Proscar^® (Tablets) Instructions for Use

ATC Code

G04CB01 (Finasteride)

Active Substance

Finasteride (Rec.INN registered by WHO)

Clinical-Pharmacological Group

Drug for the treatment of benign prostatic hyperplasia. 5α-reductase inhibitor

Pharmacotherapeutic Group

Testosterone reductase inhibitor

Pharmacological Action

An inhibitor of 5-alpha reductase, the enzyme that converts testosterone into the more active dihydrotestosterone.

It reduces the content of dihydrotestosterone in the blood and prostate tissue.

It suppresses the stimulating effect of dihydrotestosterone on the development of prostate adenoma.

Finasteride helps to reduce the size of the enlarged gland, improves urine flow, and reduces symptoms associated with benign prostatic hypertrophy.

It may take several months of treatment to reduce the clinical manifestations of the disease.

Pharmacokinetics

It is well absorbed and penetrates into tissues and body fluids, and is detected in the ejaculate.

Bioavailability is 80% and does not depend on food intake.

C_max is reached in 1-2 hours.

Plasma protein binding is 90%.

It is excreted as metabolites by the kidneys (39%) and through the intestines (57%).

T_1/2 is 6-8 hours.

Long-term (3-7 months) use at a dose of 5 mg/day reduces the concentration of 5-alpha-dihydrotestosterone in the blood serum by 70%.

Indications

Benign prostatic hyperplasia (to reduce the size of the prostate gland; improve urine flow and reduce symptoms associated with hyperplasia; reduce the risk of acute urinary retention requiring catheterization or surgical intervention, including transurethral resection of the prostate and prostatectomy).

ICD codes

Dosage Regimen

Take one 5 mg tabletorally once daily, with or without food.

Swallow the tablet whole; do not crush or chew.

Adhere to a long-term treatment course, as a clinical response may require six months or more of continuous therapy.

Continue treatment indefinitely, as cessation will lead to a reversal of therapeutic effect within approximately 14 weeks.

Prior to initiating therapy, conduct a thorough evaluation to confirm benign prostatic hyperplasia and exclude conditions that mimic its symptoms, such as prostate cancer, infection, or stricture.

Perform a digital rectal examination and assess prostate-specific antigen levels before treatment and periodically thereafter.

Monitor patients with a large residual urinary volume or significantly reduced urinary flow for potential obstructive uropathy.

Exercise caution in patients with moderate to severe hepatic impairment; dosage adjustment may be necessary.

Avoid handling crushed or broken tablets by women who are pregnant or may become pregnant due to the risk of absorption and potential teratogenicity to a male fetus.

Do not use in pediatric patients or for the treatment of female patients.

Adverse Reactions

From the reproductive system rarely – impotence, decreased libido, decreased ejaculate volume, gynecomastia.

Allergic reactions skin rash, angioedema are possible.

Contraindications

Hypersensitivity to finasteride, obstructive uropathy, prostate cancer. Finasteride is not used in women and children.

Use in Pregnancy and Lactation

Women of childbearing age and pregnant women should avoid contact with the drug, as it has teratogenic properties (the ability to suppress the conversion of testosterone to dihydrotestosterone can cause impaired development of the genital organs in a male fetus) and penetrates into the seminal fluid.

Use in Hepatic Impairment

Finasteride should be used with caution in hepatic insufficiency.

Pediatric Use

The drug is not used in children.

Special Precautions

Finasteride should be used with caution in hepatic insufficiency.

In case of a large volume of residual urine and/or a sharply reduced urine flow, the development of obstructive uropathy should be considered.

Before starting treatment with finasteride and periodically during treatment, a rectal examination, as well as examination by other methods for the presence of prostate cancer, should be performed.

Drug Interactions

No clinically significant interaction of finasteride with propranolol, digoxin, gliburide, warfarin, theophylline and antipyrine has been found.

Apparently, Finasteride does not have a significant effect on the cytochrome P450 enzyme system and, accordingly, does not affect the pharmacokinetic parameters of drugs metabolized by hepatic microsomal enzymes.

When finasteride is used concomitantly with ACE inhibitors, alpha-blockers, beta-blockers, calcium channel blockers, nitrates, diuretics, histamine H₂-receptor blockers, HMG-CoA reductase inhibitors, NSAIDs, quinolones and benzodiazepines, no clinically significant drug interaction has been noted.

Storage Conditions

Store at 2°C (36°F) to 30°C (86°F). Keep in original packaging, protected from light. Keep out of reach of children.

Dispensing Status

Rx Only

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.