Usmle - Pharmacology - Antiarrhythmic Drugs

Front 1

Quinidine

Back 1

Class IA - Na+ channel blocker
Slow phase 0, prolong action potential, increase ventricular effective refractory period
Intermediate speed of association with activated/inactivated Na+ channels

Hint 1

Atrial, AV-junctional, and ventricular tachyarrhythmias; Maintenance of sinus rhythm after direct current cardioversion of Afib or flutter

Front 2

Disopyramide

Back 2

Class IA - Na+ channel blocker
Slow phase 0, prolong action potential, increase ventricular effective refractory period
Intermediate speed of association with activated/inactivated Na+ channels

Hint 2

Atrial, AV-junctional, and ventricular tachyarrhythmias; Maintenance of sinus rhythm after direct current cardioversion of Afib or flutter

Front 3

Procainamide

Back 3

Class IA - Na+ channel blocker
Slow phase 0, prolong action potential, increase ventricular effective refractory period
Intermediate speed of association with activated/inactivated Na+ channels

Hint 3

Atrial, AV-junctional, and ventricular tachyarrhythmias; Maintenance of sinus rhythm after direct current cardioversion of Afib or flutter

Front 4

Lidocaine

Back 4

Class IB - Na+ channel blocker
Shorten phase 3 repolarization
Rapid interaction with Na+ channels

Hint 4

Ventricular arrhythmias resulting from myocardial ischemia

Front 5

Tocainide

Back 5

Class IB - Na+ channel blocker
Mild decrease in slope of Phase 0.
Shorten phase 3 repolarization
Rapid interaction with Na+ channels

Hint 5

Treatment of ventricular tachyarrhythmia

Front 6

Mexiletine

Back 6

Class IB - Na+ channel blocker
Shorten phase 3 repolarization
Rapid interaction with Na+ channels

Hint 6

Chronic treatment of ventricular arrhythmias associated with MI

Front 7

Flecainide

Back 7

Class IC - Na+ channel blocker
Markedly slows phase 0 depolarization, little effect on duration of membrane action potential or refractory periods
Slow interaction with Na+ channels

Hint 7

Refractory ventricular arrhythmias; paroxysmal atrial fib or flutter, PSVT

Front 8

Propafenone

Back 8

Class IC - Na+ channel blocker
Markedly slows phase 0 depolarization, little effect on duration of membrane action potential or refractory periods
Slow interaction with Na+ channels

Front 9

Moricizine

Back 9

Class IC - Na+ channel blocker
Markedly slows phase 0 depolarization, little effect on duration of membrane action potential or refractory periods
Slow interaction with Na+ channels

Front 10

Amiodarone

Back 10

Class III - K+ channel blocker
Prolongation of the action potential duration and refractory period
Exhibits activity from all 4 classes of antiarrhythmic drugs

Hint 10

Severe refractory ventricular and supraventricular tachyarrhythmias

Front 11

Ibutilide

Back 11

Class III - K+ channel blocker
Prolongation of the action potential duration and refractory period

Front 12

Dofetilide

Back 12

Class III - K+ channel blocker
Prolongation of the action potential duration and refractory period

Hint 12

1st line in pts with persistent atrial fib and heart failure or in CAD with impaired LV function

Front 13

Sotalol

Back 13

Class III - K+ channel (delayed rectifier) blocker but also has β-blocker activity
Prolongation of the action potential duration and refractory period

Hint 13

Prevent sudden death following acute MI

Front 14

Verapamil

Back 14

Class IV - Ca2+ blockers
Use-dependent
Decrease rate of Phase 4 spontaneous depolarization
Slow conduction in tissue dependent on calcium current (e.g. AV node)
Affects heart > vascular smooth muscle

Hint 14

Atrial arrhythmias; reentrant supraventricular tachycardia; reducing ventricular rate in Afib and flutter; hypertension; angina

Front 15

Diltiazem

Back 15

Class IV - Ca2+ blockers
Use-dependent
Decrease rate of Phase 4 spontaneous depolarization
Slow conduction in tissue dependent on calcium current (e.g. AV node)
Intermediate activity between heart and vascular smooth muscle

Hint 15

Atrial arrhythmias; reentrant supraventricular tachycardia; reducing ventricular rate in Afib and flutter; hypertension; angina

Front 16

Digoxin

Back 16

Shortens refractory period in atrial and ventricular myocardium while prolonging refractory period and diminishing conduction velocity in AV node

Front 17

Adenosine

Back 17

At high doses, decreases conduction velocity, prolongs refractory period & decreases automaticity of AV node