Wk 10: Sympatholytics

Question 1

alpha and beta adrenergic receptor antagonists prevent the interaction of the endogenous neurotransmitter ________ or _________ with the corresponding adrenergic receptors

Answer 1

NE
sympatathomimetics

Question 2

alpha and beta antagonists attenuate _________ nervous system homeostatic mechanisms and evoke predictable pharmacologic responses

Answer 2

sympathetic

Question 3

alpha-adrenergic receptor antagonists (4)

Answer 3

Phentolamine
Prazosin
Phenoxybenzamine
Yohimbine

Question 4

alpha-adrenergic receptor antagonists bind selectively to _____ adrenergic receptors

Answer 4

alpha

Question 5

alpha-adrenergic receptor antagonists interfere with the ability of catecholamines or other sympathomimetics to provoke a response at the _______ and ______ vasculature

Answer 5

heart
peripheral

Question 6

Side effects of alpha-adrenergic receptor antagonists (3)

Answer 6

Orthostatic hypotension
Baroreceptor-mediated reflex
tachycardia
Impotence

Question 7

Phentolamine, prazosin, and yohimbine are ________ alpha-adrenergic antagonists

Answer 7

competitive

Question 8

Phentolamine and phenoxybenzamine are _________ alpha blockers, while prazosin is a _______ alpha blocker

Answer 8

nonselective (alpha 1 and alpha 2)
selective (alpha 1)

Question 9

Phentolamine produces __________ (competitive) nonselective alpha-adrenergic blockade

Answer 9

transient

Question 10

Phentolamine administered IV produces ________ vasodilation and a decrease in systemic _______ that reflects alpha 1 receptor blockade and direct action on vascular smooth muscle

Answer 10

peripheral
blood pressure

Question 11

Phentolamine

Decreases in blood pressure elicit _________-mediated response

Answer 11

baroreceptor

Question 12

The principal use of phentolamine is the treatment of acute ________ _________

Answer 12

hypertensive emergencies

Question 13

Phentolamine sometimes seen during intraoperative manipulation of a ___________ or autonomic nervous system _____________

Answer 13

pheochromocytoma
hyperreflexia

Question 14

Local infiltration of phentolamine-containing solution is appropriate when a ___________ is accidentally administered extravascularly

Answer 14

symathomimetic

Question 15

Phenoxybenzamine (prazosin is an alternative) is administered preoperatively to control blood pressure in patients with ___________

Answer 15

pheochromocytoma

Question 16

Chronic alpha-adrenergic blockade, by relieving intense peripheral vasoconstriction, permits expansion of ___________ fluid volume, as reflected by a decrease in _________

Answer 16

intravascular fluid
hematocrit

Question 17

Alpha adrenergic antagonists

Treatment of peripheral vascular disease characterized by intermittent __________ is not favorably influenced by alpha adrenergic blockade because _________ rather than skeletal muscle blood flow is increased

Answer 17

claudication
cutaneous

Question 18

The most beneficial clinical responses to alpha adrenergic blockade are in diseases with a large component of ___________ vasoconstriction, such as _______ disease

Answer 18

cutaneous
Raynaud’s

Question 19

Prazosin is a ________ postsynaptic alpha 1 antagonist

Leaves intact the inhibiting effect of ___ receptor activity on norepinephrine release from nerve endings

As a result, is less likely than nonselective alpha adrenergic antagonists to evoke ______ _________

Answer 19

selective
alpha 2
reflex tachycardia

Question 20

Beta antagonist therapy should be continued throughout the perioperative period to maintain desirable drug effects and to avoid risk of sympathetic nervous system ________ associated with abrupt discontinuation of these drugs

Answer 20

hyperactivity

Question 21

Beta adrenergic receptor antagonists exhibit selective affinity for beta adrenergic receptors, they act by _______ inhibition

Answer 21

competitive

Question 22

Chronic administration of beta adrenergic antagonists is associated with a ___________ in the number of beta-adrenergic receptors

Answer 22

increase

Question 23

The principal difference in the pharmacokinetics between all beta adrenergic receptor antagonists is the ______ ______ _______ ranging from brief for ______ (about 10 mins) to hours for other drugs

Answer 23

elimination half time
esmolol

Question 24

Beta adrenergic receptor antagonists are eliminated by several different pathways and this must be considered in the presence of _____ and/or ______ dysfunction

Answer 24

renal
hepatic

Question 25

Metoprolol is a _______ beta __ adrenergic antagonist that prevents inotropic and chronotropic responses to beta adrenergic stimulation

Answer 25

selective beta 1

Question 26

In metoprolol, bronchodilator, vasodilator, and metabolic effects of ___ receptors remain intact less likely to cause adverse effects in patients with _____ ______ _____ disease and ______ ______ ______

Answer 26

beta 2 chronic obstructive airway peripheral vascular disease

Question 27

Metoprolol Selectivity is dose related, and large doses are likely to become _______, exerting antagonist effects at ___ receptors as well as beta 1 receptors

Answer 27

beta 2

Question 28

Metoprolol is readily absorbed from the GI tract, which is offset by substantial ______ _____ _____ metabolism; only about ___% of the drug reaches the systemic circulation

Answer 28

hepatic first pass 40%

Question 29

_________ is a rapid-onset and short-acting selective beta 1-adrenergic receptor antagonist

Answer 29

Esmolol

Question 30

Esmolol is only administered _____

Answer 30

IV

Question 31

Esmolol After a typical initial dose of 0.5mg/kg IV over about 60 seconds, the full therapeutic effect is evident within ___ mins, and its action ceases within ___ to ___ minutes after administration is discontinued

Answer 31

5 10 to 30

Question 32

Which beta 1 agonist is useful for preventing or treating adverse systemic blood pressure and heart rate increases that occur intraoperatively in response to noxious stimulation, as during tracheal intubation

Answer 32

Esmolol

Question 33

Which beta 1 antagonists are available IV?

