PURGATIVES (cathartica) — the pharmaceuticals causing acceleration of advance of contents of intestines at intake and promoting approach of defecation. The mechanical or chemical irritation of receptors of a mucous membrane of intestines is the cornerstone of S.'s action by the village. Villages of the village can also exert reflex impact on a uterus, cardiovascular and nek-ry other systems.
On the main orientation of action among S. the page is distinguished: 1) the drugs strengthening motor function of preferential small bowel; 2) the drugs stimulating motor function of intestines on all its extent and increasing the volume of its contents; 3) the drugs strengthening motor function of preferential large intestine.
The page increasing motility of preferential small bowel carry to S. castor oil (see) and the pitches which are contained in roots of nek-ry medicinal plants, napr, jalaps, a may-apple. Include so-called salt laxatives in group C. of the page increasing motility throughout intestines — sodium sulfate (see), magnesium sulfate (see. Magnesium, drugs ), laxative mineral waters, napr, morshinsky, batalinsky, slavyanovsky, etc., and also Karlovy Vary salt (see) and morshinsky epsom salt natural, received from mineral water of a source of the resort of Morshin, the hl contains edges. obr. sodium sulfate and small amounts of magnesium sulfates and calcium. Motility of preferential large intestine S. stimulate the pages of a plant origin containing antra-glycosides, napr, drugs of a root rhubarb (see), fruits of a buckthorn (see. Medicinal plants ), bark buckthorns (see), leaves Sennas (see), aloe (see), and also it is gray cleared (see. Seurat, drugs ) and nek-ry synthetic substances — phenolphthalein (see), Isapheninum (see). Besides, hl. obr. affect a large intestine liquid paraffin (see) and vegetable oils, napr, sweet-almond oil (see), etc., causing a softening of fecal masses; The Villages of the village which are bulking up in a gleam of intestines and by that increasing volume of its contents (a laminaria, an agar-agar). Carry the laxative candles containing hydrosodium carbonate to the same group, at decomposition to-rogo in a rectum carbon dioxide gas is emitted. Accumulation of the last in an ampoule of a rectum leads to mechanical stretching of its walls and reflex causes defecation.
The villages of the village operating preferential on a small bowel and throughout intestines cause laxative effect in 4 — 6 hours, and the drugs operating preferential on a large intestine — in 6 — 12 hour.
On force of action of S. of page conditionally divide into aperient (aperitiva), laxative the average force of action (laxantia) and drastichesky (drastica). At reception of aperient means the chair happens issued, on a consistence close to normal. The agar-agar, a laminaria belong to aperient S. of page, it is gray cleared, the vegetable laxatives containing antragliko-zida (drugs of Senna, a rhubarb, a buckthorn, etc.), a liquid paraffin, and also castor oil and magnesium sulfate in small doses.
At reception of laxatives of average force of action a chair kashitseobrazny or liquid. Carry salt laxatives, Isapheninum to this group C. of page. The aperient means applied in higher doses can cause similar effect.
Drastichesky (pronosny) S. pages cause a rough peristaltics, a liquid chair, sometimes — abdominal pains and tenesmus. Salt laxatives, castor oil, Podophyllinum have such properties in high doses.
Under the influence of S. of page motor function of intestines therefore advance of food masses on intestines accelerates amplifies, concentration and a consistence of its contents changes, processes of absorption are broken.
On the mechanism of action of S. of page divide into the drugs causing chemical irritation of receptors of a mucous membrane of intestines (e.g., the vegetable laxatives containing antraglikozida, castor oil, phenolphthalein, Isapheninum, etc.), the drugs causing mechanical irritation of receptors of intestines due to increase in volume and fluidifying of its contents (salt laxatives, the bulking-up substances), the drugs softening fecal masses and thereof mechanically facilitating their advance (a liquid paraffin, vegetable oils).
Villages of the village belong to substances of various chemical groups. Pages from among inorganic compounds belong to S. sodium sulfate and magnesium sulfate, easily water soluble, but difficult diffusing through a mucous membrane of intestines. In went. - kish. a path these salts dissociate with formation of ions, to-rye are very slowly soaked up in blood and create the increased osmotic pressure in a gleam of intestines that interferes with absorption of a liquid part of a chyme and water. Besides, salt laxatives stimulate intestinal secretion. Increase in volume of intestinal contents leads to excitement of mechanioreceptors and reflex strengthening of a vermicular movement of intestines. Laxative effect of sulfates is promoted by also increased education in intestines of the hydrogen sulfide which is fiziol. stimulator of a vermicular movement. Salts of magnesium, besides, form in intestines insoluble magnesian soaps and, perhaps, stimulate release of cholecystokinin.
Antraglikozida belong to the organic compounds possessing laxative action, to-rye are partially soaked up in a small bowel, are exposed in an organism to hydrolytic decomposition with the subsequent allocation in a large intestine of active agents — oemodin and chrysophanic acid. Partial release of the last happens also directly in intestines under the influence of enzymes of a bacterial flora. The greatest number of these substances collects in a large intestine where their main action is shown. Exciting interoretseptor of a large intestine, oemodin and chrysophanic acid strengthen its peristaltics. On the mechanism and the nature of effect synthetic S. are close to page to antraglikozida — phenolphthalein and Isapheninum. Besides, these drugs slow down absorption of electrolytes and water.
Aperient effect of vegetable oils (castor, almond, olive, etc.) depends on their consistence and education in a small bowel fat to - t under the influence of a lipase, to-rye, being saponified, cause irritation of receptors of intestines and reflex strengthening of a vermicular movement. The liquid paraffin interferes with absorption of water and softens contents of a large intestine. The substances which are bulking up in water, stretching a wall of intestines, mechanioreceptors irritate and reflex accelerate advance of intestinal contents.
Villages of the village apply to stimulation of motility of intestines according to different indications. Most often they are appointed at locks. At the same time in case of short-term locks use salt S. of page, castor oil, phenolphthalein, and at hron. locks — vegetable S. the pages containing antraglikozida (drugs of Senna, a rhubarb, a buckthorn, etc.), Isapheninum, laxative candles, a liquid paraffin, the bulking-up S. of page (a laminaria, an agar-agar, etc.). For removal of poisons and toxins from went. - kish. a path at acute poisonings use hl. obr. salt laxatives and in nek-ry cases — castor oil. Besides, salt laxatives are appointed after use of nek-ry helminthicides for acceleration of their removal and prevention of toxic effect. For purgation before rentgenol. a research, rekto-or a kolonosko-piya use castor oil, drugs of Senna, a rhubarb, etc.
At systematic use of S. of page to them accustoming can develop. In this case it is necessary to alternate various drugs. At S.'s overdose by the village the diarrhea, vomiting, kolikoobrazny abdominal pains are possible.
S.'s use by the village is contraindicated at acute inflammatory diseases went. - kish. a path and a peritoneum, existence of mechanical obstacles for advance of contents of intestines, uterine bleedings. With care it is necessary to appoint S. page at pregnancy, during periods and at senile age. It is impossible to appoint magnesium sulfate at a renal failure.
Bibliography: Clinical pharmacology, under the editorship of V. V. Zakusov, page 334, M., 1978; Mashkovsky M. D. Pharmaceuticals, p.1, page 332, M., 1977; I Am glad - and l to O. S. Pharmacological bases of treatment of diseases of digestive organs, page 107, M., 1976; The pharmacological basis of therapeutics, ed. by A. G. Gilman a. o., N. Y., 1980.