Quiz 1: Vasoconstrictors and DIrect Vasodilators Flashcards
1
Q
How is Norepinephrine made?
A
- Dompamine enters the synaptic vessel
- Dopamine beta Hyroxylase converts dopamine to Norepiniphrine .
- An action potential releases NE from the synaptic vessel.
2
Q
Termination of Norepinephrine is done by:
A
- reuptake
- Dilution by diffusion
- Metabolim: Monamine Oxidae (MAO) and catechol-o0methyltranserase
3
Q
List the Adrenergic receptors for the Sympathetic Nervous System?
A
- Alpha 1: Periphery
- Alpha 2: Central
- Beta 1: heart
- Beta 2: other smooth muscle
4
Q
List the sympathetic nervous system Alpha 1 (Receptor) Postsynaptic effect on the body?
A
- Increase intracellular calcium
-Smooth muscle contraction
-Peripheral vasoconstriction
-Bronchoconstriction
-Inhibits Insulin secretion
Stimulate glycogenolysis and gluconeogenesis
-Mydriasis
-GI relaxatioin
5
Q
List the sympathetic nervous system Alpha 2 (Receptor) Postsynaptic effect on the body?
A
PRESYNAPTIC IN THE PNS
- Decreases entry of calcium into the cell
- Limits the release of norepinephrine
POSTSYNAPTIC IN THE CNS
- Sedation
- Decreased sympathetic outflow
- Decreased BP
- Platelet aggregation
6
Q
List the sympathetic nervous system Beta 1 (Receptor) Postsynaptic effect on the body?
A
INCREASE
- Heart Rate
- Conduction velocity
- myocardial contractility
7
Q
List the sympathetic nervous system Beta 2 (Receptor) Postsynaptic effect on the body?
A
- Smooth muscle relaxation
- Peripheral vasodilitation
- Decrease in B/P
- Bronchodilitation
- Increases insulin secreation
- Increases glycogenolysis and gluconeogenesis
- Decreases GI mobility
8
Q
What is the Sympathetic Nervous System?
A
- Thoracolumar origin (T1-T12)
- Preganglia near spinal cord
- Postganglia secret norpinephrine ->adrenergic fibers
9
Q
What is the Parasympathetic Nervous System?
A
- Craniosacral origin 3, 5, 7, 10
- Preganglia near organs of innervation
- Postganglia secret acetylcholine (Ach) -> Cholinergic fibers
10
Q
T/F: Acetylcholine activates both arms of the SNS.
A
TRUE
11
Q
What creates acetylcholine?
A
- Choline + Acetyl CoA
12
Q
What deactivates acetylcholine?
A
- Acetylcholinesterse
13
Q
What are the cholinergic receptors?
A
- Nicotinic
- Muscarinic
14
Q
_______ _________ : extended exposure to agonists reduces the number, but not their response. Results in tachyphylaxis.
A
- Down regulation
15
Q
_______ ______ : chronic depletion of catecholamine or use of antagonists increases the number of receptors, but not their sensitivity. May account for withdrawal syndrome with beta blockers.
A
- Up regulation
16
Q
Describe receptor Uncoupline?
A
- Occurs rapidly
- Inability of the receptor to bind G protein ( alter the function of the receptor)
17
Q
Describe receptor Sequestration?
A
- Occurs more slowly
- Movement of receptors from the cell surface to intracellular compartments
18
Q
Describe receptors downregulation on a cell?
A
- Prolonged process
- Movement of receptors from the cell surface to intracellular compartments, but then DESTROYED
19
Q
What is pheochromocytoma?
A
-Uncontrolled release of catacolamines via a adrenal tumor which causes SNS stimulation.
20
Q
T/F: a Catecholamine can be either a neurotransmitter or a hormone.
A
TRUE
21
Q
What receptor does a catecholamine work on?
A
-Adrenergic receptor
22
Q
What is a sympathomimetic?
