Cholinergic Mechanism Flashcards
Primarily, acetylcholine is associated with ____ neurons and the activation of ________.
motor
muscle function
Nicotinic receptors function within the ___ nervous system and at the _______
While
muscarinic receptors function in _______ nervous systems, mediating innervation to __________
central; neuromuscular junction.
both the peripheral and central; visceral organs
Nicotinic receptors are also used by PNS
T/F
F
Only CNS
Choline esters (____,_____), which act at ___ sites, like acetylcholine, but are ____________
bethanechol, carbachol
all
resistant to degradation by acetylcholinesterases
Mention 2 examples of choline esters?
Bethanecol
Carbachol
Cholinomimetics ______________, esp. acetylcholine.
mimick the action of choline
medications that directly act on muscarinic or nicotinic receptors are called _______________, because they mimic acetylcholine.
Examples of these medications include _____,_________ ,_______, and _______
direct cholinomimetics
bethanechol, carbachol, methacholine, and pilocarpine.
Cholinesterase are chemicals that __________________.
breakdown the neurotransmitter acetylcholine
Cholinesterase
This ____eases the amount of the acetylcholine or ________ in the synaptic cleft that can bind to muscarinic receptors, nicotinic receptors and others
Decr
butyrylcholine
Anticholinesterase
Cholinesterase inhibitors, also known as anti-cholinesterase, are chemicals that ___________________. This ___eases the amount of the acetylcholine or butyrylcholine in the synaptic cleft that can bind to muscarinic receptors, nicotinic receptors and others
prevent the breakdown of the neurotransmitter acetylcholine or butyrylcholine
Incr
Cholinergics
They are drugs that act on the _______,______, or _______
They ______ the effects that are mediated by acetylcholine
peripheral nervous system, central nervous system, or both.
enhance
Cholinergics
Also known ______pathomimetic
parasym
Cholinergics
It works in 2 ways;
1. Act ______ by _______ the effects of acetylcholine on acetylcholine receptors present in the body.
2. Act ________ by ____________________
Directly; enhancing
indirectly; inhibiting the enzyme that is responsible for the degradation of acetylcholine
Types of anticholineesterases
Reversible –Bind to cholinesterase for a period of ______ to _____
Irreversible –Bind to cholinesterase and form a ________ –
minutes to hours
permanent covalent bond
Drug Effects of Cholinergic Agonists
___eased gastric secretions
____eased gastrointestinal motility
____eased urinary frequency
Incr
Incr
Incr
Drug Effects of Cholinergic Agonists
(Stimulate or Inhibit?) pupil Constriction (miosis)
(Increased or Reduced?) intraocular pressure
(Increased or decreased?) salivation and sweating
Stimulate
Reduced
Increased
Drug Effects of Cholinergic Agonists
(Increased or Decreased?) heart rate
Causes (Vasodilation or Vasoconstriction?)
Decreased
Vasodilation
It is important to know that:
At recommended low doses, the cholinergics primarily affect the ________ receptors.
At high doses, cholinergics stimulate the _______ receptors.
MUSCARINIC
NICOTINIC
CNS excitation
High dose or low dose
High dose
Ganglionic stimulation
High dose or low dose
High dose
Adrenaline release
High dose or low dose
High dose
RISE in BP
High dose or low dose
high dose
Fall in BP
High dose or low dose
Low dose
Increased GI motility
High dose or low dose
Low dose
Bladder constriction
High dose or low dose
Low dose
Salivation
High dose or low dose
Low dose
Lacrimation
High dose or low dose
Low dose
Bradycardia
High dose or low dose
Low dose
Broncho Constriction
High dose or low dose
Low dose
Examples of Cholinergic Agonist
Examples of Direct-acting: ______,_____,____,____
Examples of In-direct-acting:
_______,_____,______
acetylcholine, carbachol, pilocarpine
Bethanechol
physostigmine, pyridostigmine, donepezil (Aricept)
physostigmine
Direct or indirect cholinergic agonist
Indirect cholinergic agonist
pyridostigmine
Direct or indirect cholinergic agonist
Indirect cholinergic agonist
donepezil (Aricept)
Direct or indirect cholinergic agonist
Indirect cholinergic agonist
carbachol
Direct or indirect cholinergic agonist
Direct cholinergic agonist
pilocarpine
Direct or indirect cholinergic agonist
Direct cholinergic agonist
Bethanechol
Direct or indirect cholinergic agonist
Direct cholinergic agonist
Therapeutic Uses of Cholinergic Agonist
Carbachol and pilocarpine are (direct or indirect?) acting cholinergic agonist Useful for _________ and _______
Direct
glaucoma and intraocular pressure in surgery.
