Alpha and Beta Receptor Antagonist Flashcards Preview

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Flashcards in Alpha and Beta Receptor Antagonist Deck (51)
1

blocking alpha 2 receptor will have a similar effect as ___________ the beta receptor.

stimulating

2

List the effect of beta 2 agonist on :
Blood vessels
Bronchioles
Uterus
Kidneys
Liver
Pancreas

Blood vessels-dilation
Bronchioles-dilation
Uterus-Relaxation
Kidneys-Renin secretion
Liver-Glycogenolysis+Gluconeogenesis
Pancreas-insulin secretion

3

What are the effects of alpha 1 activation on :
Bklood vessles
Pancreas
Intestine and bladder

Blood vessels-constrict
Pancreas-inhibition of insulin secretion
Intestine and bladder: Relaxion + constriction of sphincters

4

What are the effects of alpha 2 activation on:
postganglionic/presynaptic nerve ending
CNS (presynaptic)
Platelets

Postganglionic: Inhibition of norepi release
CNS: Increase of K+ conductance
Platelets: aggregation

5

What are clinical uses of alpha antagonism?

Tx of:
pheochromocytoma
CHF
BPH
Raynauds

6

What are the effects fo alpha 2 blockade?

Increased sympathetic outflow and increased release of epi from nerve endings

7

What are the effects of alpha adrenergic receptor antagonists. What are side effects?

Binds selectively to alpha receptors to block effects of catecholamines at receptor sites
Causes orthostatic hypotension and syncope
Reflex tachycardia
Impotence

8

What are uses for phentoalamine.

Phentoalamine is a competive nonselcetive alpha antagoinst used to treat acute hypertensive emergencies s.a. pheochromocytoma or autonomic nervous system hyperreflexia.
Alpha 1 blockade causes decrease in Systemic BP, reflex tachycardia
Apha 2 blockade causes a release of norepi increasing HR and CO. It also gives a parasympathetic response s.a. abdominal pain and diarrhea

9

What kind of drug is prazosin? How does it work? What are its uses?

Prazosin is an alpha 1 selective competive alpha antagonist
Its effects: less likely reflex tachycardia
Dilates both art and venous
Primarily antihypertensive
Used for preop bp in pheochromocytoma and in reynauds and BPH

10

How do taxazosin and tamulosin work?

Act preferentially on alpha-1 receptors of vesical trigone muscle, urethra, and prostate
Relax prostatic smooth muscle to tx BPH

11

Where does yohimbine work?
What is its clinical use?

Selective antagonist at presynaptic alpha 2
Increases release of norepi
Used as a tx for idiopathic orthostatic hypotension
Tx for impotence
Too much causes tachycardia and hypertension

12

HOw does phenoxybenzamine interact with the receptor?
What is duration of action?

Non competitive (irreversible) nonselective alpha blocker
Alpha 1 > alpha 2
Lasts for 14-48 hours or longer

13

What are the uses for phenoxybenzamine?

Used as preop tx for pts with raynaud's or pheochromocytoma
Prevents inhibitory action of epi on secretion of insulin
Causes orthostatic hypotension

14

What are the cardiovascular uses of beta blockers?

Treatment of essential hypertension
Management of Angina Pectoris
Treatment of Acute Coronary Syndrome
Perioperative Beta blockade
Treatment of Intraoperative myocardial ischemia
Supression of Cardiac Dysrythmias
Mangagement of Congestive Heart Failure
Preop prep of hyperthyroid

15

Beta blocker therapy should be continued thru the periop period. t/f

T

16

What are two strategies to prevent/treat cardiac ischemia?

Minimize cardiac O2 demand
Maximize O2 supply

17

What are uses of beta blockers that are not cardiac related?

prevention of primary and secondary digestive bleeding in portal hypertension by rupture of esophageal varices
treatment of migraine, tremor, transitory somatic symptoms of anxiety, alcohol addiction in which there appears a beta overstimulation
treatment of glaucoma by ophthalmic solutions

18

Beta blockers are competitive inhibitors. What determines whether partial or full antagonism?
What drug would be used to overcome beta blockers?

Competitive inhibition over come by atropine
Partial or full antagonist based on intrinsic sympathomimetic activity

19

Beta blocker receptor selectivity is _______ dependent

Dose

20

What are the CV side effects of beta blockers?

