Anti-arrhythmic Drugs

Question 1

Quinidine protein bindings

Answer 1

80-90%

Question 2

Procainamide protein binding

Answer 2

15%

Question 3

Lidocaine protein binding

Answer 3

55%

Question 4

propranolol protein binding

Answer 4

90-95%
(Propranolol is Pro Proteins)

Question 5

Amiodarone protein binding

Answer 5

96%

Question 6

sotalol protein binding

Answer 6

0%

Question 7

verapamil protein binding

Answer 7

90%

Question 8

What triggers Torsades de pointes?

Answer 8

early after depolarization in a setting of delayed repolarization and increased duration of refractoriness

Question 9

What is EKG characteristic of torsades?

Answer 9

QTc interval prolongation

Question 10

What are exacerbating factors of torsades?

Answer 10

hypokalemia
hypomagnesemia
poor LV function
concomitant administration of QT prolonging drugs

Question 11

Incessant ventricular tachycardia is more likely to occur with high doses of class ___ drugs

Answer 11

IC

Question 12

Wide complex ventricular rhythm easily degenerates to what?

Answer 12

V Fib

Question 13

T/F: Lidocaine increases occurence of fatal bradycarrhythmias and asystole with prophylactic treatment of acute MI

Answer 13

True

Question 14

Is CCB recommended as routine treatment of patients with acute MI?

Answer 14

No

Question 15

In patients with HF, ____ reduces the risk of sudden cardiac death by 29%

Answer 15

amiodarone

Question 16

Amiodarone is associated with a 2 and 5 fold increased risk of ____ and ___ toxicity, respectively.

Answer 16

pulmonary; thyroid

Question 17

What is the only drug that plays a role for prophylactic antiarrhythmic medication for the primary prevention of sudden cardiac death in patietns with HF?

Answer 17

Amiodarone

Question 18

Class I drugs are ___ channel blockers

Answer 18

sodium

Question 19

What are 3 examples of class IA drugs?

Answer 19

Quinidine
Procainamide
DIsopyramide

Question 20

What are 3 examples of class IB drugs?

Answer 20

Lidocaine
Mexiletine
Tocainide

Question 21

What are 2 examples of class IC drugs?

Answer 21

Flecainide
Propafenone

Question 22

What are class II drugs?

Answer 22

Beat blockers

Question 23

What are class III drugs?

Answer 23

K+ channel blockers

Question 24

Name 3 class III drugs?

Answer 24

Amiodarone
Bretylium
Sotalol

Question 25

What are class IV drugs?

Answer 25

Calcium channel blockers

Question 26

What are 2 examples of Class IV drugs?

Answer 26

Diltiazem and Verapamil (CCB)

Question 27

What is the MOA of class IA/Na+ channel blocking drugs?

Answer 27

Slows phase 0 depolarization in ventricular muscle fibers (prolong AP)

Question 28

What is the MOA of class IB/Na+ channel blocking drugs?

Answer 28

Shortens phase 3 repolarization in ventricular muscle fibers (decrease duration of AP)

Question 29

What is the MOA of class IC/Na+ channel blocking drugs?

Answer 29

Markedly slows phase 0 depolarization in ventricular muscle fibers

Question 30

What is the MOA of class II drugs/BB?

Answer 30

Inhibits phase 4 depolarization in SA and AV nodes

Question 31

What is the MOA of class III/K+ channel blocking drugs?

Answer 31

prolongs phase 3 repolarization in ventricular muscle fibers (phase 0 is not altered)

Question 32

What is the MOA of class IV/Ca+ channel blocking drugs?

Answer 32

inhibits action potential in SA and AV nodes

Question 33

The QT interval is ____ with Class IA drugs

Answer 33

prolonged

Question 34

Do Class IA drugs affect atrial arrhythmias, ventricular arrhythmias or both?

Answer 34

Both

Question 35

What are S/S of Quinidine toxicity?

Answer 35

Cinchonism -- HA, tinitus, thrombocytopenia, Torasades

Question 36

What are S/S of procainamide toxicity?

Answer 36

lupus like syndrome

Question 37

Class II antiarrhythmics ___ cAMP

Answer 37

decrease

Question 38

Class II antiarrhythmics ___ Ca+ current

Answer 38

decrease

Question 39

Class II antiarrhythmics ___ slope of phase 4

Answer 39

decrease

Question 40

Class II antiarrhythmics ___ PR interval

Answer 40

increase

Question 41

Class II antiarrhythmics ___ myocardial O2 consumption

Answer 41

decrease

Question 42

What are uses for class II antiarryhtmics?

Answer 42

V-tach, SVT, A Fib, A flutter

Question 43

What are toxicity effects of BB?

Answer 43

impotence, bronchospasm, bradycardia, AV block, mask hypoglycemia

Question 44

Class III antiarrythmic drugs ____ AP duration

Answer 44

increase

Question 45

Class III antiarrythmic drugs ____ effective refractory period

Answer 45

increase

Question 46

When do you use Class III antiarrhytmic drugs?

Answer 46

when other antiarrhythmics fail

Question 47

What is Amiodarone toxicity S/S?

Answer 47

Pulmonary fibrosis Hepatotoxicity Hypo or hyperthyroidsm Corneal Deposits Skin deposits

Question 48

Class IV antiarrhythmics ___ conduction velocity

Answer 48

decrease

Question 49

Class IV antiarrhythmics ___ ERP

Answer 49

increase

Question 50

Class IV antiarrhythmics ___ PR interval

Answer 50

incrase

Question 51

What is the use of class IV (CCB) drugs?

Answer 51

prevents nodal arrhythmias

Question 52

In the heart, adenosine binds with _____

Answer 52

A1 receptor (Gi protein)

Question 53

When adenosine binds to the A1 receptor, it leads to opening of what channels?

Answer 53

K+ channels (which in turn leads to hyperpolarization

Question 54

Adenosine decreases ___ in cardiac cells --> decreased entry of ___

Answer 54

cAMP; Calcium Slows HR and conduction

Question 55

In vascular smooth muscle, adenosine binds to ____

Answer 55

A2 (Gs protein)

Question 56

In vascular smooth, Adenosine causes a ___ of cAMP, which in turn causes ____

Answer 56

increase; vasodilation

Question 57

What is the drug of choice for SVT?

Answer 57

Adenosine

Question 58

What is the DOA of Adenosine?

Answer 58

15 seconds

Question 59

What antagonizes adenosine?

Answer 59

Xanthines (Theophylline and Caffeine)

Question 60

What potentiates adenosines effects?

Answer 60

Dipyridamole "Persantine" (adeonsine uptake inhibitor)

Question 61

Digozin is what type of drug?

Answer 61

Cardiac glycoside

Question 62

Digoxin _____ AV node conduction

Answer 62

decreases

Question 63

Digoxin causes depression of the ___ node

Answer 63

SA

Question 64

What are s/s of digoxin toxicity?

Answer 64

NVD, yellow vision, increased PR, decreased QT, T wave inversion

Question 65

What electrolyte abnormality worsens Digoxin toxicity?

Answer 65

Hypokalemia