The 5-alpha reductase (5-ARI) inhibitor dutasteride (Avodart) is likely the most effective of the three drugs currently used to treat androgenetic alopecia (AGA), or male pattern baldness, according to a meta-analysis in network.
Overall efficacy ranking on the four endpoints of change in total and terminal hair count (longest and thickest strands on the head) after 24 and 48 weeks of treatment favored 5 mg/ day of oral dutasteride, followed by:
- 5 mg/day oral finasteride (Propecia)
- 5 mg/day oral minoxidil (Rogaine)
- 1 mg/day oral finasteride
- 5% topical minoxidil
- 2% topical minoxidil
- 0.25 mg/day minoxidil orally
“The robustness of this control may be confirmed by the results of future randomized clinical trials,” reported Aditya Gupta, MD, PhD, of Mediprobe Research in London, Ontario, and colleagues in JAMA Dermatology.
“As efficacy data from head-to-head trials accumulate, there may be a better sense of the relative effectiveness of different doses of 5-ARI and minoxidil,” the authors suggested.
Dutasteride 0.5 mg/day may be the most effective treatment for AGA because its half-life is 5 weeks compared to just 6 hours for finasteride, they said.
While dutasteride and oral minoxidil are often used off-label for hair loss in men, finasteride is FDA-approved for the treatment of AGA, as are both topical formulations of minoxidil.
Which option is better is a common question for patients, and these results should help doctors and patients make more informed choices, Kathie Huang, MD, Brigham and Women’s Hospital, and Maryanne Senna, MD, of Massachusetts General Hospital , both in Boston, pointed out in an accompaniment editorial.
While the study results won’t surprise many clinicians, they noted, doctors should remember that each of the three drugs used to treat AGA has side effects, some of them serious.
Sexual dysfunction and depression have been associated with finasteride. High-dose oral minoxidil is in turn also associated with risk of pericardial effusion and cardiac tamponade, with an FDA black box warning.
Additionally, although dutasteride appears to have the greatest benefit of the three AGA drugs evaluated, “the adverse effect profile is not as well studied as that of finasteride, 1 mg, and patients should be advised that that the adverse effect profile is not well studied,” Huang and Senna wrote.
“Patients and physicians have different risk thresholds for adverse events, even when the frequency is low, because they can affect quality of life,” the editorialists add. “As more and more direct-to-consumer companies treating male AGA emerge, it is especially important that the potential risks of these drugs are clearly explained to patients.”
In the meta-analysis, the 23 studies – 21 of which were randomized controlled trials – investigated monotherapy with any dose and any route of administration of the three drugs being evaluated.
The average age of the cohort ranged from 22.8 to 41.8 years. The four parameters were quantified in hair/cm2.
For the change in total hair count at 24 weeks, the greatest increase was observed with 0.5 mg/day dutasteride. The difference in hair/cm2 has been:
- 23.7 vs minoxidil 0.25 mg/day
- 15 vs minoxidil 0.5 mg/day
- 8.5 vs 2% minoxidil solution
- 7.1 vs finasteride 1 mg/day
The increase in terminal hair count at 24 weeks showed that minoxidil 5 mg/day was perhaps, unsurprisingly, significantly more effective than the lower dose of 0.25 mg/day, with a mean difference in favor of the higher dose of 43.6 hairs/cm2. The same pattern held true for its topical forms in both 2% and 5% concentrations.
Minoxidil 5 mg/day also significantly outperformed finasteride 1 mg/day.
At 48 weeks, the greatest increase in total hair count was observed with finasteride 5 mg/day, followed by finasteride 1 mg/day and 2% topical minoxidil, where the mean difference between higher dose finasteride high and topical minoxidil was 20.7. hair/cm2. However, oral minoxidil and dutasteride had no results available for this endpoint, as noted by the investigators.
Available results on terminal hair count at 48 weeks favored finasteride 1 mg/day over topical minoxidil, with a mean difference of 32.1 hairs/cm2 for the 2% formulation and 26.2 hairs/cm2 for the 5% formulation. The other drugs had no study data.
As the authors pointed out, there were no exclusion criteria for participants’ race and ethnicity, so the results may not be generalizable to all races and ethnicities.
Huang and Senna also pointed out that the study highlights the lack of therapeutic options for the treatment of male pattern baldness and suggested that it is time to explore other ways to treat AGA to help improve the quality of life of men with this problem.
Gupta and his co-authors said they have no relevant industry relationships.
Huang disclosed relationships with Concert, Pfizer, Incyte, and Aclaris, as well as patent/royalty/intellectual property interests.
Senna revealed relationships with Follica, Lilly, Pfizer, Arena Pharma and Deciphera.