Beta-blockers

Question 1

What is the MOA of beta-blockers

Answer 1

Competitive inhibition of Beta-1 receptors in SA and AV node

beta receptors influence influx of calcium into myocytes

Question 2

What are the different subtypes of beta-blockers

Answer 2

1. Selective beta 1 blockers
2. Non-selective beta 1 & beta 2 blockers
3. Mixed beta 1/beta 2, alpha 1 blockers

1. e.g. metoprolol, 2. Nadolol, 3. carvedilol

Question 3

What effects do beta-blockers have on chronotropy?

Answer 3

Decrease

Question 4

What effects do beta-blockers have on inotropy?

Answer 4

Decrease

Question 5

What are the hemodynamic effects of beta-blockers

Answer 5

Decreased HR (chronotropy)
Decreased strength of contraction (inotropy)

Question 6

Beta blockers ________ myocardial oxygen demand

Answer 6

Decrease

Question 7

True or false:

Beta blockers are indicated in treating angina

And why?

Answer 7

True

decrease myocardial oxygen demand

Question 8

Describe how beta blockers prevent remodeling of the heart

Answer 8

Prevents beta 1 mediated renin release (we know that aldosterone has remodeling effects)
Also, calcium may play a role in remodling (beta blockers affect calcium concentrations in cardiac myocytes)

Question 9

True or false:

Beta blockers are effective as first line monotherapy in HTN

Answer 9

False

Question 10

Explain why non-selective beta blockers are ineffective at reducing BP

Answer 10

Block beta 2 receptors as well, which prevents smooth muscle relaxation

Question 11

Name a selective beta blocker

beta 1 activity only

Answer 11

Metoprolol tartrate
Metoprolol succinate

Question 12

Which formulation of metoprolol is extended release

tartrate or succinate

Answer 12

Succinate

Question 13

Name two non-selective beta blockers

Beta 1, beta 2 activity

Answer 13

Nadolol
Propranolol

Question 14

Name the two mixed Beta blockers

Beta 1, 2, and alpha 1 activity

Answer 14

Carvedilol
Labetalol

Question 15

Which beta blockers are FDA approved for HF

Answer 15

Metoprolol Succinate
Carvedilol

Question 16

Which beta blocker has the shortest half-life and is used IV

Answer 16

Esmolol

Question 17

Which beta blocker is a first line agent for aortic dissection

Answer 17

Esmolol

Question 18

Name a relative contraindication for beta blockers

Answer 18

1st degree heart block

Question 19

Name an absolute contraindication for beta blockers

Answer 19

2nd/3rd degree heart block
Sick sinus syndrome

Question 20

List some of the side effects of beta blockers

Answer 20

Bradycardia
Bronchospasm (in patients with asthma)
Depression (lipophilic drugs)
Mask hypoglycemia, teach pts to look for sweating
Fatigue (lipophilic drugs)
Sexual dysfunction (lipophilic drugs)

Question 21

What are the three primary uses of beta-blockers?

Answer 21

HF
After an acute MI
Asymptomatic LV dysfunction

Question 22

Where is the highest concentration of beta-1 adrenergic receptors?

Answer 22

Heart

Question 23

Possible effect of beta-blockers on existing DMII

Answer 23

May precipitate or exacerbate DMII, use with caution

Question 24

For their decreased chronotropic effect, who are beta-blockers recommended for?

Answer 24

Hyperthyroid patients

Question 25

Main reason for non-adherence of beta-blockers

Answer 25

Sexual disfunction and impotence

Question 26

Effect of beta-blockers when combined with OTC cold medicines (ex. phenylephrine)

Answer 26

Unopposed alpha stimulation resulting in rebound hypertension.

Question 27

If clonidine when taken concurrently with beta-blockers is not tapered, what can result?

Answer 27

Fatal increases in hypertension

Question 28

Beta-blockers are the drugs of choice in...

Answer 28

Exertional angina

Question 29

What mechanism is caused by chronic beta-blocker use that can result in life-threatening consequences in abrupt withdrawal?

Answer 29

Upregulation of beta receptors over time, makes the system sensitive to SNS tone changes.