Cholinergic Drugs Flashcards
0
Q
Nicotine
A
A= cholinopositive drug, N-agonist (direct acting), tertiary natural cholinomimetic alkaloid B= binds to and activates nicotinic receptors (both Nn and Nm receptors) on dopaminergic neurons in the cortico-limbic pathways --> increase release of dopamine--> euphoric and addictive features of nicotine C= smoking cessation and relief of withdrawal symptoms (non medical uses: smoking and insecticide)
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Q
Pilocarpine
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A= cholinopositive drug, M-agonist(direct acting), tertiary natural cholinomimetic alkaloid B= Binds to and activates muscarinic receptors (m1 through m3) in all peripheral tissues, ⬆️ca2+ levels by 2nd messenger systems (IP3, DAG) --> negative chrono-ino-dromotrophic effects in heart, ciliary muscle contraction etc (parasympathetic effects) C= Glaucoma, Sjögren's syndrome, decreased/lack of tone of GIT and urinary bladder.
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Q
Varenicline (champix)
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A= cholinopositive drug, N-agonist, selective partial agonist B= binds to and activates Nalpha4beta2 receptors in the brain--> release of dopamine in smaller amounts and simultaneously blocks nicotinic activation of receptors (small antagonistic property) C= smoking cessation, relief of withdrawal symptoms
3
Q
Neostigmine (acts peripherally)
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A= cholinopositive drug, indirect acting parasympathomimetics, reversible anticholinesterase (carbamate + modest direct acting property; activates nicotinic receptors too) B= blocks enzymes cholinersterases (ACHE and butyrylcholinesterase) by forming covalent bonds with them --> evokes prolonged effects of acetylcholine in the synaptic cleft--> stimulates N and M receptors through the activity of ACE C= glaucoma(physostigmine), myasthenia gravis(improves muscle tone), decurarization (reversal of anticholinergic effects), muscle paralysis, atony of guts and bladder, central paralysis
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Q
Pyridostigmine (acts peripherally)
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A=cholinopositive drug, indirect acting parasympathomimetics,reversible peripheral ACE (carbamates)
B= blocks enzymes cholinesterases=> amplifies endogenous concentration of ach and evokes prolonged effect of ach=> stimulates both m and n receptors thru ACE activity
C= glaucoma, myasthenia gravis, decurarization (reversal of anticholinergic effects), muscle paralysis, atony of guts and bladder, central paralysis
5
Q
Ipidacrine (cross blood-brain barrier)
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A= cholinopositive drug, indirect acting parasympathomimetics, ACE B= inhibits and block enzymes cholinesterases=>amplifies endogenous conc of ach=>stimulates both n and m receptors thro ACE, able to cross blood brain barrier C= Alzheimer's disease, central paralysis. (Substitutes the loss of cholinergic neurons in alz disease)
6
Q
Donepezil (long half life–> once daily)
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A= cholinopositive drug, indirect acting parasympathomimetics, selective ACE B= blocks enzymes cholinesterases (forms covalent bonds with them) => amplifies endogenous conc of ach (cross blood-brain barrier) C= Alzheimer's disease (improves cognitive functions but do not cure)
7
Q
Rivastigmine
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A= cholinopositive drug, indirect acting parasympathomimetics, selective ACE B= blocks enzymes cholinesterases => amplifies endogenous conc of ach => increases cholinergic activity (cross blood-brain barrier) C= Alzheimer's disease (improves cognitive functions but do not cure)
8
Q
Atropine (first line drug against heart block)
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A= cholinonegative drug (direct acting), competitive muscarinic antagonist (tertiary amine alkaloid ester) B= binds to and prevents activity of muscarinic receptors=> reversable blockade of Vagal nerve=> oppose parasympathetic effects C= Parkinson's disease (reduces tremor and rigidity), intoxication and poisoning treatment of mushrooms and muscarinic agonists, eye treatment (dilating pupil/mydriadis and cytoplegia! , bradycardia and heart block, premedication (reduces hyper secretion of airway glands).
9
Q
Hyoscine butyl bromide (scopolamine) acts more centrally
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A= antiemetics, cholinonegative drug (direct-acting), muscarinic antagonist B= depresses cholinergic activities by blocking m receptors, which reduces vertigo and post operative nausea. Interfers with the transmission of nerve impulses by ach in the parasympathetic nervous system, specifically the vomiting center. C= prevention of motion sickness (emesis due to vestibular disturbances) and post operative nausea and vomiting. Used as an antispasmodic and mydriatic and cycloplegic agent as well.
10
Q
Trihexyphenidyl
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A= cholinonegative drug, selective m1 muscarinic antagonist of CNS B= partially blocks cholinergic activity in the CNS and increases the availability of dopamine--> brings about smoother control of voluntary muscle movement and corrects the relative cholinergic excess in basal ganliga C= reduces tremor and rigidity--> Parkinson's disease and other drug induced extrapyramidal movement disorders, antispasmodic agents and is thought to relief sialorrhoea symptoms.
11
Q
Ipratropium (short duration of action!)
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A= cholinonegative drug, synthetic competetive non selective muscarinic antagonist (quaternary ammonium compounds) B= blocks M3 receptors --> reduces/prevents bronchospasm (opposite effects of parasympathetic system) by reducing the formation of cGMP which leads to decreased contractility of smooth muscle C= prevention and relief of acute episodes of bronchospasm and in inhalations against COPD and asthma.
12
Q
Tiotropium (long duration of action)
A
A=cholinonegative drug, competetive synthetic non selective muscarinic antagonist
B= blocks M3 receptors –> reduces/prevents bronchospasms by decreasing amount of cGMP decreases contractility of SMC (SMC relaxation)
C= bronchodilator used for COPD and other chronic obstructive disorders (never acute episodes)
13
Q
Tolterodine
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A= cholinonegative drug, m3 selective competetive antagonist B= blocks M3 and M2 receptors located on detrusor muscle of bladder -->inhibition of bladder contraction, decrease in detrusor pressure and an incomplete emptying of bladder C= urinary incontinence
14
Q
Tropicamide
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A= cholinonegative drug, muscarinic antagonist B= binds to and blocks muscarinic receptors in eye muscles (mainly M4 receptors)--> blocks the responses of the iris sphincter muscle and ciliary muscles to cholinergic stimulation, producing dilation of pupil and paralysis of ciliary muscle C= promotes mydriasis and cycloplegia for eye examinations
