Other than oral finasteride, vitamins, and topicals, there has been little advancement in the treatment of AGA leaving many (including me) desperate for anything remotely new.
Oral minoxidil is a peripheral vasodilator approved by the Food and Drug Administration for use in patients with hypertensive disease taken at doses ranging between 10 mg to 40 mg daily. Animal studies have shown that minoxidil affects the hair growth cycle by shortening the telogen phase and prolonging the anagen phase.
Dr. Lily Talakoub
Recent case studies have also shown growing evidence for the off-label use of low-dose oral minoxidil (LDOM) for treating different types of alopecia. Topical minoxidil is metabolized into its active metabolite minoxidil sulfate, by sulfotransferase enzymes located in the outer root sheath of hair follicles. The expression of sulfotransferase varies greatly in the scalp of different individuals, and this difference is directly correlated to the wide range of responses to minoxidil treatment. LDOM is, however, more widely effective because it requires decreased follicular enzymatic activity to form its active metabolite as compared with its topical form.
In a retrospective series by Beach and colleagues evaluating the efficacy and tolerability of LDOM for treating AGA, there was increased scalp hair growth in 33 of 51 patients (65%) and decreased hair shedding in 14 of the 51 patients (27%) with LDOM. Patients with nonscarring alopecia were most likely to show improvement. Side effects were dose dependent and infrequent. The most frequent adverse effects were hypertrichosis, lightheadedness, edema, and tachycardia. No life-threatening adverse effects were observed. Although there has been a recently reported case report of severe pericardial effusion, edema, and anasarca in a woman with frontal fibrosing alopecia treated with LDOM, life threatening side effects are rare.3
To compare the efficacy of topical versus oral minoxidil, Ramos and colleagues performed a 24-week prospective study of low-dose (1 mg/day) oral minoxidil, compared with topical 5% minoxidil, in the treatment of 52 women with female pattern hair loss. Blinded analysis of trichoscopic images were evaluated to compare the change in total hair density in a target area from baseline to week 24 by three dermatologists.
Results after 24 weeks of treatment showed an increase in total hair density (12%) among the women taking oral minoxidil, compared with 7.2% in women who applied topical minoxidil (P =.09).
In the armamentarium of hair-loss treatments, dermatologists have limited choices. LDOM can be used in patients with both scarring and nonscarring alopecia if monitored regularly. Treatment doses I recommend are 1.25-5 mg daily titrated up slowly in properly selected patients without contraindications and those who are not taking other vasodilators. Self-reported dizziness, edema, and headache are common and treatments for facial hypertrichosis in women are always discussed. Clinical efficacy can be evaluated after 10-12 months of therapy and concomitant spironolactone can be given to mitigate the side effect of hypertrichosis.Patient selection is crucial as patients with severe scarring alopecia and those with active inflammatory diseases of the scalp may not see similar results. Similar to other hair loss treatments, treatment courses of 10-12 months are often needed to see visible signs of hair growth.
Dr. Talakoub and Naissan O. Wesley, MD, are cocontributors to this column. Dr. Talakoub is in private practice in McLean, Va. Dr. Wesley practices dermatology in Beverly Hills, Calif. Write to them at dermnews@mdedge.com. Dr. Talakoub had no relevant disclosures.
References
Beach RA et al. J Am Acad Dermatol. 2021 Mar;84(3):761-3.
Dlova et al. JAAD Case Reports. 2022 Oct;28:94-6.
Jimenez-Cauhe J et al. J Am Acad Dermatol. 2021 Jan;84(1):222-3.
Ramos PM et al. J Eur Acad Dermatol Venereol. 2020 Jan;34(1):e40-1.
Ramos PM et al. J Am Acad Dermatol. 2020 Jan;82(1):252-3.
Randolph M and Tosti A. J Am Acad Dermatol. 2021 Mar;84(3):737-46.
Vañó-Galván S et al. J Am Acad Dermatol. 2021 Jun;84(6):1644-51.