I am the person that posted the link to the full article on HLH. Following is my last HLH post on this subject, which contains my relatively uneducated analysis. I look forward to reading your and Bryan's analysis of the article.
I found the following conclusions to be interesting:
1. "[D]utasteride is a more efficient steroid 5-reductase type II inhibitor than finasteride in vitro for most of the enzyme variants."
2. "However, two of the enzyme variants do not follow this trend: the F194L variant (independently of reaction time) and the P48R variant (but only in the 10-min reaction) display lower apparent Ki (higher affinity) for finasteride than dutasteride."
3. "[T]he pharmacogenetic variation we uncovered for both finasteride and dutasteride is still very significant."
Some of my relatively uneducated thoughts are as follows:
A. This study arguably indicates that someone that has not responded well to finasteride may respond better to dutasteride because dutasteride appears to inhibit certain 5-reductase type II enzyme variants that finasteride does not inhibit. Of course, dutasteride also inhibits a significant level of the type I enzyme (which may or may not be an important factor in hair loss), while finasteride does not (unless an unreasonably high dose is taken).
B. Finasteride may work better for people that have the F194L variant of the type II enzyme (or a relatively large amount of it) but not the variants that are inhibited by dutasteride but not finasteride. I am skeptical that many people, if anyone, would fall into this category, although, I suppose it is possible that inhibiting the 194L variant could be more effective than blocking other variants for some people.
C. It may be beneficial to some people to take both finasteride and dutasteride. Of course who knows how the two drugs may interact with each other or whether taking both drugs is safe?
