Muscle relaxants are curare-like drugs. Curare-like drugs (peripheral muscle relaxants)
Curariform agents.
Muscle relaxants - used to relieve muscle tone. For the first time in surgical and anesthetic practice, muscle relaxants were used by Griffith (American) in 1942, which was of great importance in the development of surgery: since the use of muscle relaxants can significantly reduce the dose of a narcotic substance (it is not necessary to introduce the patient into the third stage of anesthesia in order to achieve muscle relaxation, you can operate at stages 1-2, since muscle relaxants will relax the muscles of the abdominal wall). According to the mechanism of action, muscle relaxants are divided into:
1. drugs of a depolarizing type of action (ditilin). The drug excites n-cholinergic receptors and causes depolarization of the postsynaptic membrane, short-term muscle spasm occurs. After a short period of time, a myoparalytic effect occurs. Drugs are used to reduce dislocations. In case of an overdose of dithylin, in no case should anticholinesterase agents (for example, prozerin) be administered, since dithylin causes depolarization and the accumulated acetylcholine causes depolarization and blocking effects occur that are added up. In case of an overdose of dithylin, fresh citrated blood containing cholinesterase is injected, which breaks down dithylin. The duration of the drug is not more than 15 minutes (which is very convenient to use in anesthesiology practice for intubation).
2. Anti-depolarizing drugs - they block n-cholinergic receptors, preventing the action of acetylcholine (d-tubocurarine, anatruxonium, etc.) these are curare-like drugs (curare is an Indian poison that was impregnated with arrows). The duration of their action is up to 4 hours. They are used in anesthesiology practice in conjunction with anesthesia. After the operation, prozerin is administered, which in this case is their antagonist.
CENTRAL N-CHOLINOLITICS
(pedifen, argenal) have a tranquilizing effect, have good effect with pruritic dermatoses).
ATRACURIUM (Atracurium).
Synonyms: Trakrium, Trakrium.
It is a non-depolarizing muscle relaxant. By the nature of the action is close to other drugs in this group. It has a fast, easily reversible muscle-relaxing effect. It has a low capacity for cumulation.
After intravenous administration at a dose of 0.5 - 0.6 mg / kg for 90 seconds, an opportunity for intubation is created. The drug can also be administered as an infusion.
The effect of the drug is removed by the introduction of prozerin (with atropine) or other anticholinesterase drugs.
Usually, the administration of the drug is well tolerated, changes in of cardio-vascular system not visible. Due to the possibility of histamine release, slight skin hyperemia, in rare cases, bronchospasm, and anaphylactic reactions may occur.
Contraindications and general precautions are the same as for other non-depolarizing muscle relaxants.
ARDUAN (Arduanum). 2b, 16b-bis(4-Dimethyl-1-piperazino)- 3a, 17b-diacetoxy-5-a-androstane dibromide.
Synonyms: Pipecuronium bromide, Pipecuronium bromide, Pipecuronii bromide, RGH 1106.
Arduan is a non-depolarizing muscle relaxant. In terms of chemical structure and action, it is close to pancuronium (synonyms: Pavulon, Pancuronium, Pancuronii bromidum, Pavulon), which received in last years widespread use as a curare-like drug. Both drugs are steroid compounds, but do not have hormonal activity. The curare-like effect is associated with the presence of two quaternary ammonium (onium) groups in these compounds with an optical distance between them approximately equal to the distance between the onium groups in d-tubocurarine.
Under experimental conditions, arduan has a muscle-relaxing effect at doses 2-3 times lower than the doses of pancuronium, and acts 2 times longer than pancuronium.
Arduan in normal doses does not cause significant changes in the activity of the cardiovascular system. Only in large doses has a weak ganglionic blocking effect; does not cause the release of histamine.
The muscle relaxant effect of arduan is removed by prozerin.
Apply arduan to relax muscles with surgical interventions different type, including during operations on the heart, as well as in obstetric and gynecological operations.
Enter arduan intravenously.
Arduan can be used for various types of anesthesia (halothane, ether, nitrous oxide, etc.) necessarily during endotracheal intubation of the patient.
Thiobarbiturates (thiopental-sodium) lengthen the muscle relaxation time.
Solution for injections is prepared on the attached solvent immediately before use.
If necessary, stop the action of arduan administered 1 - 3 mg of prozerin after a preliminary intravenous injection of 0.25 - 0.5 mg of atropine.
The drug is contraindicated in myasthenia gravis and in early dates pregnancy. Caution is necessary in violation of the excretory function of the kidneys, since the drug is partially excreted by the kidneys.
DITILIN (Dithylinum). b-Dimethylaminoethyl ester of succinic acid diiodomethylate.
Synonyms: Suxamethonii iodidum, Suhamethonium iodide.
Similar dichlorides and dibromides are available under the names: Listenone [Name of the drug (suxamethonium chloride) from Hafslund Nycomed Pharma AG], Myorelaxin, Anectine, Brevidil M., Celocaine, Celocurin, Chlorsuccilin, Сuraсholin, Сuracit, Сuralest, Diacetylcholine, Lertosuccin (Yu )), Lysthenon, Myo-Relaxin, Pantolax, Quelicin chloride, Scoline, Succinylcholini chloridum, Sucostrin, Sukhamethonii chloridum, Suxinyl, Syncuror, etc.
According to the chemical structure, the dithylin molecule can be considered as a double molecule of acetylcholine [diacetylcholine]. It is the main representative of depolarizing muscle relaxants. At intravenous administration disrupts the conduction of neuromuscular excitation and causes relaxation of skeletal muscles.
Dithylin is destroyed by pseudocholinesterase and breaks down into choline and succinic acid. The drug has a quick and short-term effect; does not have a cumulative effect. For prolonged muscle relaxation, repeated administration of the drug is necessary. The rapid onset of the effect and the subsequent rapid recovery of muscle tone allow you to create controlled and controlled muscle relaxation.
The main indications for the use of dithylin (listenone) are tracheal intubation, endoscopic procedures (broncho- and esophagoscopy, cystoscopy, etc.), short-term operations (suturing on abdominal wall, reduction of dislocations, etc.). With an appropriate dose and repeated administration, dithylin (listenone) can also be used for longer operations, however, for prolonged muscle relaxation, antidepolarizing muscle relaxants are usually used, which are administered after preliminary tracheal intubation against the background of dithylin. The drug can also be used to eliminate convulsions in tetanus.
Enter ditilin intravenously. Repeated doses of Dithylinum last longer.
Complications with the use of ditilin are usually not observed. However, it should be borne in mind that in some cases there may be increased sensitivity to ditilin with prolonged respiratory depression, which may be associated with a genetically determined violation of the formation of cholinesterase. The reason for the prolonged action of the drug may also be hypokalemia.
