SYMPATHOMIMETIC AGENTS Flashcards
1
Q
Catecholamines any compound
- hydroxyl is on_____carbon positions.
A
any compound that has CATHECOL nucleus (benzene ring with 2 adjacent hydroxyl groups with and amine containing side chain; 3,4
2
Q
Endogenous catecholamines, 3
A
Epinephrine, norepinephrine, dopamine,
3
Q
Sympathomimetic drugs does what?
A
mimic action of the SNS via activation of sympathetic receptors
4
Q
Pharmacologic effects of catecholamines.
SV, HR, Force of contraction via receptor ______
Patients are more vulnerable to develop?
A
Cardiac stimulation (B1 receptors of heart)
- SV
- cardiac arrhythmias
5
Q
Pharmacologic effects of catecholamines.
SVR, BP via receptor ______ mediated vaso________ of blood vessels
Shunts blood to ________(_______non essential organs)
Vasodilation results from _______activation in certain blood vessels such as _____ ______
Lung effect( Brandi/constri)
Inc/dec pulmonary blood flow.
GI effect on : secretions and motility
A
Cardiac stimulation (B1 receptors of heart)
-all increase
-constriction ; to muscle (vasoconstrict)
Alpha 1; skeletal muscle blood vessels.
bronchodilation
Improve pulmonary blood flow
Decreases GI motility and secretions
6
Q
SYMPATHOMIMETIC
A
Increase nutritional supply
Modulation of the secretion of insulin, renin and pituitary hormones.
7
Q
The predominant effect seen by the SNS for the ENDOCRINE SYSTEM
A
INHIBITION of INSULIN
8
Q
Alteration that occur in the ANS in case of injury?
Effect in the eye? Enhancement of ______
A
Fluid retention
renin secretion –> angiontensin II –> Aldosterone
Posterior pituitary hormone secretion (ADH)
MYDRIASIS : far vision
9
Q
They can alter potassium through?
Remember sodium potassium pump has ____receptors.
A
Beta 2 agonism by plasma epinephrine (Exogenously administered drug) produces HYPOKALEMIA, because Na -K pump has beta 2 receptors, which shift potassium from outside to the inside of the cell (RBCS and muscle cells)
10
Q
CNS stimulation of Sympathomimetics?
is EPINEPHRINE a powerful CNS stimulant ?
A
Lipophillic enough drugs can cross brain
No; because it is a polar molecule
11
Q
Analgesia : sympathomimetic with analgesia
A
enhanced specially in the presence of OPIOIDS
12
Q
Physiological Basis of Adrenergic Receptor Function:
An important factor in the response of any cell, organ tissue to sympathomimetic agents is the _______ _________
A
density and proportion of ALPHA and BETA Adrenergic in various tissues.
13
Q
For example: Norepinephrine as a drug does not activate
A
B2 receptor.
14
Q
_________ and _________ can activate beta 2 receptors and are potent ________since they have affinity for _____receptors
A
Isoproterenol and epinephrine ; and Beta2 receptor.; BRONCHODILATORS; B2
15
Q
NE and EPINEPHRINE cause vasoconstriction of _________ where as ISOPROTERENOL _______ effect on blood vessel. why? ______lacks
A
cause vasoconstriction of these blood vessels, where as ISOPROTERENOL HAS little effect on blood vessels since its lack alpha agonism activity
16
Q
Explain the reflex homeostatic adjustments
A
The reflex homeostatic adjustments
17
Q
Phenylephrine can cause ________ (side effect or adverse effect) (1)
A
Reflex BRADYCARDIA
18
Q
Norepineprhine can cause activation of ______ reflex and ______ ____ tone leading to a ______ in HR.
A
Baroreceptor reflex
and increase VAGAL tone decreasing HR>
19
Q
The most effective agents for enhancement of analgesia is ________ and __________
A
amphetamine and amphetamine derivatives
20
Q
All sympathomimetic amines are derived by
A
beta phenylethylamine–> Benzene ring & Ethylamine side chain.
