The importance of dual 5alpha-reductase inhibition in the treatment of male pattern hair loss: results of a randomized placebo-controlled study of dutasteride versus finasteride.
BACKGROUND
Male pattern hair loss (MPHL) is a potentially reversible condition in which dihydrotestosterone is an important etiologic factor.


OBJECTIVE
Our aim was to evaluate the efficacy of the type 1 and 2 5alpha-reductase inhibitor dutasteride in men with MPHL.


METHODS
Four hundred sixteen men, 21 to 45 years old, were randomized to receive dutasteride 0.05, 0.1, 0.5 or 2.5 mg, finasteride 5 mg, or placebo daily for 24 weeks.


RESULTS
Dutasteride increased target area hair count versus placebo in a dose-dependent fashion and dutasteride 2.5 mg was superior to finasteride at 12 and 24 weeks. Expert panel photographic review and investigator assessment of hair growth confirmed these results. Scalp and serum dihydrotestosterone levels decreased, and testosterone levels increased, in a dose-dependent fashion with dutasteride.


CONCLUSIONS
The study was limited to 24 weeks.


CONCLUSIONS
Dutasteride increases scalp hair growth in men with MPHL. Type 1 and type 2 5alpha-reductase may be important in the pathogenesis and treatment of MPHL.
Olsen
Elise A
EA
Duke University Medical Center, Durham, North Carolina, USA. olsen001@mc.duke.edu
Hordinsky
Maria
M
Whiting
David
D
Stough
Dow
D
Hobbs
Stuart
S
Ellis
Melissa L
ML
Wilson
Timothy
T
Rittmaster
Roger S
RS
D058891:5-alpha Reductase Inhibitors; D000328:Adult; D000505:Alopecia / Q000188:drug therapy* / Q000201:enzymology; D000726:Androgen Antagonists / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D001378:Azasteroids / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D013196:Dihydrotestosterone / Q000032:analysis / Q000097:blood; D004305:Dose-Response Relationship, Drug; D000068538:Dutasteride; D018120:Finasteride / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D006197:Hair / Q000187:drug effects / Q000254:growth & development; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D007989:Libido / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D012535:Scalp / Q000737:chemistry / Q000187:drug effects; D013739:Testosterone / Q000032:analysis / Q000097:blood; D016896:Treatment Outcome
D058891:5-alpha Reductase Inhibitors; D000726:Androgen Antagonists; D001378:Azasteroids; D007527:Isoenzymes; D013196:Dihydrotestosterone; D013739:Testosterone; D018120:Finasteride; D000068538:Dutasteride