VASOCONSTRICTORS

From Big Medical Encyclopedia

VASOCONSTRICTORS — the pharmaceuticals raising a vascular tone and the general arterial pressure.

There is no standard classification of S. of page. As S. villages use the means influencing nervous control of a vascular tone or exerting the direct stimulating impact on smooth muscles of vessels. In this regard by the principle of action of S. of page it is possible to divide on neurotropic and myotropic.

Among neurotropic S. pages distinguish drugs of the central and peripheral action. Neurotropic S. pages of the central action raise a vascular tone, exerting the direct stimulating impact on vasomotor centers. Hl concern to this group C. of page. obr. analeptical means (see) — Corazolum (see), camphor (see), Cordiaminum (see), etc. They are applied generally at acute arterial hypotension, a faint, shock and a collapse.

Besides, nek-ry have neurotropic S.' properties of page of the central action psychogogic means (see), napr, caffeine (see), Phenaminum (see), and also all-tonics, napr, Pantocrinum (see), drugs of a ginseng, an eleuterokokk, levzea, etc., to-rye use hl. obr. at hron. the hypotension developing against the background of an adynamy and neurosises.

Neurotropic S. of page of peripheral action are N - cholinomimetic (see. Cholinomimetic substances ) and adrenomimetichesky means (see). n-Holinomimetiki lobeline (see) and Cytitonum (see) reflex (through carotid balls) stimulate vasomotor centers and at the expense of it cause vasoconstriction and increase in the ABP. It is promoted by also exciting influence of N cholinomimetics on vegetative a ganglion and N-holinoretseptory of chromaffin tissue of adrenal glands therefore from adrenal glands in a blood channel adrenaline is emitted.

Sympathomimetic ephedrine (see), and also alpha and beta-adrenergic agonist adrenaline (see) S. of page with kardiotropny properties are. Along with vasoconstrictive effect they have the expressed other and chronotropic effect on heart. alpha Adrenomimetiki — noradrenaline (see), phenylephine hydrochloride (see) etc. — are characterized by rather weak kardiotropny action. Villages of the village from among adrenomimetik apply at a collapse and shock. However at shock (in particular cardiogenic) it is necessary to approach use of these drugs with care since they owing to a spasm of pulmonary vessels reduce saturation of an arterial blood oxygen and at the same time increase requirement in it of a myocardium and other fabrics. Besides, adrenomimetik can cause arrhythmias of heart.

In modern medical practice at shock of different genesis apply dopamine, to-ry for this purpose enter intravenously. Efficiency of dopamine at shock is connected by hl. obr. with the fact that it stimulates R-adrenoceptors of heart in small and medium therapeutic doses and thereof increases force and heart rate. Dopamine excites in high doses also alpha adrenoceptors of a vascular wall and has in this regard vasoconstrictive effect. However renal and mezenterialny vessels under the influence of dopamine extend that, apparently, is connected with its influence on dofaminergichesky receptors of these vessels. Their expansion promotes strengthening of blood circulation in abdominal organs, a cut at shock is sharply broken.

Pages carry vasoactive polypeptides to myotropic S. vasopressin (see), Angiotensinamidum (see) and glucagon (see). In medical practice use generally Angiotensinamidum and a glucagon. Vasopressin, despite high vasoconstrictive activity, in a wedge, practice is not applied since it causes sharp narrowing of coronary vessels. Angiotensinamidum surpasses noradrenaline in pressor activity. It raises a tone of arteries to a large extent, than a tone of veins. Along with direct myotropic vasoconstrictive action this drug renders mediated (through c. N of page) the stimulating influence on a tone of vessels, strengthens secretion of Aldosteronum adrenal glands. At the same time does not exert noticeable impact on action of the heart and a coronary blood stream and does not cause arrhythmias of heart. Works quickly and shortly (within several minutes) that allows to regulate easily expressiveness of its effect at drop intravenous administration. It is applied at a collapse and shock of various genesis.

The glucagon raises the ABP generally thanks to kardiotropny (positive inotropic and chronotropic) to action that is caused by activation of adenylatecyclase. It is applied at cardiogenic and septic shock intravenously kapelno. At cardiogenic shock drug is less effective, than and-adrenomimetiki. At long introduction promotes development of a hypopotassemia. After drug withdrawal emergence of a hyperglycemia is possible. It is contraindicated at a pheochromocytoma since promotes allocation from it of catecholamines and development thereof hypertensive crisis.

Except S. pages, at therapy of hypotensive states appoint drugs of glucocorticoids, the miner-lokortikoidov, and also a shelter - and plasma substitutes.

As S. villages for topical administration use hl. obr. adrenomimetik. So, for vasoconstriction of mucous membranes (e.g., at inflammatory and allergic rhinitises) appoint ephedrine, adrenaline, Naphthyzinum and Halazolinum. As S. villages add to solutions of local anesthetics usually adrenaline.

S.'s use by the village is contraindicated at a hypertension and symptomatic hypertensia, the expressed atherosclerosis, a thyrotoxicosis, pregnancy.



Bibliography: Pharmaceuticals in clinical cardiology, under the editorship of A. I. Gri-tsyuk, page 79, Kiev, 1976; Mashkov-with to and y M. D. Pharmaceuticals, p.1, page 107, etc., M., 1977; V. I Blizzard. Reference book of the cardiologist on clinical pharmacology, page 228, M., 1980; Mukhin E. A., Gikavy V. I. and B. I. Pariahs. Hypertensive means, Chisinau, 1983; The Guide to cardiology, under the editorship of E. I. Chazov, t. 4, page 101, M., 1982; Klinische Pharmakologie und Pharmakotherapie, hrsg. v. H. P. Kuemmerle u. a., S. 705, Miinchen u. a., 1976; The pharmacological basis of therapeutics, ed. by A. G. Gilman a. o., N. Y., 1980.


G. V. Kovalyov.

Яндекс.Метрика