21
Q
Basic catecholamines structure:
A
are monoamine substances with the presence of hydroxyl groups (-OH) specifically on the 3 and 4 carbon positions on the benzene ring
22
Q
All sympathomimetic amines are derived by
A
beta phenylethylamine–> Benzene ring & EthylAMINE side chain.
23
Q
_____makes polar and not lipid soluble. Catecholamines Catecholamines have a brief duration of action and are ineffective when administered orally because they are ?
Which 2 enzymes: _______ & ________
A
Hydroxyl group; rapidly inactivated in the intestinal mucosa and in the liver via both MAO & COMT before reaching the systemic circulation.
24
Q
Sympathomimetic agents can exert their mechanism of action and pharmacologic effects by either _________ OR __________
A
DIRECTLY binding to and activating alpha-adrenergic, beta-adrenergic, or dopaminergic receptors
INDIRECTLY releasing substances which will bind to alpha-adrenergic, beta-adrenergic, or dopaminergic
receptors which activates the receptors
25
Epinephrine – binds to α1,
| α2, β1, β2 receptors
binds to α1, α2, β1, β2 receptors
26
NE – binds only to ________
α1, α2, β1
27
Isoproterenol – binds only to_______
β1 and β2 receptors
28
Phenylephrine binds
SELECTIVELY to only α1 receptors
29
Synthetic non-catecholamines Generally, do/ don’t have hydroxyl groups on benzene ring. They are metabolized primarily by _______. ________ is an exception
Don’t have 3- hydroxyl groups on benzene ring and
| Phenylephrine is an exception
30
____ , ____ and _____ are able to penetrate BBB more readily and have more central nervous system activity? and considerable CNS activity, they are synthetic non catecholamines.
ephedrine, amphetamine, methamphetamine exhibit
| considerable CNS activity
31
The potency or affinity of agents to the adrenergic _________between sympathomimetic agents ; depends on
varies; depends; on structure binding.
32
β1 Receptor: _______
β2 Receptor: ________
Alpha 1 receptor:
ISO>Epi>NE
ISO>Epi>>>>NE
Epi >NE>>>>>>>>>ISO
33
Epi slightly more potent at B1 recepotrs
yes
34
The concentration required to give NOREPINEPRHINE to activate alpha 2
Would kill a patient.
35
Isoproterenol
Non-selective beta agonist (beta 1 or 2)
36
Clinical uses of sympathomimetics
Shock, vasopressors, positive inotrope
37
Albuterol is a
Sympathomimetic.
38
Why is the Addition of EPINEPHRINE to local anesthetics? 2 reasons
decrease systemic absorption
| increase the duration of action of local anesthetics
39
Caution when using pure α1 agents
The disadvantages of using sympathomimetics that lack significant β1 adrenergic effects to maintain systemic blood pressure include
As a result of this reflex activation, sympathetic tone is ________ and vagal tone is ________
Selective α1 agents produce so much _________that they trigger a r_____________ Since,
CO = HR x SV
intense vasoconstriction and associated blood pressure increases that evoke reflex-mediated bradycardia (via the carotid-aortic baroreceptor system), which leads to a decreases in cardiac output
decreased; increased
vasoconstriction
reflex bradycardia response.
decreasing HR will ultimately decrease your CO.
40
How to classify Sympathomimetic agents:
a)Sympathomimetic agents can be classified based on their chemical structure
b)Sympathomimetic agents can ALSO be classified based upon how they activate adrenergic receptors
c)
41
Endogenous catecholamines :
a) Dopamine
b) Norepinephrine
c) Epinephrine
42
Synthetic catecholamines:
a) Isoproterenol
| b) Dobutamine
43
Synthetic non-catecholamines
Direct-acting : Phenylephrine
Indirect-acting: Amphetamines
Direct- and indirect-acting: Ephedrine
44
What are Direct-Acting Sympathomimetic Agents
Give examples
synthetic catecholamines : ____ and ________
What are the only 2 synthetic non-catecholamines that are direct acting ?
