The purge of the mucosal stasis induced by expectorants frees the airways, improving the well-being of the patient suffering from bronchitis, cold or other catarrhal affections of the respiratory tree.
The ways in which the various substances carry out their expectorant action are manifold.
In general, expectorants of plant origin can be divided into:
- Direct expectorants;
- Indirect expectorants.
However, while it is possible to define precise mechanisms of action for synthetic drugs, herbal drugs - by virtue of the numerous substances that compose them - tend to act simultaneously on several fronts.
which, once taken orally, are absorbed in the intestine and partially eliminated through the respiratory tree.
At the bronchial level, the essential oils contained in plant drugs stimulate the serous glands (tubulo-acinar) by increasing the aqueous component of catarrhal secretions (for this reason they are known as balsamic expectorants); at the same time and at the same level, these substances inhibit the activity of the goblet glands muciparous (for this reason they are known as secretolytic expectorants). Overall, therefore, the mucus results more fluid and easier to eliminate, thanks also to the stimulus exerted on the "ciliary activity. This last property is characteristic of the so-called expectorants stimulating the motility of the secretion, which facilitate the transport of mucus towards the pharynx, through the stimulation of ciliary movement.
Among the herbal drugs containing essential oils with this type of expectorant action we remember eucalyptus, mint, pine.
, bitter substances, acids or emetic substances that act in the stomach, irritating the mucous membrane of the stomach.
This insult translates into an indirect stimulus to bronchial secretion, according to a physiological mechanism known as the gastropulmonary reflex. Saponin drugs, such as ivy, mullein, horehound, belong to this category.
standardized in active ingredients. Instead, its use in herbal teas for oral use is not recommended, because the essential oil would float in the aqueous preparation, irritating the mucous membrane of the oral cavity; Particular caution should also be taken when using it by inhalation. These natural expectorants, in concentrated solutions, are typically dispersed in the tubs of radiators or in vaporizers for fumigations, to the extent of very few drops per liter of water. However, excessive inhalation of vapors can cause allergic reactions, bronchospasm and asthma attacks, especially in children and predisposed subjects; hence the advice to use hot, but not boiling, water.Indirect expectorants
Drugs with saponins, by virtue of the mechanism of action described above, tend to cause nausea and gastrointestinal irritation, especially in case of prolonged use. At dosages about 10 times higher than those used for expectorant purposes, these herbal remedies become emetic. to be used to induce vomiting.
PLEASE NOTE
Before taking any type of natural remedy or herbal drug against oily cough (productive cough or wet cough, if you prefer), it is necessary to consult with your doctor in order to exclude the presence of situations or conditions that contraindicate the use. of similar products (for example, presence of particular allergies, pharmacological therapies in progress, state of pregnancy or lactation, presence of particular pathologies, etc.).
