Adrenergic & Cholinergic Flashcards
1
Q
Which system is considered as the body’s command system?
A
Nervous system
2
Q
What are the 3 main components of the nervous system ?
A
Brain
Spinal cord
Nerves
3
Q
How does the nervous system function?
A
By sending messages or electrical signals between the brain and other parts of the body
4
Q
What role does the nervous system play in the body ?
A
It keeps track of internal and external conditions and decides how to respond
5
Q
What are examples of involuntary actions controlled by the nervous system ?
A
Blushing, sweating, and blinking
6
Q
True or false
The nervous system controls both voluntary and involuntary actions.
A
True
7
Q
What are the two main parts of the nervous system ?
A
Central nervous system CNS
Peripheral nervous system PNS
8
Q
What components make up the CNS?
A
Brain
Spinal cord
9
Q
What is the PNS composed of?
A
A network of nerves branching out from the spinal cord
10
Q
What are the two parts of the PNS?
A
SOMATIC nervous system
AUTONOMIC nervous system
11
Q
What does the somatic nervous system control?
A
Voluntary movements
12
Q
What does the autonomic nervous system regulate/control?
A
Involuntary activities that happen without conscious control
13
Q
What are the two branches of the autonomic nervous system?
A
Sympathetic nervous system
Parasympathetic nervous system
14
Q
What is the role of the sympathetic nervous system ?
A
Fight or Flight
It carries signals that put the body’s systems on alert
15
Q
What is the role of the parasympathetic nervous system ?
A
Rest and Digest
It carries signals that relax the body’s systems.
16
Q
How do the sympathetic and parasympathetic nervous systems work together ?
A
They work in opposition to maintain body balance (homeostasis)
17
Q
Which branch of the autonomic nervous system is responsible for activating the “fight or flight” response?
A
Sympathetic nervous system
18
Q
Which branch of the autonomic nervous system helps the body return to a calm state “rest and digest”?
A
Parasympathetic nervous system
19
Q
What are the two divisions of the autonomic system neurotransmitters ?
A
Adrenergic system
Cholinergic system
20
Q
What are the primary neurotransmitters of the adrenergic system ?
A
Epinephrine (adrenaline)
Norepinephrine (noradrenaline)
21
Q
What is the primary neurotransmitter of the cholinergic system?
A
Acetylcholine
22
Q
Which autonomic system neurotransmitters are involved in the sympathetic nervous system?
Another way of asking this question:
Which neurotransmitters have sympathetic effects?
A
Norepinephrine (noradrenaline)🏃🏼♂️➡️
Epinephrine (adrenaline) 🏃🏻♂️➡️
23
Q
Which autonomic system neurotransmitters are involved in the parasympathetic nervous system?
Another way of asking this question:
Which neurotransmitters have parasympathetic effects?
A
Acetylcholine 💤
24
Q
Where is norepinephrine and epinephrine primarily released from in the body ?
A
Norepinephrine - postganglionic fibers
Epinephrine - adrenal medulla
25
What are the physiological effects of norepinephrine and epinephrine ?
(Sympathetic system)
- increased heart rate
- bronchial dilation
- increased blood glucose levels
26
What are the physiological effects of acetylcholine?
(Parasympathetic system)
- decrease heart rate
- dilation of visceral blood vessels
- increased digestion
27
Is the sympathetic nervous system usually activated all at once as a whole or in parts?
As a whole (mass activation)
28
True or false
The physiological response associated with the parasympathetic nervous system is a relaxing/restorative
True
29
Is the parasympathetic nervous system activated as a whole?
No, it usually stimulates individual parasympathetic nerves
30
True or false
Epinephrine gives relaxing effects .
False
Acetylcholine
31
True or false
Dilated visceral blood vessels are one of the many sympathetic effects .
False
Parasympathetic
(Think of it as increasing the blood flow to the digestive tract thus aiding digestion which is one of the parasympathetic effects)
32
What neurotransmitter is used by all PREGANGLIONIC fibers in both sympathetic and parasympathetic systems?
Acetylcholine
33
What is the term for synaptic transmission that involves acetylcholine ?
Cholinergic transmission
34
What is the term for synaptic transmission that involves epinephrine or norepinephrine?
Adrenergic transmission
35
What is the main neurotransmitter released by most sympathetic POSTganglionic fibers?
