Muscarinic And Nicotinic Blockers Flashcards
The efferent (motor) division of the PNS is sub-divided into ______ Nervous System and the ______ Nervous System.
Somatic
Autonomic
The somatic nervous system innervates the ______ muscles.
The ANS supplies motor impulses to ____ muscle, _____ muscles and to the glandular epithelium.
skeletal
cardiac; smooth
The ANS is divided into ______ and ______ systems.
sympathetic and the parasympathetic
Autonomic efferent pathway uses ___ neurons arranged in ___ to integrate CNS to the peripheral organs.
Somatic efferent pathway, however, uses _____ neuron for the integration of CNS to the skeletal muscles
two; series
a single
Cholinergic Transmission: Site Differences
Skeletal Muscle
Neurotransmitter:_______
Receptor type: _______
Acetylcholine
Nicotinic
Cholinergic Transmission: Site Differences
Autonomic Effectors
Neurotransmitter: _______
Receptor type:_________
effector coupled to receptor by _______
Acetylcholine
Muscarinic
a G protein
Cholinergic Transmission: Site Differences
Autonomic Ganglia
Neurotransmitter: ______
Receptor type: _____
Acetylcholine
Nicotinic
Nicotinic Receptor Agonists
These are drugs that mimic the action of acetylcholine at __________ receptor sites.
Examples include: ???
nicotinic acetylcholine
nicotine, acetylcholine, choline, epibatidine, lobeline, varenicline and cytisine
Ganglion stimulants
These are drugs which stimulate the ___ receptors in ___________ ganglia.
nicotinic
both sympathetic and parasympathetic
Ganglion stimulants
The dominant receptors are the _________.
In addition, there are subsidiary ___________________________________ receptors
nicotinic NN
M1, M2, adrenergic, dopaminergic, aminergic and peptidergic
autonomic ganglion is a one transmitter – one cell junction system
T/F
F
autonomic ganglion is not merely a one transmitter – one cell junction, but a complex system
therapeutic application of ganglion stimulants??
There is no therapeutic application of ganglion stimulants , as no useful purpose could be served by stimulating both sympathetic and parasympathetic ganglia concurrently.
Ganglion stimulants
Nicotine is available as ________ for treating nicotine dependence and as an aid to smoking cessation.
It ameliorates the symptoms of _________ but does not completely ______
transdermal patches
nicotine withdrawal
suppress craving.
Varenicline:
As a ___________, it reduces both the __________ and ________ of cigarettes and other tobacco products. Through these mechanisms it can assist some patients to quit smoking.
partial agonist
craving for and the pleasurable effects
ANTICHOLINERGIC DRUGS
Also known as Cholinergic Antagonists, ___________
Parasympatholytics
ANTICHOLINERGIC DRUGS
If via the nicotinic receptors, they are referred to as “______,” and “________.”
Ganglion blockers
Neuromuscular blockers
Muscarinic Receptor Subtypes:
M1
Location: ____ neurones , _____
Functions: Improves learning, memory, motor functions
Gastric glands:____ release, ___ secretion
Salivary: ____eased secretion
Clinical Effects: _____ Secretion
Clinically Selective Anticholinergic Drugs:
____,_____,____,______
CNS; Stomach
histamine; acid ; incr
Hydrogen Ion
Pirenzepine, Telenzepine, Dicyclomine, trihexyphenidyl
M1 is It is primarily a _____ receptor
neuronal
M2:
Location: ____,_____
- Functions: SA node: ____polarization, (enhanced or reduced?) rate of impulse generation
- AV node: (enhanced or reduced?) conduction velocity
- Atrium: (shortening or lengthening ?) of APD, (enhanced or reduced?) contractility
- Ventricle: (enhance or reduced?) contractility
- Presynaptic terminals/Cholinergic nerve endings of peripheral and central neurones : reduced ACh release
- CNS: tremor, analgesia
Heart, CNS
hyper ; Reduced; reduced
Shortening; Reduced
Reduced
M2 receptor exert (excitatory or inhibitory?) effects, mainly by increasing ___ conductance and by (stimulating or inhibiting?) _____ channels. Thus, its activation is responsible for the vagal ____ of the heart, as well as presynaptic ______ in the CNS and periphery.
inhibitory
K+; inhibiting; calcium
inhibition
inhibition
M2:
Clinical Effects: ______
Clinically Selective Anticholinergic Drugs: _______,_________
Bradycardia
Tripitamine, Methoctramine
M3:
Effects mainly (excitatory or inhibitory?) , except on the ______ muscle, where its activity is mediated through the release of ___, to produce vaso______.
excitatory; vascular smooth; NO
dilatation
M3:
- Location : ______,_____,_______,_____
Clinical Effects
CNS - Visceral smooth muscle (contraction or relaxation?)
- Iris (pupillary (constriction or dilatation?)
