While up to 90% of men experience AGA in their lifetime, only three therapies are currently approved for treatment of the condition by the Food and Drug Administration – topical minoxidil, oral finasteride 1 mg, and low-level light therapy.
However, with common use of off-label oral minoxidil, as well as oral dutasteride and higher doses of oral finasteride, the latter two being 5-alpha reductase inhibitors, Aditya K. Gupta, MD, PhD, of Mediprobe Research, in London, Ont., and colleagues sought to compare the data on the three agents. Their results were published in JAMA Dermatology.
They note that, while there have been recent comparisons between oral and topical minoxidil, “to our knowledge no study has determined the comparative effectiveness of these 2 [formulations] with that of local and systemic dutasteride and finasteride.”
For the meta-analysis, the authors identified 23 studies meeting their criteria, involving patients with mean ages ranging from 22.8 to 41.8 years.
For the primary endpoint of the greatest increases in total hair count at 24 weeks, the analysis showed the 0.5-mg/day dose of dutasteride topped the list, with significantly greater efficacy, compared with 1 mg/day of finasteride (mean difference, 7.1 hairs per cm2).
The 0.5-mg/d dutasteride dose also showed higher efficacy than oral minoxidil at 0.25 mg/day (mean difference, 23.7 hairs per cm2) and 5 mg/day (mean difference, 15.0 hairs per cm2) and topical minoxidil at 2% (mean difference, 8.5 hairs per cm2).
For the secondary endpoint of the greatest increase in terminal hair count at 24 weeks, the 5-mg/day dose of minoxidil had significantly greater efficacy compared with the 0.25-mg/day dose of the drug, as well as with minoxidil’s 2% and 5% topical formulations.
The minoxidil 5-mg/day dose was also significantly more effective than 1 mg/day of finasteride for terminal hair count at 24 weeks.
In longer-term outcomes at 48 weeks, the greatest increase in total hair count at 48 weeks was observed with 5 mg/day of finasteride, which was significantly more effective, compared with 2% topical minoxidil.
And the greatest increase in terminal hair count at 48 weeks was observed with 1 mg/day of oral finasteride, which was significantly more effective than 2% as well as 5% topical minoxidil.
Based on the results, the authors ranked the agents in a decreasing order of efficacy: 0.5 mg/day of oral dutasteride, 5 mg/day of oral finasteride, 5 mg/day of oral minoxidil, 1 mg/day of oral finasteride, 5% topical minoxidil, 2% topical minoxidil, and 0.25 mg/day of oral minoxidil.
Commenting on the analysis in an accompanying editorial, Kathie P. Huang, MD, of the department of dermatology, Brigham and Women’s Hospital, Boston, and Maryanne M. Senna, MD, of the department of dermatology, Massachusetts General Hospital, Boston, said the results, in general, are consistent with their experiences, noting that 2% minoxidil is typically not used in men.
They noted that, “although topical minoxidil ranked higher than the very-low-dose 0.25 mg oral minoxidil, our personal experience is that oral minoxidil at doses of 1.25 mg to 5 mg are far superior to topical minoxidil for treating AGA.”