In the treatment of male androgenetic alopecia (AGA), low-dose dutasteride (0.5 mg/d), used off label in the US, tops a ranking of the most commonly used oral and topical agents in a new meta-analysis.
While up to 90% of men experience AGA in their lifetime, only three therapies are currently approved for treatment of the condition by the US Food and Drug Administration (FDA) ― 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-α reductase inhibitors, Aditya K. Gupta, MD, PhD, of Mediprobe Research Inc, in London, Ontario, Canada, and colleagues sought to compare the data on the three agents. Their results were published this month 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/d dose of dutasteride topped the list, with significantly greater efficacy compared with 1 mg/d 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/d (mean difference, 23.7 hairs per cm2) and 5 mg/d (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/d dose of minoxidil had significantly greater efficacy compared with the 0.25 mg/d dose of the drug, as well as with minoxidil's 2% and 5% topical formulations.
The minoxidil 5 mg/d dose was also significantly more effective than 1 mg/d 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/d 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/d 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:
0.5mg/d of oral dutasteride
5mg/d of oral finasteride
5mg/d of oral minoxidil
1mg/d of oral finasteride
5% topical minoxidil
2% topical minoxidil
0.25 mg/d 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, Massachusetts, and Maryanne M. Senna, MD, of the Department of Dermatology, Massachusetts General Hospital, Boston, say the results, in general, are consistent with their experiences, noting that 2% minoxidil is typically not used in men.
They note 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."
Adverse Event Considerations Important
Importantly, however, strong consideration needs to be given to adverse event profiles, as well as patient comorbidities in selecting agents, the editorial authors assert.
With 1 mg finasteride, for instance, potential adverse events include decreased libido, erectile dysfunction, decreased ejaculatory volume, reduction in sperm count, testicular pain, depression, and gynecomastia, they note.
And while finasteride appears to be associated with a decreased risk of prostate cancer, those receiving the drug who do develop prostate cancer may be diagnosed with higher-grade prostate cancer; however, that "might be related to tissue sampling artifact," the editorial authors say.
Less has been published on dutasteride's adverse event profile, and that, in itself, is a concern.
Overall, "as more direct-to-consumer companies treating male AGA emerge, it is especially important that the potential risks of these medications be made clear to patients," they add.
Further commenting on the analysis to Medscape Medical News, Antonella Tosti, MD, the Fredric Brandt Endowed Professor of Dermatology and Cutaneous Surgery at the University of Miami Miller School of Medicine, in Miami, Forida, said the study offers some important insights ― and caveats.
"I think this is a very interesting study, but you have to consider what works for your patients," she said.
Tosti noted that the 5-mg dose of minoxidil is a concern in terms of side effects. "That dose is pretty high and could feasibly cause some hypertrichosis, which can be a concern to men as well as women."
She agrees that the lack of data on side effects with dutasteride is also a concern, especially in light of some of the known side effects with other agents.
"That's why I don't use it very much in younger patients ― because I'm afraid it could potentially affect their fertility," Tosti said.
In general, Tosti says she finds a combination of agents provides the best results, as many clinicians use.
"I find dutasteride (0.5 mg/d) plus oral minoxidil (1 to 2.5 mg/d) plus topical 5% minoxidil is the best combination," she said.
The authors and Tosti have disclosed no relevant financial relationships.
JAMA Derm. Published online February 2, 2022. Abstract, Editorial
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Image 1: Dr Antonella Tosti
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Cite this: Male Alopecia Agents Ranked by Efficacy in Meta-Analysis - Medscape - Feb 10, 2022.