Agents that bind directly to one or more of the adrenergic receptors and activate the receptor
```
Natural catecholamines;
Synthetic catecholamines (Dobutamine, Isoproterenol)
```
Synthetic non-catecholamines – only Phenylephrine and Methoxamine are the only synthetic non-catecholamines that are direct-acting
45
Their actions are independent of endogenous stores of NE --> DASA
Direct-Acting Sympathomimetic Agents (doesnt need endogenous NE)
46
****Denervation or depletion of neurotransmitters does not alter activity of these drugs (i.e.: heart transplant, training)
Direct-Acting Sympathomimetic Agents
47
Direct acting sympathomimetic agents Response may be potentiated (increased) by drugs such as_____,______,______more indirect release
Response may be potentiated (increased) by drugs such as cocaine, reserpine and guanethidine
48
Selective agents –
| Non-selective agents
bind primarily to only 1 adrenergic receptor
binds to more than 1 adrenergic
receptor
49
Indirect-Acting Sympathomimetic Agents
“Releasing agents” are a type of indirect-acting agent
Most, not all, synthetic non-catecholamine agents are indirectacting agents i.e., __________
Agents that increase the release of endogenous NE to stimulate adrenergic receptors
} i.e., Amphetamines
50
Below lists the 3 mechanisms of how indirect-acting
| sympathomimetic agents increase the release of endogenous NE:
1. ***** By releasing or displacing NE from sympathetic nerve varicosities from the presynaptic nerve which increases NE concentrations in the synaptic cleft
2. By blocking the re-uptake of NE back into sympathetic neurons (i.e.: Cocaine, TCA’s) which increases NE concentrations in the synaptic cleft
3. By blocking the metabolizing enzymes MAO (called MAOInhibitors) or COMT (called COMT inhibitors)
51
Their actions are dependent on adequate neuronal stores of endogenous NE
Pharmacology of Indirect-Acting Sympathomimetics Agents (IASA)
52
Pharmacology of Indirect-Acting Sympathomimetics Responses are abolished by prior treatment with _________ __________
reserpine or guanethidine ;
53
Indirect-acting SYMPATHOMIMETICS are characterized mostly by ______ because ______
The actions of indirect-acting sympathomimetic amines are subject to ________ which means_________
alpha and beta 1 adrenergic agonists; NE has very little to no B2-adrenergic agonists activity.
Tachyphylaxis ; Repeated administration results in rapidly decreasing effects due to the depletion of neuronal stores of endogenous NE
54
Denervation (cases such as ________ ________) Clinical question: Would a indirect-acting sympathomimetic agent work in a heart transplant patient?
(i.e.: spinal cord injury, heart transplant)
| Cant use in those situations because there is damage to nerve ending.
55
Mixed-Acting Sympathomimetic Agents are :
| Denervation or depletion of neurotransmitter reduces or blunts the drug response of these agents
Agents that both indirectly release NE AND also directly bind to and activate adrenergic receptors
56
Examples of Mixed-Acting Sympathomimetic Agents
Ephedrine and Dopamine.
57
For Mixed-Acting Sympathomimetic Agents, drug response is
reduced or blunted by prior treatment with reserpine or guanethidine
58
What effects does Denervation or depletion of neurotransmitter have on Mixed-Acting Sympathomimetic Agents _______
reduces or blunts the drug response of these agents
59
Be careful ENDOGENOUS enzymes metabolizing
COMT and MAO enzymes
60
___________enzyme The circulating catecholamines are primarily metabolized by COMT
Catechol-O-methyltransferase (COMT) enzyme
61
____,____, _____, _____primarily metabolized by COMT (WHEN GIVEN AS A DRUG) --DINE
DINE: Epinephrine, norepinephrine, dobutamine and isoproterenol
62
The lungs also act as a filter for central venous blood
_______of circulating NE is extracted during a single passage through the lungs
________of clinical doses of dopamine are cleared by the lungs after a single pass
________- is not broken down or extracted by lungs
~25%
~20%
Epinephrine
63
Synthetic non-catecholamines that lack a 3-hydroxyl group are primarily metabolized by ______
These agents are not metabolized by COMT due to the _____________
Metabolism of these agents is ______ than catecholamines, thus these agents have ___________
MAO; loss of the hydroxyl group
| slower; a longer duration of action
64
Oral administration of catecholamines is NOT effective due to_____________
due to the presence of the 3- and 4-hydroxyl groups
65
Catecholamines are ineffective when administered orally
| Why?
