From Big Medical Encyclopedia

EXPECTORANTS (expectorantia) — the pharmaceuticals facilitating expectoration from respiratory tracts of hl. obr. due to reduction of its viscosity.

By the principle of action of O. of page divide into drugs of reflex and direct types of action.

Pages of reflex type of action carry drugs of nek-ry medicinal plants to O., napr, ipecacuanhas (see), thermopsis (see), effective agents to-rykh are alkaloids, and also drugs of a milkwort, a glycyrrhiza, a Jacob's ladder, primrose spring and some other the plants containing saponins. Pages of reflex type of action rank as O. also alkaloid lycorine (see). As O. villages use the powders, infusions, broths, tinctures and extracts from the called plants intended for internal use. At introduction inside effective agents of these drugs (alkaloids and saponins) render irritant action on receptors of a stomach and reflex strengthen secretion of bronchial glands that is followed by reduction of viscosity of a phlegm, and also increase activity of a ciliary epithelium and stimulate peristaltic reductions of smooth muscles of bronchial tubes, facilitating thereby expectoration from respiratory tracts. In high doses (in 10 and more times exceeding expectorating) O. pages of this group make sick and vomiting of a reflex origin.

On the nature of influence on secretory and motor function of bronchial tubes to O. to page of reflex type of action it is close Apomorphinum (see). However unlike reflex the pages operating with O. it strengthens secretion of bronchial glands and motility of unstriated muscles of bronchial tubes by stimulation of trigger zones of the emetic center in a myelencephalon. In this regard the expectorant effect of Apomorphinum is shown at different ways of introduction (inside, parenterally). In the doses exceeding expectorating Apomorphinum causes vomiting of the central origin. Range between expectorant and emetic doses of Apomorphinum is much less, than O. have a page of a reflex effect.

Include the drugs exerting the direct stimulating impact on bronchial glands, and the drugs liquefying a phlegm at direct contact with it in group O. of page of direct action.

The page of direct type of action stimulating secretion of bronchial glands carry nek-ry drugs to O. iodine (see), essential oils (see) and the drugs supporting them, ammonium chloride (see), solution of ammonia, sodium benzoate (see. the Benzoic acid as drug ), etc.

From drugs of iodine as O. villages use sodium iodide and potassium iodide, expectorant effect to-rykh is caused by the fact that ions of iodine are partially allocated with bronchial glands and cause strengthening of their secretory activity at the expense of irritation of ferruterous fabric. As O. appoint drugs of iodine page usually inside, it is possible to appoint Natrii iodidum as well intravenously.

Also other oils, terpin hydrate, the gum spirit of turpentine purified, etc. belong to O. of page of direct action from group of essential oils anisic, fennel, thyme, eucalyptus. Effective agents of essential oils are the terpenes and aromatic hydrocarbons exerting preferential direct stimulating impact on secretion of bronchial glands. Along with expectorant properties essential oils possess also moderately expressed deodorizing, antimicrobic and antiinflammatory action. The expectorant effect of essential oils is observed both at their inhalation use, and at intake. In the latter case the stimulating influence of essential oils on bronchial secretion can be partially caused by reflex mechanisms (at the expense of irritation of a mucous membrane of a stomach). As O. essential oils can be used by page in pure form, napr, anisic oil, terpin hydrate (see), and as a part of irregular dosage forms in a combination with other O. of page, napr, nashatyrno-anisic drops (see), pertussinony Besides, essential oils contain in drugs of the nek-ry medicinal plants (an anise, a timian, a thyme, an inula, etc.) used as O. by page.

Synthetic drugs from number O. of page of direct action (solution of ammonia, ammonium chloride and sodium benzoate) like essential oils have expectorant effect preferential due to direct irritant action on bronchial glands and partially reflex way (at the expense of irritation of a mucous membrane of a stomach).

The page of direct action liquefying a phlegm at direct contact with it carry so-called mucolytic O. to O. of page and hydrosodium carbonate. Pages mean the means liquefying a phlegm by reduction of polymerization or a depolymerization of the mucopolysaccharides which are a part of a phlegm by mucolytic O. Mucolytic properties drugs of a number of enzymes (trypsin crystal, chymotrypsin crystal, a deoxyribonuclease, chemical opsin), some derivatives of amino acids (e.g., Acetylcysteinum), and also drug Bromhexine have (a synonym Bisolvon). As O. the specified drugs of enzymes and Acetylcysteinum are applied by page is inhalation, and rinatiol and Bromhexine — inside.

Hydrocarbonate sodium (see) renders weak expectorant effect of hl. obr. by reduction of viscosity of a phlegm due to alkaline properties inherent in it. Hydrosodium carbonate is more effective at inhalation use, than at intake.

Indication to O.'s use by the village of different types of action the inflammatory respiratory diseases and lungs which are followed by dry cough or cough with knitting are it is difficult the separated phlegm (bronchitis, pneumonia, a bronchoectatic disease, etc.). At O.'s appointment the page should be meant that their action amplifies at plentiful drink. At O.'s appointment the page of a reflex effect matters also observance of a certain frequency of reception (every 2 — 3 hour) since the expectorant effect of these means is short. At inf. diseases of upper respiratory tracts and easy O. of page it is necessary to accept against the background of the corresponding antibacterial therapy (antibiotics, streptocides, etc.). At obstructive diseases of easy O. of page it is possible to appoint together with broncholitic means.

Side effect The lake of page of different groups is unequal. So, O. page of reflex type of action and Apomorphinum as side effects cause hl. obr. nausea, is more rare vomiting. At administration of drugs of iodine there can be phenomena of an iodism, signs of hyperfunction of a thyroid gland and other side effects inherent to iodides. Ammonium chloride raises a diuresis, reduces alkaline reserves of blood and at prolonged use can cause a compensated acidosis. Hydrosodium carbonate, on the contrary, increases alkaline reserves of blood and in this regard can lower excitability of a respiratory center. Mucolytic O. villages from among enzymes and Acetylcysteinum most often cause allergic reactions and can aggravate the course of bronchial asthma. The lake of page, the irritating mucous membranes of respiratory tracts (iodides, essential oils), can promote an aggravation nek-ry hron, respiratory diseases and lungs (tuberculosis, a bronchoectatic disease).

Contraindications to O.'s use by the village are various for separate groups of drugs. A contraindication for all O.' appointment pages are open forms of a pulmonary tuberculosis and other diseases with tendency to pulmonary bleedings.

Bibliography: In otchat B. E. Sketches of clinical pharmacology, page 408, M., 1965; Clinical pharmacology, under the editorship of V. V. Zakusov, page 305, M., 1978; Mashkovsky M. D. Pharmaceuticals, p.1, page 321, M., 1978.

V. K. Muratov.