Atropine is a vegetable alkaloid
Atropine (Atropine) is a well-known medicinal product that has a natural origin - it is contained in some plants. Despite its active use in medicine, atropine is a dangerous substance - it is easy for them to poison, especially children. To do this, you need to eat blue bellies growing everywhere.
So, what is it - atropine, how it works and where it is applied? How to determine the poisoning to them and what to do with it? What antidotes exist? Let's understand.
Atropine - a dangerous alkaloid
What is atropine? This substance belongs to the group of alkaloids. Alkaloids are heterocyclic bases containing a nitrogenous group present in some plants and exhibiting biological activity. In other words, alkaloids refer to compounds that can somehow affect the living organism. Several alkaloids may be present in one plant.
Such an alkaloid is found in the belladonna (belladonna), bleach, dope, scopolia and other plants of the family of the nightshade. Atropine (Latin atropinum) is a natural poison, but in small doses it is used for medical purposes.
According to its chemical structure, atropine refers to crystalline powders. It is amorphous, colorless, odorless. The substance has two isomers. The left-handed is called the hyoscyamine, which is much more active than atropine. It is hyoscyamine and is found in plants. But this substance is unstable and when chemically isolated it turns into atropine.
The mechanism of action of atropine
This alkaloid disrupts the conduct of the nerve impulse by blocking the receptors. That is, he competes with the natural substance of the body (acetylcholine) in the ability to communicate with sensitive endings on the path of the impulse. There are several types of sensitive endings: M and H. Atropine blocks only M-receptors.
The mechanism of action of atropine is that it binds to specific structures of the nerve cell instead of acetylcholine. Accordingly, the transmission of the nerve impulse is blocked. Depending on which organ system acts, atropine causes various effects.
- Relaxation of smooth muscle cells. This effect of atropine is observed in the bronchi (expansion), gastrointestinal tract, bladder. Relaxation of muscles in these organs is due to inhibition of impulses from the side of the parasympathetic nervous system.
- Decrease in secretory activity of glands of external secretion, namely: bronchial, digestive, sweat, salivary, tearful. The mechanism of suppression of bronchial and digestive secretion is due to blockade of parasympathetic, and salivary, tearful and sweaty - on the contrary, blockade of the sympathetic nervous system.
- Mydriasis (dilated pupils). Circular and radial muscles of the iris of the eye are antagonists and counterbalance the effect of each other. Atropine binds to the M3-holinoretseptorami circular muscle of the iris, it relaxes, and the radial muscle is thus strained, its action prevails and the pupil expands.
- Paralysis of accommodation (adaptation of the eye to a change in external conditions for a clear perception of objects located at different distances). Atropine relaxes the ciliary muscle of the eye and flatten the lens, which causes hyperopia.
- The increase in the rhythm of the heart is due to the inhibition of the parasympathetic effect on the sinoatrial node. But sometimes an increase in the rhythm of the heart can be preceded by a bradycardia (a decrease in the heart rate), this is due to the stimulation of vagal centers.
- Improves atrial-ventricular conduction.
- Affects the vessels, but only in very high doses. At the same time, they expand, the skin of a person turns red. In small doses, atropine does not dilate the vessels, but it still binds to the receptors. Therefore, drugs that dilate blood vessels may not work, since the sensitive endings with which they should have been contacted are already occupied by atropine.
Where is atropine used
There are 2 drugs, the main active ingredient is alkaloid belladonna:
- Atropine tablets;
- "Atropine sulfate" - 0.1% solution for injection and 1% eye drops.
The drug is widely used in clinical practice. The use of atropine is practiced in gastroenterology. It is appointed:
- with ulcers of the duodenum and stomach to suppress gastric secretion;
- spasm of the pyloric sphincter of the stomach for its relaxation;
- cholelithiasis and with inflammation of the gallbladder to expand the ducts and drain the stagnant bile;
- with spasms of the intestine;
In other branches of medicine, atropine is used:
- with spasms of the bladder;
- bronchial asthma, as a remedy for eliminating bronchospasm;
- to reduce the secretion of glands: salivary, sweaty, tearful;
- with a decrease in the pulse associated with the tone of the vagus (should be prescribed cautiously, as, perhaps, a short-term increase in bradycardia);
- in anesthesiology for premedication and introduction to anesthesia, during surgery, intubation, to eliminate laryngospasm and bronchospasm, to reduce salivation;
- when radiographing the stomach to reduce its tone during the study;
- with excessive sweating.
