CV Drugs- Adrenergic-receptor Antagonists Flashcards
(160 cards)
1
Q
alpha-adrenergic antagonists- MOA: binds
A
competitively or covalently with alpha receptors
2
Q
alpha-adrenergic antagonists- MOA: prevent the effect of
A
catecholamines and other alpha agonists form entering with the alpha receptor
3
Q
alpha-adrenergic antagonists- MOA: located in
A
the heart and peripheral vasculature
4
Q
alpha-adrenergic antagonists- effects
A
- vasodilation (orthostatic hypotension)
- reflex tachycardia
- blocks inhibition of insulin secretion
5
Q
alpha-adrenergic antagonists- side effects prevent use as
A
essential antihypertensives
6
Q
alpha-adrenergic antagonists- if beta blockade is not present,
A
maximal cardiac stimulation is allowed
7
Q
phentolamine (Regitine)- MOA
A
competitive binding
8
Q
phentolamine (Regitine)- blockade is
A
nonselective, alpha 1 and alpha 2
9
Q
phentolamine (Regitine)- effects: vasodilation- __ blockade and direct action on __
A
alpha1
vascular smooth muscle
10
Q
phentolamine (Regitine)- cardiac effects
A
cardiac stimulation (increased HR and CO)
reflex and alpha 2 blockade (blocks negative feedback of NE)
11
Q
phentolamine (Regitine)- side effects
A
- dysrhythmias
- angina
- hyperperistalsis
- abdominal pain
- diarrhea due to parasympathetic tone
12
Q
phentolamine (Regitine)- uses
A
- acute HTN emergencies, pheochromocytoma
- accidental infiltration of a sympathomimetic (5-15 mg in 10ml)
13
Q
phentolamine (Regitine)- onset
A
2 min
14
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phentolamine (Regitine)- duration
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10-15 min
15
Q
phenoxybenzamine (Dibenzyline)- MOA
A
irreversible covalent binding to alpha-receptors
16
Q
phenoxybenzamine (Dibenzyline)- blockade
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nonselective, alpha1>alpha2
17
Q
phenoxybenzamine (Dibenzyline)- effects: vasodilation
A
orthostatic hypotension exaggerated with hypovolemia, HTN
18
Q
phenoxybenzamine (Dibenzyline)- effects: impariment of
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compensatory vasoconstriction (lower BP with hypovolemia and vasodilation drugs like volatile agents)
19
Q
phenoxybenzamine (Dibenzyline)- __ CO
A
increased
20
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phenoxybenzamine (Dibenzyline)- very little change in
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renal blood flow even with decreased BP
21
Q
phenoxybenzamine (Dibenzyline)- prevents the inhibition of
A
insulin secretion
22
Q
phenoxybenzamine (Dibenzyline)- causes pupil
A
constriction
23
Q
phenoxybenzamine (Dibenzyline)- chronić use may cause
A
sedation
24
Q
phenoxybenzamine (Dibenzyline)- __ congestion
A
nasal
25
phenoxybenzamine (Dibenzyline)- uses
1. control BP in pheochromocytoma
2. in trauma patients, used to reverse vasoconstriction (shock), only after volume replacement
3. Raynaud's syndrome
26
phenoxybenzamine (Dibenzyline)- onset
up to 60 min (IV)
27
phenoxybenzamine (Dibenzyline)- elimination 1/2 life
24 hours (duration can last up to 4 days)
28
prazosin (Minipress)- MOA
competitive, reversible binding with alpha receptors
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prazosin (Minipress)- blockade
selective alpha 1 antagonist
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prazosin (Minipress)- effects
1. vasodilation of both arterioles and veins
2. less reflex tachycardia (alpha 2 not blocked)
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prazosin (Minipress)- uses
1. HTN
2. severe CHF
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prazosin (Minipress)- onset
within 2 hours
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prazosin (Minipress)- duration
10-24 hours
34
doxazosin (Cardura)- blockade
selective, alpha 1 antagonist
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doxazosin (Cardura)- dose
once daily
36
doxazosin (Cardura)- peak
2-3 hours
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doxazosin (Cardura)- elimination 1/2 life
22 hours
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doxazosin (Cardura)- indications
1. BPH
2. HTN
39
