Flutamide, tablets 250 mg 84 pcs

Flutamide is a nonsteroidal drug with anti-androgenic, anti-tumor effects.

Pharmacodynamics

Competitively blocks androgen receptors of target tissue cells and prevents androgens binding to them. Prevents the manifestation of the biological effects of androgens in androgen-sensitive organs (including the prostate gland and seminal vesicles). After flutamide administration, an increase in plasma levels of testosterone and estradiol has been observed. Flutamide’s ability to inhibit the action of testosterone at the cellular level is in addition to the drug-induced castration caused by gonadotropin-releasing hormone (GnRH) analogues.

Pharmacokinetics

When taken orally, it is rapidly and completely absorbed from the GI tract. It is metabolized in the liver. At least 6 metabolites are identified. The main metabolite found in blood plasma – alpha-hydroxylated derivative (2-oxiflutamide) – is biologically active. Binding to plasma proteins is 94-96% (flutamide) and 92-94% (2-oxiflutamide). C_max of 2-oxiflutamide is 2 h. T_1/2 2-oxiflutamide is 6 h (in elderly patients, 8 h after a single dose and 9.6 h when stable concentration is reached). It is excreted mainly by the kidneys as metabolites, 4.2% – with the feces within 72 hours.

Indications

Active ingredient

Composition

1 tablet contains:

Active ingredients:

Flutamide 250 mg.

How to take, the dosage

Flutamide is prescribed 1 tablet 3 times a day every 8 hours. If a positive effect is achieved, the drug is used until signs of tumor disease progression appear.

In case of combined therapy with LHRH agonists, both drugs may be given simultaneously or flutamide may be started three days before the first LHRH agonist.

Interaction

It is believed that there may be a drug interaction when flutamide is used simultaneously with paracetamol, opioid analgesics, NSAIDs.

Special Instructions

In the treatment of prostate cancer it is necessary to monitor the liver function (laboratory tests should be performed once a month for the first four months and then regularly).

In case of increase in the level of liver enzymes by 2-3 times in comparison with the upper limit of normal values and/or appearance of jaundice in the absence of liver metastases, flutamide should be discontinued. If the first symptoms of liver dysfunction occur, such as itching of the skin, darkened urine, nausea, vomiting, persistent loss of appetite, yellowing of the skin or whites of the eyes, pain in the right subcostal area or flu-like symptoms of unclear origin should be immediately consulted with a physician.

When evaluating the differential diagnosis of male hypogonadism, the following indicators should be considered: in healthy individuals with normal basal gonadotropin excretion after administration of the drug there is an increase in their excretion by 1.5 times or more; in primary hypogonadism the initial gonadotropin excretion is significantly increased, less often normal, the drug administration leads to a further increase in their excretion by 1.5-2 times or more; in secondary hypogonadism the initial gonadotropin excretion is reduced, less often normal, no significant increase in their excretion after the drug administration is observed.

Contraindications

Hypersensitivity, severe liver, kidney, thyroid diseases.

With caution: patients with reduced liver function, patients with a tendency to thrombosis and with cardiovascular disease.

Side effects

Endocrine system disorders: gynecomastia and/or galactorrhea.

Digestive system disorders: nausea, vomiting, jaundice, diarrhea, increased liver transaminase activity.

Water-electrolyte metabolism: fluid retention.

Other: rarely – headache, thromboembolism, renal dysfunction, sleep disorders, subcutaneous hemorrhage, lupus-like syndrome.

Overdose

Treatment: if the patient is conscious and without spontaneous vomiting, vomiting should be induced.

Vital function control and symptomatic therapy are necessary.

Hemodialysis and peritoneal dialysis are ineffective (due to high plasma protein binding).

Pregnancy use

It does not apply.