Wk 10: Sympathomimetic agents Flashcards by Ashley Campbell

Naturally occurring catecholamines (3)

Epinephrine
Norepinephrine
Dopamine

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Synthetic catecholamines (2)

Isoproterenol
Dobutamine

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Epinephrine is a hormone synthesized, stored, and released from the _______ _______

adrenal medulla

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Epinephrine’s natural functions upon release into circulation include (5)
-Regulation myocardial _______
- _________ _________
-_____ and ____ smooth muscle tone
-________ secretions
-Metabolic processes (______ and ______)

-Regulation myocardial contractility
-Heart rate
-Vascular and bronchial smooth
muscle tone
-Glandular secretions
-Metabolic processes
(glycogenolysis and lipolysis)

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Epinephrine receptors

Alpha 1
Alpha 2
Beta 1
Beta 2

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Why isn’t oral administration of epinephrine effective?

Rapid metabolism in GI mucosa and liver

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What routes can epinephrine be administered?

Subcutaneous
IM
IV

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Epinephrine is poorly _______ soluble, preventing its ready entrance into the _____ ______ _____ and accounting for the lack of _______ _______

lipid
central nervous system
cerebral effects

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Epinephrine clinical uses:

-___________
-Severe ________ and _______
-Cardiopulmonary __________
-Promotion of myocardial ________ and increase __________ ________
-Can be added to LA as a “marker” or to decrease _______ absorption and prolong DOA

-Anaphylaxis
-asthma and brochoconstriction
-Cardiopulmonary resuscitation
-promotion of myocardial contractility and increase vascular resistance
-systemic

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____________ has the most significant metabolic effect on metabolism of all the catecholamines

Epinephrine

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Release of endogenous epinephrine and the resulting __________ and inhibition of _______ secretion is the most likely explanation for perioperative hyperglycemia

glycogenolysis
insulin

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Coagulation is accelerated by _________

epinephrine

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A hypercoagulable state present during the intraoperative and postoperative period may reflect stress-associated release of _________

epinephrine

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Norepinephrine is the endogenous neurotransmitter synthesized and stored in __________ sympathetic nerve endings and released with sympathetic nerve stimulation

postganglionic

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Norepinephrine receptors

Alpha 1 > B1

B2 (weak)

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The primary utility of norepinephrine is as a potent ________ to increase total peripheral vascular resistance and mean arterial pressure

vascoconstrictor

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What is first-line agent in the treatment of refractory hypotension during severe sepsis?

Norepinephrine

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Norepinephrine-induced vasoconstriction and redistribution of flow may increase ________ blood flow and _______ _______ in severely hypotensive septic patients

splanchnic
urine output

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Norepinephrine side effects

Use as an inotropic agents limited by its action as a ___________ _________

potent vasoconstrictor

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Norepinephrine side effects

Excessive vasoconstriction and decreased perfusion of renal, splanchnic, and peripheral vascular beds may lead to end-organ _______ and ________

hypoperfusion
ischemia

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__________ is an endogenous catecholamine that regulates cardiac, vascular, and endocrine function.

Is an important neurotransmitter in the central and peripheral nervous systems

Dopamine

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Despite identical IV infusion rates, there may be a ___ to ____ -fold variability in plasma concentrations produced by this drug, even in healthy individuals with normal drug metabolism

Dopamine

10-75

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Dopamine receptors

B1 > B2
Alpha 1
D1 D2

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Dopamine increases cardiac output by stimulation of ____ receptors, increasing ______ ______

Beta 1
stroke volume

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Rapid metabolism of dopamine with an elimination half life of ___ to ___ minutes mandates its use as a continuous infusion

1 to 2 minutes

______________ is used clinically to increase cardiac output in patients with decreased contractility, low systemic BP, and low urine output as may be present after cardiopulmonary bypass or with chronic heart failure

Dopamine

Dopamine is unique among the catecholamines in being able to simultaneously: -Increase myocardial _________ -Increase ________ blood flow -Increase ________ _________ rate -Excretion of _________ -Increase __________ output

contractility renal glomerular filtration sodium urine

Which catecholamine is associated most with dose-related sinus tachycardia and the potential to cause ventricular arrhythmias?

Dopamine (vs. dobutamine or epinephrine)

Dopamine may presdispose to mycardial ischemia by: precipitating ________, increasing ________, increasing _______, and precipitating coronary artery _________

tachycardia contractility afterload vasospasm

__________ is the most potent activator of all sympathomimetics with beta 1 and beta 2 activity ____ to ____ times more potent than epinephrine and at least _____ times more active than NE

Isopreterenol 2 to 3 100

Isoproterenol receptors

Beta 1 Beta 2

The cardiovascular effects of isoproterenol reflect activation of beta 1 receptors in the ______ and beta 2 receptors in the _______ _______

heart skeletal muscle

Isoproterenol Although cardiac output may increase, the ___________ may decrease

Mean arterial pressure (MAP)

Does baroreceptor-mediated reflex bradycardia occur with isoproterenol?

