Flutasin - Dosage | Overdose | Effects

This article was medically reviewed by M.Pharm, Marko Tanaskovic on August 12, 2018. To read more about an author, click here.

Flutasin contains flutamide, and belongs to a family of medicines that are called hormone antagonists (anti-androgens). It exhibits an anti-androgenic effect because it inhibits the binding of androgens to the receptor in tissues. The combination of this medicine and surgical castration leads to suppression of secretion of androgens from both the testicles and adrenal glands. Therefore, Flutasin blocks the action of male sex hormones and prevents the spreading of prostate cancer because prostate cancer progresses with the help of male sex hormones. This effect is used in the treatment of advanced prostate cancer in which there is increased secretion of testosterone.

It is often used in combination with LHRH agonists (lutein releasing hormone).

Flutasin can also be applied in cases of surgical castration.

Contraindications and precautions

Flutasin must not be used in patients taking other drugs that are toxic to the liver, because there are reported cases of hepatic necrosis (even with fatal outcome) in patients taking this medicine. Determination of liver enzymes (AST and ALT) is therefore recommended prior to starting treatment. If these values are two times higher than normal, Flutasin therapy should not be started.

If you notice symptoms of liver damage (itching, anorexia, tenderness in the upper right quadrant of the abdomen and flu-like symptoms), you should contact your doctor. Regular monitoring (once a month) of liver enzymes is necessary while you are being treated with this drug.

Patients who haven't had surgical castration can experience reduced sperm count if treated with Flutasin.

This medicine decreases testosterone levels and increases estradiol levels, which can lead to fluid retention and therefore this drug should not be administered to patients with heart failure. The increase in estradiol level can also lead to thromboembolic complications.

Caution is advised in patients taking anticoagulant drugs or corticosteroids.


Flutasin is administered in a dosage of 250 mg three times a day (every 8 hours). This drug is often administered in combination with other drugs called LHRH agonists. In this case, it is necessary to first introduce Flutasin and after 24 hours, start with the implementation of LHRH agonists.

Dose adjustment in patients with hepatic impairment is necessary.

Take the tablet with 8 fl. oz. of water. Food has no influence on the effect of this drug.


Symptoms of Flutasin overdose include:

  • Hypoactivity
  • Goose bumps (piloerection)
  • Unusual calmness
  • Methaemoglobinaemia
  • Teary eyes

No fatal outcomes were reported after overdose with this drug.

There has been one case in which the patient took 20 tablets of flutamide 250 mg tablets and he didn't experience any side effects.

The treatment of overdose is symptomatic. Dialysis cannot be applied because 94% of the drug binds to plasma proteins which means that dialysis will not be helpful.


Drugs that should not be administered in combination with Flutasin include:

  • Blood thinners (warfarin, acenocoumarol and heparin). Flutasin can prolong prothrombin time, and your doctor will probably reduce the dosage of these drugs.
  • Corticosteroids - Flutasin slows the metabolism of these drugs and increases the risk of side effects of corticosteroids
  • Theophylline (an anti-asthmatic) - Flutasin increases the concentration of theophylline in the blood and thus increases the risk of side effects
  • Gentamicin, furosemide, acetaminophen in high doses and other hepatotoxic drugs

In view of the detrimental effects of alcoholic beverages on the liver, they should be avoided while taking Flutasin.

Flutasin adverse reactions

Reported adverse reactions include:

  • Gynecomastia (breast enlargement) - this side effect quickly disappears after discontinuation of the drug
  • The appearance of milk in the breasts of men (galactorrhea)
  • Liver damage (itching, anorexia, dark colored urine, tenderness in the upper right quadrant of the abdomen and jaundice). Immediately contact your doctor if you notice these symptoms.
  • Gastrointestinal disorders
  • Insomnia
  • Herpes zoster
  • Ecchymosis (blood pours into the tissue)
  • Decreased sperm count
  • Decreased libido

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If you have any concerns or questions about your health, you should always consult with a physician or other health-care professional.

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