Superiority of dutasteride over finasteride in hair regrowth and reversal of miniaturization in men with androgenetic alopecia: A randomized controlled open-label, evaluator-blinded study.

Abstract

Finasteride and dutasteride are inhibitors of the enzyme 5-alpha-reductase which inhibits the conversion of testosterone to dihydrotestosterone. Dutasteride inhibits both type I and type II 5-alpha-reductase while finasteride inhibits only the type II enzyme. As both isoenzymes are present in hair follicles, it is likely that dutasteride is more effective than finasteride. To compare the efficacy, safety and tolerability of dutasteride and finasteride in men with androgenetic alopecia. Men with androgenetic alopecia between 18 and 40 years of age were randomized to receive 0.5 mg dutasteride or 1 mg finasteride daily for 24 weeks. The primary efficacy variables were hair counts (thick and thin) in the target area from modified phototrichograms and global photography evaluation by blinded and non-blinded investigators. The secondary efficacy variable was subjective assessment using a preset questionnaire. Patients were assessed monthly for side effects. Ninety men with androgenetic alopecia were recruited. The increase in total hair count per cm[2] representing new growth was significantly higher in dutasteride group (baseline- 223 hair; at 24 weeks- 246 hair) compared to finasteride group (baseline- 227 hair; at 24 weeks- 231 hair). The decrease in thin hair count per cm[2] suggestive of reversal of miniaturization was significantly higher in dutasteride group (baseline- 65 hair; at 24 weeks- 57 hair) compared to finasteride group (baseline- 67 hair; at 24 weeks- 66 hair). Both the groups showed a similar side effect profile with sexual dysfunction being the most common and reversible side effect. Limitations include the short duration of the study (6 months), the small sample size and the fact that it was an open-label study. Dutasteride was shown to be more efficacious than finasteride and the side-effect profiles were comparable.