Ditilin can be used for various types anesthesia (ether, nitrous oxide, halothane, barbiturates). In all cases, the introduction of ditilin in large doses is allowed only after the transfer of the patient to artificial (controlled) respiration. When using small doses, spontaneous breathing may be maintained. However, in these cases, it is necessary to have all the devices for artificial lung ventilation at the ready.
Prozerin and other anticholinesterase substances are not antagonists in relation to the depolarizing action of dithylin, on the contrary, by inhibiting the activity of cholinesterase, they lengthen and enhance its action.
In case of complications due to the use of dithylin (prolonged respiratory depression), artificial respiration is used, and if necessary, blood is transfused, thus introducing the cholinesterase contained in it.
It should be borne in mind that in high doses, dithylin can cause a "double block" when, after a depolarizing action, an antidepolarizing effect develops. Therefore, if after the last injection of ditilin, muscle relaxation does not go away for a long time (within 25-30 minutes) and breathing is not completely restored, they resort to intravenous administration of prozerin or galanthamine (see) after the preliminary administration of atropine (0.5-0.7 ml 0.1% solution).
One of possible complications when using ditilin, there are muscle pains that occur 10 to 12 hours after the administration of the drug. Introduction 1 min before ditilin 3-4 mg of d-tubocurarine or 10-15 mg of diplacin almost completely prevents fibrillar twitching and subsequent muscle pain.
Ditilin is contraindicated in children infancy and with glaucoma (a sharp increase in intraocular pressure is possible).
Ditilin should be used with caution when serious illnesses liver, anemia, cachexia, during pregnancy (the drug passes through the placental barrier).
Pharmacological properties of ditilin allow its use in patients with myasthenia gravis.
It is impossible to mix dithylin solutions with solutions of barbiturates (a precipitate forms) and with blood (hydrolysis occurs).
1) means of non-depolarizing action;
2) means of depolarizing action.
Curare, a specially processed juice of a South American plant, has long been used by the Indians as an arrow poison that immobilizes animals. In the middle of the last century, it was established that the relaxation of skeletal muscles caused by curare is realized by stopping the transmission of excitation from the motor nerves to the skeletal muscles.
Main active substance curare - alkaloid d-tubocurarine. Many other curare-like drugs are now known.
Indications for the use of all muscle relaxants:
Curare-like drugs are used in surgical operations to relax skeletal muscles.
For ventilation during surgery
Reduction of dislocations, reposition of bone fragments
convulsions
NON-DEPOLARIZING MIORELAXANTS.
Tubocurarine chloride, pipecuronium bromide, pancuronium bromide. These drugs, when administered intravenously, cause a rapid relaxation of the skeletal muscles, lasting 30-60 minutes. First, the muscles of the head and neck relax, then the muscles of the limbs, vocal cords, torso and, last but not least (at high doses), respiratory (intercostal and diaphragm muscles), which leads to respiratory arrest. to the central nervous system they do not work because they do not cross the blood-brain barrier well.
Mechanism of action
Antidepolarizing muscle relaxants, binding to the H-cholinergic receptor, cover (shield) it from the effects of synaptic acetylcholine. As a result, the nerve impulse will not cause depolarization of the muscle fiber membrane (therefore, the drugs are called non-depolarizing).
These compounds compete (competitive muscle relaxants) with acetylcholine for the N-cholinergic receptors of the postsynaptic membrane: with an increase in the amount of acetylcholine in the synapse (for example, with the introduction of anticholinesterase agents), the mediator displaces the muscle relaxant from its connection with the membrane and itself forms a complex with the receptor, causing depolarization.
Antagonists antidepolarizing (competitive) muscle relaxants are anticholinesterase agents (prozerin, etc.), which, by inhibiting synaptic cholinesterase (an enzyme that destroys acetylcholine), contribute to the accumulation of acetylcholine. They are used for overdose of non-depolarizing muscle relaxants.
Indications for use
With major surgical interventions for prolonged relaxation of the muscles.
In addition, they are used to relieve seizures in patients with severe tetanus.
Non-depolarizing drugs can cause side effect- lowering blood pressure by blocking the H-cholinergic receptors of the ganglia.
DEPOLARIZING MUSCLE RELAXANT
suxamethonium chloride, iodide (dithylin) is widely used in medical practice.
Mechanism of action
Due to the great structural similarity with acetylcholine, it not only binds the H-cholinergic receptor of skeletal muscles (similar to tubocurarine), but also excites it, causing depolarization of the postsynaptic membrane (like acetylcholine). Unlike acetylcholine, which is instantly destroyed by cholinesterase, dithylin gives a stable depolarization: after a short (several seconds) contraction, the muscle fiber relaxes, and its H-cholinergic receptors lose their sensitivity to the mediator. The action of dithylin ends after 5-10 minutes, during which it is washed out of the synapse and hydrolyzed by pseudocholinesterase.
Naturally, anticholinesterase agents, contributing to the accumulation of acetylcholine, lengthen and enhance the action of depolarizing muscle relaxants.
Applies dithylin for short-term muscle relaxation during tracheal intubation, reduction of dislocations, reposition of bones in fractures, bronchoscopy, etc.
Side effects:
1) muscle postoperative pain. At the beginning of depolarization, muscle fibrillar contractions, twitches appear, they are the cause of postoperative muscle pain;
2) increased intraocular pressure;
3) violation of the rhythm of cardiac activity. In case of an overdose of dithylin, fresh (high pseudocholinesterase activity) blood is transfused and electrolyte disturbances are corrected. The use of muscle relaxants is permissible only if there are conditions for tracheal intubation and artificial lung ventilation.
Atropine Solutio Atropini sulfatis 1%for in/in, in/m or s/c injections, tablets, eye drops (1%)
Application: - spasms of the intestines and biliary and urinary tract, pylorospasm, bradyarrhythmias, for premedication, poisoning with phosphorus poisoning agents, for radiological researches of a gastrointestinal tract,
Fundus examination (rare), to create functional rest at inflammatory diseases and eye injuries, gastric ulcer and duodenum, bronchial asthma, bronchitis with hyperproduction of mucus.
Side effects: mydriasis, accommodation paralysis, tachycardia, intestinal atony and Bladder, headache, dizziness, loss of touch.
Federal Agency for Education
Test
4th year students (group M/2004 - 5)
correspondence department
Revvo Olga Nikolaevna
Teacher:
Evstigneeva Antonina Petrovna
Apatity 2007
Introduction
1. Ganglion blockers
1.1 Mechanism of action and main pharmacodynamic effects
1.2 Pharmacokinetics
1.3 Indications and dosage regimen
1.4 Contraindications and side effects
2. Curariform drugs
2.1 Mechanism of action and main pharmacodynamic effects
2.2 Indications for prescribing curare-like drugs
2.3 Pharmacokinetics and dosing regimen of drugs
2.4 Contraindications and side effects
Conclusion
List of used literature
Introduction
Ganglioblockers and curare-like drugs belong to one large group of drugs that affect efferent innervation, but they are completely different drugs in their effect on the human body.
