B. 3- Cholinomimetics Flashcards by שני דוידפור

classify the direct-acting cholinomimetics (cholinergic agonists) and give examples

1. choline esters: 
Acetylcholine 
Carbachol
2. Alkaloids: 
pilocarpine
3. synthetic: 
Varenicline

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list choline esters

Acetylcholine
Methacholine
Bethanechol
Carbachol

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which choline ester is only M agonist (selective)?

bethanechol

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does Acetycholine have clinical use?

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which choline esters are resistant to acetylcholinesterase?

bethanechol

carbachol

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are choline esters lipid soluble?

they are poorly lipid-soluble

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how is Carbachol given?

topically

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for what is Carbachol given?

glaucoma

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indications for Bethanechol

non obstructive ileus (post-operative/neurogenic)
urinary retention

“B” think -Bowls and Bladder

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what is methacholine used for?

methacholine provocation test (DD of bronchial hyperactivity)

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list the Alkaloids type cholinomimetics

Muscarine
Nicotinic
Pilocarpine

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are alkaloids lipid soluble?

yes

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how is pilocarpine given?

oral, parenteral

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duration of action of bethanechol and pilocarpine

30min-2 hours

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indications for pilocarpine

Glaucoma
Xerostomia- dry mouth (Sjögren syndrome, radiation, drug-induced)
* pilocarpine ↑ fluid production
pilocarpine-induced sweat test (cystic fibrosis diagnosis)

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where is muscarine found?

mushroom poison

can result in poisoning effects- nausea, vomiting, diarrha

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is Vareniciline N or M agonist ?

N (partial agonist)

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why do we give varenicline?

for smoking cessation (inhibits the reward effect of nicotine in the limbic system)

classify the indirect-acting cholinomimetics (acetylcholinesterase inhibitors)

Carbamates (non-competitive, reversible inhibition)
Organophosphates (irreversible inhibition)
Alcohol (non-competitive, reversible inhibition)

signs for AchE inhibitor poisoning

"DUMBBELS"
Diarrhea 
Urination
Miosis
Bradycardia
Bronchoconstriction
Excitation (CNS, muscles)
Lacrimation 
Secretion (sweating, salivation)

*atropin helps reverse most effects

what is the difference between a tertiary amine to a Quaternary amine?

Tertiary amine freely crosses the BBB and has CNS effects

Quaternary doesn’t

list Carbamates

Neostigmine
Pyridostigmine
Physostigmine

Rivastigmine
Galantamine
Donepezil

mechanism of Carbamates

bind to AchE and undergo hydrolysis, preventing binding and hydrolysis of endogenous Ach

give the carbamates that are Quaternery amines

Neostigmine

pyridostigmine

indications for Neostigmine

Myasthenia gravis--> muscle weakness non-obstructive ileus (post-operative/neurogenic) Urinary retention Reversal of Nm Block (curare- like overdose)

indication for pyridostigmine

myasthenia gravis

indications for Physostgimine

antidote in atropin overdose (IV) | glaucoma (topical)

duration of neostigmine and physostigmine

2-4 hours

duration of pyridostigmine

4-8 hours

half life of Rivastigmine, Donepazil

1.5- 70 hours

what Carbamates are Tertiary amines?

Physostigmine Rivastigmine Galantamine Donepezil

what are the indications for Rivastigmine, Galantamine, donepazil?

Alzheimer disease (transdermal patch)

list the OPS

Malathion Parathion Sarin

where is Sarin found?

nerve gas (lethal, rapid acting)

mechanism of OPS

binds to AchE and undergo hydrolysis--> phosphorylation of serine residue--> preventing binding and hydrolysis of endogenous Ach

where is malathion found?

in insecticides (highly toxic)

what is the duration of action of Malathion and Parathion?

days-weeks

is Malathion/Parathion lipid soluble?

HIGHLY lipid-soluble

what is the half-life of Edrophonium?

short (5-10min)

what is Edrophonium?

Alcohol type Ach inhibitor (non competitive, reversible inhibition)

what are the indications for Edrophonium?

Diagnosis of myasthenia gravis (improved muscle tone-->positive diagnosis) DD ('Tensilon test') : cholinergic crisis vs. myasthenia crisis

what drug is given with AchE inhibitors to control muscarinic side effects?

selective muscarinic antagonist (e.g glycopyrrolate)

Mechanism of AchE inhibitors

inhibits AchE--> ↑ in the concentration, half-life and activity of Ach in synapses--> induce both muscarinic and nicotic effects