beta-adrenergic antagonist- MOA: competitive binding to __ to block __
beta receptors
the effect of catecholamines and agonist on the heart and smooth muscles of airways and blood vessels
40
beta-adrenergic antagonists- prolonged or chronic use of beta blockers causes
up-regulation of beta receptors
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classifications of beta-adrenergic antagonists
1. nonselective
2. cardioselective
3. partial antagonist
4. pure antagonist
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nonselective beta-adrenergic antagonists block
both beta 1 and beta 2 (timolol and propranolol)
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cardioselective beta-adrenergic antagonists block
beta 1 (metoprolol, atenolol, esmolol)
44
beta-adrenergic antagonists partial antagonists
intrinsic sympathomimetic effect (less myocardial depression and HR reduction)
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beta-adrenergic antagonists put antagonist
no sympathomimetic effect
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selectivity of beta-adrenergic antagonists is
dose-related; if a big enough dose of a carioselective beta-blocker is give, the effect can impact beta-2 receptors
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beta 1 blockade removes
sympathetic stimulation to the heart
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beta 1 blockade effects
1. negative inotropic effects
2. negative chronotropic effects
3. negative dromotropic effects
4. increased in lusitropy
5. decrease in bathmotropy
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beta 1 blockade negative inotropic effects
myocardial depression
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beta 1 blockade negative chronotropic effects
slows HR, sinus rate
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beta 1 blockade negative dromotropic effects
1. slows the conduction of impulse through the AV node
2. slows rate of phase 4 depolarization
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beta 1 blockade increase in lusitropy effects
ventricular relaxation
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beta 1 blockade decrease in bathmotrophy effects
reduced degreee of excitability
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beta 2 blockade effects
1. vasoconstriction
2. unopposed alpha vasoconstriction can cause decreased LV ejection
3. bronchoconstriction
4. prevents glycogenolysis, blocks tachycardia related to hypoglycemia, alters fat metabolism (lipolysis)
5. inhibits uptake of K into skeletal muscle cells (increased serum K)
55
effects of beta-adrenergic antagonists- additive __ with anesthetics
myocardial depressant effects but safe to continue
hal>iso
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effects of beta-adrenergic antagonists- CNS
cross BBB- fatigue, lethargy, vivid dream, memory loss, depression
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effects of beta-adrenergic antagonists- cross placenta so
fetal bradycardia, hypotension, hypoglycemia
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effects of beta-adrenergic antagonists- GI
nausea, vomiting, diarrhea
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effects of beta-adrenergic antagonists- chronic use
fever, rash, myopathy, alopecia, thrombocytopenia
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contraindications to beta-blockade-
1. AV heart block
2. hypovolemia
3. COPD
4. diabetic
5. PVD, Raynaud's syndrome, alpha-adrenergic agonist
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contraindications to beta-blockade- AV heart block
slowed conduction may be enhanced
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contraindications to beta-blockade- hypovolemia
eliminates tachycardia that is compensating for decrease in volume
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contraindications to beta-blockade- COPD
increased airway resistance (nonselective or high doses)
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contraindications to beta-blockade- diabetic
mask signs of hypoglycemia (nonselective or high doses)