A
-Compound that resemble catecholamines except that hydroxyl groups are not present in both the 3 and 4 posetions of the Benzene ring.
23
Q
How are sympathomimetic classified?
A
- By their selectivity for stimulating the alpha and/or beta receptor.
24
Q
Indirect acting sympathomimetics are:
A
- Synthetic non-catecholamines
- release endogenous neurotransmitter NE from postganglionic sympathetic nerve endings
25
Direct-acting sympathomimetics are:
-Catecholammines and synthetic non-catecholamines
26
All sympathomimetic are derived from ______.
-B phenylethylamine
27
Presence of ______ groups on the 3 and 4 postion of the benzene ring of the B phenylethylamine creates a CATACHOL.
- hydroxyl
28
Pharmacological effects of sympathomimetics for vasoconsticition effect:
-cutaneous and renal circulations
29
Pharmacological effects of sympathomimetics for vasodilation effect:
-skeletal muscle
30
Pharmacological effects of sympathomimetics for respiratory effect the lungs in what way?
-bronchodilation
31
Pharmacological effects of sympathomimetics for cardiac stimulation effect:
- Increased heart rate
- Increased myocardial contractility
- Vulnerability to dysrhythmias
32
Pharmacological effects of sympathomimetics for hepatic effect:
-glycogenolysis
33
Pharmacological effects of sympathomimetics modulate what hormones:
- insulin
- renin
- pituitary
34
Pharmacological effects of sympathomimetics for the CNS is:
Stimulation
35
T/F: The only time a vaopressor should be used is when the patient's blood pressure must be increased immediately to avoid pressure dependent reduction in organ perfusion with subsequent ischemia.
TRUE
36
The pharmacologic response caused by a sympathomimetic is related to the _____ of the alpha and beta adrenergic receptors in the tissues.
-density
37
T/F: There is a direct relationship between the concentration of available sympathomimetic and the number of receptors.
FALSE (There is an inverse....)
38
What enzymes are responsible for inactivating the drugs containing the 3,4 dihydroxybenzene (catecholamines) structure?
- Monoamine oxidase (MAO)
| - Catechol-o-transferase (COMT)
39
T/F: Administration of catecholamines is effective through oral, SQ, or IV routes.
FALSE (....effective through SQ and IV routes.)
40
Where are monoamine oxidase (MAO) primarily found?
- liver
- Kidnerys,
- GI tract
41
What is the best way for administration of Epi.
- SQ
| - IV
42
What is the best way for administration of Dopa. or Norepi.
-IV
43
Metabolism of synthetic noncatecholamines would be:
- lack the 3 hydroxyl group
- Metabolism is often SLOWER that that of catechos
- Inhibition of MAO may prolong their duration of action.
- Patients on MAO inhibitors may manifest exaggerated responses when treated with synthetic non-catecholamines.
44
Metabolism of a synthetic non-catecholamine is metabolized by ______ and not by _______.enzymes.
- MAO
| - COMT
45
Vasoconstrictors increase aterial _____ and ____ as well increase venous ______.
- resistence
- afterload
- return
46
What would be some reflex changes seen with vasoconstrictors?
DECREASE
- Heart Rate
- conduction
- contractility
47
What noncardiac effects are seen with vasoconstictors?
- Bronchodilate
- Glycogenolysis
- Insulin, renin, pituitary hormone
- CNS stimulation
48
What would be the indication for a vasconstrictor?
-Decrease in arterial resistance
49
After administering a proper dose of a vasoconstrictor iatrogenic affects can be seen in the patient. What would be the proper action?
-All is well....Iatrogenic means the results of administering the vasoconstrictor
50
What would be contraindications/complications for using vasoconstrictor:
- Worsen LV failure
- exacerbate RV failure
- Decrease renal blood flow
- Can mak hypovolemia
51
What would be the three natural catecholamines?
