Sympathomimetics

Question 1

Transportvof Dopamine into vesicles is blocked by?

Answer 1

Reserpine

Question 2

Release of vesicles from cell membrane is blocked by?

Answer 2

Guanethidine and bretylium

Question 3

Reputake of NorEpi is inhibited by?

Answer 3

Cocaine and TCA

Question 4

Where is NorEpi metabolized?

Answer 4

By COMT in plasma and MAO in synaptic cleft

Question 5

What is the MOA of M2 receptors in the heart?

Answer 5

Inhibition of adenylate cyclase > opening of K channels, slowing rate of Phase 4 depolarization and decrease HR

Question 6

MOA of M3 receptors in smooth muscles and glands

Answer 6

Formation of IP3 and increase intracellular Ca+

Question 7

Epinephrine (chart)

Answer 7

Mechanism: direct general agonist (a1, a2, b1, b2)

App: anaphylaxis, glaucoma (open angle), asthma, hypotension with LA

Question 8

NorEpinephrine (chart)

Answer 8

Mechanism: a1, a2, b1

App: Hypotension (decreases renal perfusion) (organ ischemia)

Question 9

Isoproterenol (chart)

Answer 9

Mechanism: B1=B2

App: AV block (rare)

Question 10

Dopamine (chart)

Answer 10

Mechanism: D1=D2 > B > a

App: Shock (increases renal perfusion & GFR), heart failure

Question 11

Dobutamine (chart)

Answer 11

Mechanism: B1>B2

App: Shock, CHF

Question 12

Amphetamine (chart)

Answer 12

Mechanism: indirect general agonist, releases stored catecholamines

App: narcolepsy, obesity, ADHD

Question 13

Ephedrine (chart)

Answer 13

Mechanism: indirect general agonist, releases stored catecholamines

App: nasal decongestant, urinary incontinence, hypotension, hypotension w/ epidural/spinal A.

Question 14

Phenylephrine (chart)

Answer 14

Mechanism: a1>a2 “pure agonist”

App: pupil dilator, vasoconstrictor, increases SVR & MAP, nasal decongestant

Question 15

Albuterol, terbutaline (chart)

Answer 15

Mechanism: B1> B2

App: asthma, premature labor

Question 16

Cocaine (chart)

Answer 16

Mechanism: indirect general agonist, uptake inhibitor

App: causes vasoconstriction and local anesthesia

Question 17

Clonidine, a-methyl dopa (chart)

Answer 17

Mechanism: centrally acting a2 agonist, decreases central sympathetic outflow

App: HTN, decreases MAC, increases anesthesia/analgesia

Question 18

Prototype of sympathomimetics

Answer 18

Epinephrine

Question 19

Where is Epinephrine?

Answer 19

Synthesized, stored, and released from adrenal medulla

Question 20

_____ is 2-10 x more potent than ______ as a renal vasoconstrictor

Answer 20

Epinephrine; NorEpinephrine

Question 21

___ receptors are more sensitive to lower epi doses while effects on ___ receptors predominate at higher doses

Answer 21

B2; a1

Question 22

Where is NorEpi located?

Answer 22

Synthesized and stored in postganglionic sympathetic nerve endings

Question 23

Vascular capacitance is = to?

Answer 23

Change in volume/ change in pressure

Question 24

Vascular capacitance

Answer 24

The measure of a blood vessel’s ability to increase the volume of blood it holds w/o a large increase in BP

Question 25

____ has a more significant chronotropic effect than NorEpinephrine

Answer 25

Epi

Question 26

With NorEpi, peripheral vasoconstriction may decrease tissue blood flow to the extent that _____ occurs

Answer 26

Metabolic acidosis

Question 27

NorEpi is primarily eliminated by?

Answer 27

Reuptake into the adrenergic nerve endings where it is stored for future release

Question 28

First line agent in tx of refractory hypotension during severe sepsis

Answer 28

NorEpi

Question 29

Use NorEpi cautiously in patients with ____

Answer 29

RV failure

Question 30

Commonly selected sympathomimetic to increase systemic BP in the presence of sympathetic nervous system blockade produced by regional anesthesia OR hypotension d/t inhaled or injected anesthetics

Answer 30

Ephedrine

Question 31

Why is Phenylephrine thout to be good for patients with CAD and aortic stenosis?

Answer 31

It increases coronary perfusion pressure w/o chronotropic side effects (unlike most sympathomimetics)

Question 32

Reflex vagal effects of ____ can be used to slow HR in the presence of hemodynamics lily significant SVT

Answer 32

Phenylephrine

Question 33

Phenylephrine can improve arterial oxygenation when used with ____?

Answer 33

Nitrous oxide

Question 34

Rapid administration ___ mcg/kg of ____ to anesthetize patients with CAD causes a transient impairment of LV global function

Answer 34

1; Phenylephrine

Question 35

Phenylephrine overdose preferentially distributes blood where?

Answer 35

To the pulmonary vascular beds

Question 36

What is the natural protection of pulmonary vascular overload?

Answer 36

Maintain CO

Question 37

How do PDE (III) inhibitors in myocardium work?

Answer 37

Increased cAMP stimulates protein kinase that phosphorylates the SR increasing the inward Ca current. This increases intracellular Ca and contractility.

Question 38

How do PDE (III) inhibitors in vascular smooth muscles work? (Venous & arterial)

Answer 38

Increased cAMP decreases Ca available for contraction by facilitating the reuptake by the SR. Leads to smooth muscle relaxation and vasodilation

Question 39

Inotropic effects of milrinone are reduced by _____ reflecting decreased ____ formation in acid optic muscle

Answer 39

Acidosis; cAMP

Question 40

Is Milrinone FDA approved for heart failure?

Answer 40

No

Question 41

What dose of NorEpi to tax refractory hypotension

Answer 41

2-16mcg/min

Question 42

What solution do you store NorEpi in to prevent oxidation

Answer 42

5% glucose solution