Autonomic pharmacology IV

Question 1

what are the three types of adrenergic agonists?

Answer 1

1. direct acting
2. mixed
3. indirect acting

Question 2

what are the two categories of direct acting adrenergic agonists?

Answer 2

1. selective

2. non-selective

Question 3

what are the selective direct acting adrenergic agonists?

Answer 3

1. phenylephrine - a1
2. clonidine - a2
3. terbutaline - B2
4. fenoldopam - D1

Question 4

phenylephrine acts on what receptor?

Answer 4

a1

Question 5

clonidine acts on what receptor?

Answer 5

a2

Question 6

terbutaline acts on what receptor?

Answer 6

B2

Question 7

fenoldopam acts on what receptor?

Answer 7

D1

Question 8

what are the non-selective direct acting adrenergic agonists?

Answer 8

1. isopreterenol
2. dobutamine
3. epinephrine
4. norepinephrine
5. dopamine

Question 9

isopreterenol acts on what receptors?

Answer 9

B1 and B2

Question 10

dobutamine acts on what receptors?

Answer 10

a1, B1, B2

Question 11

epinephrine acts on what receptors?

Answer 11

a1, a2, B1, B2

Question 12

NE acts on what receptors?

Answer 12

a1, a2, B1

Question 13

dopamine acts on what receptors?

Answer 13

D1, D2, a1

Question 14

are the effects of direct acting adrenergic agonists reduced by prior treatment with reserpine or guanethidine?

Answer 14

no (may be potentiated)

Question 15

are the effects of mixed acting adrenergic agonists reduced by prior treatment with reserpine or guanethidine?

Answer 15

yes

Question 16

what is the effect of phenylephrine on vascular smooth muscle? which receptor does it activate?

Answer 16

1. increase BP, increase TPR

2. alpha adrenergic (a1)

Question 17

what are the clinical indications for phenylephrine?

Answer 17

1. hypotension, shock
2. paroxysmal atrial tachycardia
3. nasal decongestant
4. mydriatic

Question 18

what are the a2 selective adrenergic receptor agonists?

Answer 18

1. clonidine
2. a-methyldopa
3. apraclonidine
4. brimonidine

Question 19

what is the mechanism of action for clonidine (a2 selective adrenergic receptor agonist)?

Answer 19

lowered BP due to decreased sympathetic outflow

Question 20

what are the clinical uses for clonidine (a2 selective adrenergic receptor agonist)?

Answer 20

1. systemic hypertension

2. glaucoma

Question 21

what are the adverse effects of a2 selective adrenergic receptor agonists?

Answer 21

1. dry mouth
2. sedation
3. hypotension

Question 22

apraclonidine and brimonidine are used for what purposes?

Answer 22

decrease aqueous humor production and intraocular pressure

Question 23

what are the B2 selective adrenergic receptor agonists?

Answer 23

1. metaproterenol
2. terbutaline
3. albuterol
4. ritodrine

Question 24

which B2 selective adrenergic receptor agonists are resistant to methylation by COMT?

Answer 24

metaproterenol and terbutaline

Question 25

what are the therapeutic uses for metaproterenol?

Answer 25

1. long term treatment of obstructive airway diseases, asthma 2. acute bronchospasm

Question 26

what are the therapeutic uses for terbutaline?

Answer 26

1. long term treatment of obstructive airway diseases, asthma 2. acute bronchospasm 3. emergency treatment of status asthmaticus (IV)

Question 27

what are the therapeutic uses for albuterol?

Answer 27

1. acute bronchospasm | 2. delay preterm labor

Question 28

what are the therapeutic uses for ritodrine?

Answer 28

1. uterine relaxant 2. arrest preterm labor 3. prolong pregnancy

Question 29

what are the adverse effects of excessive activation of B receptors?

Answer 29

1. tachycardia 2. increased plasma glucose 3. increased plasma K+

Question 30

what is the best way to avoid adverse effects of excessive activation of B receptors?

Answer 30

inhalation therapy

Question 31

fenoldopam acts on what receptor?

Answer 31

D1 (some a2)

Question 32

what are the effects of D1 activation by fenoldopam?

Answer 32

1. vasodilation in (renal, mesenteric, peripheral, coronary) vascular beds: 2. renal blood flow maintained and natriuresis promoted

Question 33

what is the clinical use for fenoldopam?

Answer 33

hypertensive crisis

Question 34

what is the side effect of fenoldopam?

Answer 34

hypotension

Question 35

isopreterenol acts on which receptors?

Answer 35

B1 and B2

Question 36

what are the cardiovascular effects of isopreterenol?

Answer 36

1. decrease TPR 2. increase HR 3. increase myocardial contractility

Question 37

what are the respiratory effects of isopreterenol?

Answer 37

bronchodilation

Question 38

what are the clinical uses of isopreterenol?

Answer 38

1. bradycardia 2. AV block 3. torsades de pointes

Question 39

what is the reason for increase in HR following isopreterenol administration?

Answer 39

activation of B1 receptors

Question 40

at therapeutic doses, dobutamine acts mainly on what receptor?

Answer 40

B1

Question 41

does dobutamine affect release of NE from sympathetic nerve endings?

Answer 41

no

Question 42

what are the cardiovascular effects of dobutamine?

Answer 42

1. positive inotropic (more so than isopreterenol) 2. positive chronotropic - SA automaticity, AV conduction 3. TPR unaffected (a1 - B2 balance)

Question 43

why is dobutamine considered the preferred agent for cardiac performance?

Answer 43

1. increases contraction without increasing HR too much (no significant increase in oxygen consumption) 2. a1 - B2 balancing leads to less impact on TPR

Question 44

what are the adverse effects of dobutamine?

Answer 44

1. excessive increase in BP and HR 2. increased ventricular response rate in pts with atrial fibrillation 3. ventricular ectopic activity 4. may increase size of myocardial infarct 5. tolerance

Question 45

what are the therapeutic uses for dobutamine?

Answer 45

1. short term treatment of cardiac failure 2. longer term efficacy unclear 3. stress test for pts with coronary artery disease