A Review on N-acetylcysteine: A Versatile Adjuvant in Respiratory Diseases

Abstract

N-acetylcysteine (NAC), the acetylated variant of the amino acid L-cysteine and precursor of glutathione, has several
therapeutic uses and has been used worldwide for over 50 years. It is used as an antidote for paracetamol poisoning, for
treating neurological illnesses and substance use disorders, and as a mucolytic, antibiofilm, antioxidant, and anti-inflammatory
agent in various respiratory diseases. Therefore, NAC exhibits promising therapeutic potential and may be an effective choice
for add-on therapy. This review aims to establish the benefits of NAC beyond its mucolytic and antibiofilm actions and
highlights the utility of its antioxidant as well as anti-inflammatory activity not only in chronic respiratory diseases, such as
chronic obstructive pulmonary disease (COPD) and bronchiectasis, but also in respiratory infections, such as tuberculosis,
pneumonia, and coronavirus disease 2019 (COVID-19). The review will be of interest to physicians as it summarizes the
advantages of using NAC in the treatment of various respiratory disorders in their clinical practice.