Administração de minoxidil por via oral e em baixa dose como estratégia de tratamento de alopecia de padrão feminino

Abstract

Introduction: Female pattern hair loss (FPHL) is the main cause of hair loss in women. Topical minoxidil is the only treatment approved by the Food and Drug Administration (FDA). However, its topical use leads to several cosmetic issues, and the adhesion to treatment is a major problem. Therefore, low-dose oral minoxidil (OM) has been used lately to approach FPHL. Objectives: We aimed to evaluate the efficacy and safety of OM in two different daily doses (0.25 and 1.0mg) in the treatment of FPHL as a strategy for improving the clinic, dermatoscopy and quality of life. Methods: a double-blind clinical trial was conducted on 30 women with ages between 18-70 years, diagnosed as having FPHL Sinclair´s Stages 2-5. Women were randomly assigned to receive 0.25mg or 1.0mg OM, once daily, during 24 weeks. The hair shafts count in a target scalp area previously marked with a tatoo ink was performed with software ImageJ Fiji (ImageJ; US National Institutes of Health, Bethesda, Maryland, EUA). The efficacy of the treatment was evaluated by means of standardized global photography; the quality of life and sideeffects were assessed by means of a self-reported questionnaire. Results: Twenty-six women completed the trial, 14 from group 1 (minoxidil 0.25 mg/ day). Both groups were homogeneous in terms of the stage and duration of alopecia. Only group 2 (n=12, minoxidil 1 mg / day) had a statistically significant improvement in the hair density (p <0.001). In these patients, a mean improvement in the count after treatment (23.58; 95% CI 15.57 to 31.59) was considered greater (p = 0.017) than the group 1 (6.78; 95% CI -3 94 a 17.51). It was possible to determine a prediction equation for counting hair shafts after 6 months with a dose of 1 mg: Y (estimate hair shafts after treatment) = 0.80x + 71.53 (hair shafts at the beginning). The global photographic comparison showed that the mean scores for group 2 were higher (p = 0.036) than group 1. Both groups had improved quality of life (p<0.001). Facial hypertrichosis was reported on two patients from group 2. Conclusion: Low-dose oral minoxidil was shown to be safe and effective to treat FPHL, and the daily dose of 1mg provided significantly better results than the 0.25mg daily dose.