Mucoactive agents are a class of chemical agents that aid in the clearance of mucus or sputum from the upper and lower airways, including the lungs, bronchi, and trachea. Mucoactive drugs include expectorants, mucolytics, mucoregulators, and mucokinetics. These medications are used in the treatment of respiratory diseases that are complicated by the oversecretion or inspissation of mucus. These drugs can be further categorized by their mechanism of action.
Mechanism of action
Mucoactive agents—expectorants—include mucolytics, secretolytics and mucokinetics (also called secretomotorics)
- Mucolytics: thin (reduce the viscosity of) mucus
- Secretolytics: increase airway water or the volume of airway secretions
- Mucokinetics: increase mucociliary transport (clearance) and transportability of mucus by cough
- Mucoregulators: suppress underlying mechanisms of mucus hypersecretion
Alternatively, attacking the affinity between secretions and the biological surfaces is another avenue, which is used by abhesives and surfactants.
Any of these effects could improve airway clearance during coughing.
In general, clearance ability is hampered by the bonding to surfaces (stickiness) and by the viscosity of mucous secretions in the lungs. In turn, the viscosity is dependent upon the concentration of mucoprotein in the secretions.
Mucolytics, secretolytics and secretomotorics are different types of medication, yet they are intended to promote drainage of mucus from the lungs.
An expectorant (from the Latin expectorare, to expel or banish) works by signaling the body to increase the amount or hydration of secretions, resulting in more, yet clearer, secretions and lubricating the irritated respiratory tract. One mucoactive agent, guaifenesin, has anxiolytic and muscle-relaxing properties. It is commonly available in cough syrups and also as sustained-release tablets.
Mucolytics can dissolve thick mucus and are usually used to help relieve respiratory difficulties. They do this by breaking down the chemical bonds between molecules in the mucus. This in turn can lower the viscosity by altering the mucin-containing components.
An expectorant increases bronchial secretions and mucolytics help loosen thick bronchial secretions. Expectorants reduce the thickness or viscosity of bronchial secretions, thus increasing mucus flow that can be removed more easily through coughing. Mucolytics break down the chemical structure of mucus molecules. The mucus becomes thinner and can be removed more easily through coughing.
— Adams, Holland, & Bostwick, 2008, p. 591
Mucoactive drugs
Mucoactive drugs include:
- acetylcysteine
- ambroxol
- ammonium chloride
- bromhexine
- carbocisteine
- dornase alfa
- erdosteine
- guaifenesin
- mecysteine
- potassium citrate
- potassium iodide
- sodium citrate
- tolu balsam
- Justicia adhatoda extracts
References
- Balsamo, R.; Lanata, L.; and Egan, C. G. (2010). "Mucoactive drugs". European Respiratory Review. 19 (116): 127–33. doi:10.1183/09059180.00003510. PMC 9682576. PMID 20956181.
- ^ Rogers, D. F. (2007). "Mucoactive agents for airway mucus hypersecretory diseases". Respiratory Care. 52 (9): 1176–93, discussion 1193–7. PMID 17716385.
- Rubin, Bruce K. (2006). "The pharmacologic approach to airway clearance: Mucoactive agents". Paediatric Respiratory Reviews. 7 (Supplement 1): S215 – S219. doi:10.1016/j.prrv.2006.04.198. PMID 16798570.
- "Definition of Expectorant". MedicineNet. 13 May 2016. Archived from the original on 11 August 2020. Retrieved 4 January 2018.
- "NCATS Inxight: Drugs – MECYSTEINE HYDROCHLORIDE". drugs.ncats.io. Archived from the original on 29 May 2019. Retrieved 29 May 2019.
- Adams, Michael; Holland, Leland Norman; Bostwick, Paula Manuel (2016). Pharmacology for Nurses: A Pathophysiologic Approach (5 ed.). Pearson Education. p. 960. ISBN 978-0134255163.
- Rubin, Bruce K (1 July 2007). "Mucolytics, Expectorants, and Mucokinetic Medications". Respiratory Care. 52 (7).