Smooth muscles, endocrine glands, lungs, pancreas
Contraction
Constriction
M3
Clinical effects
-Ciliary muscle (contraction or relaxation)
- Exocrine glands (______)
- Vascular endothelium (release of ___ to produce vaso____)
Clinically Selective Anticholinergic Drugs:
Mention 4
Contraction
Secretion
NO; dilatation
Darifenacin, Solifenacin, oxybutynin, tolterodine.
M4:
They function as (inhibitory or excitatiry?) autoreceptors for ACh.
When activated M4 receptors (inhibit or stimulate ?) ACh release in the striatum. Antagonist:_______
inhibitory
Inhibit
Himbacine
Atropine
Is sufficiently lipid (soluble or insoluble?)
Soluble
Atropine -from _______(_____)
Hyoscine- from ________-(_____).
Both are ______\ compds
Atropa belladonna
deadly nightshade
Datura stramonium
thorn apple
tertiary ammonium
Atropine
readily penetrate the BBB.
T/F
T
Semi-synthetic derivatives: Homatropine, Atropine methonitrate, Tiotropium, Ipratropium (quaternary amine) and Hyoscine butyl bromide
Synthetic: Cyclopentolate, Propantheline, Oxyphenonium, Glycopyrolate, Dicyclomine, Valethamate, Pirenzepine and Tropicamide (quaternary amine
Lmao
Atropine (prototype)
Effect on heart rate: causes ______, but in low doses it causes a _______, which results from a central action, increasing vagal activity.
Eye: Pupillary dilatation (mydriasis), which makes the eye _______. Relaxation of ______ causes paralysis of accommodation (cyclopegia), as a result, ___ vision is impaired.
tachycardia; paradoxical bradycardia
unresponsive to light
ciliary muscle
near
Effects of atropine
GIT: (enhanced or Reduced ?) motility
Other smooth muscles: ______,____, and _______ tract are all relaxed by atropine
Reduced
Bronchial, biliary and urinary
Effects of atropine
CNS: Atropine produces mainly (inhibitory or excitatory?) effects.
Low doses cause _______, higher doses cause ________
These central effects could be opposed by _________ drugs
Excitatory
mild restlessness
agitation and disorientation.
anticholinesterase
__________ is an effective antidote to atropine poisoning
Physostigmine
Hyoscine (low dose) causes marked ____ but is similar to ______ in high dosage.
sedation
atropine
Hyoscine also useful as an _____ and used in _____ sickness.
antiemetic
motion
Atropine-like drugs affect ________ system, reducing _______ movement and ______ in Parkinson’s disease.
Body temperature: (Increase or decrease)
Local anaesthestic: Atropine produces a mild anaesthetic action on the ___
extrapyramidal
involuntary
rigidity
Increase
cornea
Pharmacokinetics of atropine
Absorption: is (slow or rapid?) after ____ and local admn of the tertiary amines.
Systemic absorption of inhaled quaternary dugs is _____
Elimination: Atropine (__% is metabolised in the liver and the remaining ————-
Half-life: approx. __
Rapid; oral
Minimal
50
excreted unchanged in the urine.
4h
Between hyoscine and atropine , which penetrates the BBB better and which is more completely metabolized?
Hyoscine is more completely metabolized and penetrates the BBB better.
Summary of AntiCholinergic Effects
In the CNS- list 5
In the eye- list 3
In the heart- at low and high dose
In the bronchioles- list 2
Sedation, hallucination, drowsiness, antiparkinsonism, amnesia
Mydriasis, cyclopegia, lacrimal glands become dry and sandy
Initial bradycardia at low doses then tachycardia
Bronchodilation, decrease in bronchial secretions
Summary of AntiCholinergic Effects
In the GIT- tone, motility, emptying time
Urinary tract- tone, emptying
Relaxation, decrease motility, antidiarrheal, prolongs gastric emptying time
Relaxation of the bladder wall, urinary retention
Summary of AntiCholinergic Effects
Glands
Skeletal muscles
Decrease secretion, salivation, lacrimation, sweating
None
Anticholinergic Toxicity
Symptoms Mnemonic
-____ as a hare ( ______ )
-____ as a bone (___)
- ____ as a beet (____)
- ____ as a bat (____)
- ____ as a hatter (______)
Hot; Hyperthemia
Dry; dry skin
Red; flushed
Blind; mydriasis
Mad; delirium
Management of anticholinergic Toxicity
1) Control hyperthemia using _______
- Agitation may require
-____________
-________(Benzodiazepines) - If ingested, ____
- Antidote: ________ (1-3 mg s.c or i.v arrests both central and peripheral effects)
cold sponging or ice bags
physical restraints
- chemical restraints
gastric lavage
Physostigmine
Why physostigmine as antidote and not Neostigmine
Neostigmine is ineffective for central effects