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contraindications to beta-blockade- PVD, Raynaud's syndrome, or alpha-adrenergic agonists
vasoconstriction unopposed (nonselective), cold extremities
66
signs/symptoms of an overdose of beta-adrenergic antagonist
1. bradycardia
2. low cardiac output
3. hypotension
4. cariogenic shock
5. bronchospasm
6. prolonged intraventricular conduction of impulses
7. hypoglycemia- rarely
67
overdose of beta-adrenergic antagonist TREATMENT
1. atropine 7 mcg/kg IV (0.5 mg IV) first
2. isoproterenol 2-25 mcg/min (with nonselective beta-blockers)
3. dobutamine
4. glucagon and CaCl
5. if heart rate dose not increase with drugs, a pacemaker
6. hemodialysis
68
dobutamine is used for overdose of beta-adrenergic antagonist TREATMENT when
when beta-blockade is from a beta-blocker with no sympathomimetic effects
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glucagon (1-10mg) overdose of beta-adrenergic antagonist TREATMENT is
drug of choice due to independent action; effects smooth muscle and cardiac contractility
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CaCl (250mg-1gm) for overdose of beta-adrenergic antagonist TREATMENT to
increase cardiac function independent of the blocked receptors
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acute withdrawal of beta-blockade
1. increased sympathetic stimulation due to up-regulation of beta receptors
2. profound hypertension, tachycardia, contractility
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acute withdrawal of beta blockade occurs within
24-48 hours
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during acute withdrawal of beta-blockade, avoid
continued preop beta-blockade therapy; infusion of propranolol 3 mg/hr IV
74
treatment of HTN with beta-adrenergic antagonists
1. decrease HR, decrease CO
2. decrease contractility in larger doses
3. with vasodilatory, prevention of reflex tachycardia
4. decrease renin, decrease aldosterone, prevention of Na/water retention
75
management of angina pectoris with beta-adrenergic antagonists
decreased myocardial oxygen consumption- decreased HR, contractility
76
post-MI infection use of beta-adrenergic antagonists- historically
decreases mortality and reinfarctions
1. increases changes of survival 20-40%
2. begin within 5-28 days after MI and continue for 1-3 years
3. within 12 hours of onset of infarct may actually decrease infarct size and dysrhythmias
77
post-MI infection use of beta-adrenergic antagonists- not with
acute coronary syndrome with ST elevation or cariogenic shock
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post-MI infection use of beta-adrenergic antagonists- both selective and nonselective drugs have __; nonselective have an effect on __
cardioprotective effects
K (prevents reduction) and may decrease dysrhythmias
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cardiac dysrhythmias use of beta-adrenergic antagonists- decrease activity of
SA node and conduction through the AV node
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cardiac dysrhythmias use of beta-adrenergic antagonists- slow
depolarization of ectopic pacemakers
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cardiac dysrhythmias use of beta-adrenergic antagonists- suppresses both
supraventicular and ventricular ectopy
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cardiac dysrhythmias use of beta-adrenergic antagonists- rapid suppression of
excessive sympathetic stimulation (thyrotoxicosis, pheochromocytoma, period stress)
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prevention of excessive sympathetic nervous system activity use of beta-adrenergic antagonists- minimizes repose to
laryngoscopy
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prevention of excessive sympathetic nervous system activity use of beta-adrenergic antagonists- __ cardiomyopathies
hypertrophic obstructive
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prevention of excessive sympathetic nervous system activity use of beta-adrenergic antagonists- __ and __
pheochromocytoma, hyperthyroidism
