Beta Blockers (Stable Angina CAD)

Question 1

MOA Beta Blocker Class

Answer 1

Lower myocardial o2 demand
-reduce ischemic time
-↓ HR
-↓BP and workload
-↓contractility
slower rates improve venous perfusion and ventricular filling
-Slow PR interval
-Slow ventricular rate
-Reduces Renin output
-Decreased RAAS activity

all BB have dose related b1/b2 activity

Question 2

Indications for Beta Blockers

Answer 2

Preferred when tolerated

Best data for reducing CV events!

Good for open angle glaucoma (↑outflow and drainage)

Perioperatively in high risk pts undergoing non cardiac surgery

Question 3

Metabolism of Beta Blockers

Answer 3

Short half life*

Hepatic metabolism* (hepatic failure might not tolerate BB at therapeutic doses)

Rapidly absorbed

Large volume of distribution

Question 4

Contraindications of BB

Answer 4

relatively CI in COPD
Renal insufficiency* increased toxic effect
Caution in pts with pulmonary dz
Pts with pulm dz can tolerate in low doses
Caution in DM-masks hypoglycemia

Question 5

BB outcome benefits

Answer 5

• ↓mortality in htn pts with recent MI
• ↑survival in htn pts after stroke
• ↑exercise tolerance!! (initially difficult) 25-50% tolerate doses

Question 6

BB DI

Answer 6

DI BB with verapamil or diltiazem
Nonselective: carvedilol (post mi, LV dysfunction, heart failure); labetalol, nadolol, sotalol, timalol

Selective: metoprolol (heart failure or post MI), biosprolol (heart failure or LV dysfunction), atenolol, esmolol, nebivolol

ISA and partial agonism are not clinically important

*fyi bb can mask thyroid strome or thyrotoxicosis (vtach)

Question 7

Considerations of BB

Answer 7

TAPER!!! To prevent rebound
-takes 2-4 weeks for full effect but will see bp decrease in 24 hrs

B1 selective (can still block B2 at high doses)

B2: bronchioles and peripheral vascular tissue for vasodilation; unopposed alpha constriction

Monitor: HR, BP, EKG, Physical function

Question 8

Metoprolol MOA

Answer 8

Selective B1 Blocker
↓inotropy
↓chonotropy
↓cardiac work
↓MV02
(reduced selectivity in higher doses)

Question 9

Metoprolol indications

Answer 9

Asthma
COPD
LIVER dz (little protein binding)

Question 10

Metroprolol considerations

Answer 10

Adjusted to bp, hr, ekg (minimum sbp 90, minimum hr 50)

• most frequently used BB
• *evidence for reducing CV events in pts with HTN, HF, LVF, CAD

Question 11

Bisprolol MOA

Answer 11

Selective Beta Blocker
↓inotropy
↓chonotropy
↓cardiac work
↓MV02

Question 12

Bisprolol indications and meteabolism precautions

Answer 12

I: HF pts with HTN

M: Adjust in pts with renal dysfunction bc long half life
50% of dose is excreted unchanged

Question 13

Bisprolol SE and

Considerations

Answer 13

Can precipitate decompensated HF if used in UNSTABLE pts with stage III/IV HF

Evidence based BB in HF pts with HTN

Question 14

Carvedilol MOA

Answer 14

1.nonselective BB
2. alpha 1 blocker***
(= less rebound tachycardia)
↓renin output
↓inotropy
↓chonotropy
↓cardiac work
↓MV02

Question 15

Carvedilol indcation

Metabolism

Answer 15

I:HF

M: Extensive hepatic metabolism: CYP2D6
Adjusted to bp, hr, ekg (minimum sbp 90, minimum hr 50

Question 16

SE of Carvedilol

Answer 16

Less rebound tachycardia!! Following hypotension

Question 17

Considerations of Carvedilol

Answer 17

*Evidence in HF, reducing MI

might reduce smooth muscle infiltration in vascular remodeling, limit free radicals, reduce lipid peroxidation

Question 18

Propranolol MOA

Answer 18

Nonselective
Lipophilic 
↓inotropy
↓chonotropy
↓cardiac work
↓MV02

Question 19

Propranolol indications

Answer 19

h/a prophylaxis with CAD
-Short acting*
1-2 hr onset and lasts 6-12 hrs

-Long Acting* slower onset and lasts 24-27 hrs and even longer in liver dz*

Question 20

Propranolol metabolism

Answer 20

high 1st pass metabolism (CYP2D6/1A2)

highly protein bound (90%)
Adjusted to bp, hr, ekg (minimum sbp 90, minimum hr 50)

Question 21

Nadolol MOA

Answer 21

Nonselective
↓inotropy
↓chonotropy
↓cardiac work
↓MV02

Question 22

Nadolol Metabolism

Answer 22

Non-metabolized: 45 hr duration in pts with renal failure—dose adjust!

Question 23

Nadolol SE

Answer 23

Can cause bronchoconstriction in large dose

↓hepatic blood flow with beta2 blockade

Question 24

Nadolol Considerations

Answer 24

OK in Liver Dz

Adjusted to bp, hr, ekg (minimum sbp 90, minimum hr 50)

Question 25

Atenolol MOA

Answer 25

``` Selective B1 Blocker ↓BP ↓HR ↓inotropy ↓chonotropy ↓cardiac work ↓MV02 ```

Question 26

Atenolol Indications

Answer 26

Asthma COPD Liver dz (little protein binding and limited hepatic met)

Question 27

Atenolol considerations

Answer 27

↓BP ↓HR but no CV outcomes in HTN with CAD or HF little hepatic metab.

Question 28

Labetalol MOA

Answer 28

1.Nonselective BB (R isomer) 2.Selective alpha 1 blockade (S) ↓ renin output

Question 29

Labetalol Metabolism

Answer 29

Alpha:beta is 1:3 oral vs 1:7 IV | Adjusted to bp, hr, ekg (minimum sbp 90, minimum hr 50)

Question 30

Labetalol SE

Answer 30

less rebound tachycardia in alpha1!

Question 31

Esmolol indications

Answer 31

Perioperative use in HTN, myocardial Ischemia, thyrotoxicosis, VT

Question 32

Esmolol Metabolism

Answer 32

ultra short acting!! For perioperative use*** 2-10 min onset, 10-30 min duration Has ester linkage for rapid hydrolysis by RBCs

Question 33

Nebivolol MOA

Answer 33

Most selective B1 antagonist with endothelium derived nitric oxide dependent vasodilation ↓HR, BP SVR

Question 34

Nebivolol metabolism

Answer 34

12%bioavailable *protein binding 98% met by CYP2D6 half life 10-12 hrs nml or 32 hrs in poor met

Question 35

Nebivodol contraindications

Answer 35

reduce dose in child pugh class B pts Reduce dose in CrCl

Question 36

Nebivodol SE

Answer 36

no hyperglycemic or lipid issues like other BB!!

Question 37

Nebivodol Contraindications

Answer 37

No role in angina Reduces hospitalizations of elderly pts with HF