查看Ch75 Dermatological Pharmacology的源代码

== Treatment of Hyperpigmentation (色素过度沉着的治疗) ==

所讨论的药物对表皮内激素或光诱导的色素沉着最有效。它们对真皮内炎症后色素沉着的疗效有限。<b style=color:#f80>防晒或避开阳光</b>是任何治疗方案的重要组成部分（Sheth 和 Pandya，2011 年）。

The agents discussed are most effective on hormonally or light-induced pigmentation within the epidermis. They have limited efficacy on postinflammatory pigmentation within the dermis. Sun protection or avoidance is a vital component of any treatment regimen (Sheth and Pandya, 2011).


'''对苯二酚''' （1,4-dihydroxybenzene） 通过抑制酪氨酸酶（黑色素生物合成途径中的初始酶）来减少黑色素细胞色素的产生。此外，它通过产生活性氧自由基导致黑色素体降解和黑色素细胞的破坏。含有 1.5% 至 2% 对苯二酚的制剂可非处方药获得;3% 至 4% 的对苯二酚制剂可通过处方获得。渗透增强剂和防晒成分被添加到一些配方中。提供由 4% 对苯二酚、0.01% 氟轻松和 0.05% 维甲酸组成的组合处方产品。不良反应可能包括皮炎和黄褐斑病。

'''Hydroquinone''' (1,4-dihydroxybenzene) decreases melanocyte pigment production by inhibiting tyrosinase, the initial enzyme in the melanin biosynthetic pathway. In addition, it causes degradation of melanosomes and destruction of melanocytes by production of reactive oxygen radicals. Formulations containing 1.5% to 2% hydroquinone are available OTC; 3% to 4% hydroquinone formulations are available by prescription. Penetration enhancers and sunscreen ingredients are added to some formulations. A combination prescription product consisting of hydroquinone 4%, fluocinolone 0.01%, and tretinoin 0.05% is available. Adverse effects may include dermatitis and ochronosis.


'''壬二酸'''是一种从糠秕马拉色菌培养物中分离的二羧酸，可抑制酪氨酸酶活性，但不如对苯二酚有效。因为它具有温和的粉刺溶解、抗菌和抗炎特性，它也常用于痤疮和丘疹脓疱性酒渣鼻，尤其是炎症后色素沉着过度的患者。

'''Azelaic acid''', a dicarboxylic acid isolated from cultures of Malassezia furfur, inhibits tyrosinase activity but is less effective than hydroquinone. Because it has mild comedolytic, antimicrobial, and anti-inflammatory properties, it also is often used in acne and papulopustular rosacea, especially in patients with postinflammatory hyperpigmentation.


'''甲喹醇''' （4-hydroxyanisole） 是酪氨酸酶的竞争性抑制剂。它被批准作为 2% 处方产品与 0.01% 维甲酸和维生素 C 联合用于美白皮肤，但目前尚未上市。

'''Mequinol''' (4-hydroxyanisole) is a competitive inhibitor of tyrosinase. It was approved as a 2% prescription product in combination with 0.01% tretinoin and vitamin C for skin lightening, but it is not currently commercially available.


'''单苯酮'''（对苯二酚的单苄醚）会导致永久性色素脱失，不应用于常规激素诱导或炎症后色素沉着过度。批准将 20% 乳膏用于影响至少 50% 以上体表面积的广泛性白癜风的最终色素脱失治疗;它很少使用，目前也没有上市销售。

'''Monobenzone''' (monobenzyl ether of hydroquinone) causes permanent depigmentation and should not be used for routine hormonally induced or postinflammatory hyperpigmentation. A 20% cream is approved for final depigmentation therapy of extensive vitiligo affecting at least more than 50% body surface area; it is rarely used and not currently commercially available.


'''乙醇酸'''是一种 α-羟基酸，用于化学换肤治疗色素沉着障碍。它被认为通过以 pH 非依赖性方式抑制酪氨酸酶起作用，并通过减少角质形成细胞粘附来引起剥落。可能的副作用是红斑、脱屑和炎症后色素沉着过度。乙醇酸换肤最好用作难治性表皮色素沉着过度患者的辅助治疗和其他局部治疗（Sheth 和 Pandya，2011 年）。

'''Glycolic acid''' is an α-hydroxy acid used in chemical peels for disorders of pigmentation. It is thought to work by inhibiting tyrosinase in a pH-independent manner and to cause exfoliation by decreasing keratinocyte adhesion. Potential side effects are erythema, desquamation, and postinflammatory hyperpigmentation. Glycolic acid peels are best used as adjunctive therapy along with other topical therapy in patients with refractory epidermal hyperpigmentation (Sheth and Pandya, 2011).


'''氨甲环酸'''是赖氨酸的合成类似物，通过竞争性抑制纤溶酶原向纤溶酶的转化而表现出抗纤维蛋白溶解活性。它被批准用于治疗月经过多或预防拔牙止血缺陷患者的出血。氨甲环酸超说明书用于治疗黄褐斑。<b style=color:#d00>紫外线辐射</b><b style=color:#0b0>诱导</b>'''角质形成细胞'''产生纤溶酶原激活剂，通过<b style=color:#f80>纤溶酶</b>、<b style=color:#f80>花生四烯酸</b>和<b style=color:#f80>成纤维细胞生长因子</b><b style=color:#0b0>刺激</b>黑色素细胞导致黑色素生成增加，然后通过<b style=color:#f80>血管内皮生长因子</b>刺激增加<b style=color:#0cf>新生血管</b>形成。氨甲环酸通过<b style=color:#0b0>抑制</b><b style=color:#0cf>纤溶酶原活化</b>来减轻这种紫外线诱导的黑色素生成和'''新生血管形成'''。氨甲环酸已局部用作 2% 至 5% 制剂，每天两次或皮内注射，浓度为 4 mg/mL，注射频率从每周一次到每月一次不等。皮内注射最常见的副作用是注射部位灼痛。氨甲环酸已口服，<b style=color:#f80>剂量</b>为 250 ~ 325mg，每天两次。最常见的<b style=color:#f00>副作用</b>是腹胀或头痛。在全身使用之前，应筛查患者'''血栓栓塞'''的危险因素。

'''Tranexamic acid''' is a synthetic analogue of lysine that exhibits antifibrinolytic activity by competitively inhibiting transformation of plasminogen to plasmin. It is approved for the treatment of heavy menstrual bleeding or to prevent hemorrhage in patients with hemostatic defects undergoing tooth extraction. Tranexamic acid is used off label for the treatment of melasma. UV radiation induces plasminogen activator production by keratinocytes, which leads to increased melanogenesis through stimulation of melanocytes by plasmin, arachidonic acid, and fibroblast growth factor, and thence to increased neovascularization via vascular endothelial growth factor stimulation. Tranexamic acid mitigates this UV-induced melanogenesis and neovascularization through inhibition of plasminogen activation. Tranexamic acid has been used topically as a 2% to 5% formulation twice daily or intradermally at a concentration of 4 mg/mL with injection frequency ranging from once weekly to once monthly. The most common side effect with intradermal injection was injection site burning. Tranexamic acid has been used orally at a dosage of 250 to 325 mg twice daily. The most common side effect is abdominal bloating or headache. Patients should be screened for thromboembolic risk factors prior to systemic use.

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