because they are rapidly metabolized by MAO & COMT in the intestinal mucosa and liver before reaching the systemic circulation
66
Mostly given IV but can also be given IM or SQ depending on the specific agent
Synthetic non-catecholamines.
67
_______Is an endogenous catecholamine agent that is a potent activator of ____________
Epinephrine: both α- and β-adrenergic receptors (non-selective α- and β-adrenergic agent)
68
Is a circulating hormone secreted by the adrenal medulla and constitutes ~80% of the catecholamine content of the adrenal medulla_________
Epinephrine
69
________ the prototype drug among the sympathomimetics
Epinephrine
70
```
EPINEPHRINE EFFECT on myocardial contractility
heart rate Vascular smooth muscle
BRONCHIOLES
Sugar and glycogen
Glandular secretions.
```
Increase myocardial contractility (Positive Inotrope)
} Increase heart rate (Positive Chronotrope)
} Vasodilation and vasoconstriction of vascular smooth muscle
} Bronchodilation
} Glandular secretions
} Metabolic processes such as glycogenolysis & lipolysis
71
Use in the treatment of severe asthma and bronchospasm
Epinephrine
72
______(drug) Is poorly lipid soluble and does not readily penetrate the CNS which accounts for the lack of __________ ____
cerebral effects
73
****The cardiovascular effects of epinephrine are from stimulation of both ___ ____ ____receptors
α- and β-adrenergic receptors
74
****For Epinephrine, the higher you go on the dose, the more ______responses predominate and too high can cause _____________
***alpha ; severe metabolic acidosis
75
Epinephrine high doses can cause
Which predominates in vascular bed?
And what happens to heart
Peripheral vasoconstriction leading to necrosis.
| Alpha 1
76
Effects of epinephrine on vascular smooth muscle are
DOSE - DEPENDENT
77
Associated with vascular smooth muscle are a large number of ________ relative to ______receptors. However, epinephrine has a ______ affinity for the β2 receptor relative to the _________
α1 receptors; β2 receptors.; higher ; α1 receptor.
78
Epi favors _____ as opposed to _____
beta 2; alpha 1
79
Epinephrine favors _____ as opposed to _____
beta 2; alpha 1
80
Therefore, the effect of epinephrine on
| vascular smooth muscle is dependent on 3 things_______ _______ and ____
relative affinity for
| α1 and β2 receptors AND epinephrine's concentration.
81
Low dose of epinephrine
0.01-0.3 mcg/kg/min
82
At low doses of epinephrine
- selective stimulate beta 2 (smooth muscle relaxation) and decrease in peripheral resistance.
- the non-selective beta-adrenergic effects predominate with little alpha-adrenergic effects
83
β2 receptor stimulation in vascular smooth muscle (peripheral vasculature) results in __________, predominately in skeletal muscle, which will decrease diastolic blood pressure (caution in
patient with _____
vasodilation; diastolic; aortic stenosis)
84
B2 the net effect is typically ______________CO with a ________ in SVR and possibly a ________ in blood pressure. Pulse pressure is _______and MAP is not __________
increased cardiac output ; decrease; decrease; increased ; generally elevated
85
Intermediate Dose of epi
Some effects: more pronounced _____ which continues to HR, contractility and SBP
Net effect--> _____in pulse pressure and increase in __BP are greater than increase in ___BP. and MAP ___
0.03 - 0.13 mcg/kg/min;
Beta 1 effect; increase HR , contractility and SBP
Increase; SBP, DBP; increases.