Ganglion blocking substances have the ability to block n-cholinergic receptors of autonomic nerve ganglions and, therefore, inhibit the transmission of nerve excitation from preganglionic to postganglionic fibers autonomic nerves. Modern ganglioblockers inhibit or completely turn off the conduction of a nerve impulse in the sympathetic and parasympathetic nodes, the carotid glomerulus and the chromaffin tissue of the adrenal glands, which leads to temporary artificial denervation. internal organs and changing their function. However different drugs may have different activity in relation to different groups of ganglia. The first ganglionic blocker to receive practical use in medicine in the early 50s, there was hexamethonium (hexonium). Then a number of other ganglionic blockers were received; some of them, like hexamethonium, are quaternary ammonium compounds, and some are tertiary amines.
Curare-like drugs used in medicine to relax skeletal muscles, mainly during surgical operations. The action of these drugs is associated with their specific effect on cholinergic receptors in the region of motor nerve endings. Curare is a mixture of condensed extracts from South American plants of Strychnos species (S. toxifera and others) and Chondodendron (Ch. tomentosum, Ch. Platyphyllum and others); has long been used by the local population as a poison for arrows. Wounded by a poisoned arrow causes immobilization of the animal or death as a result of asphyxia due to the cessation of contractions of the respiratory muscles. In 1935, it was found that the main active ingredient of the "pipe" curare and Chondodendrontomentosum is the alkaloid d-tubocurarine. d-Tubocurarine has found medical use as a skeletal muscle relaxant (peripheral muscle relaxant).
The aim of the work is to study the pharmacological properties of the presented groups medicines, as well as the possibility of their application in practical medicine.
1. Ganglioblockers
1.1 Mechanism of action and main pharmacodynamic effects
Ganglion blockers competitively block n-cholinergic receptors and inhibit the transmission of a nerve impulse in the ganglia of sympathetic and parasympathetic nerves. Some drugs (benzogexonium, pentamine, pyrilene, dimecoline) block sympathetic and parasympathetic ganglia to almost the same extent, others act mainly on parasympathetic ganglia (quateron). In large doses, these substances can block n-cholinergic receptors of neuromuscular synapses and the central nervous system. Interrupting the conduction of nerve impulses through the autonomic nerve nodes, ganglionic blockers change the functions of organs supplied with autonomic innervation. In this case, a decrease in blood pressure occurs, which is associated mainly with a decrease in the flow of vasoconstrictor impulses to the blood vessels and the expansion of the peripheral vascular bed (primarily arterioles). Inhibition of impulse conduction along cholinergic nerve fibers leads to a violation of accommodation, expansion of the bronchi, a decrease in the motility of the organs of the gastrointestinal tract, inhibition of the secretion of the glands, an increase in heart rate, and a decrease in the tone of the bladder. Inhibition of the chromaffin tissue of the adrenal glands leads to a decrease in the release of adrenergic substances and a weakening of the reflex pressor reactions.
Some ganglionic blockers (pachycarpine, dimecolin) have a direct stimulating effect on the contractile activity of the uterus. Pachycarpine hydrochloride increases the tone and increases the contraction of the myometrium, without causing, unlike pituitrin, an increase in blood pressure, and therefore pachycarpine can be prescribed for weak labor activity in women in labor with concomitant hypertension.
1.2 Pharmacokinetics
According to the chemical structure, ganglionic blockers are divided into quaternary ammonium compounds(benzogexonium, pentamine, dimecolin, hygronium, camphonium, imekhin) and tertiary amines(pachycarpine, pyrilene, etc.). Their main difference is that tertiary amines are better absorbed from the gastrointestinal tract. Quaternary compounds are worse absorbed, poorly penetrate the blood-brain barrier, but they are more active when administered parenterally. According to the duration of action, ganglionic blockers are divided into fast ganglionic blockers, medium duration and long-term action. To drugs fast action include trimetofan camsylate, hygronium, imekhin (from 4 to 30 minutes). Average duration actions of pentamin, benzohexonium, quateron - from 2 to 6 - 8 hours. Long duration of action (10 - 12 hours or more) have: pahikarpin, camphonium, dimecolin.
At intravenous administration ganglioblockers, their action begins after 2-3 minutes, the maximum effect occurs after 5-10 minutes with the introduction of gigronium, trimetophane, imekhin and after 30-60 minutes with the introduction of pentamin, benzohexonium, dimecolin.
At intramuscular and subcutaneous administration drugs begin to act after 15-20 minutes, and the maximum effect occurs after 30-60 minutes (pentamine, benzohexonium, quateron, dimecolin, temekhin, pahikarpin, camphonium).
Some ganglionic blocking substances (benzohexonium, quateron, pyrylene, dimecolin, temekhin, pachycarpine, camphonium) are used to take inside. With this method of administration, their action begins 30-60 minutes after ingestion, and the maximum effect is achieved after 1-2 hours.
1.3 Indications and dosage regimen
Short acting drugs(trimethophane camsilate, hygronium, imechin) are used mainly in anesthesiology for controlled hypotension and prevention of autonomic reflexes associated with the operation (in particular, during neurosurgical operations). During operations on the brain, the risk of developing its edema is reduced. Correct Application ganglionic blocking agents usually reduce the risk of shock and facilitate postoperative period. In addition, the use of ganglionic blockers for general anesthesia reduces the required amount of drug. Sometimes they are used to stop severe hypertensive crises, as well as in obstetric practice for the treatment of nephropathy in pregnant women, eclampsia.
Intermediate and long acting drugs(benzogexonium, dimecolin, pyrilene, temekhin, camphonium) are used orally (rarely) for the treatment of hypertension, toxicosis of pregnant women. For the treatment of hypertensive crises, pulmonary edema against the background of a hypertensive crisis, eclampsia, pentamine, benzohexonium, dimecolin, temekhin, camphonium are administered parenterally.
Initially, ganglioblockers were widely used in diseases associated with impaired nervous regulation, when a decrease in the flow of nerve impulses to the organs can give the desired therapeutic effect. These include arterial hypertension, spasms of peripheral vessels (endarteritis, intermittent claudication, etc.), diencephalic syndrome, causalgia, peptic ulcer of the stomach and duodenum, bronchial asthma, hyperhidrosis, etc. peptic ulcer stomach and duodenum, chronic cholecystitis, chronic colitis, the appointment of benzohexonium, pyrilene, dimecolin, temekhin, quateron, camphonium is indicated. With spasms of peripheral vessels, pentamine, benzohexonium, dimecoline are used parenterally. In case of causalgia, ganglionitis, sympathalgia, long-acting ganglion blockers were prescribed - pyrilene, dimecolin, temekhin.