Why still use atropine? This drug is an antidote for poisoning with organophosphorus compounds including poisons, an overdose of cholinomimetic and anticholinesterase drugs. In addition, atropine is used in ophthalmology as a drug that dilates the pupil in the study of the fundus.
Overdose and poisoning
Atropine can be used intramuscularly, orally, intravenously, subcutaneously or as eye drops. Orally it is prescribed from 0.25 to 1 mg 1-3 times a day. This variation in dosage is due to the individuality of each organism and the amount of the drug should be selected individually. Intravenously, intramuscularly, subcutaneously at the same dosage, but 1-2 times per day. Atropine in the form of eye drops are instilled in 1-2 drops 3 times a day. To expand the pupil for the study - 1-2 drops 1-2 times. The maximum single dose of atropine is 1 mg, the maximum daily dose is 3 mg.
Atropine poisoning can be accidental or targeted. The severity of manifestations depends on this. In general, poisoning occurs with the occasional use of the fruits of the family of the nightshade. Children are in the main risk group.
The toxic effect of atropine begins to manifest itself 40-60 minutes after ingestion. Depending on the dose, they distinguish between light, medium and severe poisoning. First of all, the substance affects the structure of the brain, causing psychosis, impaired coordination, hallucinations. Then the heart and lungs suffer.
Overdose of atropine is revealed by the following symptoms:
- decreased sweating;
- redness of the mucous membranes;
- heart palpitations up to arrhythmia;
- nausea, vomiting;
- tremor (trembling) of limbs;
- hoarseness of voice, difficulty swallowing;
- redness of the skin;
- impaired vision;
- quickening of breathing;
- convulsive syndrome.
Such symptoms can occur with an unintentional overdose.
Targeted poisoning has more serious symptoms:
paralysis of the respiratory muscles;
- decreased heart rate, atrial fibrillation, or ventricular fibrillation.
The dose of atropine, which is fatal - 100-150 mg or 1-1.5 mg per 1 kg of body weight. In children, the dose is less. In terms of belladonna berries - 3-6 pieces can cause a lethal outcome in the child. Death usually comes not earlier than 5 hours after poisoning.
The consequences of poisoning can be not only death. With a long stay in a coma, irreversible organic changes in the brain can occur, leading to a loss of intelligence and memory.
Treatment of poisoning begins with the washing of the stomach with water, potassium permanganate or salt laxatives. Immediately need to give poisoned antidote atropine. It can be:
- 0.1% aminostigmine solution 2 mg;
- 0.05% galantamine solution (preparation "Nivalin") 2 mg.
It is necessary to repeat the administration of the antidote after 90 minutes. The heavier the poisoning, the less antidote is introduced with a shorter interval. In a severe case, it can be administered every 15 minutes.
Aminostigmine quickly restores consciousness, eliminates psychomotor agitation and hallucinations. It is used not only to treat an overdose, but also to prevent the recurrence of coma.
There is another antagonist atropine - alkaloid pilocarpine. Preparations based on it (eye drops) are used in ophthalmology to reduce intraocular pressure. Atropine, expanding the pupil, can cause glaucoma. With a strong increase in pressure inside the eye, retinal detachment can occur. Therefore, when poisoning plants or preparations containing atropine, pilocarpine should be administered immediately according to the following scheme:
- every 15 minutes, one drop in each eye for an hour;
- the next 2-3 hours drop 1 drop in 30 minutes;
- then 4-6 hours - drop by drop every hour;
- then 3-6 times a day drop by drop until the high intraocular pressure is relieved.
Let's sum up. Atropine - an alkaloid of plants from the family of nightshade. It is a holinolitic drug, actively used in medicine. It is used in gastroenterology, pulmonology, cardiology, ophthalmology, anesthesiology, toxicology, urology. Serious overdose of this drug can occur with the occasional use of berries of nightshade plants or a large amount of medicinal product. The poisoning clinic depends on the dose taken. Death comes from taking 100 mg of atropine. There are specific antidotes that need to be taken immediately - aminostigmine and galantamine. They are administered intravenously repeatedly. The consequences of poisoning with atropine can be a coma, a violation of intelligence and memory.