Weak drugs  - a class of drugs (pharmacological group) used to treat constipation , ATC code . Mechanisms of action - increased peristalsis of the large intestine and inhibition of the reabsorption of water in the large intestine.
Apply laxatives to stimulate intestinal motility for various reasons. Most often they are prescribed for constipation . In the case of short-term constipation, saline laxatives , castor oil , phenolphthalein are used , and in case of chronic constipations, plant laxatives containing antraglycosides ( rhubarb , senna, buckthorn preparations), phenolphthalein , isaphenine , vaseline oil , sea kale , laxative candles are used. To remove poisons and toxins from the gastrointestinal tract in acute poisoning, saline laxatives are used mainly. In addition, saline laxatives are prescribed after taking some antihelmintic drugs to accelerate their elimination and prevent toxic effects. For intestinal cleansing before X-ray examination, rectoscopic or colonoscopy, use castor oil, preparations of senna, rhubarb, etc.
Herbal remedies containing antraglycosides ( senna extract, rhubarb ) were widely distributed before; saline laxatives and first synthetic ( phenolphthalein ). Currently, all these drugs are rarely available, due to the fact that new drugs have been developed, with the best efficacy / safety ratio.
Among modern laxatives can be distinguished group of laxatives stimulating action, such as lactusan , portal , weaklaks , etc.
According to their strength, laxatives are sometimes conditionally divided into laxatives (aperitiva), medications of moderate potency (laxantia) and drastic (drastica). Laxatives cause a soft decorated chair, which is close to normal in consistency. Seaweed, agar-agar , purified sulfur , as well as plant-derived laxatives (preparations of senna, buckthorn, rhubarb, etc.), castor oil and petroleum jelly, magnesium sulfate and sodium sulfate in small doses have the properties of laxatives. In addition, some fruits (apples, grapes, prunes, etc.) give a laxative effect.
Medium-strength laxatives cause a mushy or liquid stool. These include phenolphthalein and isaphenine . Saline laxatives (magnesium sulphate, sodium sulphate) in moderate therapeutic doses and laxative laxatives in high doses have a similar effect.
Pervasive laxatives cause abundant liquid stools and violent bowel movements, often accompanied by abdominal pain and tenesmus. Drastic effect has saline laxatives and castor oil in high therapeutic doses, as well as podofillin (a drug of cytotoxic action, external use, gastrointestinal disorders are possible as a side effect).
According to the mechanism of action, among the laxatives, there are drugs that cause an increase in the volume and liquefy the intestinal contents, which leads to mechanical irritation of the intestinal receptors - saline laxatives, drugs that cause chemical irritation of the intestinal mucous receptors - plant laxatives containing antraglycosides (preparations of buckthorn, rhubarb, sennas, etc.), castor oil, phenolphthalein, isafenin, and others; drugs that soften fecal masses and, consequently, mechanically facilitate their promotion - petroleum jelly, vegetable oils.
Modern anatomical and therapeutic classification identifies 6 groups of drugs with a laxative effect:
- Contact Laxatives
- Laxatives that increase intestinal contents
- Osmotic laxatives
- Laxatives in enemas
- Other laxatives
Most laxatives are applied overnight so that the increase in peristalsis occurs in the morning.
With the systematic use of laxatives to them can develop addiction. In this case, various drugs should be alternated. In case of laxative overdose, diarrhea , vomiting , and colicky abdominal pain are possible; with prolonged appointment - violations of water-salt metabolism, atony of the colon . In addition to these manifestations of side effects, characteristic of a group of laxatives in general, certain drugs may cause other side effects . So, when using rhubarb preparations, it is possible to stain urine , sweat and milk (in nursing mothers) in yellow (in case of acidic reaction of the environment) or in reddish (in case of alkaline reaction of environment) color, abnormal liver functions . Phenolphthalein in alkaline urine stains it red, may cause allergic reactions , palpitations . With prolonged use of phenolphthalein in children, osteomalacia is possible. Frequent use of saline laxatives, castor oil or petroleum jelly sometimes leads to digestive disorders.
The use of laxatives is contraindicated in acute inflammatory diseases of the gastrointestinal tract, the presence of mechanical obstacles to the promotion of intestinal contents, uterine bleeding, acute febrile conditions. Precautions should be prescribed laxatives during pregnancy, during menstruation, in old age. Saline laxatives, especially magnesium sulfate, cannot be used in case of renal failure.
- radar, 2000–2019 .
- Pharmacological group - laxatives // Encyclopedia of drugs and pharmacy assortment. - Radar Patent, 2000–2019. - Date of appeal: 03/28/2019.