Proscalpin or Finasteride (Propecia) is a 4-azasteroid compound that selectively and competitively inhibits 5α-reductase. This nicotinamide adenine dinucleotide phosphate (NADP) -dependent enzyme converts testosterone to dihydrotestosterone. The drug specifically inhibits isoenzyme 5α-reductase type 2, which leads to a significant decrease in dihydrotestosterone levels in the prostate gland (> 90%) and in the circulatory system (from 60% to 80%).
Finasteride increases testosterone levels in the prostate gland (approximately 85%) in patients with BPH; this does not affect the growth and morphology of the prostate gland. The drug has no pronounced affinity for androgen receptors. Finasteride significantly reduces plasma PSA levels by 41% – 71% in patients with symptoms of BPH. However, the drug does not affect the ratio of unbound and total PSA levels.
The size of the prostate gland decreases under the influence of finasteride due to atrophy and apoptosis. The histological changes caused by the drug effect were observed after 6 months from the start of treatment. The glandular elements of prostate tissue are most sensitive to finasteride. The drug reduces the detrusor tone in patients with urinary retention caused by BPH.
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 surgery, including prostatic transurethral resection and prostatectomy).
On the part of the reproductive system: rarely – impotence, decreased libido, decreased ejaculate volume, gynecomastia.
Allergic reactions: possible skin rash, angioedema.
Dosage and administration
Finasteride is taken orally regardless of food intake and 1 tablet (5 mg) per day for 6-7 months.