No because MAP is not increased

Metabolism of isoproterenol in the _______ by catechol-O-methyltransferase is ________, necessitating a continuous infusion to maintain therapeutic plasma concentrations

liver rapid

_________ is used to increase heart rate in adults in presence of heart block

Isoproterenol

_________ is used to provide sustained increases in heart rate before insertion of a temporary or permanent cardiac pacemaker

Isoproterenol

___________ is a synthetic catecholamine derived from isoproterenol consisting of a 50:50 racemic mixture of two sterioisomers

Dobutamine

Dobutamine receptors

Beta 1 > Beta 2 Alpha (high doses)

Dobutamines effects on ____ receptors increases at higher doses

alpha

_________ stimulates SA node automaticity as well as AV node and ventricular conduction

Dobutamine (tachyarrhythmias)

Rapid metabolism of dobutamine (half life ___ mins) necessitates continuous infusion

2 mins

Dobutamine increases myocardial contractility (____ and ______ receptors) and causes a modest degree of peripheral vasodilation ( _____ receptors)

Beta 1 and alpha 1 Beta 2

Dobutamine is used to : (2)

-improve cardiac output in patients with CHF -Weaning from CPB

Vasodilators may be combined with ________ or _________ to decrease afterload, optimizing cardiac output in the presence of increased _______

dobutamine dopamine SVR

The use of dobutamine may be limited by the occurrence of ________

tachyarrhythmias

Tachyarryhthmias in dobutamine occur more frequently at ______ _____ or in patients with underlying _______ or _______ _________

higher doses arrhythmias heart failure

Synthetic noncatecholamines

Ephedrine Phenylephrine

_________ is an indirect and direct acting synthetic sympathomimetic Indirect: stimulates release of endogenous ____ Direct: stimulates ___ and ___ -adrenergic receptors

Ephedrine NE alpha and beta

The slow inactivation and excretion of ________ are responsible for the prolonged duration of action of this sympathomimetic

ephedrine

Ephedrine uses: -Increase BP in presence of SNS blockade produced by _____ _____ -Hypotension due to _______-or _________ anesthetics

regional anesthesia inhaled or injected anesthetics

__________ was considered the preferred sympathomimetic for administration to parturients experiencing decreased systemic blood pressure owing to spinal or epidural anesthesia alpha agonists such as __________ may be preferable for treatment of maternal hypotension

Ephedrine Phenylephrine

Cardiovascular effects of ephedrine resemble those of __________, its systemic BP-elevating response is ________ ________ and lasts approximately ____ times longer

epinephrine less intense 1o

IV ephedrine results in increases in: (3)

-Sys. and dys. BP -HR -CO

Ephedrine receptors

Alpha 1 Beta 1 > Beta 2

Phenylephrine receptor

Alpha 1

The principle mechanism for cardiovascular effects produced by ephedrine is increased myocardial _________ due to activation of ___ receptors

contractility B1

In the presence of ______________, the cardiovascular effects of ephedrine may resemble responses more typical of alpha-adrenergic receptor stimulation

preexisting beta-adrenergic blockade

A second dose of ephedrine produces a less intense systemic blood pressure response than the first dose (_______________, occurs with many sympathomimetics

tachyphylaxis

___________ mimics the effects of NE but is less potent and longer lasting

Phenylephrine

Phenylephrine stimulates ____ receptors by a direct effect, with only a small part of the pharmacologic response being indirect-acting d/t its ability to evoke the release of ________

alpha 1 NE

Phenylephrine primarily causes ________ rather than ________ constriction

venoconstriction

Phenylephrine uses: -Increase BP in presence of SNS blockade produced by _____ _____ -Peripheral vasodilation due to _______-or _________ anesthetics -As a _________ infusion in adults to maintain normal BP during surgery

regional anesthesia inhaled or injected anesthetics continuous

Selective Beta 2- adrenergic agonists (3)

Albuterol Metaproterenol Terbutaline

Selective phophodiasterase inhibitors

Milrinone Amrinone

Selective beta 2 agonists relax ________ and _______ smooth muscle, but in contrast to isopreterenol generally lack stimulating ____ effects on the heart

bronchiole and uterine B1

Which of the beta 2 agonists can be administered MDI, PO, and subcutaneously?

