The Clinical Use of N-Acetylcysteine in Other Medical Disorders

Abstract

N-acetylcysteine (NAC) is used in medicine for a wide variety of conditions, with its use continuously being expanded. Its ubiquitous use is driven by its excellent safety profile along with its multiple mechanisms of action, including targeting oxidative stress, inflammation, apoptosis, and mitochondrial and neurotransmitter metabolism. This chapter reviews some of the less common investigated uses for NAC in medicine, including treatment of autoimmune, skin, infectious, hematological, metabolic, and ophthalmological diseases, as well as for patients in the intensive care unit (ICU), including neonates, undergoing surgery or with fertility disorders, diabetes, or burns. It has been investigated for its role in the prevention of hearing loss and other adverse effects of chemotherapy and antibiotics as well as in preventing and treating cancer. For many of these areas, the studies are limited, making it difficult to make any recommendations based on the current published research. Certain areas, such as pretreatment with hyperoxic ventilation in the ICU, treatment for burns and prevention of antibiotic-induced hearing loss, adjunctive treatment for human immunodeficiency virus infection, and improving outcomes in chronic bronchitis and polycystic ovary syndrome, appear to have enough positive evidence in clinical trials to recommend the use of NAC. Many other areas have promising findings from clinical trials, but there is not enough evidence to make a recommendation. These areas include autoimmune and metabolic disease, prevention and treatment of cancer, chorioamnionitis, skin disorders such as acne and lamellar ichthyosis, treatment and prevention of otitis media, influenza and bronchiolitis, hematological disorders, and male infertility. In some areas there has been a number of clinical trials performed without any benefit seen, resulting in a recommendation not to use NAC. These areas include general use in the ICU, multiple organ failure, extensive abdominal surgery including aortic aneurysm surgery, prevention of atelectasis during surgery, treatment of photodermatosis or malaria, and preventing chronic lung disease in neonates or adverse reaction to sulfamethoxazole. There are ongoing clinical trials in some of these areas for the use of NAC, including its use in cancer, preventing hearing loss, treatment of human immunodeficiency virus infection, diabetes, and hematological disorders. Overall, there appears to be many potential uses for NAC in many disorders in medicine, but for many, further studies are needed to define the dosing and/or better define the subpopulation of patients which would most benefit from treatment with NAC.