An anticholinergic is an active ingredient that acts on the parasympathetic nervous system. The parasympathetic nervous system is part of the autonomic nervous system. It involuntarily, i.e. not subject to the will, controls most of the internal organs and the blood circulation. It has a braking and dampening control function in the metabolism, so it ensures regeneration, relaxation and protection. The transmitter substance (neurotransmitter) of the parasympathetic nervous system is acetylcholine. When acetylcholine is released, it acts on various receptors, which in turn transmit information from the parasympathetic nervous system to the cell. The term ´´Anticholinergika´´ is used to summarize a group of active substances that suppress the effect of acetylcholine. These act on a certain type of receptor, the muscarinic receptor type. These types of receptors are found primarily in the heart and smooth muscles, especially in the digestive tract. Here, anticholinergics cause nerve stimuli to be interrupted and thus counteract the parasympathetic nervous system, which slows down and dampens the metabolism
The parasympathetic nervous system stimulates digestion and lowers the heart rate, anticholinergics do exactly the opposite. Anticholinergics relax the smooth muscles of the digestive tract and thus to one Inhibition of gastrointestinal activity. Furthermore there is a Increase in heart ratewhat to do with slow (bradykarden) Cardiac arrhythmias exploits. Anticholinergics do one Suppression of saliva, sweat and gastric juice formation and in mind one Dilation of the pupil (mydriasis)what to look for, for example, at the ophthalmic Examination of the fundus makes use of. This widening of the pupil reduces the ability to see (especially in the vicinity) and leads to increased sensitivity to light (photophobia). Anticholinergics can also be used to Treatment of urinary and urge incontinence, be used for very frequent urination and for an overactive bladder, as they have a relaxing effect on the smooth muscles. This is also used, for example, in the case of nocturnal wetting (enuresis nocturna) in children. Anticholinergics also play a role in Treatment of Parkinson's disease used, for example, on a Parkinson's patient used against body stiffness and fixed gaze.
Atropine and similar anticholinergics
Of the most famous active ingredient the anticholinergic is that Atropine. Atropine is a toxic agentwho is in Nightshade family like the angel's trumpet, the thorn apple and the deadly nightshade (Atropa belladonna). In the Renaissance, large pupils were considered particularly beautiful among European women (´´bella donna´´). The use of deadly nightshade extracts in the eyes caused pupil dilation lasting up to several days. It will also still used today in ophthalmology, because with wide pupils the Examination of the fundus is facilitated. The anticholinergic effect of atropine takes place however also for biliary or urinary tract colic and gastrointestinal cramps Use. The anticholinergic effect of atropine is also important in the Resuscitation after cardiovascular failure and at the Treatment of a slow heartbeat (bradycardia) due to its frequency-increasing effect on the heart.
Anticholinergics, which are closely related in their chemical structure to atropine, such as Tiotropium bromide, are used in medicine used in chronic obstructive pulmonary diseases (COPD)because they have the Dilate bronchi. Also against travel sicknesst one uses something related to atropine drug one, for example suppresses one Scopolamine patch the nausea. Against excessive sweating (hyperhidrosis) Atropine can also be used because of its inhibitory effect on sweat production.
Anticholinergics are very common Dry mouthbecause the production of saliva is inhibited. Also, some of the most common unwanted side effects are Constipation, fatigue, blurred vision and urinary retention. Even in small doses, the effects of anticholinergics on the cardiovascular system play a role, for example it can ´´ Palpitations´´ (tachycardia) come.
Are anticholinergics in given very high doses, can Symptoms of poisoning occur under the term of anticholinergic syndrome summarizes. This denotes a condition in which the parasympathetic nervous system largely switched off has been. Symptoms of anticholingering syndrome can be Sleep disorders, seizures, memory disorders and cardiac arrhythmias, dilated pupils, rise in intraocular pressure (glaucoma attack), dry, hot skin, bowel and urinary retention be. Patients with such severe side effects to anticholinergics must be monitored in an intensive care unit. A possible antidote is the active ingredient Physiostigminethat cancels the effect of anticholinergics. The First aid for atropine poisoning consists in the immediate Administration of activated charcoalwhich prevents the absorption of atropine into the bloodstream in the gastrointestinal tract. also artificial respiration may be necessary, as from very high doses of anticholinergics a fatal respiratory paralysis can use. In children, this can occur even at lower doses.