Minoxidil: main differences between topical and oral use

Abstract

Minoxidil was, in the seventies, introduced as an oral medication that was initially used for the treatment of hypertension, in view of its vasodilator potential - activation of the potassium channels located in the smooth muscles of the peripheral arteries, allowing the efflux of potassium so that hyperpolarization of the cell membrane and relaxation of the smooth muscles occur. However, a side effect observed by patients using this drug was hair and body hair growth. Soon, in the eighties, it was launched in the market under a new presentation: the topical version - in concentrations of 2% and, later, 5% -, aiming to be an alternative for hair loss disorders and to promote hair growth. Currently, it is the most widely used drug for the purposes described above. Thus, this work has as main objective to analyze differences, especially regarding adverse reactions, between topical and oral use - which has also been implemented, but in lower doses than the treatment for hypertension - of minoxidil, and the efficacy of the two routes of administration.