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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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Dutasteride - Medical Treatment for Hair Loss
Trade Name
Avodart, Avidart, Avolve, Duagen, Dutas, Dutagen, Duprost
Chemical Structure
(5α, 17β)-N-{2,5 bis(trifluoromethyl) phenyl}-3-oxo-4-azaandrost-1-ene-17-carboxamide
Mechanism of Action
Dutasteride 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 both type 1 and type 2 5α-reductase
- reduces conversion of testosterone into dihydro-testosterone (DHT)
- dual-enzyme inhibition decreases scalp level of DHT by 90% to 93%
- blood level of DHT reduced by 75%
- very long half-life of 5 weeks, a disadvantage in that side effects if occurs will last many weeks even when dutasteride is stopped
Dosage
0.5mg once to twice a week, but the optimal dosage has not be determined.
Efficacy
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Compared to 5mg finasteride
A Phase II study showed that 0.5 mg dutasteride was more effective as measured by change in hair count from baseline at 24 weeks.
Compared to placebo
Korea phase III data showed Dutasteride 0.5mg had significant results over placebo in 153 men at 6 months in objective hair counts and patient assessment.
Comparing Dutasteride & Finasteride
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Dutasteride 0.5mg |
Finasteride 1mg |
Reduces serum DHT |
90% |
70% |
Blocking Type II
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5X more rapid
3X more potent |
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Blocking Type II |
60% more potent |
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Overall adverse events |
5-11% |
3.8% |
Decrease libido |
3% |
1.8% |
Half life |
> 240 hours |
6-8 hours |
Concentration in semen |
13X more |
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Uses & Recommendations
At present Dutasteride is only approved by FDA for use in the treatment of benign prostatic hyperplasia. Development of the drug in treating AGA has been stopped in America. A phase III study was continued in Korea with apparently good result. It is not known when it will be available on the market for AGA.
Side Effects
Similar to that of finasteride, with a small number of men complaining of decreased libido or increased ejectile dysfunction.
- sperm count decreased by 25% after 24 weeks
- serum volume and sperm motility decreased
- sperm morphology remains normal
Korea phase III data showed no major difference in the incidence of side effects between the treatment and placebo groups, including :
- libido 3.3% ( placebo 1.6% )
- erectile dysfunction 9% ( placebo 5.7% )
- Gynaecomastia 2% ( placebo 1% )
Warnings
- Patients should not donate blood while taking dutasteride
- Yearly Prostate Specific Antigen ( PSA ) level is recommended in appropriate group ( please consult your physician )
- The drug is not yet officially approved for treating AGA
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