Antiarrhythmic Agents

Question 1

Class 1 Anti dysrhythmics (3)

Answer 1

• Block sodium channels (atrial & ventricular arrhythmias)
• IA: quinidine (PO)
• A-fib/flutter, Ventricular arrhythmias
• CYP 3A4 (grapefruit juice is an inhibitor)
• Photosensitivity
• IA: disopyramide (Norpace) (PO)
• Ventricular arrhythmias (only if life-threatening), A-fib conversion/prevention
• Anticholinergic AEs: urinary retention, dry mouth, constipation
• Photosensitivity
• IC: propafenone (Rhythmol) (PO)
• Paroxysmal a-fib/flutter prevention, PSVT, ventricular arrhythmias
• Proarrhythmic & increased mortality post-MI

Question 2

Class II Anti dysrhythmias

Answer 2

Beta-blockers (a-fib/flutter, supraventricular arrhythmias)
* Decrease conduction through SA and AV nodes
* Refractory period is increased
* atenolol (Tenormin) – beta-1 selective
* propranolol (Inderal) – nonselective

Question 3

Class III

Answer 3

• Potassium channel blockers
• sotalol (Betapace) (PO, IV)
• Non-selective BB
• Ventricular arrhythmias (life-threatening)
• Proarrhythmic
• Take on empty stomach (food decreases absorption)
• dronedarone (Multaq) (PO)
• A-fib/flutter prevention
• Contraindicated in pts with symptomatic CHF and recent decompensation
  requiring hospitalization, NYHA Class IV CHF with/without permanent a-fib

Question 4

quinidine

Answer 4

Class I A - Na channel blocker
-A fib / flutter, ventricular
- CYP 3A4 (Grapefruit juice is an inhibitor

Question 5

disopyramide (Norpace)

Answer 5

Class 1 A Na Channel Blocker* Ventricular arrhythmias (only if life-threatening), A-fib conversion/prevention
* Anticholinergic AEs: urinary retention, dry mouth, constipation
* Photosensitivity

Question 6

propafenone (Rhythmol)

Answer 6

Paroxysmal a-fib/flutter prevention, PSVT, ventricular arrhythmias
* Proarrhythmic & increased mortality post-MI

Question 7

Class II Anti Arthymics

Answer 7

Beta Blockers(a-fib/flutter, supraventricular arrhythmias)
* Decrease conduction through SA and AV nodes
* Refractory period is increased

Question 8

atenolol (Tenormin)

Answer 8

beta 1 selective

Question 9

propranolol (Inderal)

Answer 9

beta 1 non selective

Question 10

Sotalol (Betapace)

Answer 10

Class III K channel blocker
Prevention of atrial and v fib
* Non-selective BB
* Ventricular arrhythmias (life-threatening)
* Proarrhythmic
* Take on empty stomach (food decreases absorption)

Question 11

dronedarone (Multaq)

Answer 11

Class III K channel blocker
A-fib/flutter prevention
* Contraindicated in pts with symptomatic CHF and recent decompensation
requiring hospitalization, NYHA Class IV CHF with/without permanent a-fib

Question 12

amiodarone (Cardarone)

Answer 12

Class III K channel blocker
a-fib, SVT, V arrhythmia

• AEs:
• Proarrhythmic
• Hypo or hyperthyroidism
• Pulmonary fibrosis
• Pigmentation (bluish discoloration of skin exposed to sun) &
  photosensitivity
• Corneal microdeposits

Question 13

Verapamil

Answer 13

Class IV Calcium Channel Blocker

Question 14

diltiazem

Answer 14

Class IV Calcium Channel Blocker

Question 15

Class IV Anti Arrythmhmics

Answer 15

Calcium Channel Blockers
Most common adverse effects of antiarrhythmics are extensions of their actions
* Hypotension
* HF (due to decreased contractility)
* Proarrhythmic (especially IC)
* GI (N/V/D/C) (especially IA)
* Pregnancy category C (except amiodarone category D)
* Interactions with warfarin (Coumadin) (especially amiodarone)
* QD or more often? Should be evenly spaced