Over time, it became clear, however, that the use of ganglionic blockers is not always effective enough and is often accompanied by side effects: orthostatic hypotension, tachycardia, atony of the intestine and bladder, etc. In connection with the advent of new, more effective and selective drugs, the use of ganglioblockers in arterial hypertension and peptic ulcer of the stomach and duodenum has become more limited.
Preparations of medium duration and long-acting are prescribed both parenterally and orally.
Pentamine (Pentaminum) belongs to list B. Available in ampoules of 1 and 2 ml of a 5% solution. For achievement therapeutic effect can be administered in the form of a 5% solution 2-3 times a day, i.m., i.v., i.v. drip. In hypertensive crises, pulmonary edema, cerebral edema, 0.2-0.3 ml or more of a 5% solution diluted in 20 ml of isotonic sodium chloride solution or 5% glucose solution is injected into a vein. The introduction is carried out slowly, under the control of blood pressure and general condition. There is significant experience effective application pentamine also with spasms of peripheral vessels, spasms of the intestines and biliary tract, renal colic, bronchial asthma(stopping of acute attacks), with eclampsia, causalgia. In urological practice, pentamine is used for cystoscopy in men to facilitate the passage of a cystoscope through the urethra. With spasms of peripheral vessels and other diseases, start with the introduction of 1 ml of a 5% solution and then increase the dose to 1.5 - 2 ml 2 - 3 times a day. Higher doses for adults: single 0.15 g (3 ml of 5% pentamine solution), daily 0.45 g (9 ml of 5% pentamine solution)
Benzohexonium ( Benzohexonium ) refers to list B. The drug is used in the form of tablets of 0.1 g and 0.25 g, as well as a 2.5% solution in 1 ml ampoules. Benzohexonium can also be used for spasms of peripheral vessels, bronchospasms, for the relief of hypertensive crises and controlled hypotension. The drug is administered under the skin, intramuscularly and orally, for controlled hypotension, the drug is administered intravenously. Doses must be individualized, given the great variability in the response of different patients in relation to the drug. With repeated use of the drug, the reaction to it gradually decreases, which requires an increase in the dose. Therefore, it is recommended to start treatment with the lowest doses that give the desired effect, and then gradually increase the dose. For the treatment of spasms of peripheral vessels, the drug is used orally (before meals), 0.1 g 3-4 times a day. For the relief of hypertensive crises, 12.5 mg - 25 mg (0.5 - 1 ml of a 2.5% solution) is administered intramuscularly or subcutaneously. If necessary, benzohexonium can be administered repeatedly (3-4 injections per day). It should be noted that benzohexonium (as well as other ganglionic blockers) is rarely used for the treatment of hypertension. For controlled hypotension, benzohexonium is administered slowly intravenously (within 2 minutes) 1 - 1.5 ml of a 2.5% solution; the effect develops in 12 - 15 minutes; if necessary, enter additional amounts of the drug. Higher doses for adults inside: single 0.3 g, daily 0.9 g; under the skin: single 0.075 g, daily 0.3 g.
Pachycarpine hydrochloride ( Pachicarpini hydrochloridi ) is available in tablets of 0.1 g and in the form of a 3% solution in ampoules of 2 ml, administered subcutaneously and orally. Pachycarpine is used as a ganglion blocker mainly for spasms of peripheral vessels, as well as for ganglionitis. The drug improves muscle function in myopathy, can be used for obliterating endarteritis. One of important features pachycarpine is its ability to increase the tone and increase the contraction of the muscles of the uterus. In this regard, pahikarpin was relatively widely used to enhance labor activity with weakness of labor pains and with early discharge of water, as well as with weakness of attempts. In recent years, due to the emergence of more effective drugs Pachycarpine is relatively rarely used for these purposes. In the case of the use of pachycarpine to stimulate labor, it is prescribed intramuscularly or subcutaneously, 2–4 ml of a 3% solution (less often, inside, 0.1–0.15 g per dose); after 1-2 hours, the drug can be re-introduced. The stimulating effect begins to appear 5-30 minutes after the administration of pachycarpine. With subinvolution of the uterus in the postpartum period, give pahikarpin inside 0.1 g 2-3 times a day. Higher doses for adults inside: single 0.2 g, daily 0.6 g; under the skin: single 0.15 g (5 ml of 3% solution), daily 0.45 g (15 ml of 3% solution).
Short-acting ganglioblockers (trimethophane, hygronium, imekhin) are mainly used for controlled hypotension as an intravenous drip.
Hygronium ( Hygronium ) refers to list B. Available in vials or ampoules of 10 ml containing 0.1 g of hygronium. Dissolve the drug immediately before use. The drug has a short-term ganglioblocking effect, and therefore it is convenient for use in anesthetic practice for controlled hypotension. Applied intravenously in the form of a 0.1% solution in isotonic sodium chloride solution. Start with 70 - 100 drops per minute and after reaching the desired hypotensive effect, reduce the number of drops to 30 - 40 per minute. The action occurs in 2-3 minutes, and the initial blood pressure is restored 10-15 minutes after the infusion is stopped. With simultaneous or fractional administration (40–80 mg in 3–5 ml of isotonic sodium chloride solution), the hypotensive effect lasts 10–15 minutes. Gigronium, like other ganglionic blockers, can be used in obstetric practice for nephropathy in pregnant women, eclampsia. There is evidence of the successful use of the drug for the relief of hypertensive crises (40-80 mg in 15-20 ml of isotonic sodium chloride solution intravenously slowly over 7-10 minutes).
Imekhin ( Imechinum ) has a short-term effect and the hypotensive effect caused by it is easily controlled with appropriate dosing. The drug also belongs to list B, is available as a 1% solution in ampoules of 1 and 2 ml. In connection with the above properties, imekhin is much more convenient for controlled hypotension in anesthetic practice than long-acting ganglioblockers, such as benzohexonium and pentamine. In addition, the drug can be used to stop hypertensive crises and edema of the lungs and brain. Imekhin is administered intravenously. For controlled hypotension, a drip of a 0.01% solution (1: 10,000) is used; for this, dilute 1 ml of a 1% solution in 100 ml of isotonic sodium chloride solution or 5% glucose solution; administered at a rate of 90 - 120 drops per minute. Upon reaching the desired effect, the number of drops is reduced to 30 - 50 per minute. In case of insufficient hypotensive effect, the concentration of imekhin solution is increased to 1: 5,000. The drug can be administered as a single dose or fractionally at a dose of 5 - 7 - 10 mg (0.5 - 0.7 - 1 ml of 1% solution) in 5 - 7 - 10 ml isotonic sodium chloride solution or 5% glucose solution. Enter slowly immediately or fractionally, 2-3 ml and 3-4 minute intervals. The duration of the hypotensive action is 4-20 minutes. You can also start with a single injection of 5-10 ml of a 0.1% solution, then switch to drip administration. After the cessation of the introduction of the imekhin solution, blood pressure is usually restored after 4-15 minutes. It must be remembered that with halothane anesthesia and the use of tubocurarine, the hypotensive effect of imechin may be stronger.
