Oxidative stress, which results in the damage of diverse biological molecules, is a ubiquitous cellular process implicated in the etiology of many illnesses. The sulfhydryl-containing tripeptide glutathione (GSH), which is synthesized and maintained at high concentrations in all cells, is one of the mechanisms by which cells protect themselves from oxidative stress. N-acetylcysteine (NAC), a synthetic derivative of the endogenous amino acid L-cysteine and a precursor of GSH, has been used for several decades as a mucolytic and as an antidote to acetaminophen (paracetamol) poisoning. As a mucolytic, NAC breaks the disulfide bonds of heavily cross-linked mucins, thereby reducing mucus viscosity. In vitro, NAC has antifibrotic effects on lung fibroblasts. As an antidote to acetaminophen poisoning, NAC restores the hepatic GSH pool depleted in the drug detoxification process. More recently, improved knowledge of the mechanisms by which NAC acts has expanded its clinical applications. In particular, the discovery that NAC can modulate the homeostasis of glutamate has prompted studies of NAC in neuropsychiatric diseases characterized by impaired glutamate homeostasis. This narrative review provides an overview of the most relevant and recent evidence on the clinical application of NAC, with a focus on respiratory diseases, acetaminophen poisoning, disorders of the central nervous system (chronic neuropathic pain, depression, schizophrenia, bipolar disorder, and addiction), cardiovascular disease, contrast-induced nephropathy, and ophthalmology (retinitis pigmentosa).

氧化应激会导致多种生物分子受损，是一种普遍存在的细胞过程，与许多疾病的病因有关。含巯基的三肽谷胱甘肽 (GSH) 在所有细胞中合成并维持在高浓度，是细胞保护自身免受氧化应激的机制之一。 N-乙酰半胱氨酸 (NAC) 是内源性氨基酸 L-半胱氨酸的合成衍生物，也是 GSH 的前体，几十年来一直被用作粘液溶解剂和对乙酰氨基酚（扑热息痛）中毒的解毒剂。作为粘液溶解剂，NAC 可以破坏高度交联的粘蛋白的二硫键，从而降低粘液粘度。在体外，NAC 对肺成纤维细胞具有抗纤维化作用。作为对乙酰氨基酚中毒的解毒剂，NAC 可恢复药物解毒过程中耗尽的肝脏 GSH 库。最近，人们对 NAC 作用机制的了解不断加深，扩大了其临床应用。特别是，NAC 可以调节谷氨酸稳态的发现促进了 NAC 在以谷氨酸稳态受损为特征的神经精神疾病中的研究。这篇叙述性综述概述了 NAC 临床应用的最相关和最新的证据，重点是呼吸系统疾病、对乙酰氨基酚中毒、中枢神经系统疾病（慢性神经性疼痛、抑郁症、精神分裂症、双相情感障碍和成瘾） ）、心血管疾病、造影剂肾病和眼科（色素性视网膜炎）。