86
Epinephrine: High doses: stimulation of ____ _____ ______ still occurs but _______ stimulation effects predominate on most vascular beds, including ____ ______ and _____ vasculature.
Stimulation of α1 & β1 & β2 receptors still occurs but α1
stimulation effects predominate on most vascular beds, including cutaneous, splanchnic and renal vasculature.
87
____________ ___________are more common at high
| doses which limits the usefulness of high dose epinephrine
Supraventricular tachyarrhythmia’s
88
Epinephrine increases heart rate by ___________________which also increases the risk of cardiac dysrhythmias
accelerating the rate of spontaneous phase 4 depolarization of nodal tissue,
89
Halothane anesthesia increases _______ ____________by
cardiac toxicity with epinephrine by sensitizing the myocardium to the action of epinephrine
90
Epinephrine _________ (inc/dec) conduction velocity and _________(inc/dec) the refractory period in the AV node, bundle of His, Purkinje fibers and ventricular muscles
conduction velocity and decreases the refractory period in the AV node, bundle of His, Purkinje fibersn and ventricular muscles
91
For epinephrine
| CO, HR, Myocardial contractility and venous return
Increased cardiac output reflects epinephrine-induced
| increases in HR, myocardial contractility and venous return
92
a) Activation of the β2 receptor by epinephrine would produce _________ while activation of the α1 receptor would result in __________. Stimulation of α2 receptors on vascular smooth muscle also leads to __________
b) Remember, the magnitude of effect is dependent on the _____________ ______
a)vasodilation ; vasoconstriction; vasoconstriction
| degree of receptor occupancy.
93
Epinephrine does what to the RAAS?
Activates the RAAS SYSTEM to raise BP
94
Supratherapeutic doses of epinephrine may lead to heart
failure, myocardial ischemia/infarction, pulmonary edema,
arrhythmias, profound hypertension which may cause
cerebrovascular hemorrhage, metabolic acidosis or kidney failure
```
heart failure
myocardial ischemia/infarction
pulmonary edema,
arrhythmias
profound hypertension which may cause
cerebrovascular hemorrhage
metabolic acidosis or kidney failure
```
95
Supra-therapeutic doses of epinephrine may lead to :
```
heart failure
myocardial ischemia/infarction
pulmonary edema,
arrhythmias
profound hypertension which may cause cerebrovascular hemorrhage
metabolic acidosis or kidney failure
```
96
Pancreas has both
alpha 2 and Beta 2
97
Insulin secretion is inhibited by________ activation and is enhanced by activation of _______
} Stimulation of β2 & β3 receptors by epinephrine increases
} Liver glycogenolysis/gluconeogenesis (β2)
} Adipose tissue lipolysis (β2 & β3)
α2 receptor ; β2 receptors;
98
The predominant effect seen with epinephrine is _________
inhibition of insulin secretion
99
Glucagon secretion is enhanced through action on ____receptors of the ______________________
beta receptors of the alpha cells of pancreatic islets
100
Stimulation of β2 & β3 receptors by epinephrine increases _______ _________and _________
Liver glycogenolysis/gluconeogenesis (β2)
| Adipose tissue lipolysis (β2 & β3)
101
*****Norepinephrine does not
AGONIZE BETA 2 RECEPTORS
102
Infusions of epinephrine usually increase plasma
| concentrations of
Glucose (hyperglycemia)
Lactate levels
Free fatty acids
Cholesterol, phospholipids, and low density lipoproteins
103
_________ and ________are minimal with systemic
administration of epinephrine but occur after intradermal
injection
Sweating and pilomotor activity
104
Activation of α1 and β2 receptors in the eye
| _________(α1) does what to the radial muscles ? therefore _____Pupil.