Bethanechol is a (direct or indirect?) acting cholinergic agonist that is used to ____ease _________ of _______ and ______.
It (constricts or relaxes?) sphincters in _______ and ______, allowing them to _____.
Direct ; Incr ; Tone and motility
bladder and GI tract
Relaxes ; bladder and GI tract
empty
Which is more important
MUSCARINIC or Nicotinic
MUSCARINIC
Acetylcholine is used for treatment of:
Myasthenia gravis ( _________)
Alzheimer’s disease (________)
Pyridostigmine
rivastigmine
Acetylcholine aids the action of muscle relaxants
T/F
F
It reverses it
Side effects of acetylcholine are:
Ocular side effects:
Corneal ______
Corneal ______
Corneal _______
swelling
clouding
decomposition
Side effects of acetylcholine are:
Systemic side effects:
_______
difficulty in _____
____tension
______
(slow or fast?) heart rate
sweating
Breathing
Hypotension
flushing
Slow
Carbachol is primarily used in the treatment of _______, but it is also used during ________.
glaucoma
ophthalmic surgery
Carbachol eyedrops are used to ___ease the _____ in the eye for people with glaucoma.
Decr
pressure
Carbachol eyedrops is sometimes used to ______ the ____ during ______ surgery.
constrict; pupils
cataract
Carbachol
Is metabolized by plasma cholinesterases
T/F
F
Is not
Carbachol is selective
T/F
F
It’s not
Therapeutic uses of bethanechol include:
_____eases _______ of ________
It relaxes __________ in _________, allowing them to empty
Incr; Tone and motility ; Bladder and GI tract
sphincters in bladder and GI tract
Bethanecol
Selective or not?
Selective
Bethanecol
Is metabolized by plasma cholinesterases
T/F
F
Structural differences between carbachol and Bethanecol?
Carbachol has an amide group only
Bethanecol has an amide group and an ethyl
Therapeutic uses of Pilocarpine are:
Pilocarpine is used to treat _______ caused by ______ in people with ___________ and to treat ______ in people with ________
dry mouth
radiotherapy; head and neck cancer
dry mouth
Sjögren’s syndrome
Sjögren’s syndrome
Is a condition that affects the _____ and causes _____ of certain parts of the body such as the ____________
immune system
dryness
eyes and mouth
Ophthalmic pilocarpine is used to treat _________, a condition in which increased pressure in the eye can lead to ____________.
glaucoma
gradual loss of vision
Opthalmic Pilocarpine is in a class of medications called ______. It works by allowing ______ to _________.
miotics
excess fluid
drain from the eye
Structure of pilocarpine?
Has an imidazole attached to it
Indirect-Acting Agents
Examples of Indirect-Acting Agents include:
1._________
2. ________
physostigmine
pyridostigmine
Therapeutic uses of physostigmine
Physostigmine cause ___ muscle (contractions or relaxations?)
Are used for treatment of _______
Are used to _________________ (antidote)
skeletal; contraction
myasthenia gravis
reverse anticholinergic poisoning
Indirect-Acting Agent—donepezil
Used in the treatment of ____ to ____ ——- disease.
Helps to increase ______ and ______
mild to moderate: Alzheimer’s
memory and learning capabilities
Drug interactions
Anti______ are known to antagonize cholinergic agents, resulting in decreased responses
histamines
Cholinergic Antagonist
They are drugs that compete with acetylcholine” for its binding sites at synaptic junctions thereby inhibiting its activity and preventing the transmission of _______pathetic nerve impulses.
parasym
Depending on the type of receptor to act on, cholinergic antagonists are either classified as ________ or ______
muscarinic antagonists or nicotinic antagonists.
