ANTIARRYTHMIC DRUGS

Question 1

o Not commonly used, usually a last resort (challenging to use)
o All have the potential to cause Torsade’s
o All decrease conduction velocity. Increase refractory period

Answer 1

class Ia
quinidine
disopyramide

Question 2

Primary effect to decrease automaticity

Answer 2

Mexiletine, Class Ib

Question 3

o Potent sodium channel blockers
▪ Most effect on phase 0 of action potential (decrease its slope)
▪ Widen QT

Answer 3

Flecainide
Propafenone

Class Ic

Question 4

o All increase refractory period, but only amiodarone and sotalol decrease AV nodal conduction

Answer 4

Amiodarone
Dronedarone
Sotalol
Dofetilide

Class III (Potassium Channel Blockers)

Question 5

▪ Antiarrhythmic action includes all Vaughn Williams classes
• Most effective antiarrhythmic available
• Many toxicities associated with use

class III

Answer 5

Amiodarone

Question 6

▪ 1/3 less effective than amiodarone

class III

Answer 6

Dronedarone

Question 7

▪ Beta blocker that has class III activity
▪ Second most used antiarrhythmic

class III

Answer 7

Sotalol

Question 8

▪ Potassium channel blocker
▪ Approved for maintaining normal sinus rhythm in patients with atrial fibrillation
▪ QT interval determined before 1st dose

class III

Answer 8

Dofetilide

Question 9

▪ Not in Vaughn Williams classification
▪ P-gp eliminated
▪ Narrow therapeutic window
-adjust dose in patients with renal dysfunction
▪ Does not convert patients out of AFIB

class V

Answer 9

digoxin