1.4 Contraindications and side effects
An absolute contraindication for the use of ganglionic blockers is pheochromocytoma, since the blockade of the autonomic ganglia increases the sensitivity of peripheral adrenergic receptors, and therefore the pressor effect of circulating catecholamines can increase dramatically.
Due to the slowing of blood flow, care should be taken with a tendency to thrombosis. For the same reason, it is undesirable to prescribe ganglioblockers to patients over 60 years of age.
When ganglioblocking substances are used, the pupils dilate, which can lead to partial closure of the filtering zone of the anterior chamber angle of the eye and deterioration of the outflow of fluid from the eye chambers. At angle-closure glaucoma therefore, there may be an increase in intraocular pressure, and therefore patients suffering from this form of glaucoma, ganglion blockers are contraindicated. With open-angle glaucoma, a decrease in intraocular pressure can be observed, which is due to a decrease in the production of aqueous humor under the influence of ganglioblockers.
Due to the ability of ganglioblockers (especially pachycarpine hydrochloride and pyrilene) to have a stimulating effect on the myometrium, they should be used with caution in pregnant women.
In addition, ganglion blockers are contraindicated in advanced shock, severe cerebral or coronary atherosclerosis, recent myocardial infarction, ischemic stroke (less than two months ago), severe renal or hepatic insufficiency, subarachnoid hemorrhage.
When using ganglioblockers, it must be taken into account that due to the inhibition of reflex mechanisms that maintain a constant level of blood pressure, orthostatic collapse may develop. To avoid this complication, it is recommended that before administration (especially with parenteral administration) and for 2–2.5 hours after the injection of the ganglioblocker, patients should be in the supine position. At the beginning of treatment, it is recommended to check the patient's response to small doses of the drug: inject half of the average dose and monitor the patient's condition. It must be taken into account that with an increased blood pressure hypotensive effect is more pronounced.
When using ganglion blockers, the following are also possible: general weakness, dizziness, increased heart rate, dry mouth, dilated pupils, injection of scleral vessels. These events go away on their own. With the introduction of large doses or prolonged use are possible: bladder atony with anuria and intestinal atony (up to paralytic ileus). This is due to the fact that ganglion blockers simultaneously block not only sympathetic, but also parasympathetic ganglia.
When prescribing ganglioblockers, it must be taken into account that they can interact with other drugs. pharmacological groups affecting each other's performance. When administered concurrently MAO inhibitors and ganglioblockers, the hypotensive effect on the body is potentiated, as a result of which there is a risk of collapse. With the introduction of ganglioblockers against the background of taking by the patient antihistamines, drugs, sleeping pills, neuroleptics, local anesthetics there is a synergism (mutual strengthening) of the action of these drugs. The same thing happens when assigning antihypertensive drugs of other groups in combination with ganglion blockers. In this case, careful monitoring of patients and dosage adjustment is necessary.
Anticholinesterase drugs and m-cholinomimetics have an antagonistic effect on ganglioblockers. This effect can be used in case of an overdose of ganglionic blockers. In particular, in atony of the bladder with anuria and intestinal atony caused by the administration of large doses or prolonged use of these drugs, the use of prozerin, galantamine or other antagonist drugs is appropriate.
Having studied the group of ganglioblocking drugs, we can conclude that despite the mass of indications, the range of their application is rather limited. This is primarily due to the presence of a large number side effects and contraindications. As already noted, the treatment of many diseases with drugs of this group often does not justify itself for this reason and can be replaced by a safer and effective therapy other groups of drugs. However, in anesthetic practice and in the provision of emergency care ganglioblockers are of great practical importance.
2. Curare-like drugs
2.1 Mechanism of action and main pharmacodynamic effects
As early as the middle of the last century, it was established that the immobilization caused by curare depends on the cessation of the transmission of excitation from the motor nerves to the muscles (Claude Bernard, E. V. Pelikan). Currently, this action of curare is considered as the result of blocking n-cholinergic receptors in skeletal muscles. This deprives them of the opportunity to interact with acetylcholine, which is a mediator of nervous excitation, which is formed at the endings of motor nerves. Synthetic compounds, alkaloids and their derivatives are also used as muscle relaxants.
Different muscle relaxants have a different mechanism of action, and due to the peculiarities of their influence on the process of synaptic transmission, they are divided into two main groups.
A. Non-depolarizing (antidepolarizing) muscle relaxants (pachycurare).
These include d Tubocurarine, diplacin, qualidil, anatruxonium and other drugs that are antagonists of acetylcholine. They paralyze neuromuscular transmission due to the fact that they reduce the sensitivity of n-cholinergic receptors of the synaptic region to acetylcholine and thereby exclude the possibility of depolarization of the end plate and excitation of the muscle fiber. The compounds of this group are true curariform substances.
Pharmacological antagonists of these compounds are anticholinesterase substances: inhibiting the activity of cholinesterase in appropriate doses, they lead to the accumulation of acetylcholine in the synapse area, which, with increasing concentration, weakens the interaction of curare-like substances with n-cholinergic receptors and restores neuromuscular conduction.
B. Depolarizing drugs (leptocurare) cause muscle relaxation, providing a cholinomimetic effect, accompanied by persistent depolarization, that is, acting in the same way as excess amounts of acetylcholine act, which also disrupts the conduction of excitation from the nerve to the muscle. The drugs of this group are relatively quickly hydrolyzed by cholinesterase and have a short-term effect with a single injection. The representative of this group is dithylin. Separate muscle relaxants can have a mixed effect of antidepolarizing and depolarizing.
2.2 Indications for prescribing curare-like drugs
Diplacin, tubocurarine and other antidepolarizing muscle relaxants are mainly used in anesthesiology as a muscle relaxant that causes prolonged muscle relaxation during surgery and the exclusion of voluntary breathing.
In orthopedics, they sometimes use tubocurarine to relax muscles during reposition of fragments, reduction of complex dislocations, etc. In psychiatric practice, tubocurarine is sometimes used to prevent traumatic injuries in the convulsive treatment of schizophrenia. Diplacin can be used to reduce or relieve seizures in complex therapy tetanus.
Melliktin, unlike other antidepolarizing muscle relaxants, it has a blocking effect on neuromuscular conduction when taken orally. In this regard, the drug is used to lower muscle tone in pyramidal insufficiency of vascular and inflammatory origin, postencephalitic parkinsonism and Parkinson's disease, Little's disease, arachnoencephalitis and spinal arachnoiditis, as well as in other diseases of a pyramidal and extrapyramidal nature, accompanied by an increase in muscle tone and motor disorders. functions.
