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20 Cards in this Set
- Front
- Back
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Cholinomimetics
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Effect similar to stimulation of cholinergic nervous system
Act on muscarinic (M) a nicotinic (N) receptors |
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Nicotinic effects
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Ganglial receptors
Depends on autonomic stimulation. When sympathetic nervous system outweighs (vessels), then their stimulation stimulates sympathetic neurons. When parasympathetic system outweighs (heart, GIT), then their stimulation stimulates parasympathetic neurons. Adrenal medula - adrenalin and noradrenalin release Neuromuscular junction - spasms and convulsions of skeletal muscles |
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Cholinomimetics
1. direct |
M receptor agonists
1. direct N receptor agonists (most of them are nonspecific) |
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Cholinomimetics
2. indirect (AChE inhibitors) |
2. indirect (AChE inhibitors)
short acting-edrofonium intermediate acting - carbamates long acting (irreversible blockers) - organophosphates |
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Direct cholinomimetics
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Acetylcholine - direct endogenous cholinomimetics, which is released in:
sympathetic and parasympathetic ganglias (N-effects) postganglial parasympathetic neurons (M-effects) neuromuscular junction (N-effects) adrenal medula (N-effect, adrenaline secretion) CNS (N-effect) Very fast hydrolysis by acetylcholinesterase. |
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Acetylcholine
properties |
poor absorption p.o. and s.c., does not cross HEB
rapid hydrolysis by AChE BP decrease, bradycardia, heart arrest sweating, salivation, lacrimation, glands secretion nauzea, cough, dyspnoe vessels dilatation EDRF (NO) release effect |
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Pilocarpine
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tercial N atom - increased lipofility, cross HE barrier and enters cornea
M and N effect miosis and decreases intraocular pressure |
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Carbachol
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quartery N atom, does not cross HEB, resistance to AChE
secretion GIT glands GIT muscles atonia miosis and decreases intraocular pressure CI - obstruction GIT |
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Metacholine, betanechol
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quartery N atom, does not cross HEB, resistance to AChE
GIT motility increasing, urinary retention after anesthesia or vagotomia examination of exocrine pancreas secretion CI - obstruction GIT |
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Intoxication
M receptors: |
M receptors: CNS stimulation, miosis, accommodation, dyspnoe, (bronchoconstriction, hypersecretion of bronchial glands), diarrhoea (hypermotility and hypersecretion), hypotension (vazodilatation), bradycardia.
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Intoxication
N receptors |
N receptors: convulsions, BP increase (adrenal and ganglia N receptor stimulation).
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Indication
Pilocarpine Carbachol Metacholine, betanechol |
postoperative and neurogenic ileus, urinary retention.
glaucoma (carbachol, pilokarpine). |
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Edrofonium
Physostigmine Neostigmine Pyridostigmine |
Reversible (competitive) AChE inhibitors
M and N effect |
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Indications for and gruop they belong to:
Edrofonium Physostigmine Neostigmine Pyridostigmine |
Reversible (competitive) AChE inhibitors
M and N effect Postoperative and neurogenic ileus, urinary retention – neostigmine Glaucoma- physostigmine Myastenia gravis – neostigmine, pyridostigmine, edrophonium Treatment of neuromuscular blocks Alzheimer disease rivastigmine, donezepil |
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Ireversible AChE inhibitors - organphosphates
AChE effect/intoxication |
M and N effect
AChE activity 70% - mild intoxication AChE activity 30% - severe intoxication |
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AChE reactivators
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pralidoxime
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atropine
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atropine - blocks muscarinic effects
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Ganglion-blocking drugs
Interference with acetylcholine release |
Interference with acetylcholine release
Botulinum toxin, hemicholinium |
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Ganglion-blocking drugs
Prolonged depolarization |
Nicotine
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Ganglion-blocking drugs
Competitive antagonist |
Hexamethonium, tetraethylamonium
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