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

BACKGROUND: 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. MATERIALS AND METHODS: 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. RESULTS: 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%). CONCLUSIONS: Dutasteride is suggestive to be an alternative treatment option to patients with AGA who do not clinically respond to finasteride in six months.