- Epinephrine
- Norepinephrine
- Dopamine
52
Epinephrine stimulate what receptors?
- Alpha 1
- Beta 1
- Beta 2
53
T/F: Epinephrine is the most potent activator of Alpha 1 receptor.
TRUE
54
What does epinephrine increase?
- lipolysis,
| - glycogenolysis
55
What does epinephrine decrease?
insulin
56
T/F: Epinephrine will still decrease renal blood flow even in the ABSENCE of changes in the systemic BP.
TRUE
57
Epinephrine stimulates renin release which is a ____ effect.
-indirect
58
A low dose of epinephrine of 1-2 mcg/min will:
-stimulate alpha 1 receptor at the skin, mucosa, and hepatorenal system WHILE beta 2 receptors are stimulated in the muscle
59
During a low dose of epi (1-2 mcg/min) does the MAP remain the same?
YES
60
Giving an intermediate does of epinephrine (4 mcg/min) will cause:
INCREASE (BETA 1)
- Heart rate
- Contractility
- Cardiac output
61
T/F: An intermediate does of epinephrine may lead to dysrhythmias (PVC) in sensitized myocardium.
TRUE
62
High dose of epinephrine (10 mcg/min) would cause:
-vasoconstriction of cutaneous, splanchnic and renal vascular beds.
63
T/F: Epinephrine at high doses has no effect on cerebral arterioles.
TRUE
64
What reflex could be seen with high doses of epinephrine?
-Bradycardia
65
What is Racemic Epinephrine made up of:
- Levo
| - dextrorotatory isomers
66
T/F: Norepinephrine effect beta more than it does alpha.
FALSE
67
Norepinephrine is a potent vasoconstrictor of the _______, ___________, and ___________ vascular beds.
- renal
- mesenteric
- cutaneous
68
What refractory can be seen with norepinephrine?
- HYPOTENSION
| - (bradycardia)
69
At high does why may C.O. be decreased?
- Increased afterload
| - baroreceptor-mediated reflex bradycardia
70
T/F: Dopamine effects both the alpha and beta receptors.
TRUE
71
Dopamine over 5 mcg/kg/min causes ______ to be released.
-noriepinephrine
72
Dopamine at 10 mcg/kg/min _____ effects start to predominate.
Alpha
73
T/F: Dopamine has NO effect on pulmonary status.
TRUE
74
What CNS effects will be seen with dopamine:
```
INCREASE
-mania
DECREASE
-Schizophrenia, ADHD, PG
-prolactiv secretion
-D2 inhibition
```
75
What monitors will be needed with dopamine:
-BP, HR, MAP, urine output, mental status
76
T/F: Ephedrine is an endogenous catecholamine.
FALSE (.....is a synthetic noncatecholamine.)
77
Ephredrine principle effect is stimulating the releases of _________
-noriepinephrine
78
Ephredrine principle mechanism is increased ______ ________.
-myocardial contractility
79
Ephedrine causes _________ greater than ________ constriction increases _______ and with ________ heart rate and myocardial __________, INCREASES CARDIAC OUTPUT (beta 1 receptor)
- venoconstriction
- arteriolar
- preload
- Increased
- contractility
80
T/F: Ephedrine preserves/increases uterine blood flow.
TRUE
81
Ephedrine is a _______ smooth muscle relaxant.
bronchial
82
Ephedrine compared to epinephrine has a ____ BP response, but a ______ duration.
-less
| longer
83
What are some side effects of ephedrine.
- HTN,
- insomnia,
- urinary retention,
- headache,
- weakness,
- tremor,
- palpitation,
- psychosis
84
Phenylephrine is a _______ ____ catecholamine.
-synthetic non
85
Phenylephrine is a increases _____ more than _______.
- Preload
| - afterload
86
T/F: Phenylephrine has a small beta 1 effect.
TRUE
87
What are other uses of phenylephrine.
- drug induced priapism
- mydriatic agent
- nasal decongestant
88
Phenylephrine causes reflex ________.
