Effect of dutasteride 0.5 mg/d in men with androgenetic alopecia recalcitrant to finasteride

Finasteride at a dose of 1 mg/d has been reported to show no significant improvement in 30-50% of patients with androgenetic alopecia (AGA). Dutasteride, a dual inhibitor of both type I and type II 5 alpha-reductase, inhibits the conversion of testosterone to dihydrotestosterone, which is the key contributor of AGA.

Our aim is to evaluate clinical efficacy and tolerability of dutasteride in men with AGA who do not show clinical improvement to the conventional finasteride treatment. A total of 35 Korean men with AGA who had not shown significant clinical improvement when treated with finasteride 1 mg/d for at least six months received dutasteride at a dose of 0.5 mg/d for six months. Efficacy was evaluated by global photograph assessment and phototrichogram. Safety assessment was performed through physical examination and adverse event report.

Of the 31 patients who completed the treatment, 24 patients (77.4%) were improved by the global photography (17 were slightly, six moderately, and one markedly improved) compared with the post-finasteride treatment. There was no significant change in seven patients (22.6%), and aggravation was not reported. Hair density and thickness significantly increased by 10.3% (87 ± 12-96 ± 12/cm(2)) and 18.9% (0.053 ± 0.012-0.063 ± 0.011 mm), respectively, in phototrichogram assessment. Side effects included transient sexual dysfunction in six patients (17.1%).

Dutasteride is suggestive to be an alternative treatment option to patients with AGA who do not clinically respond to finasteride in six months.