Atropine

Atropine, Atropinum, C₁₇H₂₃NO₃, an alkaloid found in thornapple (Datura stramonium), henbane (Hyoscyamus niger), and mainly in deadly nightshade (Atropa Belladonna), growing in deciduous forests of central and southern Europe, in the Crimea and Caucasus; obtained from the seeds and leaves of these plants, as well as synthetically—from tropine and tropic acid. Atropine is a white crystalline powder of bitter taste, with an alkaline reaction, soluble in alcohol, in 300 parts of cold water and in 50 parts of boiling water, optically inactive, being an equimolecular mixture of levo- and dextrorotatory hyosciamines; with acids it forms neutral salts. In medicine, the sulfate salt is used, which dissolves in water. Atropine acts on the central nervous system and the endings of the parasympathetic nervous system. On the central nervous system, atropine first has an exciting, and then a paralyzing effect. On the endings of the parasympathetic nerves, atropine has only a paralyzing effect. The exciting effect of atropine on the brain manifests itself mainly in the sharp excitation of the cerebral cortex with its centers of mental activity. The higher the animal is organized, the stronger its central nervous system reacts to the exciting effect of atropine, therefore in humans the symptoms of excitation under the influence of atropine are very sharply expressed, manifesting as restlessness, dizziness, delirium, hallucinations and attacks of rage. The exciting effect of atropine on the medulla oblongata manifests itself on the respiratory and vasomotor centers: respiratory movements become deep and frequent, and blood pressure rises. Under the influence of atropine, however, dilation of the skin vessels also occurs, as a result of which redness and turgescence of the skin are observed. The effect of atropine on the spinal cord manifests itself first in excitation, and then in paralysis of reflex activity. When toxic doses of atropine act, depression and paralysis of the central nervous system are observed, which manifests as drowsiness, intoxication, a comatose state, a sharp drop in blood pressure, weak, irregular pulse, loss of reflex movements, paralysis and cessation of breathing. Small amounts of atropine cause paralysis of the cardiac endings of the n. vagi and somewhat excite the contractions of the cardiac muscles, as a result of which acceleration of the heartbeat occurs; from large doses, paralysis of the cardiac muscle occurs. The paralyzing effect of atropine on the endings of motor nerves of smooth muscle is especially sharply manifested in the eye and intestine. Due to the paralyzing effect of atropine on the endings of the n. oculomotorii, a strong dilation of the pupil, paralysis of accommodation of the eye and an increase in intraocular pressure occur, depending on the fact that when the pupil dilates, the iris covers the Fontana spaces, which prevents the outflow of fluid from the anterior chamber of the eye. On the intestine, small doses of atropine act by increasing peristalsis, while from large doses of atropine, peristalsis decreases and stops. Atropine also has a paralyzing effect on other organs; thus, under the influence of atropine, due to paralysis of the endings of the n. vagi, spastic contractions of the esophagus, stomach, gallbladder and bladder cease; the spastic contraction of small bronchi observed in bronchial asthma also passes under the influence of atropine, which paralyzes the endings of the bronchial branches of the n. vagi. On the uterus, atropine acts as on the intestine: small doses enhance the contraction of the uterus, large doses stop them. The effect of atropine on the secretory nerves manifests in the reduction and cessation of the secretion of glands by their secretions: the secretion of sweat, saliva and mucus ceases, as a result of which dryness of the skin and mucous membranes appears. Atropine inhibits the function of the gastric glands, reducing the amount of gastric juice by 8-10 times and lowering the acidity of the stomach contents by ²/3-¹/2. On the secretion of the pancreas and intestines, atropine also acts in a paralyzing way. The secretion of bile under the action of atropine does not cease, but is limited, just as the secretory activity of the mammary glands weakens (although slightly) under the influence of atropine. Atropine also has a depressing effect on the endings of sensory nerves. Atropine is excreted from the body unchanged, mainly by the kidneys. The presence in the urine of even traces of atropine can be easily detected by the physiological reaction to the cat's eye, since even one drop of a 1:100,000 solution of atropine causes a sharp dilation of the pupils in cats. Symptoms of poisoning: restlessness, reaching attacks of rage, delirium, hallucinations, dry, reddened skin, especially on the head and neck, wide, non-reacting pupils, weakening of vision, dryness in the mouth, pharynx and throat, difficult swallowing and breathing, frequent and small pulse, retention of urine and constipation, convulsions, gradual transition of the excited state into narcosis, paralysis of respiration and heart. Treatment of poisoning: wash the gastrointestinal tract, subcutaneously inject morphine (carefully—due to the possibility of paralysis of the respiratory center) 0.02 every hour until the patient is calmed down; internally tannin, strong tea or coffee; chloral hydrate (1.0-2.0), cold douches, rubbings, mustard plasters. Atropine and its preparations are used for dilation of the pupil, paralysis of accommodation and to provide rest to the diseased eye (contraindicated in glaucoma), as well as to limit sweating and excessive salivation, to excite cardiac and respiratory activity, in poisoning with morphine, chloroform, muscarine, pilocarpine and nicotine, in vagotonia, expressed by extremely diverse diseases of the gastrointestinal tract, cardiovascular system and respiratory tract, to reduce the painful spasm of smooth muscle of various canals and sometimes, as an analgesic, in various neuralgias, cardialgias, persistent vomiting, abdominal pain, etc., in bronchial asthma. Atropinum sulfuricum is administered internally, under the skin and in the form of eye drops (0.5-1% solutions), the highest single dose according to Ф (VII) is 0.001, the highest daily dose is 0.003.

D- Russian. Discovery in court cases. When examining internal organs, vomit and other objects for alkaloids (see Poisons), atropine is transferred to chloroform from an alkaline solution. The chloroform extract is evaporated at room temperature. Part of the residue is moistened in a porcelain cup with a few drops of fuming nitric acid and evaporated to dryness on a water bath. The residue is moistened with a drop of 5% alcoholic solution of caustic soda: a red-violet coloring (Vitali reaction). Hyosciamine (optically active isomer of A.) gives a similar reaction, strychnine and veratrine give similar (inconstant) coloring. Great importance is attached to physiological testing: dilation of the cat's pupil from a drop of solution and coincidence of this experiment with the Vitali reaction, which is not observed in protein breakdown products that sometimes give the physiological reaction of atropine. For quantitative determination, an excess of ^ or ^fjj solution of sulfuric acid, indicator methylrot or eosine, is added, and the excess acid is titrated with ~ or ^i solution of caustic soda. Determination requires special precautions. Lit.,- Gadamer J., Lehrbuch der chemischen Toxikologle, p. 493, 2 Aufl., 1924.