10 - ANS III

Question 0

The side affects of a1 receptor blockage are

Answer 0

Hypotension, orthostatic hypotension, tachycardia
(Worse with hypovolemia, standing position)

Other side effects: miosis, nasal stuffiness, diarrhea

Question 1

Vessels with higher initial tone have a _____ response to alpha 1 blockade, which causes

Answer 1

Greater

Smooth muscle relaxation

Question 2

What happens with chronic alpha antagonist use?
Phenylephrine?
Norepi?
Epi?

Answer 2

Blunted sympathetic response

Phenyl: response completely blocked
Norepi: tachycardia due to b1 activation
Epi: tachy and sever hypotension due to b2 mediated vasodilation

Question 3

Why does a2 receptor blockade lead to more NE release? What does this cause?

Answer 3

It eliminates negative feedback

Tachycardia

Question 4

Two nonselective a receptor antagonists are

Answer 4

Phentolamine

Phenoxybenzamine

Question 5

What is chemical sympathectomy? What drugs are used for this?

Answer 5

Removal of pain by increasing blood flow to an area through vasodilation
Nonselective alpha antagonists

Question 6

Complete offset of the effects of nonselective alpha antagonists must be accomplished by

Answer 6

Synthesis of new receptors

Question 7

Phentolamine and phenoxybenzamine are almost exclusively used for the treatment of

Answer 7

Pheochromocytoma

Question 8

Why is alpha blockade before beta blockade necessary in management of pheochromocytoma?

Answer 8

I opposed alpha stimulation can lead to hypertensive crisis - heart pumping against constricted vessels

Question 9

Nonselective alpha antagonists have _____ that can be treated with atropine

Answer 9

Cholinomimetic activity

Question 10

Phentolamine binds _____ to the alpha receptor and phenoxybenzamine binds

Answer 10

Reversibly

Irreversibly

Question 11

What is the dose of IV phentolamine?

Answer 11

5 mg bolus

Can also be used as an infusion

Question 12

What are other uses (due to vasodilation) of phentolamine aside from management of pheochromocytoma?

Answer 12

Intercavernosal injection for treatment of impotence
Injection of treatment of norepi extravasation
Reversal of local anesthetic injection

Question 13

How is phenoxybenzamine taken for preop management?

Answer 13

Orally

Question 14

Phenoxybenzamine overdose is treated with

Answer 14

Norepi (some receptors are still free)

Question 15

Prazosin is an ____ antagonist

Answer 15

Alpha 1 selective

Question 16

What is used for the treatment of hypertension and benign prostatic hypertrophy (BPH) as well pheochromocytoma?

Answer 16

Alpha 1 selective antagonist

Prazosin

Question 17

______ cause less tachycardia than nonselective alpha antagonists, but still some orthostatic hypotension

Answer 17

Alpha 1 selective antagonists

Question 18

Drugs similar to prazosin

Answer 18

Terazosin
Doxazosin
Tamulosin

Question 19

First generation beta antagonists are _____ and second generation beta antagonists are

Answer 19

Nonselective

Selective

Question 20

Beta antagonists reduce _____ in patients with heart failure!reduce incidence of perioperative ____, and control

Answer 20

Mortality
MI
Tachydysrhythmias

Question 21

Nonselective beta antagonist that lowers BP

Answer 21

Propranolol (inderal)

Question 22

How does propranolol lower BP, reduce myocardial O2 demand, and slow ventricular response to SVT and VT?

Answer 22

Decreasing myocardial contractility, HR, and releasing renin

Question 23

Propranolol may help treat the symptoms of ______ and _____ but should only be used after

Answer 23

Thyrotoxicosis (thyroid storm), pheochromocytoma

After alpha blockade

Question 24

Side effects of propranolol (inderal)

Answer 24

Bronchospasm, CHF, bradycardia, AV heart block

Question 25

Why does propranolol cause ______ after being stopped?

Answer 25

``` Withdrawal syndrome (rebound HTN, tachy, angina) Because of upregulation of beta receptors ```

Question 26

Good choice in patients with reactive airway disease

Answer 26

Beta 1 selective antagonists Metoprolol, atenolol

Question 27

What is the IV dose of metoprolol?

Answer 27

2-5 mg bolus

Question 28

How is metoprolol (lopressor) metabolized and what is its elimination half life?

Answer 28

Hepatic | 3-4 h

Question 29

How is atenolol (tenormin) excreted and what is its elimination half life?

Answer 29

Renally | 6-7 hours

Question 30

Esmolol (breviblock) is a _____ abut also causes ____ at high doses

Answer 30

Beta 1 selective antagonist | Beta 2 antagonism

Question 31

Used to prevent tachy/HTN during intubation, emergence, and electroconvulsive therapy (ECT)

Answer 31

Esmolol

Question 32

Esmolol is eliminated by

Answer 32

Ester hydrolysis (9 min) Not plasma cholinesterase

Question 33

What is the dose of Esmolol?

Answer 33

Bolus - .25-.5 mg/kg IV | Infusion: 50-200 mcg/kg/min

Question 34

Mixed alpha and beta receptor antagonist?

Answer 34

Labetalol

Question 35

Why doesn't Labetelol cause reflex tachycardia?

Answer 35

alpha is mostly alpha 1 | Beta is nonselective

Question 36

What is the ratio of alpha to beta antagonism in Labetelol taken orally? By IV?

Answer 36

Orally - 1:3 | IV- 1:7

Question 37

Is bronchospasm a common complication when using Labetelol?

Answer 37

No, despite beta being nonselective

Question 38

Common drug of choice for intraoperative HTN?

Answer 38

Labetelol

Question 39

How does Labetelol decrease HTN?

Answer 39

Decreases peripheral vascular resistance and renin | Also some decrease in HR

Question 40

What is the initial bolus does of Labetelol?

Answer 40

2.5-10 mg IV - works in minutes

Question 41

Why should Labetelol be used in caution as an infusion?

Answer 41

It is a long acting agent

Question 42

What is the hepatic elimination half life of Labetelol?

Answer 42

5-6 hours

Question 43

What is another nonselective beta antagonist and alpha 1 antagonist aside from Labetelol? What is it used for?

Answer 43

Carvedilol (coreg) | Oral medication used for managing heart failure, left ventricular dysfunction after MI, and HTN