Mechanism of Action of Cholinergic Antagonists
Block ACh at the _____ receptors in the PNS
prevent ACh from ______
Once these drugs bind to receptors, they inhibit nerve transmission at these receptors.
muscarinic
binding to the receptor site.
Cholinergic Antagonist are:
Natural group of ______ found in _____ (_______)
1. ____
2. _______
alkaloids; plants
BELLADONA ALKALOIDS
Atropine
Scopolamine
Atropine (________/ _____)
Scopolamine ( ____ pills causing ______.
properative; antidote
Sleeping; drowsiness
Drug Effects of Cholinergic Antagonist
Small doses: ___ease heart rate.
Large doses: ___ease heart rate .
Small doses: ____ease tremors.
Large doses: _____,_____,______ pupils
Decr
Incr
Decr
drowsiness, hallucinations.
Dilated
Dilated pupils aka ?
mydriasis
Drug Effects of Cholinergic Antagonist
____ease gastric secretion.
___ease motility and peristalsis.
____eased constriction of internal sphincter causing urinary retention
____eased salivation, sweating.
____eased bronchial secretions
Decr
Decr
Incr
Decr
Decr
Therapeutic Uses of Cholinergic Antagonists
It is used in treatment of
_______ disease by decreasing _____ and _______
Low doses:___ the heart rate.
High doses: ______ heart rate
Parkinson’s
muscle rigidity and power tremors.
slow; increased
Therapeutic Uses of Cholinergic Antagonists
Atropine Used primarily for _____ disorders
________ disease.
________ disease.
_________ states
cardiovascular
Peptic ulcer
Irritable bowel
GI hypersecretory
Cholinergic agonists are used to Used to treat Chronic bronchitis and Asthma
T/F
F
It’s cholinergic antagonists Used to treat Chronic bronchitis and Asthma
Side effects at cholinergic antagonists
________
_________
_________
_____eased salivation
____eased sweating
____eased bronchial secretions
Irritability
disorientation
halucination
Decr
Decr
Decr
Structure of acetylcholine can be divided into 3 parts
Name them
Acyl group
Ethylene bridge
Onium group
Side Effects of Indirect cholinomimetics
____cardia, ___tension, _____ abnormalities
___,___,______
Abdominal _____, ___eased secretions, nausea, vomiting
Bradycardia; hypotension; conduction
Headache, dizziness, convulsions
cramps
Incr
Side Effects of Indirect cholinomimetics
____eased bronchial secretions
____eased Lacrimation, sweating, salivation
Loss of binocular ______
Incr
Incr
accommodation
Ganglionic stimulants
Is predominantly on SYMP in what and what ?
Blood vessels
Sweat glands
Ganglionic blockade
Is predominantly on SYMP in what and what ?
Blood vessels
Acetylcholine has 3 parts in its structure
Mention them
Acyl group
Ethylene bridge
Onium group
Modifications in Acyl group(Ch3-COO) of acetylcholine
If the methyl group is substituted with ______, it results in ______ compound
If the ester group is substituted for ____ or ____, _____ compound is formed
Primary amine; more potent
Ether; ketone group; more potent
Modifications in ethylene bridge(Ch2-Ch2) of acetylcholine
Replacement of hydrogens in methyl group with ______ leads to ______ cholinergic activity. But replacing with a larger group than methyl leads to a _____ in activity
Substitution of methyl group at ____ carbon acts (selectively or non-selectively?) on _______ receptors
methyl group
equal or greater ; decrease
beta; selectively
MUSCARINIC
Modifications in Onium group (N-Ch3-Ch3-Ch3) of acetylcholine
If methyl group is replaced by ———- or ______ group it produces (active or inactive?) compounds
ethyl group or larger alkyl
inactive
Which amines is more active?
Pry,sec, tert
Or
Quaternary
Quaternary