Hormones 2016

Finasteride
Also known as
Proscar, Propecia, Finasterid in Germany, Finastéride in France, Finasterida
in Spain.
Manufacturer
Merck Sharp & Dohme Ltd [MSD]
Contains
Proscar - Finasteride 5mgs in blue-coloured, apple-shaped, film coated
tablets marked ’Proscar’ on one side and ’MSD 72’ on the other (emc, 2016).
Propecia - Finasteride 1mg. in a film-coated tablet. Tan octagonal, filmcoated,
convex tablets, marked with a ’P’ logo on one side and ’PROPECIA’
on the other (emc, 2016).
Pharmacology
A specific inhibitor of the enzyme 5a-reductase that metabolises testosterone
into the more potent androgen, dihydrotestosterone (BNF, 2016a).
Indications
Benign prostatic enlargement (BNF, 2016a), male-pattern baldness in men
(BNF, 2016a).
How it works
The mechanism of action of Finasteride is based on its preferential inhibition
of Type II 5a-reductase through the formation of a stable complex with
the enzyme. Inhibition of Type II 5a-reductase blocks the peripheral
conversion of testosterone to DHT, resulting in significant decreases in
serum and tissue DHT concentrations, minimal to moderate increase in
serum testosterone concentrations, and substantial increases in prostatic
testosterone concetrations. As DHT appears to be the principal androgen
responsible for stimulation of prostatic growth, a decrease in DHT
concentrations will result in a decrease in prostatic volume (approximately
20-30% after 6-24 months of continued therapy). In men with androgenic
alopecia, the mechanism of action has not been fully determined, but
finasteride has shown to decrease scalp DHT concentration to the levels
found in hairy scalp, reduce serum DHT, increase hair regrowth, and slow
hair loss (drugbank, 2013d).
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Version 2016.3576– – Document LATEXed – 1st May 2016
[git] • Branch: 1.5 @ 26b5e6d • Release: 1.5 (2016-05-01)