(-) iontropic and chronotropic
AV node conduction decrease
Accentuates AV block--may increase to a 3rd degree block
(AV blocks are a contraindication to prescription)

21

Beta blockers may increase concentrations of local anesthetics and fentany T/F?

T
B blockers bind to albumen and kicks the other stuff off

22

How do beta blockers affect MAC?

decrease

23

Beta blockers may ________ triglycerides and ________ glucose.

increase triglycerides and cause hypoglycemia.
A rebound in symptoms may occur at abrupt discontinuation

24

Beta blockers should be continued during lactation. T/F

False, they are contraindicated in lactation

25

Beta blockers are good for Aortic ________, but bad for Aortic _______.

Good-aortic stenosis
bad-aortic insufficiency

26

Why would a beta blocker be bad in anaphylactic shock?

Epi is tx.

27

Propanolol may cause retention of which electrolyte?

Na

28

Propanolol is a selective B1 antagonist. T/F

False-nonselective

29

Propanolol decreases HR, Contractility and CO. Decrease in HR lasts longer than contractility. T/F

T

30

Which nonselective Beta blocker has a 20-40 huour half life?

nadolol

31

Which nonselective Beta blocker is used to treat glaucoma?

Timolol

32

What are the effects of Satolol? What can it be used to treat? What is the potential problem?

prolongs cardiac action potental
Increases refractory period
Used to Tx SVT
Since it prolongs Q-T it may lead to V-tach

33

What is the most selective B1 antagonist?

Atenolol

34

What are the effects of metoprolol? What is the dose?

negative chronotropy and ionotropy
Dose dependent selectivity
IV dose is 1-2 mg

35

How is esmolol metabolized? What is the elimination half life?

hydrolysis by plasma cholinesterase
Elimanation half life is 9 minutes
--works in 5 min done in 10-30

36

What is the bolus dose of esmolol?

0.5mg/kg iv
0.1-0.3mcg/

37

How does labetolol affect receptors?

Alpha1 and noselective B1 and B2 antagonist
Beta:Alpha 3:1 oral
7:1 IV

38

What are the effects of labetalol?

Decreases SVR
HR decrease
Reflex tachycardia blocked
CO unchanged
May be used in pheo
Beware: asthmatics

39

What is the dose of lablatolol? What is the onset, duration and elimination half time?

.1-.5mg/kg
works in 5-10 minutes
Elimination time is 5 hours

40

What are the effects of carvedilol?

Beta antagonist activity with alpha1 antogonist activity
Tx of pts with essential hypertension
Causes both precapillary vasodilation bymeans of alpha1 blockade and nonselective B blockade and devoid of intrinsic sympathomimetic activity

41

What are the most common adverse reactions to carvedilol?

edema, dizziness, bradycardia, hypotension, nausea, diarrhea and blurred vision

42

What is the ratio of beta: alpha1 blockade in carvedilol?

10:1

43

What are the effects of alpha-2 agonists?

Norepi inhibition
sympatholytic
anesthetci adjuvant
analgesia for acute and chronic paine

44

What are effects of Clonidine?

alpha 2:alpha 1 200:1
Antihypertensive--withdrawl can precipitate hypertensive crisis
can be given neuraxially
Other uses: Anti emetic, sedation

45

What properties do dexmedetomidine posess?

Anxiolytic, anesthetic, hypnotic and analgesic--thru specific and selective postsynaptic alpha2 adrenoreceptors

46

What are the side effects of dexmedetomidine?

Hypotension and bradycardia
Use with caution in hypovolemic, hypotensive, or elderly
Also: advanced heart block, severe ventricular dysfunction, DM or chronic HTN

47

Pts receiving dexmedetomidine infusions are _____ aroused, calm and comfortable.

easily

48

What are teh benefits fo precedex over currently available sedative agents?

lack of resp. depression
decreases need for opioid analgesiscs

49

Pts on chronic beta blocker therapy must be given beta blocker within ____ hours of surgery

24

50

For cardiac cases, most pts should be given a beta blocker dose within 6 hours of surgery. T/F

F
all pts regardless of preop regimen MUST be given beta blocker within 6 hours of surgery

51

beta blockers are contraindicated in which heart pts?

AV blocks