Answer 33

Esmolol Propranolol Metoprolol

Question 34

________ __________ responsible for hydrolysis of esmolol are distinct from plasma cholinesterase, and the duration of action of succinylcholine is not predictably prolonged in patients treated with esmolol

Answer 34

plasma esterases

Question 35

Short duration of action of esmolol returns HR to predrug levels within ___ minutes after DC of drug

Answer 35

15

Question 36

The principle contraindication to administration of beta adrenergic antagonists is preexisting _________ _______ _______ or ________ _______ not caused by tachycardia

Answer 36

atrioventricular heart block cardiac failure

Question 37

The usual clinical manifestations of excessive myocardial depression produced by beta adrenergic blockade include (4):

Answer 37

Bradycardia Low cardiac output Hypotension Cardiogenic shock

Question 38

Excessive bradycardia and/or decreases in cardiac output d/t drug-induced beta blockade should be treated initially with ________ If that doesn't work, continuous infusion of ________ in doses sufficient to overcome competitive beta blockade

Answer 38

atropine isoproterenol

Question 39

If atropine, isoproterenol not effective for myocardial depression d/t beta blockade, ________ administered to adults, ___ to ___ mg followed by ___mg per hour IV effectively reverses b/c these drugs do not exert their effects by means of beta adrenergic receptors

Answer 39

glucagon 1 to 10 mg 5 mg

Question 40

beta blockers In the presence of bradycardia that is unresponsive to pharmacologic therapy, it may be necessary to place a ___________ artificial ______ ________

Answer 40

transvenous cardiac pacemaker

Question 41

_________ beta adrenergic antagonists such as _________ consistently increase airway resistance as a manifestation of bronchoconstriction d/t blockade of beta 2 receptors exaggerated in patients with preexisting _______ _______ disease

Answer 41

nonselective propranolol obstructive airway

Question 42

Nonselective beta blockers such as ___________ interfere with _______ that ordinarily occurs in response to release of epinephrine during hypoglycemia

Answer 42

propranolol glycogenolysis (can cause/worsen hypoglycemia)

Question 43

__________, which is an important warning sign of hypoglycemia in insulin-treated diabetics, is blunted by beta adrenergic antagonists _______ beta blockers are not recommended for administration to patients with _______ who may be at risk for developing hypoglycemia

Answer 43

tachycardia nonselective diabetes mellitus

Question 44

Additive myocardial depression with beta blockers and anesthetics is ____ excessive, and treatment with beta blockers may therefore be safely maintained throughout the perioperative period An exception may be patients treated with _______ in whom profound ________ has been observed in presence of inhaled anesthetics

Answer 44

not timolol bradycardia

Question 45

beta blockers may cross the ________ to produce side effects: (2)

Answer 45

BBB fatigue lethargy

Question 46

________ and ________ are less lipid soluble than other beta blockers and thus may be associated with a lower incidence of CNS side effects

Answer 46

atenolol nadolol

Question 47

Perioperative beta blockade is recommended for patients considered at risk for ________ _______ (CAD, positive preop stress test, DM tx with insulin, LV hypertrophy) during high-risk surgery

Answer 47

myocardial ischemia

Question 48

High risk surgeries (4)

Answer 48

Vascular surgery Thoracic surgery Intraperitoneal surgery Anticipated large blood loss

Question 49

The advantage of esmolol is the ability to titrate its effects to desired ______

Answer 49

HR

Question 50

Beta blockers useful for suppression of cardiac _______ as a result of enhanced SNS stimulation

Answer 50

dysrhythmias

Question 51

________ and _________ are effective for controlling the ventricular response rate to atrial fibrillation and atrial flutter effective for controlling ______ dysrhythmias following cardiac surgery

Answer 51

esmolol and propranolol atrial

Question 52

beta blockade is associated with attenuated _____ and _____ changes in response to direct laryngoscopy and tracheal intubation

Answer 52

HR BP

Question 53

Combined alpha and beta adrenergic receptor antagonists

Answer 53

Labetalol Carvedilol

Question 54

________ is a unique parenteral and oral antihypertensive drug that exhibits selective alpha 1 and nonselective beta 1 and beta 2 adrenergic antagonist effects

Answer 54

Labetalol

Question 55

Labetalol beta to alpha blocking ratio PO: ___:___ IV: ___:___

Answer 55

PO: 3:1 (beta:alpha) IV: 7:1 (beta: alpha)

Question 56

Labetalol metabolism is by conjugation of glucuronic acid the elimination half-time is prolonged in the presence of ____ disease and unchanged by ____ dysfunction

Answer 56

liver

Question 57

Labetalol lowers systemic blood pressure by decreasing SVR (____ blockade) reflex tachycardia triggered by vasodilation is attenuated by simultaneous ___ blockade cardiac output is _________

Answer 57

alpha 1 beta unchanged

Question 58

The maximum systemic blood pressure-lowering effect of an IV dose of labetalol is present in __ to ___ min

Answer 58

5 to 10

Question 59

_______ _______ is the most common side effect of labetalol ________ is possible is susceptible patients, reflecting the ___ adrenergic antagonist effects

Answer 59

orthostatic hypotension bronchospasm, beta

Question 60

Fluid retention in patients treated chronically with labetalol is the reason for combining this drug with a ______ during prolonged therapy

Answer 60

diureticw