ANTISPASMODICS (Greek spasmos a spasm, a spasm + lysis release, disposal) — the pharmaceuticals lowering a tone and a physical activity of unstriated muscles; apply to the prevention or elimination of spasms of smooth muscle bodies.
Depending on a preferential orientation of action of separate S. of page can be the main clinically significant effects of these drugs elimination of the pains caused by spasms of muscles of abdominal organs, improvement of ventilation of the lungs owing to a bronchiectasia at a bronchospasm, decrease in the raised general ABP (see. Blood circulation ) owing to reduction of resistance of peripheral vessels or increase in a regional blood-groove at a local vasomotor spasm.
There is no standard classification of S. of page. On the mechanism of action of S. of page divide on myotropic and neurotropic. Myotropic S. pages reduce a tone of smooth muscle bodies by a direct impact on biochemical processes in smooth muscle cells. Neurotropic S. pages render spasmolytic effect by disturbance of transfer of nervous impulses in vegetative gangliya or in the field of the terminations of the autonomic nerves stimulating unstriated muscles. Villages of the village of myotropic type of action in the conditions of in vitro lower a tone of all smooth muscle bodies (vessels, bronchial tubes, abdominal organs). In the conditions of the whole organism separate gruypa of these substances show tropism to separate smooth muscle bodies and in this regard are used preferential at defined a wedge, indications, napr, as broncholitic or antihypertensives, anesthetics at the pains of spastic character accompanying pathology of abdominal organs etc.
of S. pages of myotropic type of action belong to different classes of chemical connections. Among them distinguish: nitrites and nitrates — amyle nitrite (see), nitroglycerine (see), aerinite (see), etc.; derivatives of isoquinoline — papaverine (see), Nospanum (see); derivatives of purine — theobromine (see), theophylline (see), Euphyllinum (see), Xantinoli nicotinas (see), etc.; derivative benzimidazole Dibazolum (see); esters carboxylic to - t — Gangleronum (see), Diprophenum (see), Tifenum (see), etc. Villages carry to myotropic S. also drugs of a different chemical structure, having the expressed vasodilating effect, napr, diazoxide, apressine, Natrium nitroprussicum, to-rye on the main orientation of action usually consider as vasodilators (see). Besides, in 60 — 70 20 century in a wedge, practice many drugs (e.g., Carbocromenum, kelline, diphryl, lidoflazinum were implemented, etc.), to-rye reduce the general peripheric resistance of a vascular bed of hl. obr. due to influence on arterioles, and also relax smooth muscles of large blood vessels. In an experiment they cause permanent expansion of coronary vessels. However along with it there can be symptoms of ischemia of a myocardium owing to adverse redistribution of blood in a myocardium, and also owing to decrease in the system ABP and developing of tachycardia. In this regard such drugs in modern medical practice are rather seldom used as anti-anginal means since by efficiency considerably concede to other means of this group, napr, to nitrites and nitrates, | 3-adre-noblokatoram. Myotropic S. pages from among derivatives of purine relax smooth muscles of bronchial tubes, expand coronary vessels of heart, vessels of a brain, reduce a tone of peripheral vessels and lower the ABP, pressure and stimulate cardiac performance in pulmonary vessels, increasing its oxygen requirement. The greatest practical value has broncholitic effect of drugs of this group.
From myotropic S. pages apply hl to stopping of hypertensive crises. obr. Dibazolum, Natrium nitroprussicum, diazoxide. Apressin (see), to-ry possesses rather permanent vasodilating action, use generally as addition to beta adrenoblockers and saluretics at treatment of severe forms of an idiopathic hypertensia.
Almost important neurotropic S. of page are m-holinoblokatory — drugs of a belladonna, atropine (see), Scopolaminum (see), etc., and also m - and N-holinoblokatory — Spasmolytinum (see), probanthene, etc., ganglioblokator — petrolhexonium (see), Dimecolinum (see), Pyrilenum (see), etc. m-Holinoblokatory cause many cooperative effects because against the background of their action dominance of a tone of a sympathetic innervation develops; m - and N-holinoblokatory can lower the ABP due to blockade gangliyev stshpatichesky department of century of N of page Nek-ry holinoblokator, e.g. Platyphyllinum (see), have myotropic spasmolytic properties. Neurotropic S. are most widely used by page from among holinoblokator for the prevention and stopping of spasms of smooth muscles of bodies went. - kish. a path and urinary tract, and also as broncholitic means (in the main m-holinoblokatory).
The page of preferential broncholitic action can be carried to neurotropic S. Isadrinum (see), ortsiprenalin, salbutamol, adrenaline (see), ephedrine (see) and other adrenomimetik, to-rye excite beta 2 - adrenoceptors of bronchial tubes. Drugs of this group are fixed assets for stopping of attacks of bronchial asthma. All of them stimulate in a bigger or smaller measure also beta 1 - receptors of a myocardium and therefore cause tachycardia and increase force of cordial reductions, increasing the need of a myocardium for oxygen. These properties are least expressed at the selection beta 2 - adrenomimetikov (a salbutamola, etc.). Spasmolytic effect of beta-adrenergic agonists concerning other smooth muscle bodies, except for a myometrium, has no wedge, values. The drugs stimulating beta 2 - adrenoceptors, use for decrease in a tone and contractility of a myometrium.
S.'s choice by the village for practical purposes is defined not only the main orientation of their spasmolytic action in relation to any body or system, but the wedge, situations shall be carried out also taking into account specific. So, the spasmolytic effect of atropine against the background of inflammatory damage of intestines, napr, at nonspecific ulcer colitis, can provoke development of adynamic Ilheus. At the stenosing deformation of the gatekeeper atropine promotes deterioration in evacuation from a stomach. Besides, atropinopodobny S. page are badly transferred by patients with akhilichesky and subacid gastritis since the delay of a physical activity caused by such drugs went. - kish. a path leads to strengthening of processes of fermentation in it.
Bibliography: Clinical pharmacology, yaod edition of V. V. Zakusov, M., 1978; M and sh-to about in with to and y M. D. Pharmaceuticals, p.1, page 377, M., 1977; The pharmacological basis of therapeutics, ed. by A. G. Gilman a. o., N. Y., 1980.
A. Ya. Ivleva.