Treatment of locally or metastatic prostate cancer, as monotherapy (with or without orchidectomy) or in combination with luteinizing hormone releasing hormone (lgrg) agonists, in patients who have not previously been prescribed any treatment or who do not respond or who have developed resistance to or intolerance to hormone therapy, in order to achieve maximum androgen blockade. In combination therapy as a means of treatment for locally limited prostate cancer B2 – C2 (t2b – T4) to reduce tumor volume, increased tumor control and increase time between exacerbations of the disease.
Flutan (flutamide) Composition
active substance: flutamide;
1 tablet contains flutamide 250 mg;
Excipients: croscarmellose sodium, povidone, lactose monohydrate, microcrystalline cellulose, sodium lauryl sulfate, magnesium stearate, colloidal anhydrous silica.
Flutan (flutamide) Dosage form
Main physical and chemical properties: light yellow round biconvex tablets with a line, almost 12 mm in diameter.
Flutan (flutamide) Pharmacotherapeutic group
Antiandrogenic drugs. ATX code L02B B01.
Flutamide is an antiandrogenic drug with a non-steroidal structure. Flutamide and its metabolites have no agonistic or antagonistic properties against glucocorticoid, estrogen, progestin and mineralocorticoid receptors.
Flutamide blocks androgen receptors on target cells in the prostate, hypothalamus, and pituitary gland and inhibits the biological effects of endogenous androgens. However, flutamide does not inhibit the effect on androgen-mediated secretion of gonadotropin-releasing hormone (GTRG) by the hypothalamus or does not affect the sensitivity of the pituitary gland to GTRG. This leads to an increase in the content of gonadotropic hormones (luteinizing and follicle-stimulating), resulting in stimulation of testosterone hyperproduction.
Flutamide and its metabolites inhibit the interaction of dihydrotestosterone with nuclear androgen receptors. Receptor blockade can also occur at the level of the cell membrane and cytoplasm of the cell. The main metabolite is 2-hydroxyflutamide. Its affinity for androgen receptors is 25 times higher than that of flutamide, which allows us to consider it as an active form of flutamide.
The combination of flutamide with chemical or surgical castration leads to testicular and adrenal effects of androgens.
After oral administration, flutamide is well adsorbed from the gastrointestinal tract. The maximum concentration in blood plasma is reached within 2 hours. Experiments using tritium-labeled flutamide indicate its rapid metabolism to the biologically active form – 2-hydroxyflutamide and to other metabolites. The half-life of the drug is 5-6 hours. There are approximately 10 metabolites of flutamide. More than 90% of flutamide and 2-hydroxyflutamide are bound to plasma proteins. It is eliminated mainly by kidneys. Approximately 4% of the administered dose is excreted in the feces.
Treatment of locally advanced or metastatic prostate cancer as monotherapy (with or without orchiectomy) or in combination with luteinizing hormone releasing hormone (LHRH) agonists in patients who have not previously received any treatment or in patients who have not responded or developed to hormone therapy or its intolerance in order to achieve maximum androgen blockade.
In combination therapy, as one of the means to treat locally limited prostate cancer B2 – C2 (T2b – T4), to reduce tumor volume, strengthen tumor control and increase the period between exacerbations.
Hypersensitivity to flutamide or to any of the excipients.
Severe hepatic impairment (baseline liver enzymes should be assessed prior to treatment).