Norepinephrine
36
Which neurotransmitter is released from the adrenal medulla?
Epinephrine (adrenaline)
37
True or false
Epinephrine and norepinephrine both share the same precursor
True
38
What is the clinical purpose of autonomic drugs?
To imitate or inhibit the normal functions of the sympathetic and parasympathetic nervous systems
39
How do autonomic drugs affect the body?
They modify physiological responses by acting on the autonomic nervous system.
40
In physical therapy, why might cholinergic and adrenergic drugs be used?
To manage or influence physiological responses related to muscle tone, blood flow, or glandular activity
41
True or false
Cholinergic and adrenergic drugs primarily impact the somatic nervous system.
False
Autonomic nervous system
42
What does cholinergic neurotransmission in the CNS depend on?
The co-expression of proteins involved in the synthesis, storage, and release of acetylcholine + recycling of choline
43
What triggers the release of acetylcholine (ACh) at the nerve ending ?
An action potential propagated by voltage-sensitive sodium (Na+) channels.
44
What happens when the action potential reaches the presynaptic membrane?
Voltage-sensitive calcium (Ca2+) channels open, leading to calcium influx
45
What does the calcium influx (increased intracellular Ca2+) into the presynaptic neuron cause?
The fusion of the synaptic vesicles with the cel membrane and the release of neurotransmitters into the synaptic space.
46
Which ion channels are responsible for the propagation of the action potential ?
Voltage-sensitive/gated sodium (Na+) channels.
47
Which ion channels are responsible for triggering neurotransmitter release?
Voltage-sensitive/gated calcium (Ca2+) channels.
48
What is the role of synaptic vesicles in cholinergic neurotransmitters ?
They store and release acetylcholine upon stimulation
49
What are the two main types of cholinergic receptors?
Muscarinic receptors
Nicotinic receptors
50
Function of muscarinic and nicotinic receptors
Just review
51
What types of receptors does acetylcholine bind to?
Postsynaptic receptors on the target cell AND presynaptic auto-receptors
52
True or false
The result of ACh binding to its receptor leads to a biological response within the cell.
True
53
What is the function of presynaptic auto-receptors?
They regulate further neurotransmitter release (feedback).
54
Why is the acetylcholine signal at the post-junctional effector site rapidly terminated?
Because AChE (acetylcholinesterase) breaks down ACh into choline and acetate
55
Into what two products does AChE cleave acetylcholine ?
Choline and acetate
56
What happens to choline after ACh is broken down ?
It is recaptured by a sodium (Na+) - coupled, high-affinity reuptake system
57
Why is choline recycling important?
It ensures continuous synthesis of ACh for future neurotransmission.
58
What are cholinergic medications ?
Pharmaceutical agents that act upon the neurotransmitter acetylcholine
59
In which branch of the nervous system do cholinergic medications primarily act?
Parasympathetic nervous system PNS
60
What are the two broad categories of cholinergic drugs?
DIRECT-ACTING cholinergic agonists
INDIRECT-ACTING cholinergic agonists
61
How do direct-acting cholinergic agonists work?
By directly binding to and activating muscarinic receptors
(Basically they pretend to be acetylcholine and do its job)
62
How do indirect-acting cholinergic agonists work?
By increasing the availability of acetylcholine at cholinergic receptors
63
What is the primary effect of cholinergic agonists?
To enhance the action of acetylcholine in the body
64
Which type of cholinergic agonists binds directly to receptors ?
Direct-acting cholinergic agonists
65
Which type of cholinergic agonist affects acetylcholine degradation or availability?
Indirect-acting cholinergic agonists
66
True or false
Direct-acting cholinergic agonists MIMIC the effect of acetylcholine by binding directly to cholinergic receptors
True
67
What types of activity do direct-acting cholinergic agonists have?
AND
What are their cardiovascular, respiratory, and gastrointestinal effects?
Muscarinic and nicotinic activity
Cardio - ↓ HR, ↓ CO, ↓ BP
Resp - Bronchoconstriction
GI - ↑ GI activity
68
What are the clinical uses of direct-acting cholinergic agonists?
- Glaucoma
- Dry mouth following radiation to head/neck
- Laryngeal surgery
69
What are the common side effects of direct-acting cholinergic agonists ?