Ditilin, which belongs to depolarizing muscle relaxants, when administered, allows you to create controlled and controlled muscle relaxation. Due to its properties, the main indications for the use of this drug are tracheal intubation, endoscopic procedures (bronchoscopy, esophagoscopy, cystoscopy), short-term operations (suturing the abdominal wall, reduction of bone fragments and dislocations, etc.). With an appropriate dose and repeated administration, dithylin can also be used for longer operations, however, for prolonged muscle relaxation, antidepolarizing muscle relaxants are usually used, which are administered after preliminary tracheal intubation against the background of dithylin. In addition, the drug can also be used to eliminate convulsions in tetanus.
2.3 Pharmacokinetics and dosing regimen of drugs
By chemical structure d - tubocurarine, diplacin, ditilin and others are quaternary ammonium compounds ; characteristic of them is the presence of two onium groups. In the process of searching for curare-like substances, it was found that tertiary amines can also have curare-like activity. from plants different types larkspur (Delphinium), fam. ranunculaceae (Ranunculaceae) isolated alkaloids ( condelphin, methyllicaconitin etc.), which are tertiary bases , but with pronounced curare-like properties.
The main representative of the group non-depolarizing muscle relaxants is tubocurarine chloride ( Tubocurarini chloridum ) . Available in ampoules of 1.5 ml of a 1% solution for intravenous administration, belongs to list A. The effect of the drug develops gradually; usually, muscle relaxation begins after 1-1½ minutes, and the maximum effect occurs after 3-4 minutes. Doses of tubocurarine, as well as other muscle relaxants, depend on the anesthesia used. When using nitrous oxide, its intravenous administration at a dose of 0.4–0.5 mg/kg causes complete muscle relaxation and apnea lasting 20–25 minutes. Satisfactory relaxation of the abdominal muscles and limbs continues for 20-30 minutes after the onset of spontaneous breathing. If a longer action is required, tubocurarine is administered repeatedly, while due to the ability to accumulate, each subsequent dose should be 1½ - 2 times less than the previous one. Usually, for an operation lasting 2 - 2½ hours, 40 - 45 mg of the drug is consumed. With ether anesthesia, the initial dose of tubocurarine is 0.25 - 0.4 mg / kg.
Diplacin ( Diplacinum ) - antidepolarizing muscle relaxant, similar in mechanism of action to tubocurarine. Refers to list A and is available in ampoules of 5 ml of a 2% solution, which is administered intravenously. When administered at a dose of 1.5 - 2 mg / kg, it relaxes the muscles of the limbs and the abdominal press without turning off spontaneous breathing. At a dose of 4 - 5 mg / kg, after 4 - 5 minutes it causes complete relaxation of the muscles and apnea lasting 20 - 30 minutes. After the restoration of spontaneous breathing, the relaxation of the muscles of the abdominal press and limbs is still preserved for some time. If it is necessary to prolong the effect, diplacin is administered again, reducing the dose to ⅔ - ½ of the original. In total, for an operation lasting 1½ - 2 hours, 400 - 700 mg of the drug is consumed (20 - 35 ml of a 2% solution). With ether and halothane anesthesia, the dose of diplacin can be increased.
Kvalidil ( Qualidilum ) refers to list A and is available in ampoules of 1; 2 and 5 ml of 2% solution. The drug is administered intravenously. At a dose of 1 mg/kg, the drug causes muscle relaxation, lasting about 10 minutes, with some respiratory depression. Doses of 1.2 - 1.5 mg / kg cause muscle relaxation, lasting 15 - 20 minutes, while some patients experience apnea for 4 - 5 minutes. Usually this dose is used in cases where tracheal intubation is done using dithylin. Complete relaxation of the muscles occurs at doses of 1.8 - 2 mg / kg; apnea at the same time lasts an average of 17 - 25 minutes. At a dose of 2 mg / kg, the muscles begin to relax after 1½ - 2 minutes, and apnea and complete muscle relaxation occur after 2½ - 4 minutes. The exit from the state of curarization occurs gradually: after the appearance of spontaneous breathing, muscle relaxation persists for 15–20 minutes; after 25-30 minutes, muscle tone and breathing are usually completely restored. If it is necessary to extend the action of qualidil, it is administered repeatedly, reducing subsequent doses by 1½ - 2 times. In total, an operation lasting 1½ - 2 hours consumes 20 - 220 mg of the drug.
Melliktin ( Melliktinum ) according to the chemical structure, it belongs to tertiary bases, is available in tablets of 0.02 g (20 mg) and belongs to list A. This is one of the few curare-like drugs prescribed orally. Take it at 0.02 g starting from 1 time and up to 5 times a day. The course of treatment is from 3 weeks to 2 months. After a 3-4 month break, the course of treatment is repeated.
As already noted to depolarizing muscle relaxants applies dithylin ( Dithylinum ) The drug belongs to list A and is available as a 2% solution in ampoules of 5 or 10 ml. Similar dichlorides and dibromides are available under the names: Listenone, Myo-relaxin, Brevidil M, Succinal and others . According to the chemical structure, dithyline can be considered as a double molecule of acetylcholine (diacetylcholine). It is the main representative of depolarizing muscle relaxants. When administered intravenously, it disrupts the conduction of neuromuscular excitation and causes relaxation of skeletal muscles. The drug has a quick and short-term effect; does not have a cumulative effect. For prolonged muscle relaxation, repeated administration of the drug is necessary. The rapid onset of the effect and the subsequent rapid recovery of muscle tone allow you to create controlled and controlled muscle relaxation. Ditilin is administered intravenously. For intubation and for complete relaxation of the skeletal and respiratory muscles during surgery, the drug is administered at a dose of 1.5–2 mg/kg. For long-term relaxation of the muscles during the entire operation, the drug can be administered fractionally after 5-7 minutes at 0.5-1 micron / kg. Repeated doses of Dithylinum last longer.
2.4 Contraindications and side effects
An absolute contraindication for the appointment of muscle relaxants is myasthenia. The exception is dithylin, pharmacological properties which allow its use in such patients.
The use of ditilin is contraindicated in infants and glaucoma(possibly a sharp increase in intraocular pressure).
Almost all drugs in this group should be used with caution when liver and kidney diseases, cachexia, pregnancy(drugs cross the placental barrier), as well as in old and old age. Some drugs (qualidil, melliktin, anatruxonium) should be used with caution in patients with cardiovascular disorders.
It must be remembered that the use of muscle relaxants is permissible only if there are conditions for tracheal intubation and artificial ventilation of the lungs. When ditilin is used in small doses, usually spontaneous breathing can be maintained, however, in these cases, it is necessary to have all the devices for artificial respiration ready. In addition, it should be borne in mind that in some cases there may be increased sensitivity to ditilin with prolonged respiratory depression, which may be associated with a genetically determined violation of the formation of cholinesterase. The reason for the prolongation of the action of the drug may also be hypokalemia.
