FINASTERIDE tablet film coated

Country: United States

Language: English

Source: NLM (National Library of Medicine)

Active ingredient:

FINASTERIDE (UNII: 57GNO57U7G) (FINASTERIDE - UNII:57GNO57U7G)

Available from:

Cardinal Health

INN (International Name):

FINASTERIDE

Composition:

FINASTERIDE 5 mg

Prescription type:

PRESCRIPTION DRUG

Authorization status:

Abbreviated New Drug Application

Summary of Product characteristics

FINASTERIDE- FINASTERIDE TABLET, FILM COATED
CARDINAL HEALTH
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DESCRIPTION
Finasteride, USP, a synthetic 4-azasteroid compound, is a specific
inhibitor of steroid Type II 5α-
reductase, an intracellular enzyme that converts the androgen
testosterone into 5α-dihydrotestosterone
(DHT).
Finasteride is 4-Azaandrost-1-ene-17-carboxamide,
_N_-(1,1-dimethylethyl)-3-oxo-,(5α,17β)-. The
molecular formula of finasteride is C
H N O and its molecular weight is 372.55. Its structural
formula is:
Finasteride is a white to off-white crystalline powder with a melting
point near 250°C. It is freely
soluble in chloroform and in lower alcohol solvents, but is
practically insoluble in water.
Finasteride tablets, USP for oral administration are film-coated
tablets that contain 5 mg of finasteride
and the following inactive ingredients: anhydrous lactose, colloidal
silicon dioxide, croscarmellose
sodium, docusate sodium, hypromellose, magnesium stearate,
microcrystalline cellulose, polydextrose,
polyethylene glycol, povidone, pregelatinized starch, sodium lauryl
sulfate, titanium dioxide and
triacetin.
CLINICAL PHARMACOLOGY
The development and enlargement of the prostate gland is dependent on
the potent androgen, 5α-
dihydrotestosterone (DHT). Type II 5α-reductase metabolizes
testosterone to DHT in the prostate
gland, liver and skin. DHT induces androgenic effects by binding to
androgen receptors in the cell
nuclei of these organs.
Finasteride is a competitive and specific inhibitor of Type II
5α-reductase with which it slowly forms a
stable enzyme complex. Turnover from this complex is extremely slow (t
~ 30 days). This has been
demonstrated both _in vivo_ and _in vitro_. Finasteride has no
affinity for the androgen receptor. In man, the
5α-reduced steroid metabolites in blood and urine are decreased after
administration of finasteride.
In man, a single 5 mg oral dose of finasteride produces a rapid
reduction in serum DHT concentration,
with the maximum effect observed 8 hours after the first dose. The
suppression o