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35 Cards in this Set
- Front
- Back
cholinergic agonists are divided into two groups which are:
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esters of chline (ACh, methacholine, bethanecol, carbachol)
Alkoloids (muscarine, nicotine, pilocarpine,) |
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Muscarinic effects on the eye and cardiovascular system include
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decrease IOP
vasodilation, dec HR and reduced contractility |
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Muscarinic effects on the respiratory and GI tract include
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bronchoconstriction, increased secretion (contraindicated in asthma)
increased secretory and motorof gut activity..digestion |
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Nicotine effects on PNS in cardiovascular system, GI, respiratory, and genitourinary
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-will activate both through post ganglionic neurons
cardiovascular effects are sympathetic all the rest are parasympathetic MATCH (muscle weakness, fasciculations, Adrenal medula inc, tachycardia, cramping of skeletal muscle, hypertension) |
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organophosphates are
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nonselective ACHe inhibitors- inhibits both nicotinic and muscarinic
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All esters of choline cross the bbb T/F
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false
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esters of choline are contraindicated for
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hyperthyroidism, asthma, coronary disease (hypotension), acid peptic disorders, obstructive urinary retention
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ACH
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ester of choline
-need high IV doses to detect effects- used to dec IOP post operatively and sweat spot test |
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Methacholine
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ester of choline
more resistant to cholinesterase and longer lasting- -used to diagnose bronchial airway hypersensitivity |
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carbachol
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-ester of choline
significant nicotinic activity at ganglia, skeletal muscle and adrenal medulla used for intracameral instillation to produce miosis in ocular surgery and to reduce postoperative rises in IOP. Ophthalmic drops to reduce IOP in glaucoma or hypertension limited to ophtalmic applications |
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bethanechol
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ester of choline
-not nicotinic, inc GI motility, -only ester of choline given systemically used for empying bladder in postpartum nonobstructive urinary retention |
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alkaloids-
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muscarine, pilocarpine, nicotine, varenecline
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pilocarpine
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-alkaloid-
crosses BBB -active on eye and sweat glands -miosis, accomodation -initial tx of open angle glaucoma- red IOP (not use if IOP is >45mmHg. -if taken orally causes Xerostomia assoc with Sjogren's syndrome |
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Nicotine
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cholinomimetic-> alkaloid
All autonomic ganglia including skeletal muscles and cns. -can activate and inhibit nicotinic ACH receptors -used as smoking cessasion agent -rapid activation of receptor followed by desensitized state. |
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Varenecline
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-Alkaloid-
partial agonist |
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ACHe inhibitor groups
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-simple alcohols - quarternary ammonium (edrophonium) 5-15 min
-Carbamic acid esters (carbamates, neostigmine) 30min-6hrs -organic derivatives of phosphoric acid (organophosphates) (irreversible 2 step process) hundreds of hours |
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pralidoxime
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PAM- if used before aging in organophosphate (ACHe inhibitor) occurs, then enzyme can be restored.
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ACHe inhibitors effects on organ systems
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mostly parasymphathetic-
CV-reduced CO, no VSM effect, CNS- coma, convulsions, respiratory failure NMJ- can be beneficial for someone with myasthenia gravis or someone given curare |
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edrophonium
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-reversible ACHe
5-15 min -dx for myasthenia gravis and evaluating efficacy of myasthenia therapies -give 2mg followed by 8ngm if muscle weakness occurs -> cholinergic crisis- need atropine -used to assess efficacy of long term tx- pyridostigmine- if patient is stronger, dosage not enough |
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physostigmine salicylate
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reversible ACHe
30m to 6hrs- -local application causes miosis, accomodation, decrease in IOP. Pilocarpine is more effective. |
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neostigmine
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reversible cholinesterase inhibitor
.5-2hrs myasthenia gravis, alleviate postoperative urinary retention and paralytic ileus -reverse neuromuscular blockade, -lower IOP in glaucoma or post ophthalmic surgery |
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donepezil
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-reversible anticholinesterase
long duration, for symptomatic tx of AD -no hepatic toxicity |
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tacrine
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like donepezil but with hepatic toxicity
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galantamine
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mild to moderate tx of AD
reversible ACHe inhibitor |
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pyridostigmine
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long term ACHe inhibitor
3-6hrs myasthenia gravis |
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ambenonium
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reversible anticholinesterase
4-8hrs |
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demarcium
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reversible ACHe
glaucoma |
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carbaryl
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reversible ACHe
lice |
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Pralidoxime 2-PAM
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irreversible ACHe
-regenerate enzyme if given before aging for organophosphates |
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echothiopate
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irreversible ACHe inhibitor
-low lipid solubility- not absorbed systemically -glaucoma -100 hrs |
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malathion and parathion
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-irreversible ACHe inhibitor
-rapidly metabolized by birds and mammals to non-toxic metabolites but not by insects or fish -parathion is not detoxified in vertebrates, more dangerous |
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nerve agents
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sarin, soman, tabun and vx
-chemical warfare -flaccid paralysis, respiratory failure -pyridostigmine given prophylactically to block binding of irreversible agents so more time for tx with atropine or 2-PAM |
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toxicity of cholinomimetics-direct acting stimulants
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tx is atropine
o |
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toxicity of cholinomimetics- direct acting nicotinic stimulants
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-toxic dose = 40mg - 2 cigarettes but it is an emetic
-tx with atropine or diazepam for cns effects |
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toxicity of cholinomimetics: cholinesterase inhibitors
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-home pesticides = source
-tx- maintain vital signs, decontaminate, parenteral atropine in large doses and PAM to regenerate, benzodiazepines to prevent seizures |