BLUDES
Bradycardia
Lacrimation
Urination
Diarrhea
Emesis (vomitting)
Salivation
70
Name 3 examples of direct-acting agonists
CARBACHOL
Bethanechol
PILOCARPINE
71
Carbachol is what type of drug?
Direct-acting cholinergic agonist
72
Pilocarpine is what type of drug
Direct-acting cholinergic agonist
73
What is the mechanism of action for indirect-acting cholinergic agonists ?
They inhibit acetylcholinesterase (AChE), preventing ACh degradation and indirectly enhancing ACh activity .
74
Are the effects of indirect-acting cholinergic agonists reversible or irreversible ? Long-term or short-term?
Reversible and short-term
75
What does inhibiting AChE accomplish ?
Increases the amount of ACh available at cholinergic receptors
76
What is Edrophonium used for ?
To temporarily increase muscle strength (indirect acting)
77
What is Neostigmine used for and what is unique about it?
It is used to reverse the effects of muscle relaxants and does not cross the blood-brain barrier (indirect acting)
78
True or false
Neostigmine does not cross the blood brain barrier
True
79
What is Pyridostigmine used for?
For patients with myasthenia gravis, similar to Neostigmine (indirect acting)
80
What is Physostigmine used to treat?
Anticholinergic overdose
81
What are some signs of overdose from indirect-acting cholinergic agonists?
Bradycardia
Hypotension
Excessive GI muscle contraction
Skeletal muscle paralysis
(Hint think exaggeration of parasympathetic effects)
(Hint: SHEB)
82
What class of drug is used in myasthenia gravis management ?
Indirect-acting cholinergic agonists like Pyridostigmine
83
Why is Physostigmine useful in anticholinergic overdose?
It can cross the blood-brain barrier to reverse central effects of anticholinergic toxicity
84
What type of drug is Edrophonium
Indirect-acting cholinergic agonist
85
What type of drug is neostigmine
Indirect-acting cholinergic agonist
86
What type of drug is Pyridostigmine
Indirect-acting cholinergic agonist
87
What type of drug is Physostigmine
Indirect-acting cholinergic agonist
88
What is the primary action of cholinergic antagonists?
They block nicotinic or muscarinic receptors in the central and peripheral nervous systems
89
How do cholinergic antagonists work?
By preventing ACh from binding to its receptors, thereby reducing cholinergic transmission
90
What systems are affected by cholinergic antagonists?
Both CNS and PNS
91
On what basis are cholinergic antagonists classified ?
Based on their receptor affinity - either muscarinic OR nicotinic
92
What are the two major subclasses of cholinergic antagonists ?
Antimuscarinic drugs
Anti-nicotinic drugs
93
What are the two types of anti-nicotinic drugs ?
Neuromuscular blockers
Ganglion blockers
94
What is the function of muscarinic receptor ANTAgonists (MRAs) ?
They COMPETITIVELY block the cholinergic effect/response caused by the ACh binding to muscarinic receptors that are present on :
- exocrine glandular cells = decreased gland secretion
- cardiac muscle cells = increased heart rate
- smooth muscle cell = muscle relaxation of smooth muscles
Summary: MRAs COMPETITIVELY block the binding of ACh to muscarinic receptors, preventing the PNS from exerting its effects
95
Where do muscarinic receptor anatogonists (MRAs) act?
They act on muscarinic receptors found on:
- EXOCRINE GLANDULAR CELLS - reduces secretion
- CARDIAC MUSCLE CELLS - increase heart rate
- SMOOTH MUSCLES (in GI, bladder, and bronchi) - relax
Note : the above is done in this manner :
(LOCATION - effect of MRA on it)
96
Knowing that MRAs effect on smooth muscle is relaxation, what happens to the bronchi?
Bronchodilation
97
What happens when muscarinic receptors are blocked?
Secretions decrease
Heart rate increases
Smooth muscle relax
98
What drug is the best-known member of the MRAs group?
Atropine
99
What is Atropine and how does it work?
It is a COMPETITVE and REVERSIBLE MRA (muscarinic receptor antagonist) that blocks the effects of ACh and other choline esters
100
True or false
Atropine has a variety of therapeutic applications
True
101
Fill in this chart regarding the effects of MRAs
102
What is the effect of anticholinergics/MRAs ( i.e atropine ) on the heart ?