Antagonists antidepolarizing muscle relaxants are prozerin and galantamine, which are administered together with atropine. For complications associated with hypersensitivity to the drug or an overdose of the drug, oxygen should be prescribed and slowly injected into the vein 0.5 - 1 ml of a 0.05% solution of prozerin together with atropine (0.5 - 1 ml of a 0.1% solution). With regard to the depolarizing action of dithylin, prozerin and other anticholinesterase drugs are not antagonists, but, on the contrary, by inhibiting the activity of cholinesterase, they lengthen and enhance its effect. In this regard, in case of complications on the administration of dithylin (prolonged respiratory depression), artificial respiration is resorted to, and if necessary, blood is transfused, thus introducing the cholinesterase contained in it. In addition, a feature is that in high doses, dithylin can cause a "double block", when an anti-depolarizing effect develops after a depolarizing effect. Therefore, if after the last injection of ditilin, muscle relaxation does not go away for a long time (within 25-30 minutes) and breathing is not fully restored, they resort to the introduction of prozerin against the background of the preliminary administration of atropine (see above).
Thus, curare-like drugs belong to the group of potent substances and have a strictly limited use in anesthetic practice.
Conclusion
The main indications for the use of drugs from the group of ganglioblockers are: relief of hypertensive crises, controlled hypotension (surgery on the brain, pancreas, spleen, lungs with separation of massive adhesions, removal of highly vascularized tumors, etc.), pulmonary edema, acute cerebral edema. Sometimes they are used for stomach ulcers, spasms of the intestines, biliary tract, renal colic. Pahikarpin can be used for a stimulating effect on the contractile activity of the uterus. They are contraindicated in hypotension of various origins, impaired liver and kidney function, uncompensated blood loss, cerebral hemorrhage, cardiac decompensation and degenerative changes in the central nervous system.
Curariform drugs are indicated for tracheal intubation, endoscopic procedures, intubation anesthesia for major surgical interventions, reposition of bone fragments, reduction of dislocations, treatment of tetanus. Melliktin is used in diseases accompanied by an increase in muscle tone (spasticity) and disorders of motor functions (postencephalitic parkinsonism, arachnoencephalitis, etc.). Non-depolarizing muscle relaxants are contraindicated in myasthenia gravis. They are used with caution in cardiovascular disorders, pregnancy, impaired liver and kidney function, and glaucoma.
Having studied the drugs of the above groups, we can conclude that the list of indications for their appointment is very specific and is mainly limited to anesthetic practice and resuscitation. Despite the fact that only tertiary amines can be used for the treatment of internal diseases, they are not always the drugs of choice. This is due to the presence of significant contraindications and side effects in curare-like and ganglion-blocking drugs, as well as the appearance on the pharmaceutical market of a large number of effective drugs from other groups that act more selectively.
List of used literature:
1. Kukes V.G. Clinical pharmacology: Uch / Scientific. Ed. A.Z Baichurin. - 2nd ed., revised. and additional - M: GEOTAR MEDICINE, 1999. - 528 p.
2. Kurbat N.M., Stankevich P.B. Doctor's prescription guide. – 3rd ed., stereotype. – Mn.: Vysh. school, 1998. - 495 p.
3. Mashkovsky M.D. Medicines: in 2 volumes. T.1. – 10th ed. erased - M: Medicine, 1985. - 624 p.
Curarin is an arrow poison, it is poorly absorbed from the gastrointestinal tract into the blood, and is destroyed in the gastrointestinal tract. The action is manifested only when it enters the bloodstream, bypassing the gastrointestinal tract. In this case, it acts only on the N-XR of skeletal muscles, causing complete or partial relaxation of the skeletal muscles. In connection with the main action on skeletal muscles, they received a second name. muscle relaxants.
Found the main application in surgical practice for relaxation of skeletal muscles during operations on the organs of the chest and abdominal cavity. In addition, muscle relaxants can be used in convulsive therapy and for the treatment of spastic paralysis. High doses of muscle relaxants can cause depression of the respiratory center, and in severe cases, paralysis of the respiratory center and death.
Functional antagonists of curare-like drugs are AChE: prozerin, physostigmine.
TUBOCURARIN,Tubocurarinichloridum, list "A"
Salt of the alkaloid tubocurarine, in therapeutic doses, blocks H-XR of skeletal muscles without significant changes in the basic functions of the body. In large quantities, it can block H-XR of the adrenal glands and the carotid sinus zone, which can lead to a decrease in blood pressure and respiratory depression. In addition, large doses of this substance can promote the release of histamine poison from the cells of the body, which becomes active and can cause bronchospasm.
It is used only in a hospital during surgical operations.
PV - ampoules of 2 and 5 ml. 1% solution.
DITILIN,Dithylinum, list “A”, “Miorelaxin”
In terms of activity, it is significantly inferior to tubocurarine, the action develops with intravenous administration after 30 seconds and lasts 3-7 minutes.
It is used during anesthesia for short-term relaxation of skeletal muscles, and in case of an overdose of this drug, AChE is not used, because. they increase the toxicity of dithylin.
FV - amp. 5 and 10 ml of 2% solution.
Substances with a predominant effect on the AR (adrenergic agents)
These are drugs that affect sympathetic adrenergic innervation. .
As a mediator in adrenergic synapses, the most importance has norepinephrine, which excites the AR of cell membranes. The synthesis of norepinephrine occurs in the endings (axons) of sympathetic nerves (i.e., in the postganglionic fibers of the SNS). The starting substance for the synthesis of norepinephrine is the amino acid tyrosine, which undergoes a number of changes under the influence of certain enzymes: tyrosine - dioxyphenylalanine (DOPA) - dihydroxyphenylalanineamine (dopamine) - norepinephrine. This complex biochemical process occurs in the adrenergic nerves, and the eventually formed norepinephrine is deposited in the nerve endings in special formations - vesicles. During the arrival of a nerve impulse, part of norepinephrine is released into the synaptic cleft and excites the AR. The action of the mediator of norepinephrine is short-lived, because. most of it (80%) after the transmission of the impulse is recaptured by the nerve endings. Part of the mediator is inactivated by special enzymes: monoamine oxidase (MAO) and catecholorthomethyltransferase (COMT).
There are α- and β-adrenergic receptors, which is due to their different sensitivity to norepinephrine, adrenaline and a number of pharmacological substances. The quantitative ratio in the organs of α - and β - AR is different.
α - AR are located mainly in the vessels of the skin, mucous membranes, kidneys, in the abdominal organs, in the lungs and muscles, in the radial muscle of the eye.
β -AR are divided into β 1 - and β 2 - AR. Mostly β 1 -AP are located in the coronary vessels and the conduction system of the heart, β 2 - in the bronchi, vessels of the skeletal muscles and the uterus.
