Finasteride, a synthetic 4-azasteroid compound, is a specific competitive inhibitor of type II 5-alpha reductase, an intracellular enzyme that converts testosterone into a more active androgen-dihydrotestosterone (DHT). In BPH, its increase depends on the conversion of testosterone to DHT in the prostate. Finasteride is highly effective in reducing the concentration of DHT in both plasma and prostate tissue. Suppression of DHT formation is accompanied by a decrease in the size of the prostate gland, an increase in the maximum rate of urination and a decrease in the severity of symptoms associated with prostatic hyperplasia.
The daily dose is 5 mg, the frequency of administration is 1 time / day. Treatment is long.
On the part of the reproductive system: rarely – impotence, decreased libido, decreased ejaculate volume, gynecomastia.
Allergic reactions: skin rash, angioedema.
Hypersensitivity to finasteride, obstructive uropathy, prostate cancer. Finasteride is not used in women and children.
Clinically significant interactions with other drugs have not been noted. Apparently, finasteride does not have a noticeable effect on the enzyme system, involved in cytochrome P450, involved in the metabolism of some drugs. In clinical trials, combinations with propranolol, digoxin, glyburide, warfarin, theophylline and antipyrin have been studied.
In clinical studies, finasteride was used as with ACE inhibitors, blockers of α- and β-adrenergic receptors, calcium channel blockers, nitrates, diuretics, antagonists of H 2 histamine receptors, inhibitors of HMG-CoA reductase inhibitors, NSAIDs, quinolones and benzodiazepines. At the same time, clinically significant negative reactions were not detected.