48] N-acetylcysteine

Abstract

Publisher Summary N-Acetylcysteine (NAC) is a thiol-containing compound that has been used in clinical practice for several years. Historically, NAC was introduced for the treatment of congestive and obstructive lung diseases; primarily those associated with hypersecretion of mucus, for example, chronic bronchitis and cystic fibrosis. NAC has also been used as the drug of choice in the treatment of paracetamol intoxication. Currently, NAC and its applications include use in the treatment of pulmonary oxygen toxicity, adult respiratory distress syndrome (ARDS), and, potentially, cases of human immunodeficiency virus (HIV-I) infections. This diversity of pharmacological applications of NAC is because of the multifaceted chemical properties of the cysteinyl thiol of the molecule. These include its nucleophilicity and redox activity, providing scavenger and antioxidant properties and its ability to undergo transhydrogenation or thiol-disulfide exchange (TDE) reactions with other thiol redox couples. Advances in the clinical use of NAC have stemmed mainly from the development of suitable analytical techniques for the analysis of NAC and potential metabolites in biological systems. These techniques are being used to determine the human pharmacokinetic behavior of NAC and its metabolic disposition. This chapter describes the analytical concepts that are currently available for the determination of NAC and metabolites in biological fluids. It also presents the available data on the disposition of NAC in humans and discusses the biological properties of NAC. It then discusses some future possibilities of NAC in clinical practice.