Autonomic Pharmacology Flashcards
(159 cards)
1
Q
What type of functions does the autonomic nervous system control?
A
- Visceral functions that occur without concious control
2
Q
What is the “only organ” not innervated by the autonomic nervous system?
A
- Skeletal muscle
3
Q
From where does the autonomic nervous system originate?
A
- The CNS/ lower brainstem
4
Q
What are the 2 divisions of the ANS?
A
- Sympathetic
- Parasympathetic
5
Q
What effect does the parasympathetic/ sympathetic nervous system have on the pupils?
A
Sympathetic: Dilates pupil
Parasympathetic: Constricts pupil
6
Q
What effect does the parasympathetic/ sympathetic nervous system have on salivation?
A
Sympathetic: Inhibits salivation
Parasympathetic: Stimulates salivation
7
Q
What effect does the parasympathetic/ sympathetic nervous system have on the heart?
A
Sympathetic: Accelerates the heart
Parasympathetic: Inhibits the heart
8
Q
What effect does the parasympathetic/ sympathetic nervous system have on the bronchi?
A
Sympathetic: Dilates bronchi
Parasympathetic: Constricts bronchi
9
Q
What effect does the parasympathetic/ sympathetic nervous system have on digestive activity?
A
Sympathetic: Inhibits digestive activity
Parasympathetic: Facilitates digestive activity
10
Q
What effect does the parasympathetic/ sympathetic nervous system have on the kidneys and gallbladder?
A
Sympathetic: Stimulates glucose release by the liver
Parasympathetic: Stimulates the gall bladder
11
Q
What effect does the parasympathetic/ sympathetic nervous system have on the bladder?
A
Sympathetic: Relaxes the bladder
Parasympathetic: Contracts the bladder
12
Q
What effect does the parasympathetic/ sympathetic nervous system have on the rectum?
A
Sympathetic: Contracts the rectum
Parasympathetic: Relaxes the rectum
13
Q
What effect does the sympathetic nervous system have on the kidneys?
A
- Secretion of epinephrine and norepinephrine
14
Q
What is the main nerve to the heart?
A
- The vagus nerve
15
Q
From which spinal segments do the sympathetic fibers originate from?
A
T1 - L3
16
Q
From which part of the nervous system/ spinal segments do the parasympathetic fibers originate from?
A
- Midbrain
- Medulla oblongata
- Sacral portion of spinal cord
17
Q
What is an autonomic ganglia?
A
- Specialized complex structure residing outside the spinal cord that contains axodendritic synapses between preganglionic and postganglionic neurons
18
Q
Is the sympathetic nervous system closer, or farther away from the spinal cord?
A
- Sympathetic closer
- Parasympathetic farther away
19
Q
What does an autonomic ganglion connect?
A
Preganglionic and postganglionic nerves
20
Q
How do reactions propogate through ganglia?
A
Neurotransmitters
21
Q
Which neurotransmitter is present in the autonomic ganglia of the sympathetic and parasympathetic nervous systems?
A
Acetylcholine
22
Q
Why do drugs need to either stimulate or block at the level of the end organ?
A
There is no specificity
23
Q
Where are receptors located typically?
A
Embedded into the target tissue (nerve, end organ, etc…)
24
Q
What neurotransmitter is located at the neuro-effector junction of the parasympathetic division?
A
Acetylcholine
25
What two compounds are acetylcholine synthesized from? What enzyme facilitates this synthesis?
- Acetyl CoA and Choline
| - Choline Acetyltranseferase
26
Where is Acetylcholine broken down?
Ganglionic junction or neuro-effector junction
27
Why can't acetylcholine be used as a drug?
It is resorbed/ disposed of too quickly
28
What happens to ACh after it is synthesized?
- Stored in vesicle at the nerve terminal
29
What ions are involved in binding the ACh vesicle to the nerve terminal and releasing ACh into the synapse?
- Sodium
| - Calcium
30
Where does norepinephrine function as a neurotrasmitter in the autonomic nervous system?
- Neuro-effector junction of sympathetic nervous system
31
What group of chemicals does norepinephrine belong to?
- Catecholamines
32
What 2 other chemicals are catecholamines?
- Dopamine
| - Epinephrine
33
What chemical do the adrenal glands release?
- Epinephrine
34
What catecholamine is a precursor to norepinephrine?
- Dopamine
35
What is the main way that NE is removed from the synapse?
- Re-uptake by pre-synaptic fibers
36
What mediates re-uptake of norepinephrine?