86
prevention of excessive sympathetic nervous system activity use of beta-adrenergic antagonists- TOF, minimizes
cyanosis
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prevention of excessive sympathetic nervous system activity use of beta-adrenergic antagonists- prevent __ with vasodilation use in deliberate hypotension
reflex tachycardia
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prevention of excessive sympathetic nervous system activity use of beta-adrenergic antagonists- public speaking
anxiety
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management of CHF (metoprolol, carvedilol, bisoprolol) use of beta-adrenergic antagonists-
1. improve EF
2. increase survival rate in HF
3. doses initially small and gradually increase
90
use of beta-adrenergic antagonists that cause cardio protection during surgery-
1. improvement of the myocardial oxygen supply-demand balance
2. decrease oxygen requirements by slowing HR and decreasing contractility
3. blocks catecholamines from the receptors to avoid increased sympathetic stimulation
4. prolongs diastole and increases time for oxygen delivery
5. suppression of dysrhythmias- improves long-term mortality
6. increase blood flow to ischemic myocardium
91
periop beta blockers are recommended for patients who
are receiving beta-blocker for the treatment of conditions with ACC/AHA Class I indication for the drug
92
periop beta blockers are probably recommended in patients who
1. undergoing vascular surgery who suffer from CAD or show ischemia on preop testing
2. in the presence of CAD or high cardiac risk (more than one risk factor) who are undergoing intermediate-risk surgery
3. when preop assessment for vascular surgery identifies high cardiac risk (more than one risk factor)
93
the usefulness of beta-blockers is uncertain in patients
1. undergoing vascular surgery with no risk factors who are not currently taking beta-blockers
2. undergoing either immediate-risk procedures or vascular surgery with a single clinical risk factor in the absence of CAD
94
beta blockers are not to be given
1. high-dose beta blockers without titration are not useful and may be harmful to patients not currently taking beta-blockers who are undergoing surgery
2. patients undergoing surgery who have an absolute contraindication to beta blockade
95
periop beta blockade should be continued
in patient on chronic treatment
96
periop beta blockade with cardiac surgery benefit
reduces risk of SVT, vent arrhythmias
97
periop beta blockade, should they be indicated perioperatively, should be started
between 30 days and 1 weeks before surgery or days to weeks before surgery
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periop beta blockade, titration of beta blocker to __ and __ is necessary in order to minimize or reduce the risk of hypotension
heart rate 60-80 beats per minute
systolic arterial pressure > 100 mmHg
99
periop beta blockade for non cardiac
no benefit, reduction in arrhythmias, acute MI is offset by increase in mortality, stroke
100
propranolol (Inderal) blockade
nonselective, pure antagonist, beta 1 = beta 2
101
propranolol (Inderal) effects
1. decreases HR and contractility (and CO)
2. increase peripheral vascular resistance (beta 2), including coronary vascular resistance
102
propranolol (Inderal) dose
0.05 mg/kg IV in increments of 0.5-1 mg every 5 minutes
103
propranolol (Inderal) metabolism
hepatic
104
propranolol (Inderal) clearance is decreased with __
decrease in hepatic blood flow; it can decrease its own metabolism
105
propranolol (Inderal) elimination 1/2 life
2-3 hours
106
propranolol (Inderal)- special effects on LA
the metabolism of amide LA is decreased by propranolol due to decreased CO and more
107
propranolol (Inderal)- special effects on fentanyl
enters the circulation of a patient on propranolol due to decreased pulmonary uptake
108
Nadolol (Corgard)- is
nonselective
109
Nadolol (Corgard)- duration of action
long; given once daily
110
Nadolol (Corgard)- metabolism
75% excreted unchanged by the kidneys, in the bile
111
Nadolol (Corgard)- elimination 1/2 life
20-40 hours
112
timolol is
