Low-dose oral minoxidil (LDOM) has a good safety profile as a treatment for patients with various types of alopecia, with a low frequency of systemic side effects, according to a study published in the Journal of the American Academy of Dermatology.
The international, retrospective, multicenter study included 1404 patients (943 women [67.2%]; mean age, 43 years [range, 8-86]) who were treated with LDOM for 3 months or longer for hair loss of any cause.
Androgenetic alopecia (82.4%) was the most common indication for LDOM, followed by telogen effluvium (4.8%) and alopecia areata (3.8%). A total of 339 patients received a fixed-dose regimen of LDOM with no increments, and the other 1065 patients received LDOM at various increased incremental doses as tolerated (2469 total doses for 1404 patients). The mean dose was 1.63 mg (range, 0.03-15), and the mean treatment duration was 7.9 months (range, 3-79).
The investigators observed adverse effects in 509 cases (20.6%), which led to treatment withdrawal in 43 patients (1.7%). Hypertrichosis (374 patients, 15.1%) was the most common adverse effect and resulted in discontinuation in 14 cases (0.5%).
Systemic adverse effects (SAEs) were reported in 135 patients (5.5%), of whom 29 (1.2%) stopped treatment. SAEs included lightheadedness (n=43), fluid retention or leg edema (n=32), tachycardia (n=21), headache (n=9), periorbital edema (n=7), and insomnia (n=6).
Dose adjustment or withdrawal of LDOM resulted in improvement of all SAEs, and no life-threatening adverse effects occurred.
Multivariate analysis demonstrated that LDOM dose was the most important risk factor for hypertrichosis [odds ratio, 1.26; 95% CI, 1.17-1.35; P <.001), after the study authors adjusted for age, weight, sex, and duration of treatment.
Study limitations include the retrospective design and lack of a control group, as well as the lack of data regarding patient comorbidities.
“Given that lightheadedness can occur with LDOM therapy, special caution should be exercised in patients with a history of orthostatic hypotension and syncope, and in patients on calcium channel antagonists,” noted the researchers.
Vañó-Galván S, Pirmez R, Hermosa-Gelbard A, et al. Safety of low-dose oral minoxidil for hair loss: a multicenter study of 1404 patients. J Am Acad Dermatol Published online February 24, 2021. doi:10.1016/j.jaad.2021.02.054