module 8 antiarrhythmics class 2 and 3

Question 1

Class 2: beta blockers indications

Answer 1

slowing ventricular rate in a-fib/flutter
SVT
suppression of PVC

Question 2

Beta Blockers MOA

Answer 2

inactivate Na channels and depresses phase 4 depolarization
slows AV node conduction
inc. diastolic filling time
prevents B1 stimulation by catecholamines

Question 3

Class 2 Beta Blocker drugs

Answer 3

esmolol

metoprolol

Question 4

Esmolol

Answer 4

Also works in multifocal atrial tachycardia (MAT)
cardioselective at low doses
IV drip for emergency situations
oral

Question 5

Esmolol AE

Answer 5

hypoTN
negative inotrope (HF)

Question 6

metoprolol

Answer 6

cardioselective at low doses

IV or oral

Question 7

metoprolol AE

Answer 7

hypoTN
negative inotrope (HF)

Question 8

Class 3 antiarrhythmic: K channel blockers

Answer 8

amiodarone
dofetilide
sotalol

Question 9

K channel blockers MOA

Answer 9

prolong phase 3 repolarization without altering phase 0

Question 10

amiodarone indication

Answer 10

antiarrhythmic class 3
life-threatening ventricular arrhythmia
off- label: atrial arrhythmias

Question 11

amiodarone MOA

Answer 11

K channel blocker that slows down phase 3 of AP

Half life: 50 days

Question 12

amiodarone AE

Answer 12

Black box: 
- pulmonary toxicity
- hepatotoxicity
- proarrhythmic effects 
Preg: category D, unsafe during lactation 
Pulmonary fibrosis
hepatitis
thyroid dysfunction 
bluish-skin
photosensitivity
mild neg. intrope
conduction abnormalities

Question 13

amiodarone interactions

Answer 13

CYP450

inc. levels of warfarin and digoxin

Question 14

sotalol indication

Answer 14

antiarrhythmic class 3
conversion of a-fib
ventricular arrhythmias

Question 15

sotalol AE

Answer 15

proarrhythmic effects
QT prolongation
hypoTN
Avoid abrupt cessation: angina, MI, ventricular arrhythmias in CAD pt

Question 16

sotalol monitoring

Answer 16

inpatient telemetry monitoring and serial EKG x 3 days with initiation of med
BP
electrolytes
renal function

Question 17

dofetilide indication

Answer 17

antiarrhythmic class 3
conversion of a-fib

Question 18

dofetilide MOA

Answer 18

selective K channel blocker

Question 19

dofetilide contraindication

Answer 19

QTc > 400msec

- dose adjusted based on QT interval and creatinine clearance

Question 20

dofetilide AE

Answer 20

torsades

Question 21

dofetilide monitoring

Answer 21

initial therapy: inpatient tele monitoring and serial EKGs x 3 days 
K 
Mg
renal function 
- potentiate arrhythmia

Question 22

initiation of drug class 3 (except amiodarone) monitoring

Answer 22

initial:
- QTc prolongation and torsades until steady-state drug levels (5 or more clearance of half-lives)
chronic:
- arrhythmias
- adverse effects