Medically reviewed by Drugs.com. Last updated on Apr 5, 2021.
Liver failure has been reported in patients taking flutamide. Evidence of hepatic injury occurred usually within the first 3 months and included elevated serum transaminase levels, jaundice, hepatic encephalopathy, and death related to acute hepatic failure. Serum transaminase levels should be measured prior to starting treatment, monthly for the first 4 months of therapy, and periodically thereafter. Flutamide is not recommended in patients whose ALT values exceed twice the upper limit of normal and should be discontinued if the ALT rises above 2 times the upper limit of normal or jaundice occurs during therapy .
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Antiandrogen
Uses for flutamide
Flutamide is used together with a luteinizing hormone-releasing hormone (LHRH) agonist to treat metastatic (cancer that has spread) prostate cancer in men. Flutamide belongs to the group of medicines called antiandrogens. It works by blocking the effects of androgen (a male hormone), to stop the growth and spread of cancer cells.
Flutamide is available only with your doctor's prescription.
Before using flutamide
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For flutamide, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to flutamide 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.
No information is available on the relationship of age to the effects of flutamide in the pediatric population. Safety and efficacy have not been established.
No information is available on the relationship of age to the effects of flutamide in geriatric patients.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking flutamide, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using flutamide 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.
Interactions with food/tobacco/alcohol
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. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of flutamide. Make sure you tell your doctor if you have any other medical problems, especially:
- Glucose-6-phosphate dehydrogenase (G6PD) deficiency or
- Hemoglobin M disease (blood disorder) or
- Tobacco smoking—Flutamide contains aniline, which may cause problems in patients with these conditions.
- Liver disease, severe—Should not be used in patients with this condition.
Proper use of flutamide
Take flutamide only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. To do so may increase the chance of side effects.
Flutamide should be taken together with other medicines used for surgery. Do not stop taking these medicines without checking with your doctor first.
Flutamide comes with a patient information insert. Read and follow the instructions in the insert carefully. Ask your doctor if you have any questions.
The dose of flutamide 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 flutamide. 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.
- For oral dosage form (capsules):
- For prostate cancer:
- Adults—Two 125-milligram (mg) capsules three times a day every eight hours for a total daily dose of 750 mg.
- Children—Use and dose must be determined by your doctor.
- For prostate cancer:
If you miss a dose of flutamide, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Precautions while using flutamide
It is very important that your doctor check your progress at regular visits to make sure that flutamide is working properly. Blood tests may be needed to check for unwanted effects.
Liver problems may occur while you are using flutamide. Stop using flutamide and check with your doctor right away if you are having more than one of these symptoms: clay-colored stools; dark urine; fever; headache; loss of appetite; nausea and vomiting; pain or tenderness in the upper right side of the stomach; unusual tiredness or weakness; or yellow eyes or skin.
Flutamide may cause gynecomastia (swelling of the breasts and breast soreness) in some patients. If you have questions on this, ask your doctor.
Do not take other medicines unless they have been discussed with your doctor. Your doctor may adjust the doses of your medications or monitor you carefully for side effects.
Flutamide side effects
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:
- Black, tarry stools
- bloody or cloudy urine
- continuing diarrhea
- continuing stomach pain
- difficult, burning, or painful urination
- frequent urge to urinate
- pale skin
- troubled breathing with exertion
- unusual bleeding or bruising
- unusual tiredness or weakness
- Blurred vision
- chest pain
- difficulty with breathing
- pounding in the ears
- shortness of breath
- slow or fast heartbeat
- sore throat
- sores, ulcers, or white spots on the lips or in the mouth
- swollen glands
- Abdominal or stomach pain
- clay-colored stools
- dark urine
- general tiredness and weakness
- light-colored stools
- loss of appetite
- nausea and vomiting
- unpleasant breath odor
- upper right abdominal pain
- vomiting of blood
- yellow eyes and skin
Incidence not known
- Back, leg, or stomach pains
- bleeding gums
- blistering, peeling, or loosening of the skin
- bluish-colored lips, fingernails, or palms
- discoloration of the urine
- dizziness or lightheadedness
- flushing or redness of the skin
- general body swelling
- joint or muscle pain
- rapid heart rate
- red irritated eyes
- red skin lesions, often with a purple center
- unusually warm skin
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
- shakiness and unsteady walk
- tearing of the eyes
- unsteadiness, trembling, or other problems with muscle control or coordination
- weight loss
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:
- Decreased interest in sexual intercourse
- feeling of warmth
- inability to have or keep an erection
- loss in sexual ability, desire, drive, or performance
- passing of gas
- redness of the face, neck, arms and occasionally, upper chest
- stomach pain, fullness, or discomfort
- sudden sweating
- swelling of the breasts or breast soreness in both females and males
- fear or nervousness
- mood or mental changes
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More about flutamide
- Side Effects
- During Pregnancy
- Dosage Information
- Drug Images
- Drug Interactions
- Pricing & Coupons
- En Español
- Drug class: antiandrogens
- Other brands
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