|
Basic information
- Generic name: Finasteride
- Brand/Trade names: Propecia, Proscar
- Dosages: Tablets 1 mg, 5 mg
- Pharmacologic category: Enzyme inhibitor
- FDA approved: December 19, 1997
- Habit forming? No
- Pregnancy risk factor: X
|
|
Medical uses
Finasteride (Propecia) is a specific type II 5-alpha reductase
inhibitor. It inhibits the enzyme responsible for regulating conversion
of testosterone to dihydrotestosterone (DHT). By reducing DHT
levels in the scalp, the drug decreases DHT effects on the hair
follicles, reversing the process of hair loss.
Daily use for three months or more may be necessary before a
person will notice increased hair growth.
Finasteride indicated uses include:
- Male pattern hair loss (androgenic alopecia) in men only
- Benign prostatic hyperplasia (BPH) in men with enlarged prostate
Decreased libido, impotence, decreased volume of ejaculate are
the most common side effects associated with Finasteride.
|
|
Pharmacological characteristics
- Absorption: bioavailability is 65%.
- Metabolism: Extensively metabolized in the liver, primarily
via the CYP-450 3A4 enzyme subfamily. Finasteride has two active
metabolites: t-butyl side chain monohydroxylated and monocarboxylic
acid. Each metabolite possesses no more than 20% activity.
- Elimination half-life: 3.3 to 13.4 h
- Excretion: 32% to 46% is excreted in the urine as metabolites,
and 51% to 64% is excreted in the feces.
|
|
Benefits
- Increases hair growth and reduces hair loss
- No drug interactions of clinical importance
|
|
Concerns
- Improvement takes 6-12 months
- Any benefits are lost when medication is stopped
- Sexual side effects
- Depression. The research suggests that finasteride may induce
depressive symptoms 2.
- Expensive
|
|
Unlabeled uses
|
|
Mode of action
Male pattern hair loss, or androgenetic alopecia, is an androgen-dependent
disorder. In genetically susceptible men, dihydrotestosterone
(DHT), a potent metabolite of the male androgen testosterone,
contributes to male pattern hair loss. The conversion of testosterone
to DHT is regulated by the enzyme 5-alpha reductase, which is
found primarily in scalp hair follicles.
Finasteride inhibits conversion of hormone testosterone into
5-alpha-dihydrotestosterone (DHT), a potent androgen. Finasteride
decreases DHT concentrations in the serum and the scalp by up
to 70 and 60%, respectively.
|
|
Propecia (Finasteride) Discussion Boards &
Forums
|
|
Reliable Sources for Information about Lexapro
|
|
References
- 1. U.S. Food and Drug Administration.
Finasteride (Propecia) U.S. Prescribing Information. Available
at (PDF format): Prescribing Information
- 2. Rahimi-Ardabili B, Pourandarjani R,
Habibollahi P, Mualeki A. Finasteride induced depression: a
prospective study. BMC Clin Pharmacol. 2006 Oct 7;6:7. BioMed
- 3. Beigi A, Sobhi A, Zarrinkoub F. Finasteride
versus cyproterone acetate-estrogen regimens in the treatment
of hirsutism. Int J Gynaecol Obstet. 2004 Oct;87(1):29-33. PubMed
|
