|
Propecia for Hair Loss
|
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
Propecia (Finasteride) 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
The most common side effects are decreased libido, impotence, decreased volume of ejaculate.
|
|
Pharmacological characteristics
- Absorption: bioavailability is 65%.
- Metabolism: Extensively metabolized in the liver, primarily
via the CYP-450 3A4 enzyme subfamily. Propecia 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 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 Propecia 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 follicles.
Finasteride inhibits conversion of hormone testosterone into
5-alpha-dihydrotestosterone (DHT), a potent androgen. The drug
decreases DHT concentrations in the serum and the scalp by up
to 70 and 60%, respectively.
|
|
Reviews, Discussion Boards &
Forums
|
|
Reliable Sources for Information
|
|
References
- 1. U.S. Food and Drug Administration.
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
|
Interesting facts
- At the end of 2004 the World Anti-Doping Agency added finasteride
to its list of banned drugs in international sports. The agency
calls the medicine as masking agent that hides the use of more nefarious
drugs like the steroid nandrolone.
- Propecia is a prescription medication approved by the FDA originally
as a prostate gland shrinking medication.
- However in 1998 it was also approved at a lower dosage as an anti-baldness
treatment.
- It is sold as a prescription prostate medication in 5 mg tablet
form under the brand name Proscar and for treatment
of hair loss it is sold in 1 mg tablets under the brand name Propecia.
- It is the first and only FDA-approved oral medication for
the treatment of male androgenetic alopecia on the vertex (top of head)
and the anterior mid-scalp (middle front of head) in men only.
|