-bradycardia
89
Phenylephrine _________ renal and splanchnic blood flow
decreases
90
Phenylephrine _______ pulmonary artery resistance and pressure.
Increases
91
T/F: Phenylephrine has no dysrrhythmias as a direct effect.
TRUE
92
Phenylephrine ______ Right to Left shunt in Tetrology of Fallot.
REVERSES
93
Unlike catecholamine, effects of arginine vasopressin are _______ during hypoxia and severe acidosis.
preserved
94
Vasopressin is used to preserve the ___________ homeostasis in patient with advanced vasodilitory shock.
cardiocirculatory
95
Vasopressin advantages over epinephrine are:
- does not increase myocardial oxygen consumption
| - may work better in acidic environment patients
96
What causes the cardiac dysrhythmias in vasoconstrictors?
Beta Stimulation
97
Pure alpha agonists can _____ baroreceptor reflex-mediated ________ and possible _________ CO.
- activate
- bradycardia
- decrease
98
Antihypertensives may _______ the pressor response to indirect acting drugs or _______ the response to direct acting drugs (denervation hypersensistivity)
- decrease
| - enhance
99
Cocaine interferes with reuptake of catecholamines. Both exogenous and endogenous catecholamines exhibit ________ effects.
enhanced
100
Acute toxicity of cocaine may best be treated with ________ blockade.
adrenergic
| Labetalol with alpha and beta effects
101
Natural weight loos products may contain "ma huang" which is ______.
ephedra
102
T/F: Ephedra contains ephedrine and psuedoephedrine.
TRUE
103
How long do you want a person to stop taking "ma huang" before surgery?
24 hours
104
T/F: Long term use of "ma huang" (ephedra) results in tachyphylaxis from depletion of endogenous catecholamine stores and may contribute to perioperative hemodynamic instability and cardiovascular collapse.
TRUE
105
Phentolamine treats:
-Skin necrosis secondary to norepinephrine, dopamine and epinephrine
106
What receptors does phentolamine work on and is it an agonist or antagonist?
- Alpha 1 and 2
| - Antagonist
107
What is idiopathic hypertension:
- over activity of the ANS
- Interaction with the Renin angiotensin system
- factors related to the sodium homeostasis and intravascular volume
108
What would cause perioperative hypertension:
- inadequaate anesthesia
- airway manipulation
- hypercarbia
- hypoxia
- medications
- aortic cross clamp
- hypervolemia
- hypothermia
- pain
109
What pre-existing disease would cause perioperative hypertension:
- pheochromocytoma
- Hyperthyroid
- autonomic hyperreflexia
- malignant hyperthermia
- intracranial hypertension
- renal disease
- poorly controlled hypertension
110
What are the complication of perioperative hypertension?
- CVA
- MI
- ischemia
- LV dysfunction
- arrhythmias
- increased suture tension
- hemorrhage,
- pulmonary edema
- cognitive dysfunction
111
What is the primary cause of perioperative hypertension?
-Increased sympathetic discharge with systemic vasoconstriction
112
What are the mechanism of action for vasodilators:
- Direct smooth muscle dilatation (Calcium channel blocker and nitrates)
- Alpha 1 antagonists (prazosin and labetalol)
- alpha 2 agonists (clonidine and alpha-methyldopa)
- A.C.E. inhibitors (captopril ad enalapril)
113
What would be the site of action for vasodilators;
- arterial dilators
- venodilators
- Balanced vasodilators
114
Pure arterioe dilator causes minimal effect on _____.
preload
115
"Pure" venodilators are ___ available. NTG acts primarily on the venous circulation, but also affects ______.
- NOT
| - arterioles
116
Balanced vasodilator (SNP) decreases ______ and ________.
- afterload
| - preload
117
T/F: Inhaled NO may be only "pure" pulmonary vasodilator.
