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Dr. Bertram Medical Hair Transplant
眉 髮 醫 學 移 植 中 心 ( 香 港 ) |
( 852 ) 3421-1138
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Finasteride - Medical Treatment for Hair Loss
Trade Name
Propecia 1mg
Chemical Structure
N-(1,1-dimethylethyl)-3-oxo-5α,17β)-4-azaandrost-1-ene-17-carboxamide
Mechanism of Action
Finasteride 1mg slows the progress of hair loss and increased hair growth in Androgenetic Alopecia ( AGA ).
- works as an Androgen modulator in the hair follicle
- blocks the action of the enzyme type 2 5α-reductase
- reduces conversion of testosterone into dihydro-testosterone (DHT)
- reduces DHT level in the scalp by 40- 60%
- when finasteride is stopped, its action on DHT still lasts up to 2 weeks
- applying finasteride over scalp fails to grow hair. It must be taken by mouth
Dosage
1mg and 5mg showed similar result, so the recommended dosage is 1mg daily.
Efficacy
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A 5-year finasteride study in men
- 90% treated had not lost hair
- 65% had increases in hair count.
- the peak increase in scalp coverage was seen at 2 years.
- over 5 years a difference of 24 FUs/sq.cm hair count from the baseline.
- when pictures were taken, 48% of the treated group showed visual improvement compared to 6% in the placebo group.
Twins Study 2002
9 pairs of identical twin males with AGA were recruited. Finasteride was given to one of each paired twins. At 1 year, 100% of the finasteride group had retained hair compared to 56% of the placebo group.
Critical Rescue Hair Size
Dr. Van Neste showed that over a 2 year period :
- Finasteride could not return vellus hair to terminal hair
- Effect is only possible for thick hair > 0.04mm diameter
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Uses & Recommendations
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In Men
In 1997 the FDA approved a 1mg dose of finasteride for the treatment of AGA. It is important to counsel patients about appropriate expectations and the need for continued therapy. Reversing miniaturization is a slow process. Should take continuously for at least a year before evaluating efficacy.
The American Hair Loss Association recommends finasteride as the first line for all men with AGA.
In Women
Finasteride fails to prevent progress of hair loss in female pattern hair loss when the blood level of androgen is normal. |
Side Effects
A very safe drug.
The most atlk about adverse effects were decreased sex drive and erectile dysfunction. Incidence however was about 0.5% or 1 in every 200 treated cases. Symptoms usually occur during the first one to three months on start, and severity diminishes or disappear with continue use. Painful or swollen breasts (Gynaecomastia) had been reported but very rare.
The amount of the active drug in semen is negligible. No evidence that exposure to pregnant women through semen is a risk to human fetus.
Warnings
- Patients should not donate blood while taking finasteride
- Yearly Prostate Specific Antigen ( PSA ) level is recommended in appropriate group ( please consult your physician )
- The drug should NEVER be taken by female of child-bearing age
Breaking a 5mg tablet
FDA officially approved the 1mg formulation (Propecia) to be used as hair loss therapy, and the 5mg for Benign Prostatic Hypertropy. Propecia is still under patent and there is no cheaper generic form. Consequently many patients, in order to save money, bought the much cheaper 5mg tablets and took a quarter ( it's impossible to cut into five ). It seems a reasonable alternative but 3 things must be bore in mind.
- It is not FDA approved for hair loss. Physicians may refuse to provide a prescription
- Once cut the coating of the tablet is scattered thus unable to resist the powerful gastric juice. How much of the ingredient gets through to be absorbed is unknown
- Don't ever ask your wife or girlfriend to cut the tablets. Accidental ingestion by pregnant women may harm the fetus.
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