Rossi Alfredo, Cantisani Carmen, Melis Luca, Iorio Alessandra, Scali Elisabetta, Calvieri Stefano
Department of Dermatology and Plastic Surgery, University Sapienza of Rome, Azienda Policlinico Umberto I, Via di Boccea n. 10 int. 16, 00167 Rome, Italy.
Recent Pat Inflamm Allergy Drug Discov. 2012 May;6(2):130-6. doi: 10.2174/187221312800166859.
Minoxidil, a vasodilator medication known for its ability to slow or stop hair loss and promote hair regrowth, was first introduced, exclusively as an oral drug, to treat high blood pressure. It was however discovered to have the important side-effect of increasing growth or darkening of fine body hairs; this led to the development of a topical formulation as a 2% concentration solution for the treatment of female androgenic alopecia or 5% for treating male androgenic alopecia. Measurable changes disappear within months after discontinuation of treatment. The mechanism by which it promotes hair growth is not fully understood. Minoxidil is a potassium channel opener, causing hyperpolarization of cell membranes and it is also a vasodilator, it is speculated that, by widening blood vessels and opening potassium channels, it allows more oxygen, blood and nutrients to the follicle. This can also cause follicles in the telogen phase to shed, usually soon to be replaced by new, thicker hairs in a new anagen phase. It needs to be applied regularly, once or twice daily, for hair gained to be maintained, and side effects are common. The most common adverse reactions of the topical formulation are limited to irritant and allergic contact dermatitis on the scalp. There have been cases of allergic reactions to the nonactive ingredient propylene glycol, which is found in some topical solution especially if they are galenic. Increased hair loss which can occur during Minoxidil use, is due to the synchronization of the hair cycle that the treatment induces. In this review, we described its mechanism of action, use in dermatology and some patents related to alternative treatment of allergic reactions due to its use.
米诺地尔是一种血管扩张剂药物，以减缓或阻止脱发并促进头发生长而闻名。它最初仅作为口服药物用于治疗高血压。然而，人们发现它有一个重要的副作用，即会使身体上的细小毛发增多或变黑；这促使人们开发出一种局部用制剂，即浓度为2%的溶液用于治疗女性雄激素性脱发，5%的溶液用于治疗男性雄激素性脱发。停药后数月内，可测量到的变化就会消失。其促进头发生长的机制尚未完全了解。米诺地尔是一种钾通道开放剂，可导致细胞膜超极化，它也是一种血管扩张剂。据推测，通过扩张血管和开放钾通道，它能让更多的氧气、血液和营养物质到达毛囊。这也可能导致休止期的毛囊脱落，通常很快就会被新的生长期的更粗的毛发所取代。为了保持已生长出的头发，需要每天定期使用一到两次，而且副作用很常见。局部用制剂最常见的不良反应仅限于头皮上的刺激性和过敏性接触性皮炎。曾有对非活性成分丙二醇过敏的案例，丙二醇存在于一些局部用溶液中，尤其是那些按照传统配方制成的溶液。米诺地尔使用过程中可能出现的脱发增加，是由于治疗引起的毛发周期同步化所致。在这篇综述中，我们描述了它的作用机制、在皮肤科的应用以及一些与因使用它而引发的过敏反应的替代治疗相关的专利。