Mechanisms of pharmacological action on adrenergic synapses are quite diverse. Some drugs interact with ARs of postsynaptic membranes, causing their excitation or inhibition and corresponding changes in cell metabolism and function. The action of other drugs is directed to the endings of sympathetic nerves and presynaptic membranes. In this case, the drug can disrupt the synthesis of norepinephrine, its deposition in vesicles, release into the synaptic cleft, reuptake of the mediator by presynaptic nerve endings. Some substances inhibit the processes of enzymatic inactivation of norepinephrine. Combinations of different mechanisms of action in one medicinal substance are possible.
CLASSIFICATION of adrenergic drugs.
Adrenomimetics - excitatory AR.
Adrenoblockers - blocking AR.
Sympathomimetics (adrenomimetics of indirect action) - do not directly affect the AR, but contribute to the release of norepinephrine from the presynaptic endings and therefore enhance adrenergic reactions.
Sympatholytics - block sympathetic innervation at the level of postganglionic sympathetic nerve endings.
ADRENOMIMETICS
α-β-AM direct action
A typical member of this group is
ADRENALIN- is formed from norepinephrine in the cells of the adrenal medulla, in its action and origin it is a steroid hormone. It has a direct stimulating effect on α, β 1, β 2 - AR. In medical practice, it is used in the form
adrenaline hydrochloride solution,SolutioAdrenalinihydrochloridum, list “B”, 1 ml.
The action on the organs is expressed by the following pharmacological effects (as in the excitation of the SNS, except for paragraph 7):
1. Expansion coronary vessels, vessels of skeletal muscles, brain and lungs. In the conditions of the whole organism, the vasoconstrictive effect of adrenaline prevails, which leads to an increase in blood pressure.
2. Strengthening the work of the heart and increased heart rate.
3. Narrowing of the vessels of the abdominal organs, skin and mucous membranes.
4. Relaxation of the muscles of the bronchi, intestines.
5. Expansion of the pupil as a result of contraction of the radial muscle of the eye.
6. Contraction of the uterus, spleen.
7. Increased tone of the sphincters of the gastrointestinal tract and bladder.
8. An increase in the amount of sugar in the blood as a result of increased metabolism and stimulation of gluconeogenesis.
9. Increasing the performance of skeletal muscles by increasing glucose and improving blood supply to skeletal muscles.
10. Increased secretion of adrenocorticotropic hormone (ACTH).
11. Increasing the amount of free fatty acids in the blood by stimulating lipolysis.
12. Slight stimulation of the central nervous system (anxiety, tremor, etc.)
Applicable:
As a vasoconstrictor in shock, collapse, acute hypotension. With intravenous administration, it lasts 5 minutes, with subcutaneous - 30 minutes.
At anaphylactic shock and some allergic reactions of the immediate type.
With acute cardiac weakness, with cardiac arrest (in this case, adrenaline is administered intracardiac).
For the relief of asthma attacks in bronchial asthma (BA).
Together with local anesthetics for vasoconstriction, delaying the absorption of anesthetics and prolonging their action.
With an overdose of insulin or with a hypoglycemic coma to restore the amount of sugar in the blood.
Outwardly in eye practice, ENT - practice for vasoconstriction.
Contraindications for use.
Hypertonic disease.
Atherosclerosis.
Diabetes.
Thyrotoxicosis (increased metabolism).
Pregnancy.
With halothane, cyclopropane and chloroform anesthesia (arrhythmia, extrasystoles may occur).
It is prescribed: intravenously, subcutaneously, intramuscularly, intracardiac, externally. Inside is not assigned, because. destroyed in the gastrointestinal tract.
VW - in ampoules of 1 ml of a 0.1% solution, it is obtained synthetically or isolated from the adrenal glands of slaughtered cattle.
NORADRENALIN,Noradrenalinihydrotartras, list "B"
Unlike adrenaline, it excites mainly α –AR, slightly - β 1 - AR, therefore exhibits a stronger vasoconstrictor effect. It has practically no effect on the bronchi, does not show a hyperglycemic effect, slows down the rhythm of heart contractions. It is used as a vasoconstrictor for shock, collapse, acute hypotension (as a result of injuries, surgical interventions). It is entered only intravenously; better - through a catheter, because. causes tissue necrosis due to severe vasospasm. Other routes of injection are not used.
Contraindications.
Atherosclerosis.
Hypertension.
FV - in ampoules of 1 ml. 0.1% - 0.2% solution.
Muscle fibers play an important role in the functioning human body. In medical practice, the need often arises when it is necessary to influence the muscle fibers with their further relaxation.
Muscle relaxants act as such means, since their direct medicinal action it is aimed at making the transverse muscles, as well as neuromuscular pulsation, less pronounced and lower their tone.
Muscle relaxants as a remedy for pain
The discovery of muscle relaxants allowed medicine to step forward in the treatment of serious diseases. According to stories, curare poison from the bark of the plant was used by the American Indians when hunting animals and birds. The poison at the end of the arrow caused the animals to stop breathing.
After 1942, the pharmacological market and pharmacies were gradually filled with drugs containing curare poison, and then synthetic substances.
In practice, the use of muscle relaxants allows them to be used in the following areas: 
- At treatment of neurology, against the background of pronounced skeletal muscle tone.
- , neck or thoracic region spine.
- Before surgery, including in the abdominal region.
- If necessary, conduct electroconvulsive therapy.
- With anesthesia while maintaining natural breathing.
- During recovery after surgery on the spine, after injuries, with the development of intervertebral hernia.
How do muscle relaxants work?
Complications and side effects
The appointment of muscle relaxants will allow you to forget about back pain, but you need to be aware of the manifestation of negative aspects and side effects:
- Decreased concentration.
- Lowering blood pressure.
- Nervousness.
- Urinary incontinence.
- The appearance of convulsions and allergic rashes.
- Disorders of the gastrointestinal tract.
If there is at least one manifestation of the above, then we can talk about an overdose of the drug, especially from the group of antidepolarizing drugs.
Even drugs latest generation have side effects and complications. Measures to stop the manifestation of anxiety symptoms should begin with a complete cessation of use, as well as immediate consultation with a doctor. Therapy of poisoning and overdose begins with the introduction of Prozerin solution.
Overdose
In the usual overdose of any of the muscle relaxant drugs, artificial respiration should be performed until it is restored. In addition, an antidote is very carefully injected into the vein - Physostigmine, Salicylate, Neo Ezerin. All this is done with a clear control of blood pressure.
In the future, it is necessary to infuse plasma-substituting solutions, oxygen breathing. Symptomatic therapy is needed, which is aimed at restoring cardiovascular insufficiency.
Muscle relaxants without prescriptions
As a rule, these drugs belong to the so-called list A - that is, a prescription is required to purchase them. However, over-the-counter drugs can be purchased without a prescription − Mydocalm, Sirdalud, Tizalud.
Conclusion
Regardless of what disease overtakes a person, it is impossible to do without proper treatment. In the role of a lifeline from the onset of pain are the appropriate drugs - muscle relaxants. They allow the body to get the necessary substances that have a beneficial effect on muscle tissue, thereby relieving pain.