Alpha-2 receptors
37
What are 2 methods of inactivation of NE?
Breakdown by:
- Monoamine oxidase
- Catechol-o-methyltransferase
38
What 2 factors of a cell can be affected by NE or ACh?
- Metabolism
| - Ion channels
39
What is the presynaptic receptor in the sympathetic nervous system? What is its function?
- Alpha-2 receptor
- If activated by an excess of NE in the synapse, it sends a signal to the nerve terminal to decrease norepinephrine synthesis
40
What two subtypes of receptors mediate ACh's effects?
- Muscarinic (M)
| - Nicotinic (N)
41
Where are M receptors found?
- Neuro-effector junction in parasympathetic division
42
Where are N receptors found?
- Autonomic ganglia of both sympathetic and parasympathetic divisions of the ANS, and at the neuro-muscular junction
43
What is the source of the name of nicotinic receptors?
Nicotine
44
What is the source of the name of muscarinic receptors?
Mushrooms
45
What is meant by neuro-effector junction?
At the end organ
46
What type of reactions are muscarine receptors related to?
Parasympathetic
47
What type of reactions are nictonic receptors related to?
Both sympathetic and parasympathetic
48
What two subtypes of receptors mediate the effects of norepinephrine, and epinephrine?
Alpha and beta receptors
49
What are the 2 types of alpha receptors?
Alpha-1
| Alpha-2
50
Where are alpha-1 fibers found, and what is their function?
- Present in arteriolar smooth muscles
| - Activation causes vasocontriction
51
Where are alpha-2 fibers found, and what is their function?
- Found pre-ganglionically, and in the CNS
| - Decreases sympathetic flow from the CNS
52
What neurotransmitter production is inhibited by alpha-2 stimulation?
- Norepinephrine
53
What are the 2 types of beta receptors?
Beta-1
| Beta-2
54
Where are Beta-1 receptors found? What is their function?
- Found in the heart and kidney
| - Increases heart rate, force of contration, and secretion of renin from kidney
55
Where are Beta-2 receptors found? What is their function?
- Found in smooth muscles of blood vessels and bronchi
| - Vasodilates, and bronchodilates
56
What are adrenergic impulses?
- Norepinephrine reactions
| - Sympathetic nervous system
57
What are cholinergic impulses?
- Acetylcholine reactions
| - Parasympathetic nervous system
58
What is the function of adrenergic and cholinergic impulses on the radial muscle of the eye?
Adrenergic: Contraction/ Opens eyes
Cholinergic: No effect
59
What is the function of adrenergic and cholinergic impulses on the spincter muscles of the eye, iris?
Cholinergic: Contraction/ closes eyes
Adrenergic: No efefct
60
What is the function of adrenergic and cholinergic impulses on the ciliary muscles of the eye?
Adrenergic: Relaxation for far vision
Cholinergic: Contraction for near vision
61
What is the function of adrenergic and cholinergic impulses on the lacrimal glands of the eye?
Adrenergic: No effect
Cholinergic: Increased secretions/ tearing
62
What is the function of adrenergic and cholinergic impulses on the SA node of the heart?
Adrenergic: Increased heart rate
Cholinergic: Decreased heart rate/ vagal arrest
63
What is the function of adrenergic and cholinergic impulses on the atria of the heart?
Adrenergic: Increased contractility and conduction velocity
Cholinergic: Decreased contractility
64
What is the function of adrenergic and cholinergic impulses on the AV node of the heart?
Adrenergic: Increased conduction velocity and automaticity
Cholinergic: Decreased conduction velocity
65
What is the function of adrenergic and cholinergic impulses on the ventricles of the heart?
Adrenergic: Increased contractility
Cholinergic: Slight decrease in contractility
66
What is the function of adrenergic and cholinergic impulses on the coronary arterioles?
Adrenergic: Contriction with Alpha-1; Dilation with Beta-2
Cholinergic: (Contriction with endothelial damage)
67
What is the function of adrenergic and cholinergic impulses on the pulmonary arterioles?
Adrenergic: Constriction with Alpha-1; Dilation with Beta-2
Cholinergic: Dilation
68
What is the function of adrenergic and cholinergic impulses on renal arterioles?
Adrenergic: Constriction with Alpha-1; Dilation with Beta-2
Cholinergic: No effect
69
What is the function of adrenergic and cholinergic impulses on system veins?
Adrenergic: Constriction with alpha-1; Dilation with beta-2
70
What is the function of adrenergic and cholinergic impulses on the tracheal and bronchial muscles of the lungs?
