Mucolytics belong to the expectorants (cough expectorants) and reduce the viscosity of mucus, so that the expectoration of bronchial secretions is facilitated. Mucolytics are not a uniform class of active ingredients. They include herbal and pharmaceutical drugs.
What are mucolytics?
Mucolytics belong to the expectorants (cough expectorants) and reduce the viscosity of mucus, making it easier to expectorate bronchial secretions. The main characteristic of mucolytics is their expectorant action by reducing the viscosity of the secretion. Because of this property, they are to be distinguished from the other expectorants. In addition to the mucolytics, the expectorants also include the secretolytics and the secretomotorics. While the secretolytics promote the formation of thin secretions, the secretomotors are responsible for the increased removal of mucus through the increased movement of the cilia. The mucolytics act in a completely different place. They alter the consistency of secretions by chemical, biological, or physical processes.
Medical use and effect
Mucolytics include such diverse biochemical agents as acetylcysteine, carbocysteine, mesna, carbocysteine, bromhexine, fennel oil, anise oil, and myrtol. The liquefaction of secretion does not take place via a uniform mechanism of action, but each active ingredient intervenes here via its own mechanism. For example, acetylcysteine chemically alters the secretion by breaking down sulfide bridges between the mucopolysaccharide fibers. As an alternative mechanism, it is discussed here that the direct antioxidant effect of acetylcysteine inhibits the inflammatory processes, whereby the secretion liquefies. Carbocysteine, in turn, intervenes intracellularly, shifting the ratio of liquid to viscous mucus in favor of the liquid secretion in the generation of the secretion. The drug guaifenesin is thought to cause parasympathetic stimulation of the bronchial glands by reflex irritation of the gastric mucosa, resulting in the production of a thin fluid secretion. Mesna alters secretion consistency by the same mechanism as acetylcysteine. However, it is now used mainly as a drug in detoxification during chemotherapy, but less so as a mucolytic. Bromhexine again favors a different mechanism of action. It stimulates the formation of enzymes that break down secretions while liquefying them. The herbal agents fennel and anise oil develop their expectorant action through the influence of essential oils. Myrtol is a mixed oil of various essential oils, which has a very good expectorant effect in acute bronchitis. However, the mechanism of action for mucolytic action via essential oils has not yet been fully elucidated.
Herbal, natural, homeopathic, and pharmaceutical mucolytics.
In the following, we will take a closer look at some commonly used medicines for their effects. Acetylcysteine as an important mucolytic is often used in chronic bronchitis or in COPD to loosen mucus. The positive effect, especially in COPD, has been proven by many years of research. The extent to which acetylcysteine leads to a lasting improvement in the state of health in chronic bronchitis has yet to be proven by further studies. However, the use of acetylcysteine in cystic fibrosis brings good results. Bromhexine, another active ingredient, is also regularly used as a mucolytic agent. Bromhexine is used in both acute and chronic respiratory diseases, such as bronchitis, asthma, colds, COPD, emphysema or cystic fibrosis for mucus clearance. It is administered in the form of tablets, drops or juice. Essential oils are also used in respiratory diseases to reduce inflammation and loosen mucus. Here, the blended oil Myrtol should be mentioned in particular. Myrtol is enclosed in capsules and is also administered in this form. In addition to its use in bronchitis, it is also used as a mucolytic in sinusitis. In addition to these commonly used agents, there are a variety of other mucolytics.
Risks and side effects
Because of the variety of different mucolytics’, there are also different side effects and risks associated with its use. For example, acetylcysteine should not be used if you are hypersensitive to histamine. Headaches, skin itching and rhinitis may occur. It is also contraindicated for use in asthma and gastric ulcers.Furthermore, acetylcysteine should not be administered to children under 2 years of age. Bromhexine is contraindicated in case of hypersensitivity. It should be administered only under medical supervision in gastric and duodenal ulcers, as it may irritate the stomach and intestines. It should also be used only under medical supervision in renal and hepatic insufficiency. Essential oils, such as Myrtol, should not be used in cases of hypersensitivity, gastrointestinal problems and biliary disorders.
