To Bryan: Dutasteride dosage/Type 1 in the human brain

[nizoralad]

Hi Bryan,

I have two questions for you.

1. Several days ago you explained the equivalency of Avodart to Propecia in that “Dutasteride (Avodart) 0.1 mg/day is virtually identical to finasteride (Propecia) (that would be an Avodart every 4-5 days).â€￾ A site called Medical Wellness Center states that Dutasteride (Avodart) 0.125 mg/day is the equivalent to finasteride (Propecia) 1 mg/day. Maybe I’m being too technical between 0.1 mg/day and 0.125 mg/day? If not, which do you think is correct?

Below is an excerpt from their site:

WHAT IS THE DIFFERENCE BETWEEN AVODART 0.5MG and DUTASTERIDE 0.125mg capsules?

Avodart 0.5mg, (active ingredient Dutasteride) manufactured by GlaxoSmithKline, is approved by the FDA for BPH (prostate). Avodart 0.5 mg is a more potent 5 alpha reductase inhibitor that Finasteride 5mg (Proscar) which is prescribed for BPH. The recommended dose of finasteride for Male Pattern Hair Loss is 1mg more commonly known as Propecia. Therefore using this model, although Avodart 0.5mg is FDA approved for BPH, one would only need 0.125mg daily of the active ingredient Dutasteride.
Medical Wellness Center

2. You stated “that at the standard Avodart dose (0.5 mg/day), only a little over half of the type 1 enzyme seems to be inhibited.â€￾ Now going by that and the fact that type 1 is in the human brain, wouldn’t you feel that even just a little over a half would still be a major concern? I just am not comfortable with any type 1 in the brain, no matter how insignificant it can be. You also stated: "At only 1 Avodart capsule every 5 days (or per week), its activity against the type 1 enzyme is fairly negligible." So obviously one would be safe at this dose as far as levels of the type 1 in the brain and any possible neurological side effects. Please tell me your thoughts.

Thanks Bryan, once again!

 

[nizoralad]

Question moved to HairSite and answered by Bryan. Good-bye.

 

[Bryan]

Here's my reply from that other site:

>Hi Bryan,
>
>I have two questions for you.
>
>1. Several days ago you explained the equivalency of Avodart
>to Propecia in that “Dutasteride (Avodart) 0.1 mg/day is
>virtually identical to finasteride (Propecia) (that would be
>an Avodart every 4-5 days).” A site called Medical Wellness
>Center states that Dutasteride (Avodart) 0.125 mg/day is the
>equivalent to finasteride (Propecia) 1 mg/day. Maybe I’m being
>too technical between 0.1 mg/day and 0.125 mg/day? If not,
>which do you think is correct?

I wouldn't worry too much about the difference between 0.1 and 0.125 mg/day!

I do agree with MWC that 0.125 mg/day of dutasteride is roughly the equivalent of Propecia, but I have a problem with the other thing they're implying (see my other comment just below).

>Below is an excerpt from their site:
>
>WHAT IS THE DIFFERENCE BETWEEN AVODART 0.5MG and DUTASTERIDE
>0.125mg capsules?
>
>Avodart 0.5mg, (active ingredient Dutasteride) manufactured by
>GlaxoSmithKline, is approved by the FDA for BPH (prostate).
>Avodart 0.5 mg is a more potent 5 alpha reductase inhibitor
>that Finasteride 5mg (Proscar) which is prescribed for BPH.
>The recommended dose of finasteride for Male Pattern Hair Loss
>is 1mg more commonly known as Propecia. Therefore using this
>model, although Avodart 0.5mg is FDA approved for BPH, one
>would only need 0.125mg daily of the active ingredient
>Dutasteride.
>Medical Wellness Center

I think MWC's use of finasteride as a "model" to conclude that the best or most appropriate dose of dutasteride for hairloss would be 0.125 mg/day is simply ridiculous. That's too simplistic.

>2. You stated: “That at the standard Avodart dose (0.5
>mg/day), only a little over half of the type 1 enzyme seems to
>be inhibited.” Now going by that and the fact that type 1 is
>in the human brain, wouldn’t you feel that even just a little
>over a half would still be a major concern?

Yes, it's of some concern for me, but let's face it: the drug was tested for 2 years in BPH patients, with no really obvious problems above and beyond what Proscar users experience. It seems to be pretty well tolerated.

>I just am not
>comfortable with any type 1 in the brain, no matter how
>insignificant it can be. You also stated: "At only 1 Avodart
>capsule every 5 days (or per week), its activity against the
>type 1 enzyme is fairly negligible." So obviously one would be
>safe at this dose as far as levels of the type 1 in the brain
>and any possible neurological side effects. Please tell me
>your thoughts.

Yes, I feel that as your (effective) daily dose declines from 0.5 mg to 0.1 mg or less, you get closer and closer to the same effect on DHT as what you get with finasteride. At 0.1 mg/day, I think there's virtually nothing to be concerned about (beyond what there is to be concerned about with finasteride, of course).

However, there would also be little reason to actually USE dutasteride in that case from a purely medical standpoint, IMHO. It would pretty much become a matter of simple economics: which is cheaper, Propecia or 0.1 mg of dutasteride? To answer my own question: 0.1 mg of dutasteride would probably be cheaper than Propecia, but probably NOT cheaper than quartered Proscar (and definitely not cheaper than quartered Fincar).

Bryan