Cardiovascular Drugs- Sympathomimetics Flashcards
(160 cards)
1
Q
endogenous catecholamines
A
- epinephrine
- norepinephrine
- dopamine
2
Q
synthetic catecholamines
A
- isoproterenol
- dobutamine
3
Q
synthetic noncatecholamines
A
- ephedrine
- amphetamine
- phenylephrine
4
Q
selective alpha2-adrenergic agonists
A
- clonidine
- dexmedetomidine
5
Q
selective beta2-adrenergic agonists
A
- albuterol
- terbutaline
- ritodrine
6
Q
sympathetic nervous system activation causes
A
- cardiac stimulation (increased HR and BP, contractility, susceptibility to ectopy)
- bronchdilation
- vasoconstriction (decreased flow to skin, GI tract, renal)
- vasodilation (improved blood flow to skeletal muscle)
- CNS stimulation- increased cognition (except alpha 2)
- increased blood sugar (lipolysis & glycogenolysis)
- increased rate of coagulation
7
Q
lipolysis is
A
breakdown of lipids
8
Q
glycogenolsysi is
A
splitting up of glycogen in the liver, yielding glucose
9
Q
used to increase __ or increase __ after sympathetic blockade caused by regional anesthesia
A
contractility
vasular tone
10
Q
used to __ or __ BP (to prevent tissue ischemia) during the time required to correct for hypovolemia or excessive inhaled anesthesia
A
increase or maintain
11
Q
used to __ of asthmatic
A
relax bronchoconstriction
12
Q
used to manage __
A
anaphylaxis
13
Q
used to prolong __
A
regional anesthesia
14
Q
direct
A
bind to receptors and activate them directly (catecholamines and phenylephrine)
15
Q
indirect causes the release of
A
norepinephrine from postganglionic sympathetic nerve endings (amphetamine)
16
Q
indirect blocks
A
the reuptake of norepinephrine to make more in circulation (cocaine, tricyclic antidepressants)
17
Q
indirect agent might not be effective if patient has
A
denervation injury, or depletion of NT
18
Q
tachyphylaxis
A
the greater the concentration of the sympathomimetic, the lower the number of receptors in tissues or decreased response
19
Q
catecholamines are inactivated by enzymes
A
- monoamine oxidase (MAO)
- Catechol-O-methyltransferase (COMT)
20
Q
catecholamines termination of effect influenced more by
A
uptake back into postganglion sympathetic nerve endings
21
Q
catecholamines are filtrated by
A
the lungs of norepinephrine and dopamine
22
Q
noncatecholamines are inactivated by
A
MAO only- slower
23
Q
epinephrine stimulates
A
both alpha and beta
24
Q
most potent alpha stimulator
A
epinephrine
25
epinephrine stimulation
alpha1=alpha2; beta1=beta2
26
epinephrine is given
IV or subq (causes vasoconstriction which slows absorption)
27
epinephrine __ soluble
poorly lipid; lack of cerebral effects
28
epinephrine uses
1. decrease absorption and prolong duration of local anesthetics
2. treatment of anaphylactic reactions
3. treatment of cardiac arrest
4. increase myocardial contractility
29
low dose epinephrine dose
0.01-0.03 mcg/kg/min
30
low dose epinephrine beta 1
increases HR, BP, CO, inotropy
31
low dose epinephrine beta 2
decrease in DBP due to decrease in SVR (vasodilation in skeletal muscle vessels)
32
moderate dose epinephrine dose
0.03-0.15 mcg/kg/min
33
moderate dose epinephrine beta 1
1. increase in SBP, HR, CO, inotropy (increase in venous return)
2. increase in susceptibility to arrhythmias
3. mixed with alpha
34
large dose epinephrine dose
>0.15 mcg/kg/min
35
large dose of epinephrine stimulates
beta and alpha-1 but alpha predominates
36
large dose epinephrine beta and alpha 1
vasoconstriction of the skin, mucosa, and hepatorenal vessels (decreased renal blood flow), SVT common
37
epinephrine respiratory effects
smooth muscle relaxed in the bronchi (beta 2)
38
if beta antagonist is present with epinephrine the respiratory effects is
