Finasteride, which is the generic name for Propecia, has been approved for the treatment of Male Pattern Hair Loss since 1998. Finasteride works by inhibiting the enzyme ,5 alpha reductase type II, that forms DHT. There has been a lot of interest by both patients and physicians in dutasteride, which is a drug that inhibits both type I and type II 5 alpha reductase enzyme.Dutasteride is three times more potent than finasteride inhibiting the type II enzyme and 100 times more potent than finasteride inhibiting the type I form of the DHT producing enzyme. Dutasteride is not approved by the FDA for the treatment of Male Pattern Hair Loss and is approved at a dose of 0.5 mg a day for the treatment of prostate enlargement. While both the type I and type II enzymes are found in the hair follicle, there is a recent study which shows that type I is present in the human brain.The function of this enzyme in the brain is still unclear.
The most extensive study of dutasteride in the treatment of male pattern hair loss was published by Olsen and others in the Journal of the American Academy of Dermatology in December of 2006. This was a randomized, placebo-controlled study of 416 men for a 24 week treatment period. The study evaluated various doses of dutasteride versus 5 mg of finasteride versus placebo. At the time of the study the 1 mg finasteride dose (Propecia) was not commercially available, but the comparison is valid since the effects on hair growth of 5 mg. 1 mg. of finasteride are equal.
The results of the study were as follows: Hair counts in the vertex showed that only dutasteride at a dose of 2.5 mg a day (which is five times the dose approved for prostate enlargement) was better than finasteride at 12 and 24 weeks. When an expert panel evaluated photographs before and after treatment, the 2.5 mg dose was better than finasteride at 12 weeks and both the 0.5 and 2.5 mg doses were better than finasteride at 24 weeks — in other words, dutasteride at a 2.5 mg daily dose worked faster than 0.5 mg .
Scalp DHT suppression, which is felt to be correlated to a drug’s effectiveness, was measured and showed that finasteride decreased scalp DHT by 32%, dutasteride 0.5 mg by 51% and dutasteride 2.5 mg showed 79% suppression. DHT concentration in the blood was decreased 73% by finasteride, 92% by dutasteride 0.5mg. and 96% by dutasteride 2.5 mg . The speed by which drugs are eliminated from the body are measured by a value which is called “half-life”. The half-life of finasteride is six to eight hours whereas for dutasteride it is four to five weeks, which means that when one stops taking dutasteride, it will take several months before the drug is out of the system. When blood DHT was measured in these patients 12 weeks after stopping the medication, the finasteride treated patients had a normal DHT level while the dutasteride 0.5 still showed a 10% decrease and the dutasteride 2.5 mg treated patients still had significantly lowered DHT levels.
Sexual side effects were determined and, although there were no statistically significant differences between placebo, finasteride and dutasteride, it is noteworthy that in the patients treated with 2.5 mg dutasteride daily, 13% complained of decreased libido. As has been the experience with finasteride, half of these patients experienced resolution of their side effects despite continuing to take the medication. The other 50% had to stop the treatment in order for side effects to subside.
Side effects of dutasteride which have been reported in the treatment of prostatic enlargement are 1) breast tenderness and enlargement, and 2) reduced sperm counts. In a separate study of 28 patients treated with dutasteride 0.5 mg daily there was a significant decrease in sperm count at 26 weeks of treatment. That study states that it is difficult to determine the significance of these sperm count abnormalities and that the reports vary as to what sperm counts are required for fertility. It is quite concerning that two of the 28 patients in the study had a greater than 90% decrease in sperm count while taking the medication and 24 weeks after stopping the drug, they still had a 70% reduction in sperm count. Although the study did not give figures on the percentage of patients that developed sperm count abnormalities, this side effect, in my opinion, is worrisome especially since we commonly treat young men for male pattern hair loss. It should be noted that finasteride 1 mg (Propecia) was shown in a separate study to have no effect on sperm count.
In conclusion, dutasteride improved hair growth in male pattern hair loss more rapidly and to a greater degree than finasteride at a dose of 2.5 mg per day which is five times the dose approved for prostate enlargement. Dutasteride is approved by the FDA for the treatment of prostatic enlargement at a dose of 0.5 mg per day and there is insufficient safety data on higher doses. Dutasteride is NOT approved by the FDA for the treatment of Male Pattern Hair Loss and patients should be informed about the benefits versus the possible adverse effects. Finasteride 1 mg (Propecia) has been shown to stop the progression of male pattern baldness in 90% of the patients treated with the drug. It has an excellent safety profile with only 2% of patients experiencing decreased sex drive and no reports of sperm count abnormalities.
We are currently awaiting the results of a phase III study being conducted in Korea to evaluate dutasteride 0.5 mg daily in the treatment of male pattern hair loss
Bernard P. Nusbaum M.D.
