Table 1.

Mucoactive drugs and their potential mechanism of action

Mucoactive drugs	Potential mechanism of action
Expectorants
Hypertonic saline	Increases secretion volume and/or hydration
Guaifenesin	Stimulates secretion and reduces mucus viscosity
Mucus regulators
Carbocysteine	Metabolism of mucus-producing cells, antioxidant and anti-inflammatory effects, modulates mucus production
Anticholinergic agents	Decrease secretion volume
Glucocorticoids	Reduce airway inflammation and mucin secretion
Macrolide antibiotics	Reduce airway inflammation and mucin secretion
Mucolytics
N-acetylcysteine	Breaks disulfide bonds linking mucin polymers, antioxidant and anti-inflammatory effects
Nacystelyn	Increases chloride secretion and disulfide bonds
Erdosteine	Modulates mucus production and increases mucociliary transport
Dornase alfa	Hydrolyzes the DNA in mucus and reduces viscosity in the lungs
Gelsolin	Severs actin filament cross-links
Thymosin β4	Severs actin filament cross-links
Dextran	Breaks hydrogen bonds and increases secretion hydration
Heparin	Breaks hydrogen bonds and ionic bonds
Mucokinetics
Bronchodilators	Improve cough clearance by increasing expiratory flow
Surfactants	Decrease sputum/mucus adhesiveness
Ambroxol	Stimulates surfactant production and inhibits neuronal sodium channels

Note: Reproduced with permission from the © ERS 2010. European Respiratory Review Jun 2010, 19(116):127–133; DOI: 10.1183/09059180.00003510.⁴³