effects may be permanent. Men who wish to have children should discuss this with their doctors before starting treatment.

Nonsteroidal antiandrogens are usually given to men. However, if one of these medicines is needed by a woman, it is very important that an effective method of avoiding pregnancy be used during treatment. Because these medicines block the effect of the male hormone, testosterone, they may interfere with the normal development of a male fetus.


Nonsteroidal antiandrogens are usually given to men, and it is not known whether any of these medicines passes into breast milk. However, nonsteroidal antiandrogens can cause serious side effects. Therefore, if a woman needs one of these medicines, she should not breast-feed during treatment.

Other medicines

Using medicines in this class with any of the following medicines is not recommended. Your doctor may decide not to treat you with a medication in this class or change some of the other medicines you take.

Using medicines in this class with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Other interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Other medical problems

The presence of other medical problems may affect the use of medicines in this class. Make sure you tell your doctor if you have any other medical problems, especially:

Proper Use of This Medicine:

The exact amount of medicine you need has been carefully worked out. Taking too much may increase the chance of side effects, while taking too little may not improve your condition.

It is best to take this medicine at the same time each day. If you have been directed to take the medicine once a day, you may take it either in the morning or in the evening.

Bicalutamide and nilutamide may be taken with food or on an empty stomach.

A nonsteroidal antiandrogen is often used together with another medicine, which is given by injection. It is very important that the two medicines be used as directed. Follow your doctor's instructions very carefully about when to use these medicines.

Unwanted effects, including hot flashes and decreased sexual ability, may occur during treatment for prostate cancer. Also, symptoms that often occur in men with prostate cancer, including difficult or painful urination, bloody urine, and urinary tract infections, may occur or continue to occur for a while, until your condition starts to improve. It is very important that you continue to take the medicine, even if it causes side effects or if you start to feel better. Do not stop taking this medicine without first checking with your doctor.

If you vomit shortly after taking a dose of this medicine, check with your doctor. You will be told whether to take the dose again or to wait until the next scheduled dose.


The dose medicines in this class will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of these medicines. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

Missed dose

If you miss a dose of this medicine, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

For bicalutamide or nilutamide: If you do not remember your missed dose until the next day, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

For flutamide: If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


Keep out of the reach of children.

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Do not keep outdated medicine or medicine no longer needed.

Precautions While Using This Medicine:

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to check for unwanted effects.

Nonsteroidal antiandrogens rarely cause liver problems during treatment. The most important signs of this side effect are pain or tenderness in the upper right side of the abdomen (stomach) and yellow eyes or skin. Check with your doctor immediately if either of these occurs. Also, check with your doctor as soon as possible if itching occurs or your urine appears unusually dark. Other possible symptoms, such as loss of appetite, nausea or vomiting, and “flu-like” symptoms (headache, muscle or joint pain, or tiredness), can occur during treatment even if you are not having any liver problems. These symptoms usually do not need medical attention. However, if two or more of them occur at the same time, and they last for more than a few days, check with your doctor even if you do not have any of the other symptoms mentioned earlier.

For patients taking nilutamide:

Side Effects of This Medicine:

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Less common
Chest pain
shortness of breath or difficult or troubled breathing
Pain or tenderness in the upper right side of the abdomen (stomach)
yellow eyes or skin

Check with your doctor as soon as possible if any of the following side effects occur:

More common
Cough or hoarseness
runny nose
sore throat
tightness in chest or wheezing
Less common
Bloody or black, tarry stools
chills (flutamide only)
lower back or side pain (flutamide only)
mental depression
numbness, tingling, pain, or muscle weakness in hands, arms, feet, or legs
skin rash
swelling of face, fingers, feet, or lower legs
unusual tiredness or weakness
Bluish-colored lips, fingernails, or palms of hands (flutamide only)
dark urine
dizziness (severe) or fainting (flutamide only)
feeling of severe pressure in head (flutamide only)
pinpoint red spots on skin
unusual bleeding or bruising

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common
decrease in or loss of appetite
impotence or decrease in sexual desire
swelling of breasts with pain or tenderness
trouble in sleeping
Less common
Bloated feeling, gas, or indigestion
change in color vision (nilutamide only)
dryness of mouth
“flu-like” symptoms, such as headache, muscle or joint pain, or tiredness (occurring together)

Although not all of the side effects listed above have been reported for all of these medicines, they have been reported for at least one of them. However, because all nonsteroidal antiandrogens are very similar, it is possible that any of the above side effects may occur with any of these medicines.

In addition to the effects listed above, hot flashes (flushing, sudden sweating, and feeling of warmth) often occur during treatment with these medicines. Also, flutamide may cause your urine to have an amber or a yellow-green color. These effects are harmless and do not need medical attention.

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Last Updated: 6/12/2013

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