Member, International Alliance of Hair Restoration Surgeons
Bernard Nusbaum, MD Dr. Nusbaum has been widely published in the fields of dermatology and hair transplantation and has been extremely active in research and professional societies. He is in demand as a lecturer and has presented dozens of programs, research findings, and clinical reports at medical conferences. He graduated from the University of Colorado in 1974, then received his doctor of medicine degree from he University of Miami School of Medicine in 1979. Dr. Nusbaum interned in Internal Medicine at Mount Sinai Medical Center in Miami Beach from 1979 to 1980. He did his residency in dermatology at Mount Sinai from 1980 to 1983, serving as chief resident in dermatology from 1981 to 1983. He has been a clinical assistant professor lecturing in dermatology in the Department of Family Medicine at the University of Miami School of Medicine and has also been a clinical instructor at the Department of Dermatology and Cutaneous Surgery at the University of Miami School of Medicine. Dr. Nusbaum has been treating patients suffering with hair loss for 23 years. In 1980 he began experimenting with hair transplants and started performing Follicular Unit Transplantation in 1996, a technique he demonstrated on the Discovery Channel. Dr. Nusbaum is a member of the International Alliance of Hair Restoration Surgeons and recommended by the American Hair Loss Association. Visit Dr. Nusbaum's Website: www.miamihair.com
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Are the results of a phase III study conducted in Korea to evaluate dutasteride 0.5 mg daily in the treatment of male pattern hair loss out? if so, were can I read this results?
Never mind I found the study! See below.
Recently released Phase III study for hair loss raises questions about approval strategy for hair loss—–
Until today I thought Avodart would never be approved for hair loss.
The company that makes it, GlaxoSmithKline, ended US approval studies with no specified reason, but most in the know believe it was due to expected cost and the sales potential not being high enough (possibly due to the cost).
Now, however, comes news of phase III studies of the currently approved 0.5mg dosage for hair loss – not from the US but from Korea. The studies give us some answers and some questions about Avodart.
The question really is what GSK’s strategy is going forward. It appears they will now try to get the currently marketed dose approved for hair loss. Are they just going to try getting it approved in Korea or a few other markets? Will they try for US approval? Do they ever intend to pursue the 2.5mg dose? We will be attempting to contact GSK to find out what they are willing to admit regarding their approval strategy going forward for Avodart for hair loss.
This study should put a lot of men who are taking the 0.5mg dosage more at ease. Many are using 0.5mg ‘off-label’ for hair loss, since it reduces DHT greater than finaseride — but the 2.5mg dose was the dose studied for hair loss previously, not 0.5mg. Now finally those people using Avodart 0.5mg for hair loss can have some idea what to expect.
The results? Men on Avodart 0.5mg grew 12.4 hairs per square centimeter compared to 4.7 per square centimeter for placebo and “significantly higher” effect compared to placebo based on patient self evaluation, investegator and photographic assessment.
The study was only for 6 months, so it is likely had it gone to 12 months, the results would have been even better. We have obtained the full study details and will be posting more infromation soon.
Study information is below.
Efficacy, safety, and tolerability of dutasteride 0.5 mg once daily in male patients with male pattern hair loss: A randomized, double-blind, placebo-controlled, phase III study.
J Am Acad Dermatol. 2010 Aug;63(2):252-258. Epub 2010 Jun 3.
Eun HC, Kwon OS, Yeon JH, Shin HS, Kim BY, Ro BI, Cho HK, Sim WY, Lew BL, Lee WS, Park HY, Hong SP, Ji JH.Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea
BACKGROUND: Dutasteride (Avodart) is a dual inhibitor of both type I and type II 5 alpha reductases, and thus inhibits conversion of testosterone to dihydrotestosterone, a key mediator of male pattern hair loss.
OBJECTIVES: The aim of this randomized double-blind phase III study was to compare the efficacy, safety, and tolerability of dutasteride (0.5 mg) and placebo for 6 months of treatment in male patients with male pattern hair loss.
METHODS: A total of 153 men, 18 to 49 years old, were randomized to receive 0.5 mg of dutasteride or placebo daily for 6 months. Efficacy was evaluated by the change of hair counts, subject assessment, and photographic assessment by investigators and panels.
RESULTS: Mean change of hair counts from baseline to 6 months after treatment start was an increase of 12.2/cm(2) in dutasteride group and 4.7/cm(2) in placebo group and this difference was statistically significant (P = .0319). Dutasteride showed significantly higher efficacy than placebo group by subject self-assessment and by investigator and panel photographic assessment. There was no major difference in adverse events between two groups.
LIMITATIONS: The study was limited to 6 months.
CONCLUSIONS: This study clearly showed that 0.5 mg of dutasteride improved hair growth and was relatively well tolerated for the treatment of male pattern hair loss.