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Autonomic pharmacology. Indirect acting cholinergic stimulants. Lector prof. Posokhova K.A. Efferent nervous fibres supply skeletal muscles – somatic ; regulate funtions of internal organs - vegetative
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Autonomic pharmacology. Indirect acting cholinergic stimulants Lector prof. Posokhova K.A.
Efferent nervous fibres supply skeletal muscles – somatic; regulate funtions of internal organs - vegetative Synaps - is a place of contact of long fibre ending (axon) of one neuron with a body of other one or cell of active organ (effector cell)
Influence of parasympathetic and sympathetic nervous system on function of organs
Cholinergic nervous fibres are: 1) preganglionic (sympathetic and parasympathetic); 2) all postgnglionic parasympathetic; 3) postganglionic sympathetic which supply sweat glands and vessels of skeletal muscles; 4) somatic nerves; 5) nerves which supply adrenal medulla and carotic sinuses; 6) neurons of CNS Adrenergic nervous fibres are: 1) postganglionic sympathetic, except those which supply sweat glands and vessels of skeletal muscles; 2) neurons of CNS
Cholinergic drugs 1) M-, N-cholinomimetics (acetylcholine, carbacholine); 2) Anticholinesterase drugs – cholinesterase inhibitors(proserin, galanthamine hydrobromide, pirydostygmine bromide, armine); 3) M-, N- cholinoblockers (amisyl, cyclodol); 4) M-cholinomimetics (pilocarpin, aceclidyn); 5) M-cholinoblockers(atropine sulphate, platyphyllin hydrotartrate, scopolamine hydrobromide, metacinum); 6) N-cholinomimetics (cytyton, lobelin); 7) N-cholinoblockers: а) ganglionblockers (benzohexonium, pentamin, hygronium, arphonade);б) myorelaxants (tubocurarinum chloride, dytylinum, melliktin)
M-, N-cholinomimetics Acetylcholine Carbacholine
Carbacholine 0,5-1 % solutions of carbacholine -eye drops for treatment of glaucoma The drug is never used orally and with injections because of its consideralbe toxicity !
M-, N-cholinoblockers Amizyl Cyclodol
Amizyl Indications for administration neurotic disorders, Parcinoson’s disease and other extrapyramidal disorders, for premedication before narcosis, for diseases which are accompanied with spasm of smooth muscles, for dilation of pupil in ophtalmology The drug is administered orally 0,001-0,002 g 3-4 times per day, as eye dropps- 1-2% solution is used Side effects : dryness of mucous membranes, tachycardia, dilation of pupils, disturbances of accomodation. The drug is contraindicated in case of glaucoma!
Cyclodol Anticholinergic drug, preferably blocks central N-cholinoreceptors and peripheral M-cholinoreceptors Usage Parcіnson’s disease, medicamentous parcinsonism
Anticholinesterase drugs Proserinum, Galanthamini hydrobromidum, Armin, Pirydostygmini bromidum
Proserinum Proserinum is an anticholinesterase drug of reverse action, its effect lasts for 2,5-4 hours. Indications for administration • Impairment of nerve conduction after polyomyelitis, paralysis, neurities, traumas • overdosing with M-cholinoblockers
Galanthamini hydrobromidum Duration of action of Galanthamini hydrobromidum is longer than of Proserinum, that’s why it can be administered 1-2 times per day Indications for administration Impairment of nerve conductionafter polyomyelitis, paralyses, neuritis, traumas, overdosing with M-cholinoblockers
Pirydostigmini bromide (calimin) Usage • myastenia gravis • after traumas, neuritis, paralyses • in a period of recovery after polyomyelitis, encephalitis
Anticholinesterase drugs are contraindicated in cases of epilepsia, hyperkinesias, bronchial asthma, stenocardia, bradycardia
Acute poisoning with anticholinesterase drugs (POC) nausea, vomiting, diarrhea, abdominal pain quick contraction of pupils, disturbance of visus (spasm of accomodation) increasing of salivation and sweating bronchospasm tachy- or bradicardia seizures, excitement, loss of consciousness, coma Death is caused by breath insufficiency, bronchospasm and lungs edema
Treatment of acute poisoning • Treatment should be started immediately (WHO) • stomach lavage with solution of Sodium hydrocarbonate salt laxatives, enterosorbents siphon enema • the poison should be carefully washed away from the skin • forced diuresis, in complicated cases - hemosorbtion, hemodialysis Usage of antagonist is necessary!!! –atropine sulphate. It should be introduced intravenously repeatedly, 2-4 ml of 0,1 % solution with the interval of 5-10 minutes. Appearance of tachycardia, dilation of pupils, dryness in the mouth are the criteria of sufficiency of atropine sulfate dose. Also reactivators of cholinesterase which renew activity of this enzyme are administered – dipyroxym, alloxym, isonitrosyn
Treatment of acute poisoning Depending on severity of poisoning dipyroxymis introduced once or a few times.An average dose of the drug in heavy cases is 3-4 ml of 15 % solution. The total dose ofalloxymis 0,4-1,6 g (0,075 g every 1-3 hours). If necessary - artificial ventilation should be performed to a patient. And after symptomatic treatment is carried on.