It blocks M2 receptors, preventing parasympathetic inhibition, leading to an increase in heart rate (prolonged effect = tachycardia)
103
What is the effect of anticholinergics/MRAs ( i.e atropine, Ipratropium, Tiotropium) on the bronchioles ?
It blocks M3 receptors on bronchioles, causing bronchodilation and a reduction in bronchial secretions (useful in asthma)
104
True or false
Ipratropium and tiotropium show both central and peripheral actions
False
Only peripheral actions (they don’t cross the blood brain barrier)
Unlike Atropine which has both central and peripheral actions
105
What is the effect of anticholinergics/MRAs on the GI smooth muscle ?
Block M3 receptors Decreases gastric motility = constipation
Relieves spasms of GI smooth muscle = antispasmodic
Drugs like: Atropine, Hyoscine, Dicyclomine
106
What is the effect of anticholinergics/MRAs ( i.e atropine ) on the bladder ?
It blocks M3 receptors, causing bladder relaxation and decreasing tone
Can be used in treating urinary incontinence to control urination (especially in elderly)
Ex of these bladder relaxants:
- Darifenacin (specific antagonist)
- Oxybutynin, Tolterodine, Solefenacin (non-selective anticholinergics)
107
Similarity and differences between the following drugs:
Darifenacin
Oxybutynin
Tolterodine
Solefenacin
Similarity: they ALL act as bladder relaxants and can be used to treat urinary incontinence (to control urination)
Difference:
- Darifenacin (specific antagonist on M3)
- Oxybutynin, Tolterodine, Solefenacin (non-selective anticholinergics)
108
What are the possible side effects of muscarinic receptors antagonists MRAs?
(Hint: 6)
1. Dry mouth & sore throat - due to ↓glandular secretions by exocrine glands
2. Tachycardia - due to blocking parasympathetic inhibition of the heart
3. Urinary retention (inability to empty bladder) - due to relaxation of the bladder
4. Obstipation - inability to pass stools or gas due to ↓smooth muscle motility and tone
5. Blurred vision and light sensitivity
6. Mood changes, hallucinations, confusion, and disorientation - in only some MRAs
109
What are nicotinic receptor antagonists NRAs?
Drugs that bind to nicotinic cholinergic receptors and block the actions of ACh or cholinergic agonists
110
Where do nicotinic antagonists act? Or NRAs block synaptic transmissions where?
Autonomic ganglia
Skeletal neuromuscular junction
CNS nicotinic synapses
111
True or false
Neuromuscular blockers is a subcategory of antimuscarinics
False
Anti-nicotinic
112
______________ are drugs that interrupt transmission of nerve impulses at the skeletal neuromuscular junction
Neuromuscular blockers (anti-nicotinic)
113
What are the two types of neuromuscular blockers ?
Neuromuscular Nondepolarizing agents
Neuromuscular Depolarizing agents
114
What is the effect of neuromuscular blockers (both nondepolarizing and depolarizing) ?
What are they used as/for?
They prevent ACh from triggering muscle contraction and are used as :
- Anesthesia adjuvants
- Relaxants during electroshock
- Treatment for convulsive states
115
The choice of neuromuscular blockers/agents (antinicotnic) depends on what?
- Desired onset and duration of muscle relaxation
- Route of elimination
116
What is the function of neuromuscular blocking drugs ?
They stop the muscles from working for a short period of time
117
When are neuromuscular blockers used?
- Surgery/procedures that require general anesthesia
- Intubation
118
How are neuromuscular blocking drugs administered?
Clear liquid into the vein (intravenously IV)
119
How do nondepolarizing neuromuscular blockers work?
They are competitive ACh antagonists that bind to nicotinic receptors on the POSTSYNAPTIC membrane, preventing depolarization at the motor endplate, leading to muscle paralysis
120
What are the two types of nondepolarizing neuromuscular blockers based on their chemical structure?
Steroidal blockers :
- rocuronium, vecuronium, pancuronium
Benzylisoquinoline
- mivacurium, atracurium, cisatracurium
(These drugs are not on the drug list)
121
Example of depolarizing neuromuscular blockers
Succinylcholine
122
What is Succinylcholine and how does it work?