TRUE
118
Prostaglandin E1 (PGE1) is excellent pulmonary ________, but also causes systemic _______ requiring noriepinephrine to maintain systemic B/P.
- vasodilator
| - hypotension
119
What is reflex effect of using a vasodilator:
increase heart rate
120
What will vasodilators do to the hear arterioles?
-cause coronary steal
121
How much artery perfusion to the LEFT VENTRICLE occurs during diastole?
70 - 90%
122
T/F: Aortic systole pressure governs perfusion.
FALSE (Aortic diastolic....)
123
Nitroglycerin preferentially dilates _______ vessels and ______ more blood toward ischemic zones.
- conductace
| - directs
124
What are the vasodilators?
- hydralazine
- nitroglycerine
- Sodium nitroprusside
125
Is Hydralazine a direct acting or indirect acting arterial vasodilator.
-direct acting
126
What effects does hydralazine have on the cardiovascular system?
INCREASES
- heart rate
- contractility
- cardiac output
- stroke volume
- renin activity
- fluid retention
- MYOCARDIAL OXYGEN DEMAND
DECREASES
-B/P (diastolic > systolic)
127
What type of patient do you want to avoid administering hydralazine to.
- CAD
- Increased ICP
- Lupus
128
What are the advantages of hydralazine?
- maintains/increases cerebral blood flow
- increases CO
- Increases Stroke volume
129
What are the disadvantages of hydralazine?
-Reflex tachy
| -
130
Nitroglycerine causes a release of ____ _____ for ___- specific relaxation of the vascular smooth muscle.
- nitric oxide
| - non
131
What does nitroglycerine do to the coronary arteries?
- relaxes
| - relieves spasms
132
What are some non-cardiac effects of nitroglycerine?
- dilates meningeal vessels
- Decrease renal blood flow with decrease BP
- dilates pulmonary vessels
133
Nitroglycerine is metabolized by ___________ nitrate reductase in the ______?
- glutathione
| - LIVER
134
A nitrite ion oxidizes Hgb to ___________.
methemoglobin
135
Nitroglycerine tolerance in _______ vessels can occur with chronic administration but not in the venous vessels.
- arterial
| - venous
136
What are warnings and contraindications for nitroglycerine?
- PDE5 (Viagra, cialis, ravashia)
- narrow angle glaucoma
- head trauma, cerebral hemorrhage
- severe anemia
- hypotension
137
Does sodium nitroprusside directly or indirectly vasodilate arteries and veins?
-DIRECTLY
138
With abrupt discontinuation of sodium nitroprusside can cause ______ _______ and _________.
- reflex
- tachycardia
- hypertension
139
Sodium nitroprusside causes a _____ in renal blood flow.
Decrease
140
Sodium nitroprusside causes pronounced hypotensive effects with ______ and _______ ________.
- spinal
- general
- anesthesia
141
T/F: Sodium Nitroprusside metabolites are active and increase the effects.
FALSE (....are not active....)
142
What are some warning and contraindication for sodium nitroprusside?
- congenital optic atrophy
- hypovolemia
- compensatory HTN (AV shunting and aortic coarctation)
- Severe renal/hepatic impairment
143
What type of toxicity could sodium nitroprusside cause:
cyanide
144
What is the presentation of cyanide toxicity:
- hypotension
- blurred vision
- fatigue
- metabolic acidosis
- pink skin
- absence of reflexes
- faint heart sounds
145
What are the thiocyanate levels: -
-therapuetic 6 - 29
-toxic 35-100
fatal >200
146
What are the advantages of sodium nitroprusside:
- immediate onset
- short duration
- reduced myocardial O2 demand
147
What are the disadvantages of sodium nitroprusside:
- reflex tachycardia
- cyanide toxicity
- intrapulmonary shunting
- precipitous drop in BP
- photodegradation
- methemoglobinemia
- coronary steal
- Enhanced bleeding
- cerebral vasodilator