Adrenergic: Relaxation with beta-2
Cholinergic: Contraction
71
What is the function of adrenergic and cholinergic impulses on the bronchial glands of the lungs?
Adrenergic: Decreased secretion by alpha-1; Increased secretion with beta-2
Cholinergic: Increased secretion
72
What is the function of adrenergic and cholinergic impulses on the motility and tone of the stomach?
Adrenergic: Decreased with alpha-1
Cholinergic: Increased
73
What is the function of adrenergic and cholinergic impulses on the sphincters of the stomach?
Adrenergic: Contraction with alpha-1
Cholinergic: Relaxation
74
What is the function of adrenergic and cholinergic impulses on the secretions of the stomach?
Adrenergic: Inhibition
Cholinergic: Stimulation
75
What is the function of adrenergic and cholinergic impulses on the motility and tone of the intestine?
Adrenergic: Decreased with alph-1
Cholinergic: Increased
76
What is the function of adrenergic and cholinergic impulses on the sphincters of the intestines?
Adrenergic: Contraction
Cholinergic: Relaxed
77
What is the function of adrenergic and cholinergic impulses on the secretions of the intestines?
Adrenergic: Inhibition
Cholinergic: Stimulation
78
What is the function of adrenergic and cholinergic impulses of the gallbladder and ducts of the intestine?
Adrenergic: Relaxation with beta-2
Cholinergic: Contraction
79
What is the function of adrenergic and cholinergic impulses on renin secretion in the kidney?
Adrenergic: increase with beta-1
Cholinergic: No effect
80
What is the function of adrenergic and cholinergic impulses on the sphincter of the urinary bladder?
Adrenergic: Contraction by alpha-1
Cholinergic: Relaxation
81
What is the function of adrenergic and cholinergic impulses of the water and potassium secretions of salivary glands?
Adrenergic: No effect
Cholinergic: Increased
82
What is the function of adrenergic and cholinergic impulses of amylase secretion of salivary glands?
Adrenergic: No effect
Cholinergic: Increased
83
What is the function of adrenergic and cholinergic impulses of nasopharyngeal glands of the salivary glands?
Aderenergic: No effect
Cholinergic: Increased secretion
84
What are parasympathomimetics?
- Drugs that mimic the effects of parasympathetic nerve stimulation
85
What is another name for parasympathomimetics?
- Muscarinic receptor agonists
86
What is the mechanism of action of direct-acting parasympathetics?
- Stimulation of M receptors at the neuro-effector junction with no or little N receptor stimulation
87
What are 4 therapeutic uses of muscarinic receptor agonists?
- GI disorders
- Urinary bladder disorders
- Xerostomia (dry mouth)
- Opthalamological (reduce acute narrow angle glaucoma attack)
88
What is the use of bethanchol in the GI tract?
- Stimulates gi tract following abdominal distension and gastric atony
89
How do indirect-acting parasympathomimetics work?
- Prolong duration of action of ACh by inhibiting ACh esterase
90
What are the therapeutic uses of indirect-acting parasympathetics?
- Similar to direct acting muscarinics
91
How are indirect-acting parasympathetics used to treat dementia?
- Donepezil manage the dementia associated with alzheimer disease
92
What are some examples of irreversible ACh esterase inhibitors?
- Paraxon
- Malaoxon
- Nerve gas sarin
- Insecticides
93
How is exposure to irreversible ACh inhibitors treated?
- Atropine (an M receptor blocker) and pralidoxime (2-PAM) given before binding of organophosorous compounds becomes permanent
94
What can used to treat serious toxic reactions to muscarinic agonists?
- Atropine sulfate administered by IV or subcanteously
| - Epinephrine for cardiovascular or bronchoconstrictor responses
95
What are parasympatholytics?
Muscarinic Receptor Antagonists
96
What is the mechanism of action of muscarinic receptor antagonists?
- Competitive blocking of muscarinic receptors at neuro-effector sites on smooth muscle, cardiac muscle, gland cells, and in the CNS with little blockage of the effects of ACh at nicotinic receptor sites
97
Do muscarinic receptor blockers show selectivity towrads the muscarinic receptor subtypes?
- No, except for pirenzepine that are selective towards M1 receptors
98
How are muscarinic receptor anatogonists used in relation to the heart?
- Increases heart rate by blocking vagal nerve effects on M2 receptors on the SA nodal pacemaker
99
Do muscarinic receptor antagonists have an effect on blood vessels when administered in isolation? Why?