the alpha1 effect causes bronchoconstriction
39
epinephrine metabolic effect
most significant effect of all catecholamines
40
epinephrine __ blood glucose
increase
41
metabolic effect of epinephrine of beta 2
increase glycogenolysis and lipolysis
42
metabolic effect of epinephrine of alpha 2
inhibits release of insulin (hyperglycemia)
43
epinephrine effects on electrolytes
beta 2- stress induced hypokalemia (activation of the sodium-potassium pump on RBCs)
44
epinephrine causes __ K
initial increased
it follows glucose out of hepatic cells
45
epinephrine ocular effects
alpha 1- contraction of the radial muscles of the iris causes pupil dilation; contraction of the orbital muscles causing bulging of the eyes (exophthalmus)
46
epinephrine GI/GU effects
relaxation of GI smooth muscle
47
epinephrine GI/GU beta effects
relaxation of the detrusor muscle of the bladder
48
epinephrine GI/GU alpha1 effects
contracts the sphincter muscles
49
norepinephrine is
a naturally occurring catecholamines released from postganglionic sympathetic nerve endings
50
norepinephrine is a potent __ agonist with __ agonist effect, but little __ effect
alpha
beta1
beta2
51
norepinephrine stimulation
alpha1=alpha2; beta1>>beta2
52
norepinephrine clinical use
vasoconstrictor to increase SVR and raise BP
53
infiltration of norepinephrine into subq tissue can
cause necrosis due to vasoconstriction
54
can treat infiltration for norepinephrine with
phentolamine
55
norepinephrine alpha 1 CV effects
1. vasoconstriction of both arterial and venous vessels of all vascular beds
2. increased SVR, MAP, increased venous return
3. decreased HR
56
norepinephrine beta 1 CV effects
overshadowed by the alpha 1 effects causing a decrease in CO, decreased tissue perfusion, decreased kidney blood flow
57
norepinephrine respiratory effects
no beta 2
58
norepinephrine metabolic effects
hyperglycemia unlikely
59
norepinephrine dose
0.02-0.4 mcg/kg/min
60
low dose norepinephrine stimulation
beta 1 selective; increase HR, inotropy
61
high dose norepinephrine stimulation
alpha 1, alpha 2, beta 1; increase SVR, BP, but decreased HR (baroreceptor reflex)
62
norepinephrine bolus
dilute; 4-16 mcgs (intermittent boluses- less bradycardia than phenylephrine)
63
dopamine
endogenous NT in the nervous system (central and peripheral)
64
dopamine stimulation
D1=D2>>beta>>alpha
65
low dose dopamine dose
1-2 mcg/kg/min
66
low dose dopamine
D1 renal vasodilation, may have decreased BP
67
moderate dose dopamine dose
2-10 mcg/kg/min
68
moderate dose dopamine
beta 1 in the heart (increased HR, inotropy, CO)
69
high dose dopamine dose
10-20 mcg/kg/min
70
high dose dopamine
alpha1 in the peripheral vessels overrides D and beta
71
dopamine indications
1. increase CO in patients with low BP, elevated atrial filling pressure, and low urine output
2. increase renal blood flow, GFR, excretion of sodium and urine output
72
renal dose dopamine
no studies have shown that dopamine decreases the incidence of acute renal failure of those at risk (UOP increases, mortality and morbidity do not improve)
73
dopamine renal effects antagonized by
arterial hypoxemia and droperidol and metoclopramide
74
dopamine beta 1 CV effects
increases CO; increased HR, BP, SVR
75
dopamine release of norepinephrine
inotropic and susceptible to dysrhythmias (less than epinephrine)
76
dopamine CV effects can raise
myocardial O2 demand > O2 supply
77
dopamine D1 CV effects
dilates renal and mesenteric vascular beds
78
dopamine respiratory effects
inhibits the ventilatory response to arterial hypoxemia
79
dobutamine stimulation
selective beta1; beta1>beta2>>>>alpha
80
dobutamine indication
CO in patients with CHF
81
dobutamine dose
