The means promoting removal of a phlegm from pulmonary ways play an important role in treatment of various bronchopulmonary diseases". A long time expectorants which effect in more considerably measure is connected with stimulation of receptors of mucous membranes of bronchial ways and mechanical strengthening of advance of a phlegm were the main drugs used for this purpose.
Recently there were new opportunities of improvement of "drainage" function of bronchial ways by means of pharmacological means. A number of new medicines allows to change rheological properties of a phlegm and its adhesive indicators and also to facilitate removal of a phlegm in the physiological way.
Now the drugs used for removal of a phlegm divide into 2 main groups:
- stimulating expectoration (sekretomotorny);
- mucolytic (bronkhosekretolitichesky).
Sekretomotorny drugs enhance physiological activity of a ciliary epithelium and the peristaltic movements of bronchioles, promoting advance of a phlegm from lower parts in upper parts of airways and to its removal. This effect is usually combined with strengthening of secretion of bronchial glands and some reduction of viscosity of a phlegm. Conditionally drugs of this group divide into 2 subgroups: reflex and resorptive effect.
Drugs of reflex effect (drugs of a thermopsis, a milkwort, mallow and other herbs, Natrium benzoicum, terpin hydrate, etc.) at intake render moderate irritant action on receptors of a mucous membrane of a stomach and reflex influence bronchial tubes and bronchial glands. The effect of some drugs is connected also with the stimulating impact on the emetic and respiratory centers (a thermopsis, etc.). Also drugs with the prevailing emetic activity (Apomorphinum, lycorine) rendering expectorant effect in small doses belong to means of reflex effect. A number of drugs of reflex effect partially renders also resorptive effect: the essential oils which are contained in them and others substances are emitted through airways and cause strengthening of secretion and fluidifying of a phlegm.
Drugs of resorptive action (iodide of sodium and potassium, ammonium chloride, partially - Natrii hydrocarbonas, etc.) render effect generally at their discharge (after intake) a mucous membrane of airways, stimulate bronchial glands and cause direct fluidifying (rehydration) of a phlegm; they stimulate also motor function of a ciliary epithelium and bronchioles in a certain measure. Especially actively iodine drugs affect viscosity of a phlegm.
In bronchopulmonary diseases long since widely apply to stimulation of expectoration not only herbs in the form of broths, infusions, mixtures, "chest collecting", etc., but also some individual substances emitted from plants.
As mucolytic (sekretolitichesky) means at first used some fermental (proteolytic) drugs (trypsin, ribonuclease, a deoxyribonuclease, etc.), and specifically operating synthetic drugs began to find application recently (Acetylcysteinum, Bromhexine, Ambroxol, etc.).
Mucolytic drugs differ on the action mechanism. Proteolytic enzymes break peptide bonds of a molecule of protein. Ribonuclease causes a RNA depolymerization. Acetylcysteinum promotes a rupture of disulfide bridges of acid mucopolysaccharides of gel of a phlegm.
Now it is proved that effect of Bromhexine and close to it on structure of new drug of Ambroxol (lasolvan) and some of their analogs is caused by their specific ability to stimulate production of endogenous surfactant (from the word "surface" - a surface), poverkhnost but - active agent lipido - proteinaceous mukopolisakharidnoy the nature, synthesized in alveolar cells. Pulmonary surfactant (anti-atelectatic factor) covers the internal surface of lungs in the form of a pellicle; it provides stability of alveolar cells in the course of breath, protects them from adverse factors, promotes regulation of rheological properties of a bronchopulmonary secret, improvement of its "sliding" on an epithelium and simplification of expectoration from airways.
Disturbance of biosynthesis of surfactant is observed in various bronchopulmonary diseases, and use of stimulators of formation of surfactant is regarded as one of important pathogenetic links of pharmacotherapy of these diseases.
It is established also that insufficiency of surfactant of lungs is observed at a syndrome of respiratory disorders (respiratory a distress syndrome) at newborns.
Recently in medical practice began to apply not only stimulators of biosynthesis of surfactant, but also the artificial surfactants substituting natural surfactant at disturbance of its education in connection with diseases of lungs or impact on them of disturbing factors (see Alveofakt).
All expectorant drugs are usually appointed in complex therapy. In need of them give together with bronchial spasmolytics, antibacterial drugs, cardiacs".
For improvement of fluidifying and department of a phlegm it is recommended at use expectorant, especially sekretomotorny, drugs to appoint plentiful warm drink.