No, because, there is no parasympathetic control of the vascular system
100
What effect can muscarinic receptor antagonists have on choline esters?
- Block vasodilation induced by choline esters effects on endothelial M3 receptors
101
What roles does the parasympathetic nervous system play in the respiratory tract?
- Regulate bronchomotor tone/ constrict broncioles
| - Facilitate secretions in the nose, pharynx and bronchi
102
What effect do muscarinic receptor antagonists have on the respiratory tract?
- Bronchodilation by means of blocking the M3 receptor
| - Block secretions of the nose, pharynx, and bronchi
103
What is a danger of muscarinic receptor antagonists to the respiratory tract?
- May dry the lungs out to the point of irritation
104
What effect do muscarinic receptor antagonists have on the gastrointenstinal tract?
- Inhibit motility and secretions
| - Inhibit gastric acid secretion
105
What effect do muscarinic receptor antagonists have on the urinary tract?
- Decrease the tone and amplitude of contractions of the bladder
106
What effect do muscarinic receptor antagonists have on sweat glands?
- Inhibition of sweating
| - Skin can become hot and dry, raising body temperature
107
What determines a muscarinic receptor antagonists effect on the CNS?
- Its ability to cross the blood brain barrier
108
What effects can muscarinic receptor antagonists have on the CNS if they can cross the blood brain barrier?
- Depression of the CNS
| - May be preceded by central excitation if atropine is used
109
What are the effects of muscarinic receptor antagonists on the eyes?
- Pupil dilation/ mydriasis
| - Cycloplegia (lack of accomodation of the eye due to a paralysed ciliary muscles
110
What effect does atropine have at a 0.5 mg dose?
- Inhibition of sweating, some dryness of the mouth
111
What effect does atropine have at a 1 mg dose?
- Definite dryness of mouth
- Heart acceleration
- Mild pupil dilation
112
What effect does atropine have at a 2 mg dose?
- Rapid heart rate
- Palpitations
- Marked dilation of pupils
113
What effect does atropine have at a 5 mg dose?
- Inhibition of parasympathetic control of the GI, urinary bladder
- Inhibited gastric secretions and motility
- Increased dryness of mouth
- Heart acceleration
- Pupil dilation
- Palpitations
114
What effect does atropine have at a 10 mg dose?
Previously listed symptoms, and CNS symptoms:
- restlessness
- Excitement
- Hallucinations
- Delirium
- Coma
115
What is ipratropium bromide/ artrovent?
A muscarinic receptor antagonist that doesn't influence the CNS. Its mostly used as a bronchodilator in COPD, but also in asthma
116
What is the effect scopolamine?
- Controls motion sickness
117
What are the therapeutic uses of atropine?
- Reduce salivary/ mucus hypersecretions
- Protect against reflex bradycardia
- Antidote for mushroom poisoning
118
What is tolterodine tartrate/ detrol used for?
Inhibit an overactive bladder
119
What is Fesoterodine fumarate/ Toviaz used for?
- Treats overactive bladder
120
What are 6 side-effects of muscarinic receptor antagonists?
- Mouth
- Urinary retention
- Anhydrosis
- Tachycardia
- Palpitations
- Constipation
121
What are sympathomimetic agents?
- Direct stimulators of the adrenergic receptors
122
What are the 3 endogenous sympathomimetic drugs?
- Epinephrine
- Norepinephrine
- Dopamine
123
What are the cardiac effects of epinephrine?
- B-1 receptors are stimulated, causing chronotropic, and postitive iontropic effects (stimulates heart)
124
What are the respiratory effects of epinephrie?
- B-2 receptor stimulation leads to potent bronchodilation (bronchial smooth muscles are relaxed)
125
Why does epinephrine have a short duration of action?
- It is rapidly metabolized by enzymes (MAO and COMT)
126
What may results from rapid intravenous injection of epinephrine? Why?
```
- Cerebral hemorrhage may occur due to the sharp rise in blood pressure
May also undergo:
- Tremors
- Palpitations
- Anxiety
- Reslessness
```
127
What are the 2 therapeutic uses of epinephrine?
- Provide rapid relief to hypersensitivity reactions including anaphylaxis to drugs and allergens
- Restore cardiac rhythm in patients with cardiac arrest
128
What receptors does norepinephrine act most powerfully on? What is the effect of this?
- NE activates alpha-1 receptors powerfully, and weakly activates beta-2
129
What is the therapeutic use of norepinephrine?