Mydriasis (α1)
| contracts the radial muscles of the iris, dilating the pupil
105
SNS regulates the ___________
filling phase
106
Epinephrine inhibits uterine tone and contraction during
pregnancy and at parturition via ____________receptors
(meaning causes relaxation) and________________ __________via activation of _______receptors.
activation of β2 ; contraction of
| pregnant uterus via activation of α1 receptors
107
Use with caution during labor and delivery. Although epinephrine improves maternal hypotension associated with anaphylaxis, it may result in ________,_______,________
uterine vasoconstriction, decreased uterine blood flow, and fetal anoxia
108
Blood coagulation is accelerated by epinephrine, presumably by ________________ and _______
Increasing factor V activity and inducing platelet aggregation
109
Epinephrine EXTRAVASATION Can cause ________ and _______
ischemic tissue necrosis and sloughing of
| surrounding tissue
110
*******Treatment of EPINEPHRINE
| Mix with and inject how ?
(Regitine®) Phentolamine mesylate 5-10 mg diluted to local tissue area
Mix 5-10 mg with 10 mL of NS and inject small amount
subcutaneously into the extravasated area
111
******Which class is PHENTOLAMINE?
Phentolamine is a competitive, non-selective α1 and α2 antagonist
112
Insulin secretion is both Inhibited by _____ and enhanced by ______
alpha 2; beta 2
113
Sympathomimetic effect on nutritional supply
Free fatty acids from adipose tissue
| Increase rate of metabolic and muscle GLYCOGENOLYsis
114
Pharmacology effect on stress hormone levels
INCREASE
115
The receptors in bronchial smooth muscle are largely of the _______ subtype.
β2 subtype.
116
Phenylephrine has______ direct effects on the heart since it is a selective for ____ receptors and lacks ____ _agonism activity
minimal ; α1 ; Beta 1 agonism activity
117
The ultimate response of a target organ to _________ agents is dictated not only by the _____ effects of the agents by also by the _________ ______adjustments of the organisms that occurs from the effects of the agents
sympathomimetic; direct; reflex homeostatic.
118
Sympathomimetic will increase SBP This stimulation elicits compensatory reflexes that are are mediated by the _____ -_____ ________ . As a result, _______ tone is diminished, and _____tone is enhanced. each of these responses leads to a ______ of the heart rate
carotid-aortic baroreceptor ; sympathetic tone ; vagal tone; slowing.
119
What happens when a drug lower mean SBP by activating beta ___ receptors? common on vagal tone and sympathetic tone.
2; the baroreceptor reflex work to restore blood pressure by REDUCING Vagal tone (parasympathetic) outflow from the CNS to the heart and INCREASING sympathetic tone outflow to the heart and blood vessels.
120
Alpha, beta and dopaminergic receptors are all
G protein coupled receptors
121
Adrenergic receptors can be found in
both the CNS and PNS
122
What is the characteristics of SYNTHETIC NON-CATECHOLAMINES? Provide the exception
Don't have HYDROXYL GROUP on BENZENE RING 3-OH and 4-OH groups; Phenylepinephrine
123
CNS stimulation is prominent with which kind of agents and why?
synthetic NON-CATECHOLAMINES because they don't have hydroxyl group with makes them able to penetrate BBB more readily
124
What are some of the SYNTHETIC NON-CATECHOLAMINES that can exhibit CONSIDERABLE CNS ACTIVITY ?
Methamphetamine
Ephedrine
Amphetamine
125
The absence of polar hydroxyl groups in synthetic non-catecholamines results in
LOSS of direct SYMPATHOMIMETIC activity.
126
Clinical use of Sympathomimetics -->
a) Addition to local anesthetics to decrease systemic absorption and increase the duration of action of local anesthetics
b) Management of life-threatening allergic reactions, including anaphylaxis
c) Vasopressors to increase systemic blood pressure after sympathetic blockade produced by regional anesthesia.
d )Vasopressors to maintain systemic blood pressure during the time needed to eliminate excess inhaled anesthetics or to restore intravascular fluid volume .
