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
Recommended by The American Hair Loss Association

I have been on 1.25mg of finasteride daily for the last 10 years, over the last year my MPB went from a norwood 2 to a 4 aggressively. I am now contemplating .5mg of dutasteride every other day, I understand that dutasteride isn’t FDA approved for MPB, some studies in 2002-03 revealed more hair counts as opposed to finasteride, but the drug just fizzled away.

Do you believe that by taking dutasteride, it may decrease shed and increased hair counts better then finasteride. Secondly what is the status quo in reference to taking dutasteride for MBP.
Answer:

It is not uncommon for 5 alpha-reductase inhibition to ultimately fail. My belief is that they prolong the anagen duration and therefore delay the inevitable, which is hair loss. All hairs cycle through a growing (anagen phase), to a resting (telogen phase), and to involution (catagen phase). This ultimately leads to exogen or temporary loss of the hair. I believe that hairs have a limited number of cycles. Once they reach the critical number of cycles, they begin to miniaturize and this in a single cycle. Miniaturized hairs become finer with less pigment. They grow slower and the anagen duration is less, which means they will not grow as long as they did prior to the onset of miniaturization. It is not possible to eliminate the resting phase altogether, but you can delay its onset.

A number of products seem to help with the prolongation of anagen. These include minoxidil, Finasteride, Avodart, and Nizoral shampoo. One can also consider saw palmetto, the laser comb, and other products that can prolong anagen such as Hair Cycle shampoo and conditioner. I generally recommend that individuals consider maximal medical management to help maintain their hair. It certainly is a better alternative than surgery for many individuals.

Combination therapy with a 5 alpha-reductase inhibitor and minoxidil is probably better than either alone.

If you are considering Avodart, you should probably take 0.5 mg every day for 2 weeks and then three times a week on Monday, Wednesday, and Friday is probably adequate. If you plan to take it every other day, you should probably still take it every day for the first 2 weeks.

It is true that Avodart did increase hair counts above finasteride in phase two clinical trials, but phase three trials were never undertaken. I suspect that the company assumed that there was more risk than reward and suspected that physicians would still prescribe it off label for hair loss.

Anecdotally, many individuals seem to respond better to Avodart than they did to finasteride. However, I have also heard of some patients who said finasteride worked better for them. You should read the warnings on the product information prior to taking Avodart. You are blocking both 5 alpha-reductase type one and two with Avodart. Finasteride primarily blocks type 2. This could lead to more long term side affects though none have been identified to date. One would expect more sexual dysfunction on Avodart than on Finasteride, but I have heard some say they had less sexual dysfunction on Avodart than they had on Finasteride.

There are also other factors that cause hair loss besides 5 alpha-reductase activity, as well. It could also be that you were on a plateau of stable hair loss for a prolonged period of time unrelated to the intake of Finasteride and that you have suddenly experienced a progression in hair loss. This scenario seems less likely given your long period of stability. Certainly, if you hair loss is bothering you, you should consider your alternatives provided that finasteride is no longer maintaining your hair.

No one has studied the status quo with regard to Avodart, but it does seem to work better based on phase two clinical trials.

John P. Cole, MD
http://www.forhair.com
IAHRS Recommended Hair Transplant Surgeon