- Can be titrated to desired pressor effect in treatment of hypotension (raises blood pressure due to vasocontriction)
130
By what route of administration is NE and epinerphrine not active?
The oral route
131
What is the effect of dopamine at lower doses?
- Increases renal, coronary, and mesenteric vasodilation due stimulation of dopamine receptors (D1)
132
What is the effect of dopamine at higher doses?
- Stimulates cardiac beta-1 receptors causing positive iontropic and chronotropic effects. (stimulating the heart)
133
In what pathway is dopamine involved?
The synthetic pathway to NE and epinephrine
134
What is the therapeutic use of dopamine?
- Treats severe congestive heart failure in patients with oligurea (low urine output) and low or normal peripheral vascular resistance
135
What is the effect of non-selective beta-agonists? What are their therapeutic effects?
- Increased cardiac output
- Dilation of muscle and mesenteric arteries
- Stimulates heart rate in patients with bradycardia or heart block in emergency situations
136
What would be the ideal selective beta-agonist for asthma? Why?
- Higher preferential affinity towards B2 receptor, and no affinity towards B1.
- Bronchodilation and vasodilation without cardiac effects
137
What types of drugs are used to treat asthma?
Beta-2-selective agonists
138
What are some short and long actin beta-2-agonists?
```
Short:
- Albuterol/ Ventolin
- Terbutaline/ Brethine
Long:
Salmetrol/ Serevent
```
139
How fast does a short acting beta-2-selective agonist onset? How do the effects last?
- Onsets in 15 minutes
| - Lasts 4 - 6 hours
140
How long does a long-acting beta-2-selective agonist last?
- Up to 12 hours
141
How do alpha-adrenergic receptor agonists work?
- Stimulate either alpha-1 or alpha-2 receptors
142
What is a common use of alpha-1-selective agonists? How does it work?
- Nasal decongestant in allergic rhinitis
| - Contricts blood vessels in the nasal tissue leading to decreased fluid accumulation
143
What can happen in chronic use of nasal decongestants?
- Loss of efficacy, and worsening of symptoms due to receptor desensitization
144
What drug is a common alpha-2-selective agonist? What is its effect?
- Clonidine/ Catapres selectively stimulates alpha-2 receptors to decrease central sympathetic outflow to lessen vasoconstrictive drive
145
What are some non-direct adrenergic agonists? What is their effect?
- Amphetamine, dextroamphetamine, and methylpehnidate shoot norepinephrine into CNS synapses stimulating CNS to treat ADHD
146
How do adrenergic receptor antagonists work?
- Competitive blockage of alpha and/or beta-adrenergic receptors
147
For what 3 issues are adrenergic receptor antagonists used for?
- Arrythmias
- Heart failure
- Hypertension
148
What are alpha-1-selective blockers used for?
- Block receptors in vscular smooth muscles of arterioles and veins, decreasing peripheral resistance and blood pressure over time
149
What is less observed with alpha-1-selective blockers as opposed to non-selective alpha-blockers?
- Tachycardia
150
What are 2 adverse effects of alpha-1-selective blockers?
- First-dose phenomenon: Marked postural hypotension and syncope observe 60 - 90 minutes after the first dose
- Water retention due to vasodilating effect
151
What is the effect of beta-adrenergic receptor blockers on the heart?
- Blocking of beta-1 receptors slows heart rate and reduces myocardial contratility
152
What is the effect of beta-adrenergic receptor blockers on the pulmonary system?
- No effect on normal individuals, but the blocking of beta-2 receptors in patients with asthma or COPD can lead to life threatening bronchoconstriction
153
What is the effect of beta-adrenergic receptor blockers on peripheral vascular resistance?
- Blockage of B-2 receptors in arteriolar smooth muscle decrease vasular resistance; beta-1 blockers can also reduce peripheral vascular resistance in hypertension patients over time
154
How do non-selective beta-blockers work?
Reversibly block beta-1 and beta-2 receptors with no selectivity towards either type
155
What are the therapeutic uses of beta-1-selective blockers?
- Hypertension
- CHF
- Angina and MI
156
What may occur in patients with AV conduction defects given beta-1-selective blockers?
- Life-threatening bradyarrhythmias
157
Why should long-term beta-1-selective blockers not be discontinued abruptly?
- Exacerabtes angina, and can bring on sudden heart attack
158
What effect can B2-selective blockers have on asthmatics?
- Worsen brochoconstriction
159
What type beta-selective-blockers produce lss broncho-constriction?
- B1 selective blockers or non-selective b-blockers with partial b2-agonism
