Chapter 13 Autonomic & Cardiac Pharmacology

Question 1

naturally occurring catecholamines

Answer 1

epinephrine, norepinephrine, dopamine

Question 2

synthetic catecholamines

Answer 2

ephedrine, phenylephrine, dobutamine

Question 3

use these drugs in a variety of situations like

Answer 3

• anesthesia-induced hypotension
• bradycardia
• anaphylaxis
• heart failure
• cardiac resucitation

Question 4

inotropic

Answer 4

force of contraction

Question 5

chronotropic

Answer 5

heart rate

Question 6

dromotropic

Answer 6

conduction velocity

Question 7

beneficial effects of beta stimulation

Answer 7

• bronchodilation
• vasodilation
• stabilization of mast cells –> decrease in histamine release

Question 8

beneficial effects of alpha stimulation

Answer 8

decrease in bronchial secretion

net effect is a decrease in airway resistance with an improvement on oxygenation

Question 9

low dose epi is how much and what does it do?

Answer 9

• 10mcg/min
• peripheral vasculature promotes the redistribution of blood flow to skeletal muscle producing a decrease in SVR

Question 10

what happens as the dose of epi increases?

Answer 10

the alpha effect predominates resulting in vasoconstriction and an increase in SVR

SBP increases while DBP remains unchanged –> increase in PP

Question 11

increased alpha effect that occurs with epi also results in

Answer 11

renal and splanchnic vasoconstriction

renal blood flow decreases

Question 12

MECHANISM 1
interference with synthesis of transmitter: cholinergic system

Answer 12

• choline acetyltransferase inhibitors
• minimal depletion of Ach
• sympatholytic

Question 13

MECHANISM 1
interference with synthesis of transmitter: adrenergic system

Answer 13

• ⍺- methyl tyrosine (inhibition of tyrosine hydroxylase)
• depletion of NE
• sympatholytic

Question 14

MECHANISM 2
metabolic transformation by same pathway as precursor of transmitter : adrenergic

Answer 14

• methyldopa
• displacement of NE by ⍺- methyl- NE, which is an ⍺2 agonist, like clonidine, that reduces sympathetic outflow
• sympatholytic

Question 15

MECHANISM 3
blockade of transport system at nerve terminal membrane: cholinergic

Answer 15

• hemicholinium
• block of choline uptake with consequent depletion of ACh
• sympathomimetic

Question 16

MECHANISM 3
blockade of transport system at nerve terminal membrane: adrenergic

Answer 16

• cocaine, imipramine
• accumulation of NE at receptors
• sympathomimetic

Question 17

MECHANISM 4
blockade of transport system at nerve terminal membrane: cholinergic

Answer 17

• vesamicol
• block of ACh storage
• sympatholytic

Question 17

MECHANISM 4
blockade of transport system at nerve terminal membrane: adrenergic

Answer 17

• reserpine
• destruction of NE by mitochondrial MAO, and depletion of adrenergic terminals
• sympatholytic

Question 18

MECHANISM 5
promotion of exocytosis or displacement of transmitter from axon terminal: cholinergic

Answer 18

• latrotoxins
• cholinomimetic followed by anticholinergic
• sympathomimetic

Question 19

MECHANISM 5
promotion of exocytosis or displacement of transmitter from axon terminal: adrenergic

Answer 19

• amphetamine, tyramine
• adrenomimetic
• sympathomimetic

Question 20

MECHANISM 6
prevention or release of transmitter: cholinergic

Answer 20

• botulinum toxin
• anticholinergic
• sympatholytic

Question 21

MECHANISM 6
prevention or release of transmitter: adrenergic

Answer 21

• clonidine, dexmedetomidine
• antiadrenergic
• sympatholytic

Question 22

MECHANISM 7
mimicry of transmitter at postjunctional sites: cholinergic

Answer 22

• Muscarinic –> cholinomimetic –> sympathomimetic
• nicotinic –> methacholine/bethanachol –> cholinomimetic –> sympathomimetic

Question 23

MECHANISM 7
mimicry of transmitter at postjunctional sites: adrenergic

Answer 23

⍺1:
- nicotine/epibatidine
- selective alpha-1 adrenomimetic
- sympathomimetic

⍺2:
- phenylephrine
- adrenomimetic (periphery)
- sympathomimetic

⍺1, ⍺2:
- oxymetazoline
- nonselective adrenomimetic
- sympathomimetic

β1:
- dobutamine
- selective cardiac stimulation
- sympathomimetic

β2:
- terbutaline, albuterol
- selective β2 receptor agonist (selective inhibition of smooth muscle contraction)
- sympathomimetic

β1, β2:
- isoprotenerol
- nonselective β adrenomimetic
- sympathomimetic

Question 24

MECHANISM 8 blockade of postsynaptic receptors: cholienrgic

Answer 24

- muscarinic --> atropine, muscarinic blockade, sympatholytic - nicotinic --> d-tubucuraine/atracurium, neuromuscular blockade, sympatholytic - nicotinic --> trimethaphan, ganglionic blockade, sympatholytic

Question 25

MECHANISM 8 blockade of postsynaptic receptors: adrenergic

Answer 25

⍺1, ⍺2: phenoxybenzamine, nonselective ⍺ blockade (irreversible) --> sympatholytic ⍺1, ⍺2: phentolamine, nonselective ⍺ blockade (reversible) --> sympatholytic ⍺1: prazosin/terazosin/doxazosin, selective alpha1 receptor blockade (reversible) --> sympatholytic ⍺2: yohimbine, selective alpha2 receptor blockade --> sympatholytic β1, β2: propanolol, nonselective beta-receptor blockade --> sympatholytic β1: metoprolol/atenolol, selective beta 1 recepetor blockade --> sympatholytic

Question 26

MECHANISM 9 inhibition of enzymatic breakdown of transmitter: cholinergic

Answer 26

AChE inhibitors (edrophonium/neostigmine) --> cholinomimetic (muscarinic sites) depolarization blockade (nicotinic sites) --> parasympathomimetic

Question 27

MECHANISM 9 inhibition of enzymatic breakdown of transmitter: adrenergic

Answer 27

nonselective MAO inhibitors (pargyline/nialamide), little direct effect on NE or sympathetic response; potentiation of tyramine --> parasympathomimetic selective MAO-B inhibitor (selegiline), adjunct in Parkinson's dx --> parasympathomimetic peripheral COMT inhibitor (entacapone), adjunct in Parkinson's dx --> parasympathomimetic peripheral and central COMT inhibitor (tolcapone), adjunct in Parkinson's dx --> parasympathomimetic

Question 28

MECHANISM 10 interference with the second messenger system: adrenergic

Answer 28

PDE 3 inhibitors (milrinone), inotrope --> sympathomimetic

Question 29

the conversion of tyrosine to __ by __ __ is inhibited by increased NE synthesis

Answer 29

DOPA; tyrosine hydroxylase

Question 30

where is epinephrine synthesized?

Answer 30

adrenal medulla

Question 31

sympathetic effect of: radial muscle, iris

Answer 31

contraction (mydriasis), alpha 1

Question 32

parasympathetic effect of: sphincter muscle, iris

Answer 32

contraction (miosis) M3,M2