0.1-15 mcg/kg/min
82
dobutamine causes
increase HR, inotropy, CO
83
dobutmaine is combined with dopamine to
improve renal blood flow
84
dobutmaine is combined with a vasodilator to
decrease SVR and further improve CO
85
dobutamine beta1 CV effects
increase in CO with little increase in HR or BP (minimal increase in oxygen demand), decreases SVR and PVR
86
dobutamine is a __ vasodilator and cannot cause __
coronary artery
renal vasodilation
87
high doses of dobutamine cause
increased HR and dysrhythmias (otherwise unlikely due to no release of norepinephrine)
88
most potent beta agonist
isoproterenol
89
isoproterenol stimulates
beta1=beta2>>>>alpha
90
isoproterenol indications
1. increase heart rate with heart block
2. decrease pulmonary vascular resistance
3. bronchodilation
91
isoproterenol beta1 CV effects
1. increased HR
2. inotropic effect
3. susceptibility to dysrhythmias
92
isoproterenol beta2 CV effects
decreased SVR due to vasodilation in skeletal muscle
93
isoproterenol summary
1. decreased MAP
2. decreased coronary blood flow
3. increased oxygen demand
94
isoproterenol is not good for
patients with coronary artery disease
95
ephedrine stimulates
alpha and beta
96
ephedrine is __ acting
indirect
97
ephedrine effects are due to
release of norepinephrine and the direct effect of ephedrine on beta adrenergic receptors
98
ephedrine may be given
orally, IM, IV
99
ephedrine dose
2.5-10 mg (must increase subsequent doses to obtain same response, tachyphylaxis)
100
ephedrine __ duration as a __
prolonged
noncatecholamine
101
ephedrine indications
1. temporarily increase BO due to sympathetic blockade from regional or hypotension due to inhaled or IV anesthesia
2. bronchdilation (slow onset) or nasal decongestant
3. antiemetic (0.5 mg/kg IM)
102
ephedrine CV effects are similar to
epinephrine but not as intense (250X)
103
ephedrine beta1 CV effects
increased systolic and diastolic BP, HR, and CO
104
principle CV effect of ephedrine beta1
increased contractility
105
ephedrine alpha1 CV effects
vasoconstriction, renal and splanchnic flow decreased
106
ephedrine beta2 CV effects
vasodilation, coronary artery and skeletal muscle vessels flow increased
107
ephedrine beta2 CV effects- SVR may not change much as
vasodilation of some vessels offset the vasoconstriction of others
108
ephedrine respiratory effects
beta1- bronchodilation
109
ephedrine CNS effects
stimulation; increases MAC- less than amphetamine
110
ephedrine ocular effects
mydriasis
111
ephedrine metabolic effects
no hyperglycemia
112
ephedrine effects of uterine blood flow
not** the drug of choice, higher incidence of fetal acidosis
113
phenylephrine is mostly __ by __ effect
alpha1
direct
114
phenylephrine stimulation
alpha1>alpha2>>>>>beta
115
phenylephrine __ effect
very small indirect
116
phenylephrine acts more like
norepinephrine
117
phenylephrine indications
1. increased BP due to sympathetic blockade or peripheral vasodilation
2. increase BP in patients with CAD or aortic stenosis to avoid increased HR
3. maintain BP during carotid endarterectomy
4. slow HR from SVT
5. nasal decongestant, mydriasis
6. prolong duration of spinal anesthesia
118
phenylephrine alpha1 CV effects
1. peripheral vasoconstriction
2. increase in BP
3. increased susceptibility to dysrhythmias
119
phenylephrine CV effects
1. decrease in CO due to increased afterload or reflex bradycardia
2. decreased blood flow to the kidneys, skin, and splanchnic system
3. increased flow to the coronary arteries
4. decreased cerebral oxygen saturation
120
clonidine is __ acting __
centrally
partial alpha2-adrenergic agonist
121
clonidine stimulation
antihypertensive, alpha2>alpha2>>>>>beta
122
clonidine decreases