A depolarizing neuromuscular blocker and it binds to POSTSYNAPTIC cholinergic receptors on the motor endplate, causing rapid depolarization, fasciculation, and flaccid paralysis.
Rapid onset + short duration of action
123
True or false
Depolarizing neuromuscular blockers like Succinylcholine are widely used due to its SLOW onset and SHORT duration of action, making it ideal for rapid sequence induction.
False
RAPID onset + short duration of action
124
True or false
Depolarizing neuromuscular blockers like Succinylcholine are widely used due to its RAPID onset and LONG duration of action, making it ideal for rapid sequence induction.
False
Rapid onset + SHORT duration of action
125
True or false
Depolarizing neuromuscular blockers like Succinylcholine are widely used due to its RAPID onset and SHORT duration of action, making it ideal for rapid sequence induction.
True
126
How quickly does Succinylcholine cause paralysis, and how long does it last?
Paralysis takes about 1 minute after administration and lasts about 7 to 12 minutes
(Short-lasting)
127
How is Succinylcholine metabolized ?
By plasma pseudocholinesterase
128
What happens if a patient has pseudocholinesterase deficiency ?
Prolonged neuromuscular blockade may occur, requiring postoperative mechanical ventilation
129
Describe the lasting effect for Nondepolarizing neuromuscular blockers VS Depolarizing neuromuscular blockers
Depolarizing - short-lasting effects
Nondepolarizing - longer lasting effects
130
What are the adverse side effects of neuromuscular blockers ?
Histamine release leading to:
- hypotension
- flushing
- tachycardia
Depolarizing effect on muscle fibers = momentarily release of large amount of potassium (↑K+) = ↑hyperkalemia and cardiac arrhythmias
131
True or false
When noradrenaline (NA) is the neurotransmitter, then the neuron is termed cholinergic.
False
Adrenergic
132
What receptors does noradrenaline act on ?
Alpha (α) or Βeta (β) adrenergic receptors
133
Review of receptor (not in the note exactly)
What does stimulation of α1 receptors do?
Vasoconstriction of blood vessels
↑ peripheral resistance
↑ BP
Mydriasis (pupil dilation)
Closure of visceral organ sphincters
134
Review of receptor (not in the note exactly)
What does stimulation of α2 receptors do?
Inhibition of NE release
Inhibition of insulin release
135
Review of receptor (not in the note exactly)
What does stimulation of β1 receptors do?
↑ HR
↑ myocardial contractility
↑ renin release from kidneys
136
Review of receptor (not in the note exactly)
What does stimulation of β2 receptors do?
Bronchodilation
Vasodilation in skeletal muscles
↓ peripheral resistance
↑ muscle and liver glycogenoolysis
↑ glucagon
Relaxation of uterine, urinary, and digestive smooth muscles
137
Review of receptor (not in the note exactly)
What does stimulation of β3 receptors do?
Lipolysis in adipose tissue
138
Steps for neurotransmission at adrenergic neurons :
139
What is the substrate for noradrenaline (NA) synthesis ?
Tyrosine ( a dietary protein )
140
True or false
EVERY step in the formation of NA depends on a SPECIFIC enzyme
True
141
What enzyme hydroxylates tyrosine to dihydroxypheylalanine ( DOPA ) ?
Tyrosine hydroxylase
142
What is the rate-limiting step in the synthesis of NA that determines the overall rate of dopamine and noradrenaline formation?
Hydroxylation of tyrosine by tyrosine hydroxylase
143
How is dopamine formed from DOPA?
DOPA is converted to dopamine by DOPA Decarboxylase
144
In case, memorize these steps for NA synthesis
Done ✅
145
What converts dopamine to noradrenaline ?
Dopamine β-hydroxylase
146
What converts noradrenaline to adrenaline?
Phenylethanolamine N-methyltransferase
147
Where does dopamine get converted and by what enzyme during the NA synthesis?
Dopamine is transported into synaptic vesicles and hydroxylated by dopamine β-hydroxylase to produce NA
148
What happens to NA in the adrenal medulla ?
NA is methylated to adrenaline
149
What triggers the release of NA from the nerve terminal ?
An action potential arriving at the nerve terminal causes an influx of calcium ions from the extracellular fluid into the neuron = ↑ intracellular calcium = synaptic vesicles fuse with cell membrane (exocytosis), and expel NA into the synapse.
