Androgenetic alopecia (AGA) is the most common type of alopecia in men and may have a negative effect on quality of life.
Currently, oral finasteride and topical minoxidil are the only drugs approved for treatment of male AGA. Therefore, we read with great interest the publication by Jimenez-Cauhe et al
reporting successful use of low-dose oral minoxidil (OM) (2.5-5 mg/d) in men with AGA. As stated by the authors, the optimum dose of OM still needs to be delineated. Recently, Sinclair
reported positive outcomes with a much lower dose of OM in women (OM 0.25 mg combined with spironolactone 25 mg). In this letter, we would like to share our results using this very low dose of OM (0.25 mg/d) as monotherapy in the treatment of 25 male patients with AGA.
We performed a retrospective review (2017-2018) of medical records from patients with male AGA using formulated capsules of OM (0.25 mg/d). Patients included had at least 24 weeks of follow-up and records of clinical and trichoscopic images. Patients with recent (<6 months) or concomitant use of other therapies for AGA were not included. For evaluation of treatment response, analysis of pretreatment and posttreatment (24 weeks) trichoscopic images from the frontal scalp (midline) and vertex was carried out by using FotoFinder TrichoLAB Snap software (TrichoLAB, Bad Birnbach, Germany) with Hair-to-Hair Matching technology. Parameters examined were total hair density (THD)/cm2, density of terminal hair (DTH)/cm2, new hairs/cm2 (NH/cm2), and new terminal hairs/cm2 (NTH/cm2) (Fig 1).
The sample included 25 patients with a mean age of 36.7 years (range, 23-53 years). Ten (40%) had mild-moderate AGA (II-III vertex by the Hamilton-Norwood scale) and 15 (60%) severe AGA (IV-VI). Improvement or stabilization after 24 weeks was observed in a percentage of individual patients for all parameters analyzed (frontal scalp: NTH, 48%; NH, 52%; DTH, 40%; THD, 60%; vertex: NTH, 44%; NH, 40%; DTH, 44%; THD, 40%). However, statistical analysis did not show a significant variation in the group as a whole (Table I). A statistical trend toward better response was detected for patients with mild-moderate AGA in DTH/cm2 (P = .075). Adverse effects reported were pedal edema in 1 (4%), hair shedding in 4 (16%) and body hypertrichosis in 5 (20%) patients. Interestingly, 13 patients (52%) reported perception of increased hair density in the beard. There was no difference in mean arterial pressure and no reports of fainting or dizziness. No patient discontinued treatment.
Table IParameters studied before and after 24 weeks of treatment
|Parameters||Before 24 Weeks||After 24 weeks||P value|
|Total hair density/cm2||25||184||130 to 223||52||259||25||176||141 to 213||53||252||.26|
|Density of terminal hair/cm2||25||114||74 to 173||34||209||25||100||68 to 151||23||213||.088|
|New hairs/cm2||25||−4.1||−18.9 to 6.3||−36.8||46.3|
|New terminal hairs/cm2||25||−3.1||−8.9 to 3.1||−34.0||24.2|
|Total hair density/cm2||25||200||143 to 221||93||255||25||194||155 to 225||109||267||.19|
|Density of terminal hair/cm2||25||130||104 to 167||57||216||25||115||96 to 165||55||212||.24|
|New hairs/cm2||25||4.1||−9.0 to 13.5||−22.7||24.7|
|New terminal hairs/cm2||25||−1.020||−3.281 to 5.725||−11.3||14.1|
IQR, Interquartile range (quartile 1-quartile 3); Max, maximum; Min, minimum.
The small sample size and high percentage of patients with advanced AGA in our study are possible explanations for the lack of statistical significance; for those reasons, we cannot exclude a type II error. As shown with topical administration, OM might have lower efficacy in advanced AGA.
Additionally, we speculate that higher doses of OM, as used by Jimenez-Cauhe et al,
might be necessary to produce significant effects in men. Different methods for assessing treatment response prevent comparison with our results. Despite the higher dosage, their profile of adverse effects was similar to ours.