Terbitaline

_______ are the preferred treatment for acute episodes of asthmas and the prevention of exercise-induced asthma

Beta 2 adrenergic agonists

Beta 2 agonists are divided into those with an intermediate DOA ( ___ to ___ hours) and those that are long acting (>___ h)

3-6 12

Beta-2 adrenergic agonists may be administered as continuous infusions to stop _______ _______ ______ (_______ )

premature uterine contractions (tocolytics)

Beta-2 adrenergic bronchodilators can be administered (4)

Orally Inhalation Subcutaneously IV injection

The _________ route for beta 2 agonist bronchodilators is the preferred route because the side effects are fewer for any degree of bronchodilation

inhaled

With optimal inhalation technique approximately ___% of alpha 2 agonists is delivered from the MDI to the lungs, the remainder is deposited in the mouth, pharynx, and larynx

12%

Technique for administering beta 2 agonist with MDI Discharge inhaler while taking a slow deep breath over ___ to___ seconds, and then hold the breath at full inspiration for ___ seconds

5 to 6 10

Beta 2 agonist The presence of an ETT decreases by approximately ___% to ____% the amount of drug delivered by a MDI that reaches the trachea

50-70

Beta 2 agonist Actuation of the MDI during a mechanically delivered __________ increases the amount of drug that passes beyond the distal end of the tracheal tube

inspiration

Side effects of Beta 2 agonists The widespread distribution of beta 2 adrenergic receptors makes it likely that undesired responses result when beta 2 adrenergic agonists undergo ___________ absorption

systemic

The principle side effect in awake subjects of beta 2 adrenergic agonists treatments is ________

tremor

Increased _________ _______ is less common with the selective beta 2 adrenergic agonists

heart rate

In patients with acute, severe ________, beta 2 agonists may cause transient decrease in ________ ______ presumed to reflect relaxation of compensatory _________ in areas of deceased ventilation

asthma arterial oxygenation vasoconstriction (supplemental oxygen indicated)

Acute metabolic responses to beta 2 adrenergic agonists include: (3)

Hyperglycemia Hypokalemia Hypomagnesemia

_________ is the preferred selective beta 2 adrenergic agonist for the treatment of acute bronchospasm due to asthma

Albuterol

Administration of albuterol is most often by a MDI, producing about ______ mcg per puff

100

The duration of action of inhaled dose of Albuterol is about ___ hours, but significant relief of symptoms may persist up to ___ hours

4 8

The effects of Albuterol and volatile anesthetics on bronchomotor tone are ________

additive

___________ is a predominantly beta 2 adrenergic agonist that may be administered ______, _______, or by _______ to treat asthma

Terbutaline orally subcutaneously inhalation

The subcutaneous administration of terbutaline ( _____mg) produces responses that resemble those of _______, but the duration of action is _________

0.25 epinephrine longer

Phosphodiesterase inhibitors are a heterogenous group of ____________ ____________ compounds that exert a competitive inhibitory action on phosphodiesterase enzymes

noncatecholamine nonglycoside

The PDE III inhibitors have their greatest clinical usefulness in patients who would benefit from combined ______ and _______ therapy

inotropic vasodilatory

___________ is a derivative of amrinone with almost ____ times the inotropic potency of amrinone but less adverse effects

milrinone 30

Because of its reduced incidence of side effects, ________ has replaced amrinone in clinical use

milrinone

PDE III inhibitors Cardiac output improves both as a result of increased ________ as well as vascular smooth muscle relaxation of _________ and ________ vessels

inotropy peripheral and pulmonary

Milrinone may be useful in management of acute _______ _______ dysfunction

left ventricular

Milrinone can be useful when weaning high-risk patients from ____________ ____________

cardiopulmonary bypass

Milrinone may potentiate the effects of ________ agents as well as help increase inotropy in chronic heart failure patients who have downregulation of _____ adrenergic receptors

adrenergic beta 1

Milrinone is useful in the setting of _______ __________ decreases _______ _______ pressures more effectively than other positive inotropic drugs

pulmonary hypertension pulmonary artery

Milrinone is associated with more ________ and greater decrease in _______ and ______ than dobutamine

vasodilation SVR BP

Unlike dobutamine, milrinone rarely causes __________

tachycardia

Milrinone may be preferred in situation with high _______ _______, elevated _______ _______ pressure, need for continued _____ blockade, decreased responsiveness to ________ therapy, and increased risk for _________________

filling pressures pulmonary artery beta catecholamine tachyarrhythmias

Rapid administration of milrinone may decrease ________, decrease ________, and result in hypotension May also be associated with arrhythmias due to enhanced ____ node conduction

SVR venous return AV

______ is present in the body in greater amounts than any other mineral

calcium

Calcium is important for -__________ transmission -________ _______ contraction -________ _______ contractility -Blood ___________ _ ___________ necessary for release of neurotransmitters

neuromuscular skeletal muscle cardiac muscle coagulation exocytosis

Calcium is the principal component of ________

bone

Calcium is a potent _________-

inotrope

Increasing the plasma concentrations of ionized calcium with exogenous administration of calcium chloride or calcium gluconate is commonly used to treat cardiac depression as may accompany: -delivery of ________ ________ -transfusion of ________ blood -following termination of _______ _____

volatile anesthetics citrated cardiopulmonary bypass

Ionized calcium typically represents approximately ___ % of the total plasma concentration

45%

Acidosis ______ ionized calcium Alkalosis _____ ionized calcium

increases decreases

Normal plasma ionized calcium (3)

1-1.26 mmol/L 2-2.5 mEq/L 4-5mg/dL

Wk 10: Sympathomimetic agents Flashcards

(108 cards)