150
Which drug blocks the release of NA ?
Guanethidine
151
What does Guanethidine do?
Blocks NA release
152
Where does the released NA bind ?
- POSTSYNAPTIC receptors on the effector organ
- PRESYNAPTIC receptors on the nerve ending
153
What happens when NA binds to postsynaptic receptors ?
It initiates a cascade of events leading to the formation of second messengers
154
How does NA affect presynaptic receptors ?
It modulates/regulates further release of the neurotransmitter = NEGATIVE feedback mechanism
155
Which receptor is responsible for inhibiting NA release?
Stimulation of presynaptic α2 receptors decrease central sympathetic outflow and thus inhibits further release of NA
156
What is the primary mechanism for terminating NA effects at the postsynaptic receptor ?
Reuptake into the neuron
(NON-ENZYMATIC mechanism)
157
What is the uptake system responsible for reuptake of NA?
Uptake 1 (neuronal uptake)
158
What percentage of released NA is taken back up into the presynaptic neuron by Uptake-1?
About 75%
159
What is Uptake 2 ?
Extra-neuronal uptake where NA diffuses out of the synaptic space into post-junctional tissues
160
What are the 2 enzymes that inactivate NA as a part of the ENZYMATIC removal of the neurotransmitter from the synaptic gap?
Monoamine oxidase (MAO)
Catechol O-methyltransferase (COMT)
161
Where does MAO metabolize NA?
Inside the neuron after reuptake (after NA re-enters the neuron)
162
Where does COMT metabolize NA?
In the synaptic space, converting it to inactive metabolites
163
Removal of the neurotransmitter (NA) from the synaptic gap can be either :
Non-enzymatic
- uptake 1
- uptake 2
Or
Enzymatic
- MAO
- COMT
164
What are the possible fates of released noradrenaline ?
- Act on presynaptic receptors
- Act on postsynaptic adrenergic receptors
- Undergo reuptake by the presynaptic terminal
- Be broken down by enzymes
165
How are adrenergic agonists classified ?
166
How do direct-acting adrenergic agonists work?
They produce their effects by binding to adrenergic receptors and mimicking the actions of natural transmitters (ex: NA, A, dopamine)
167
True or false
Indirect interaction with receptors is the most common mechanism by which drugs activate peripheral adrenergic receptors.
False
Direct interaction
168
Therapeutic uses of adrenergic agonists
Adjunct to local anesthesia
Treating Anaphylactic shock
169
Which adrenergic agonist is widely used as an additive in local anesthetics to improve the duration of anesthesia ?
Epinephrine
170
True or false
Epinephrine can be used as an adjunct to local anesthesia
True
171
What are the therapeutic uses of epinephrine as an adjunct to local anesthesia ?
Improving the duration of the anesthesia as it causes vasoconstriction induced by activation of α1 receptors thus reducing blood flow to the site of anesthetic administration
Summary :
Epinephrine = activation of α1 = vasoconstriction = ↓blood flow to site = longer duration of anesthesia at that site
172
What is the first-line of treatment for anaphylactic shock ?
Intramuscular (IM) injection of adrenaline (NA)
173
____________ is a life threatening, severe allergic reaction
Anaphylaxis
174
How does epinephrine reverse the effects of anaphylaxis ?
Reduces swelling
Opens the airways
Maintains heart function and blood pressure
175
How do indirect-acting adrenergic agonists work ?
(Promotion of NA release !!!)
They do not act directly on postsynaptic receptors
AND
They cause NA release from the nerve terminals by displacing NA from vesicles
176
What are examples of indirect-acting adrenergic agonists ?
Amphetamine
Tyramine
177
What is the mode of action for amphetamine ?
Amphetamine enters the nerve terminal & enters the synaptic vesicles in exchange for NA.
THEN, NA accumulates in the cytosol and while some get degraded by MAO within the nerve terminal, others escape and act on postsynaptic receptors
178
What are mixed-action adrenergic agonists?
They stimulate adrenergic receptors directly and also cause the release of noradrenaline from the adrenergic neuron
179
What is an example of a mixed-action adrenergic agonists?
Ephedrine
180
What is Ephedrine ?
Mixed-action adrenergic agonists
181
What is the clinical use of ephedrine ?
