Acetylcysteine for Patients Requiring Mucous Secretion Clearance: A Review of Clinical Effectiveness and Safety

Mucus secretion clearance is a defense mechanism used by the lung to protect itself from pathogens and particles present in the inhaled air., Mucus traps pathogens and particles in inhaled air, and is usually cleared from the lungs and airways by airflow and ciliary hairs. Impaired mucous clearance results in abnormal lung function.Mucus is a viscoelastic gel-like substance and consists of glycoproteins known as mucins, mixed with other proteins, lipids and water. In healthy individuals, mucus has low viscosity and elasticity and is easily cleared, however in certain lung diseases the mucus has higher viscosity and elasticity and is not easily cleared. Pharmacologic treatments for impaired mucous secretion clearance include agents such as isotonic saline, hypertonic saline, dornase alpha, and acetylcysteine (also known as N-acetylcysteine [NAC]). NAC hydrolyzes the disulfide bonds of mucus proteins to decrease mucus viscosity, thereby facilitating its clearance. NAC is used as a treatment option in various conditions in which there are problems with clearance of lung mucosal secretions (such as chronic obstructive pulmonary disease [COPD], chronic bronchitis, and intubated or post-operative patients).,–The purpose of this report is to review the comparative clinical effectiveness and safety of NAC for treating adult patients requiring mucous secretion clearance. Additionally, tfor this patient population, the clinical effectiveness of treatment with nebulized acetylcysteine versus oral acetylcysteine will be reviewed. A subsequent report will review the evidence-based guidelines regarding NAC for the treatment of adult patients requiring mucous secretion clearance.