Atropine

A naturally occurring substance belonging to the group of active substances known as "anticholinergics". Atropine forms colourless crystals, which are sparingly soluble in water, but readily soluble in ethanol, ether, fatty oils. Atropine is a 1:1 mixture of the isomers L-hyoscyamine (naturally occurring in this form) and D-hyoscyamine, which is formed during the preparation process.

Alkaloid in Atropa belladonna and Hyoscyamus niger, among others.

As a parasympathetic agent, atropine inhibits the action of acetylcholine, the main transmitter of the parasympathetic nervous system. The substance inhibits the transmission of excitation at the nerve endings of the parasympathetic nervous system. Atropine cancels the effect of acetylcholine at the target cells of organs and tissues. It causes tachycardia in the heart, leads to dilation of skin vessels and inhibition of smooth muscles of the gastrointestinal tract, bladder, bile ducts and bronchial muscles. Inhibition of the secretory function of salivary and sweat glands; furthermore inhibition of the secretion of bronchial and gastric juice. Mydriasis (pupil refusal) occurs in the eye. At the CNS, atropine leads to motor excitation, as well as to delirium and hallucinations.

Spasmolytic for stomach and intestinal cramps. It is also used in children with enuresis nocturna, smooth muscle cramps and/or hypersecretion in gastrointestinal tract, urinary tract, asthma and bronchitis, Parkinson's disease. Treatment of bradycardia and cardiac rhythm disorders; atropine sulphate eye drops (0.5%/1.0%/2.0%) to dilate the pupil.

EMD: 1.0mg, TMD: 3.0mg.

The most common adverse effects of anticholinergics include fatigue, constipation, visual disturbances, dry mouth and urinary retention.

There is individual variation in sensitivity. In overdose, risk of death from respiratory paralysis. Infants and small children are particularly sensitive. The lethal dose is 0,05-02g.
Therapy of poisoning:gastric lavage, activated charcoal (Carbo activatus), in case of convulsions: 10-20mg diazepam i.v.; antidote = physostigmine.

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