Used to manage and treat clinically significant HYPOTENSION
182
What class of drugs does ephedrine belong to ?
Sympathomimetic class of drugs.
183
Epinephrine
What receptors does it act on ?
Therapeutic uses ?
184
Norepinephrine
What receptors does it act on ?
Therapeutic uses ?
185
Isoproterenol
What receptors does it act on ?
Therapeutic uses ?
186
Dopamine
What receptors does it act on ?
Therapeutic uses ?
187
Dobutamine
What receptors does it act on ?
Therapeutic uses ?
188
Easy picture
Take a Quick Look
Done ✅
189
What are adrenergic antagonists ?
Compounds that inhibit the action of adrenaline, noradrenaline, and other catecholamines that control autonomic outflow at adrenergic receptors.
190
What are adrenergic antagonists primarily used for?
They are used in the treatment of cardiac diseases and others.
191
Physiological effects of adrenergic antagonists
Vasodilation , which ↓BP and ↓HR
192
What do α1-adrenergic receptor antagonists ( α1-blockers ) do?
They bind to α1 receptors and inhibit smooth muscle contraction = ↓ sympathetic tone of blood vessels = ↓ peripheral resistance = ↓ BP
193
Where do α-adrenoceptor antagonists bind?
What is its effect?
They bind to α-adrenoceptors located on vascular smooth muscle.
They dilate both arteries and veins because both are innervated by sympathetic adrenergic nerves
194
Which vessels are more affected by α-adrenoceptor antagonists?
The vasodilator effect is more pronounced in the arterial resistance vessels
195
How are α-adrenergic antagonists classified
Non-selective α-blockers ( both α1 & α2 )
Selective α1-antagonists
Selective α2-antagonists
Some drugs block both α1 & β adrenoceptors
196
PHENOXYBENZAMINE and PHENOLAMINE
Are what type of drugs ?
Non-selective α-blockers (type of α adrenergic antagonists)
197
PRAZOSIN and doxazosin
Are what type of drugs
Selective α1-antagonists
(type of α adrenergic antagonists)
198
Yohimbine is what type of drug
Selective α2-antagonists
(type of α adrenergic antagonists)
199
Labetolol and carvedilol
Are what type of drugs
α1 & β adrenoreceptor blockers
(type of α adrenergic antagonists)
200
How are β -adrenergic antagonists classified
Nonselective β receptor antagonists (both β1 and β2)
Nonselective β receptor antagonist (all β1, β2, and β3)
Selective β1 antagonists
Selective β2 antagonists
201
PROPRANOLOL is what type of drug
Nonselective β receptor antagonists ( β1 and β2)
(type of β adrenoreceptor antagonists)
202
Cyanopindolol is what type of drug ?
Nonselective β receptor antagonist ( all β1, β2, and β3)
(type of β adrenoreceptor antagonists)
203
ATENOLOL and Metoprolol
Are what type of drugs
Selective β1 antagonists
(type of β adrenoreceptor antagonists)
204
Butoxamine is what type of drug
Selective β2 antagonists
(type of β adrenoreceptor antagonists)
205
Review this drug chart
Done ✅
206
Drug list review :
Cholinergic agonists (direct and indirect acting)
Direct acting : Carbachol & Pilocarpine
Indirect acting: Neostigmine & Edrophonium
207
Drug list review :
Cholinergic antagonists
- antimuscarinic
- ganglionic blockers
- neuromuscular blockers
Antimuscarinic:
- Atropine & Scopolamine
Ganglionic blockers :
- Mecamylamine & Nicotine
Neuromuscular blockers:
- Succinycholine & Metocurine
208
Drug list review :
Adrenergic agonists (direct, indirect, and mixed acting)
Direct: Epinephrine, dopamine, norepinephrine, dobutamine, isoproterenol
Indirect: amphetamine, cocaine
Mixed: ephedrine
209
Drug list review :
Adrenergic antagonists ( α-blockers, β-blockers, impact neurotransmitter uptake or release)
α-blockers:
Prazosin, Phenylamine, Phenoxybenzamine
β-blockers:
Atenolol, Propranolol, Timolol
Affect neurotransmitter uptake or release:
Guanethidine , Reserpine
210
211
True or false
Atropine is reversible and competitive
True
