Finasteride

ROUTE OF ADMINISTRATION

Oral route

PHARMACOLOGICAL PROPERTIES:

Pharmacodynamics  Finasteride is a specific and competitive inhibitor of 5-alpha-reductase type-2, the enzyme that converts testosterone to 5-alpha-dihydrotestosterone (DHT), an androgen that stimulates prostate growth. Clinical experience shows that in patients with benign prostatic hypertrophy, Finasteride substantially reduces tissue concentrations of DHT, decreases prostate volume and produces a marked improvement in the characteristic symptoms of the condition.

Pharmacokinetics  After oral administration, 63% of finasteride is absorbed from the gastrointestinal tract and causes a rapid reduction in serum DTH levels, which is maximal at 8 hours and is maintained for 24 hours. Food does not affect its bioavailability. It is bound to plasma proteins by 90-93% and has a steady-state volume of distribution of 76 L. It is extensively metabolized in the liver via cytochrome P-450 (through CYP3A4) giving rise to partially active products that are excreted 39% in urine and 57% in feces. Its terminal elimination half-life is 5-6 hours and increases in elderly patients, although to an extent that is not clinically important and does not warrant dosage adjustment. In patients with renal insufficiency, the kinetic parameters of finasteride are similar to those observed in healthy volunteers. It has not been studied in patients with hepatic insufficiency.

INDICATIONS:

Treatment and control of Benign Prostatic Hyperplasia.

POSOLOGY:

Adults:  5 mg once daily.

Maximum daily dose:  The indicated dose (5 mg/day). The use of higher doses does not generate additional therapeutic benefits and, on the contrary, could cause adverse effects.

Dosage in special patients Renal impairment :  No dosage adjustments are required.

Hepatic insufficiency :  The need for dosage adjustments in these patients has not been described; however, use with caution is recommended.

Elderly :  No dosage adjustments are required.

HOW TO USE:

Administer orally with water, with or without meals.

WARNINGS:

Patients with high residual urine volume and/or decreased urinary flow should be evaluated for the possibility of obstructive uropathy. Use of the product in such cases may not be advisable. Patients with Benign Prostatic Hyperplasia who have high residual urine volume or decreased urinary flow should be monitored. The benefits of treatment are not immediate and may require at least 6 months to be noticed. Breast disorders, including cases of breast cancer, have been reported in patients treated with Finasteride for a long time. Therefore, patients should immediately notify their physician if breast changes such as lumps or nodules, pain, growth and/or nipple discharge occur during treatment. Systemic absorption of Finasteride through the skin has been demonstrated and there is experimental evidence of teratogenicity (in male fetuses) associated with the drug. Therefore, pregnant women or those who may become pregnant should avoid handling dosage units of the product that are broken or fractured and/or that may leak or spill the active ingredient. If accidental contact occurs, the exposed area should be washed immediately with plenty of soap and water. During treatment with Finasteride, a reduction in sperm volume, decreased sexual desire and impotence may occur. The product is not indicated for use in children.

PRECAUTIONS:

Before starting treatment with Finasteride, the patient should be evaluated and the possibility of prostate cancer or other urological conditions that could cause symptoms similar to those of benign prostatic hypertrophy should be ruled out.

There is clinical evidence suggesting a possible relationship between the use of 5-alpha-reductase inhibitors (including Finasteride) and an increased incidence of high-grade prostate cancer (Gleason 8-10). Therefore, during treatment, patients should be examined periodically and serial PSA determinations performed for early identification of risk.

After administration for 6 months or more, Finasteride may reduce serum prostate-specific antigen (PSA) concentrations by approximately 50%. For this reason, in order to correctly interpret the value in such circumstances, it is recommended that a PSA determination be performed 6 months after starting treatment and that the result be taken as the new baseline value. After this, any increase detected in subsequent determinations, even if the value is within the normal range, could be indicative of the presence of prostate cancer (for which the respective diagnostic tests should be performed) or of noncompliance by the patient with the prescribed regimen. For the isolated interpretation of a PSA value determined after 3-6 months of therapy, it should be doubled for comparison with normal values ​​in untreated subjects. Since Finasteride is extensively metabolized in the liver, its serum levels can be expected to be elevated in patients with liver dysfunction. Therefore, it is recommended to use it with caution in such cases.

Pregnancy  The product is not indicated for use in women.

Breastfeeding  The product is not indicated for use in women.

CONTRAINDICATIONS:  Hypersensitivity to Finasteride, other 5-alpha-reductase inhibitors or to the components of the formula. Pregnant women or women of childbearing age.

ADVERSE REACTIONS:

Hepatobiliary disorders:  Increased liver enzymes.

Cardiovascular disorders:  Palpitations.

Nervous system disorders:  Decreased libido. Depression.

Reproductive system and breast disorders:  Reduced ejaculation volume, impotence. Ejaculation disorders, gynecomastia, breast tenderness. Testicular pain. Male infertility.

Skin and subcutaneous tissue disorders:  Rash.

Immune system disorders:  Hypersensitivity reactions, including pruritus, urticaria and angioedema.

General disorders:  Breast cancer in men.