pharmacology: adrenergic drugs Flashcards Preview

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Flashcards in pharmacology: adrenergic drugs Deck (48):
1

where are alpha 1 receptors? effects?

1. radial muscle eye (contraction = mydriasis without cyclopegia@)
2. arterioles (contraction = increased TPR = increased diastolic pressure = increased afterload)
3. veins (contraction = increased venous return = increased preload = increased systolic BP)
4. bladder trigone and sphincter and prostatic urethra (contraction = urinary retention)
5. male sex organs (vas deferens = ejaculation)
6. liver (increased glycogenolysis)
7. kidney (decreased renin release - safety valve - don't want too much increase in BP)

2

where are alpha 2 receptors? effects?

1. prejunctional nerve terminals (decreased transmitter release and NE synthesis
2. platelets (aggregation)
3. pancrease (decrease insulin secretion)

3

what type of receptor is alpha 1?

Gq = increased calcium

4

what type of receptor is alpha 2?

Gi couples = decreased cAMP

5

where are B1 receptors? effects?

1. heart: oppose muscarinic 2
SA node - (increased HR (positive chronotropy))
AV node (increased conduction velocity (positive dromotrophy))
atrial and ventricular muscle (increase force of contraction (positive inotropy), conduction velocity, CO and oxygen consumption)
his-purkinje (increase automaticity and conduction velocity
2. kidney: increase renin release (complementary effect with rest of Beta 1)

6

what type of receptor is beta 1?

Gs coupled: increase cAMP

7

what type of receptor is beta 2?

Gs coupled = increased cAMP
MOSTLY NOT INNERVATED - NE CAN'T REACH!! EPI!!!!!!!

8

where are beta 2 receptors? effects?

1. blood vessels (all) - (vasodilation = decreased TPR = decreased diastolic pressure = decreased afterload)
2. uterus (relaxation - prevent premature labor)
3. bronchioles (dilation - relaxation)
4. skeletal muscle (increased glycogenolysis - contractility (tremor))
5. liver (increased glycogenolysis, gluconeogenesis, lipolysis)
6. pancrease (increase insulin secretion - in order to allow glucose uptake)

9

which receptors are most sensitive?

beta receptors! when drugs have both effects, beta responses are dominant at low doses!! alpha at higher doses

10

where are D1 receptors located? effects?

renal, mesenteric, coronary vasculature (vasodilation - in kidney increased RBF, increased GR, increased Na+ secretion)

11

fenoldopam - mechanism and clinical

D1 agonist - used for severe hypertension (causes vasodilation)

12

what type of receptor is D1?

Gs coupled - increased adenylyl cyclase = increased cAMP

13

how is potential reflex bradycardia blocked with alpha 1 agonists?

M2 blockers

14

what is the direct acting alpha 1 agonist? clinical use?

phenylephrine - nasal decongestant and ophthalmologic use (mydriasis without cycloplegia)

15

phenylephrine effect on blood pressure

increase mean blood pressure via vasoconstriction of both arterioles and veins - no change in pulse pressure

16

what are the alpha 2 agonists? clinical use?

clonidine and methyldopa - mild to moderate hypertension (decrease sympathetic outflow)

17

what are the beta agonists? clinical use?

isoproterenol (B1=B2) - bronchospasm, heart block, bradyarrhythmias
dobutamine (B1>B2) - CHF (increased CO)

18

isoproterenol side effects

flushing, angina, arrhythmias

19

beta 1 agonist effects

increased HR, increased SV, increased CO, increased pulse pressure (d/t increase in contractility)

20

beta 2 agonist effects

decreased TPR, decreased BP

21

what are the selective beta 2 agonists? clinical uses?

salmeterol (prophylaxis asthma), albuterol (asthma), terbutaline (premature labor)

22

NE effect on BP

can NEVER lower BP because it has NO B2 activity

23

low dose epinephrine effects

B1: increased HR, increased SV, increased CO, increased PP
B2: decreased TPR and decreased BP

24

medium dose epinephrine effects

B1: increased HR, increased SV, increased CO, increased PP
B2: decreased TYPR, decreased BP
A1 effects!!!: increased TPR, increased BP (antagonism causes no change in BP)

25

high dose epinephrine effects

similar to NE = A1 predominance (increased TPR and increased BP)

26

how to distinguish between epinephrine and NE

CANNOT distinguish based on cardiovascular - bronchioles dilated with epi

27

what are the beta 2 specific effects

smooth muscle relaxation; bronchioles, uterus, blood vessels
also: increased glycogenolysis, increased gluconeogenesis, increased mobilization and use of fat

28

use of NE and epi

cardiac arrest, adjunct to local anesthetic, hypotension, anaphylaxis (epi only), asthma (epi only)

29

what are the indirect-acting adrenergic receptor agonists? mechanism?

releasers (displace NE from mobile pool): tyramine, amphetamines, and ephedrine
reuptake inhibitors: cocaine and tricyclic antidepressant

30

drug interaction with adrenergic receptor agonists releasers (tyramine, amphetamines, ephedrine)

MAOa inhibitors - causes HTN crisis when mixed with tyramine (red wine, cheese)

31

alpha receptor antagonists effects? clinical uses?

decreased TPR, decreased mean BP (normal alpha 1 constriction) - may cause reflex tachycardia and salt/water retention
clinical: HTN, pheochromocytoma, BPH (a1 blocker)

32

nonselective alpha receptor antagonist drugs? competitive/noncompetitive? clinical uses?

phentolamine - competitive - (acute management HTN)
phenoxybenzamine - noncompetitive (pheochromocytoma)

33

MAO type A

mainly in liver, but Anywhere (metabolizes NE, 5HT, tyramine)

34

MAO type B

mainly in brain (metabolizes DA)

35

what are the selective alpha 1 blockers? clinical use?

-ZOSIN
prazosin, doxazosin, terazosin, tamsulosin
clinical? HTN and BPH (symptomatic treatment)

36

what is the selective alpha 2 blocker? clinical use?

mirtazapine, antidepressant

37

what are the beta receptor antagonists?

-olol
acebutolol, atenolol, metoprolol, pindolol, propranolol, timolol

38

which beta receptor antagonists are beta 1 selective?

(A-M) acebutolol, atenolol, metoprolol

39

which beta blocker causes the least amount of sedation? why?

atenolol - no CNS entry

40

which beta blockers have no increase in blood lipids? why?

acebutolol, pindolol (because partial agonists)

41

which beta blocker is best for asthmatics?

pindolol

42

which beta blocker is used in social phobias?

propranolol

43

uses for beta blockers

angina, HTN, post==MI

44

labetalol and carvedilol

combined alpha-1 and beta blocking activity - NOT -olol becuase not full beta blockers

45

carvedilol use

CHF

46

labetalol use

hypertensive emergencies

47

what does chronic use of beta blockers lead to?

receptor upregulation

48

which adrenergic drugs are used to treat glaucome?

pilocarpine, echothiphate --> increased outflow d/t contraction of ciliary muscle which increases flow through canal of schlemm
timolol --> block actions of NE at ciliary epithelium (decrease aqueous humor formation)