PROVIBOL ALPHA PHARMA 50X25 MG

Provibol (Mesterolone) Alpha Pharma 50 tablets (1 tablet 25 mg)

COMPOUND

One tablet contains

active substance – mesterolone 25 mg,

Tablets, round, white, with a line on one side and an engraving “AX” inside a hexagon on the other side.

PHARMACOTHERAPEUTIC GROUP

Sex hormones and modulators of the reproductive system. Androgens. Derivatives of 5-androstenone. Mesterolone.

ATX code G03BB01

PHARMACOLOGICAL PROPERTIES

Pharmacokinetics

After oral administration, mesterolone is rapidly and almost completely absorbed over a wide dose range from 25 to 100 mg. Maximum serum drug levels are 3.1 + 1.1 ng/ml after 1.6 + 0.6 hours. Serum levels of the drug then decline with a final half-life of 12–13 hours. 98% of mesterolone is bound to serum proteins. Binding to albumin is 40%, while binding to SHBG (sex steroid binding globulin) is 58%.

Mesterolone is rapidly metabolized. The rate of metabolic clearance in serum is 4.4 + 1.6 ml min-1 kg-1. The drug is not excreted unchanged by the kidneys. The main metabolite is 1-methyl-androsterone, the conjugated form of which accounts for 55-70% of the metabolites excreted by the kidneys. The ratio of the main glucuronide metabolite to its sulfate is about 12:1. Another metabolite, accounting for about 3% of metabolites excreted by the kidneys, is 1-methyl-5-androstane-3, 17-diol. There is no metabolic conversion to estrogens or corticosteroids.

About 77% of a dose of mesterolone is excreted as metabolites in the urine and about 13% of the dose in feces.

Within 7 days, 90% of the dose is excreted, 50% of which is excreted by the kidneys within 24 hours.

The absolute bioavailability of mesterolone when taken orally is about 3%.

Pharmacodynamics

Proviron® is an androgenic drug for oral administration. The presence of a C-1 methyl group in the structure of the drug determines the special properties of this steroid: unlike testosterone and its derivatives used for androgen therapy, it is not metabolized into estrogen.

This difference fully explains the observational data that, at a standard therapeutic dose used in healthy men, Proviron® does not significantly suppress the release of gonadotropins from the pituitary gland. In this regard, Proviron® (1) does not affect spermatogenesis and (2) does not affect the body's production of its own testosterone, which distinguishes it from other androgens, which replace testosterone levels by suppressing the production of endogenous androgens.

Unlike other androgens for oral administration, Proviron® is well tolerated by the liver, which may be due to the absence of alkyl substitution at the C-17 position of the steroid core.

INDICATIONS FOR USE

- androgen deficiency or male infertility associated with primary or secondary male hypogonadism.

DIRECTIONS FOR USE AND DOSES

Adults:

Initial dose:

3 or 4 tablets daily for several months, and then maintenance therapy: 2-3 tablets (50-75 mg) daily.

Children:

not recommended for children.