nonselective
113
timolol- is used for
topical eye gets for glaucoma
114
timolol- side effects
bradycardia and hypotension caused by gets during anesthesia
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timolol- can cause
apnea in neonates with immature blood brain barrier
116
metoprolol (Lopressor)- blockade
selective for beta1- receptors
117
metoprolol (Lopressor)- effects
blocks inotropic and chronotropic responses
118
metoprolol (Lopressor)- beta 2 receptors remain unblocked allowing
bronchodilation, vasodilation, and metabolic stability (unless higher doses are used)
119
metoprolol (Lopressor)- bolus
5mg IV (if HR > 80); 2.5 mg IV (if HR 60-80); hold if HR <60 or SBP < 100mmHg
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metoprolol (Lopressor)- metabolism
hepatic
121
metoprolol (Lopressor)- elimination 1/2 life
3-4 hours
122
most selective beta 1 antagonist
atenolol (Tenormin)
123
atenolol (Tenormin) elimination
renal excretion
124
atenolol (Tenormin) elimination 1/2 life
6-7 hours
125
atenolol (Tenormin) does not interfere with __ so can be given with caution to __
metabolism
diabetic patients
126
betaxolol blockade
beta 1 antagonist
127
betaxolol is an alternative to
timolol (nonselective)
128
betaxolol reduces
elevated as well as normal intraocular pressure, whether or not accompanied by glaucoma
129
betaxolol __ effects with clinical doses
minimal pulmonary and cardiac
130
bisoprolol blockade
beta 1 antagonist
131
bisoprolol prominent effect
decreased HR
132
bisoprolol is used for treatment of
essential HTN, mild to moderate CHF
133
esmolol (Brevibloc) blockade
selective beta 1 antagonist
134
esmolol (Brevibloc) dose
0.5 mg/kg IV over 60 seconds
135
esmolol (Brevibloc) onset
within 5 minutes
136
esmolol (Brevibloc) duration
10-30 minutes
137
esmolol (Brevibloc) metabolism
rapid hydrolysis by plasma esterases (independent of renal and hepatic function)
138
esmolol (Brevibloc) elimination 1/2 life
9 minutes
139
esmolol (Brevibloc) uses: protection against
tachycardia and hypertension related to laryngoscopy- give esmolol 150 mg 2 minutes prior to laryngoscopy; better protection than lidocaine or fentanyl against HR
140
esmolol (Brevibloc) uses: __, __, __ induced CV toxicity
pheochromocytoma, thyrotoxicosis, cocaine-induced
141
esmolol (Brevibloc) uses: __ and __ cardiomyopathy
TOF and hypertrophic obstructive
142
esmolol (Brevibloc) uses: __ surgery
cardiac surgery off bypass
143
esmolol (Brevibloc) uses: to reduce requirements of
propofol, opioids
144
esmolol (Brevibloc) uses: ECT dose
500 mcg/kg/min
145
labetalol (Normodyne, Trandate)- blockade
selective alpha 1 and nonselective beta 1 and beta 2
146
labetalol (Normodyne, Trandate)- 1/4 to 1/3 as potent as __ in beta blockade
propranolol
147
labetalol (Normodyne, Trandate)- CV effects
1. decreases SVR (vasodilation- alpha 1 antagonists and beta 2 agonist effect)
2. prevents reflex tachycardia (bc beta 1)
3. unchanged CO
148
labetalol (Normodyne, Trandate)- dose
0.1-0.5 mg/kg IV
149
labetalol (Normodyne, Trandate)- onset of peak effect
5-10 minutes
150
labetalol (Normodyne, Trandate)- metabolism
conjugation of glucuronic acid (hepatic)
151
labetalol (Normodyne, Trandate)- elimination 1/2 life
5-8 hours
152
labetalol (Normodyne, Trandate)- uses
1. HTN emergencies, increased SNS activity, pheochromocytoma
2. angina pectoris
3. controlled, deliberate hypotension
153
labetalol (Normodyne, Trandate)- side effects, most common
orthostatic hypotension
154
labetalol (Normodyne, Trandate)- __spasm from __
bronchospasm
nonspecific beta
155
labetalol (Normodyne, Trandate)- from beta effects
CHF, bradycardia, heart block (incidence and severity decreased)
156
labetalol (Normodyne, Trandate)- chronic use necessitates
addition of diuretic from fluid retention
157
carvedilol (Coreg)- blockade
alpha 1 blocking activity, non selective beta blocking (no intrinsic beta agonist effect (different from labetalol)
158
carvedilol (Coreg)- metabolites produce
weak vasodilation effect
159
carvedilol (Coreg)- indicated for
CHF and essential HTN
160
carvedilol (Coreg)- is shown to
decrease mortality with CHF