sympathetic output from the CNS
123
clonidine MOA- stimulates
alpha1 inhibitory neurons in the medullary vasomotor center
124
clonidine MOA- __ sympathetic outflow
decreased
125
clonidine MOA- cell membranes
hyper polarized in the CNS
126
clonidine MOA- neuraxial
inhibits spinal substance P release and blunts perception of noxious stimuli
127
clonidine CV effects
1. decrease in BP, HR, CO
2. reflexes are maintained; avoid orthostatic hypotension
3. renal blood flow is maintained
128
clonidine indications
1. analgesia
2. premedication
3. prolongs the effect of regional anesthesia
4. diagnose pheochromocytoma
5. treatment of opioid withdrawal
6. treatment of shivering
129
clonidine for analgesia
neuraxial- without depression of ventilation, pruritus, N/V, or delayed gastric emptying
130
clonidine as premedication
1. blunts response from laryngoscopy
2. decrease lability of BP and HR
3. decrease catecholamine concentrations
4. decreases MAC and requirements of injected drugs
5. accentuates effect of ephedrine
6. decreases incidence of myocardial ischemic episodes in patients with CAD
131
clonidine to diagnose pheochromocytoma
reduces release of catecholamines from nerve endings, not pheo
132
clonidine for treatment of opioid withdrawal
inhibition of CNS
133
clonidine for treatment for shivering
inhibit central thermoregulatory control, vasoconstriction- more susceptible to hypothermia
134
most common side effect of clonidine
sedation
135
clonidine has agonist effect on
postsynaptic alpha2- 50% reduction in anesthetic requirements of MAC
136
clonidine decreased catecholamine levels so may require
anticholinergic to treat bradycardia
137
clonidine has __ if abruptly stopped
rebound hypertension
138
dexmedetomidine is a
alpha2-adrenergic agonist
139
dexmedetomidine is selective for
7X more selective for alpha2 receptors than clonidine
140
dexmedetomidine duration of action
shorter than clonidine (2hr 1/2life)
141
dexmedetomidine decrease
MAC by > 90%
142
dexmedetomidine causes __ and __ with little __
sedation and analgesia
depression of ventilation
143
dexmedetomidine increased likelihood of
hypotension and hypothermia
144
albuterol is selective
beta2
145
albuterol stimulation
beta2>>beta1>>>>alpha
146
albuterol indications
1. prevention and treatment of bronchoconstriction in asthma or COPD
2. stop premature uterine contractions
147
albuterol- inhaled route minimizes __; inhaler delivers __ of dose to lungs; an ETT decreases that amount by __
side effects
12%
50-70%
148
albuterol side effects
1. tremors
2. increased HR, vasodilation
3. relaxation of compensatory vasoconstriction
4. hyperglycemia, hypokalemia, hypomagnesium with acute admin
149
albuterol is __ with volatile agent
additive (bronchodilation)
150
alpha agonist
1. phenylephrine alpha1>alpha2>>>>>beta
2. clonidine alpha2>alpha1>>>>>beta
151
mixed alpha and beta agonist
1. epinephrine alpha1=alpha2; beta1=beta2
2. norepinephrine alpha1=alpha2; beta1>>beta2
152
beta agonists
1. isoproterenol beta1=beta2>>>>alpha
2. dobutamine beta1>beta2>>>>alpha
3. albuterol, terbutaline beta2>>beta1>>>>alpha
153
dopamine agonist
dopamine d1=d2>>beta>>alpha
154
vasopressin (arginine vasopressin) antidiuretic hormone (ADH) regulates
extracellular fluid by affecting the kidney's handling of water
155
vasopressin principle sites of action
1. kidneys
2. vessels
156
vasopressin action on kidneys
water reabsorption V2
157
vasopressin action on vessels
arterial vasoconstriction V1
158
vasopressin dose
20 units, diluted to 1U/cc
159
1 unit of vasopressin
approximately increases systolic BP 20mmHg
160
vasopressin is used to treat
refractory hypotension after ephedrine, phenylephrine, etc.
