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

Indian J Dermatol Venereol Leprol. Jan-Feb 2017;83(1):47-54. doi: 10.4103/0378-6323.188652.

Abstract

Background: 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.

Aims: To compare the efficacy, safety and tolerability of dutasteride and finasteride in men with androgenetic alopecia.

Methods: 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.

Results: 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: Limitations include the short duration of the study (6 months), the small sample size and the fact that it was an open-label study.

Conclusions: Dutasteride was shown to be more efficacious than finasteride and the side-effect profiles were comparable.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • 5-alpha Reductase Inhibitors / administration & dosage
  • 5-alpha Reductase Inhibitors / adverse effects
  • Administration, Oral
  • Adolescent
  • Adult
  • Alopecia / diagnosis*
  • Alopecia / drug therapy*
  • Dutasteride / administration & dosage*
  • Dutasteride / adverse effects
  • Erectile Dysfunction / chemically induced
  • Finasteride / administration & dosage*
  • Finasteride / adverse effects
  • Hair / drug effects*
  • Hair / growth & development*
  • Humans
  • Male
  • Prospective Studies
  • Single-Blind Method
  • Young Adult

Substances

  • 5-alpha Reductase Inhibitors
  • Finasteride
  • Dutasteride