127
Selective α1 agents produce so much vasoconstriction that they trigger a ____ ______response.
Since, CO = _______ decreasing HR will ultimately _______ CO
reflex bradycardia
| HR x SV; decrease your CO
128
Which is more potent ? Catecholamines or SYNTHETIC CATECHOLAMINES?
Catecholamines.
129
________Breaks down catecholamines in food _________
MAO; Tyramine
130
The presence of methyl group on the alpha carbon , as with ______ and ______ slows the metabolism by _______ and further increases theses duration of action.
EPHEDRINE
AMPHETAMINE
MAO
131
Metabolic of non-synthetic catecholamines is ______ than catecholamines.
slower
132
Ephedrine is not ______or _____By _____(organs)
Broken down, extracted
133
Certain Medications can cause transmitter depletion
Methyldope
Reserpine
Guanethidine
134
How does Reserpine work
Inhibits transport of Monoamine into synaptic storage vesicles ultimately leaks to DEPLETION of Catecholamines from nerve endings. in CNS
135
Guanethidine
systemic BP response to indirect age is decreased when given in conjunction with these depleting agents
136
RESPONSE OF INDIRECT ACTING SYMPATHOMIMETIC (IASA) AGENTS MAY BE ACCENTUATED BY
MAO Inhibitors.
137
The mechanism of the rise in blood pressure, mainly ______due to epinephrine is due to
- direct myocardial stimulation (increase strength ventricular contraction
- increase in HR
- Vasoconstriction in vascular bed(skin, mucosa, splanchnic area and kidneys, veins)
138
As the concentration of EPINEPHRINE increases , the predominant effect will be
Vasoconstriction; ALPHA 1
139
___________ state present during the intraoperative and post-operative period may reflect stress-associated release of ________
HYPERCOAGULABLE
| EPINEPHRINE
140
GI EPI effects: ________Through which receptors?
GI muscle tone is
SPHINCTERS and secretion
Relaxation of GI smooth muscle in the GI wall ; Beta 2
decreased.
contraction of sphincters and decrease secretion.
141
SNS control of radial muscles
Alpha -1 activation causes --> radial muscles to shorten -->
| Increase pupil size =mydriasis
142
Epinephrine predominantly stimulates _______ in the _____, mucosa , _________ vasculature producing intense vaso_______
Alpha 1 receptors; skin; hepatorenal ; vasoconstriction.
143
In the skeletal vasculature epinephrine principally stimulate _______ receptors producing vaso _______
Beta 2; dilation
144
The net effect o f changes in the peripheral vascular tone is _______
Distribution of cardiac output to skeletal muscles and increased SVR
145
What happens to myocardial oxygen consumption?
Increased with enhanced LV preload
Increased contractility
Increased afterload and
Tachycardia
146
Repeased doses of epinephrine does not lead to _______ like _______do
Tachyphylaxis; catecholamines.
147
What is substantially decreased by Epi?
Renal blood flow
148
In usual therapeutic doses, epinephrine has relatively ______ ______ action on cerebral arterioles because epinephrine is
little vasoconstriction
| Poorly lipid soluble.
149
What causes hyperglycemia in perioperative?
Release of endogenous epinephrine and the resulting GLYCOGENOLYSIS/ GLUCONEOGENESIS and inhibit of insulin secretion
150
Why is the measurement of serum potassium levels immediately before induction of anesthesia are usually lower than 1- 3 days prep
due to STRESS INDUCED RELEASE OF EPINEPHRINE
151
B2 stimulation ________ intracellular concentration of ________ and ______ release of ______Mediatrors associated with bronchial asthma
increasing
decreasing
vasoactive
152
The bronchodilator effect of Epinephrine ( is or is not) ________ seen with B2 adrenergic blockade instead, epinephrine induces _______ from stimulation of _______
is not
broncho-constriction
alpha receptors.
