Unit 4-Antiarrhythmics

Question 1

Quinidine, procainamide, disopyramide

Drug class

Answer 1

Class IA anti-arrhythmics

Question 2

Quinidine, procainamide, disopyramide

Mechanism

Answer 2

Block inward potassium rectifying channel (slow rate) at normal concentrations; blocks sodium channels (fast rate) at high concentrations

Question 3

Quinidine, procainamide, disopyramide

Uses

Answer 3

Atrial fibrillation/flutter, paroxsymal supraventricular tachycardia, ventricular tachycardia

Question 4

Quinidine, procainamide, disopyramide

Side effects

Answer 4

QT prolongation; TdP arrhythmias; heart block; hypotension; lupus-like syndrome

GI symptoms; cinchonism, hepatitis, & thrombocytopenia w/ quinidine; anticholinergic effects w/ disopyramide

Question 5

Lidocaine, mexiletine

Drug class

Answer 5

Class IB anti-arrhythmics

Question 6

Lidocaine, mexiletine

Mechanism

Answer 6

Block sodium channels in inactivated state mostly; no action on atrial tissue

Question 7

Lidocaine, mexiletine

Uses

Answer 7

Digitalis toxicity

Question 8

Lidocaine, mexiletine

Side effects

Answer 8

Tremor; nausea; seizures; local anesthetic action

GI toxicity w/ mexiletine

Question 9

Flecainide, propafenone, moricizine

Drug class

Answer 9

Class IC anti-arrhythmics

Question 10

Flecainide, propafenone, moricizine

Mechanism

Answer 10

Sodium channel blockers (most potent in class I), acting as negative ionotrope

Question 11

Flecainide, propafenone, moricizine

Uses

Answer 11

Atrial fibrillation/flutter, paroxsymal supraventricular tachycardia, ventricular tachycardia

Question 12

Flecainide, propafenone, moricizine

Side effects

Answer 12

Worsened heart failure, proarrhythmia in ischemic tissue, increased mortality

Blurred vision w/ flecainide; sinus bradycardia & brochospasm w/ propafenone

Question 13

Propanolol, carvedilol.

Drug class

Answer 13

Class II anti-arrhythmics - beta blockers (non-selective)

Question 14

Propanolol, carvedilol

Mechanism

Answer 14

Blocks beta-adrenergic receptors; decrease SA, AV node activity (phase 4 depolarization)

Question 15

Propanolol, carvedilol.

Uses

Answer 15

Control of ventricular rate in atrial fibrillation/flutter; long-term suppression of SVTs; PVCsControl of ventricular rate in atrial fibrillation/flutter; long-term suppression of SVTs; PVCs

Question 16

Propanolol, carvedilol.

Side effects

Answer 16

Heart block; hypotension, brochospasm; bradycardia

Contraindicated in WPW

Decreases mortality in CHF.

Question 17

Metoprolol, acebutolol, esmolol

Drug class

Answer 17

Class II anti-arrhythmics - beta blockers (selective)

Question 18

Metoprolol, acebutolol, esmolol

Mechanism

Answer 18

Blocks beta-adrenergic receptors; decrease SA, AV node activity (phase 4 depolarization)

Question 19

Metoprolol, acebutolol, esmolol

Uses

Answer 19

Control of ventricular rate in atrial fibrillation/flutter; long-term suppression of SVTs; PVCs

Question 20

Metoprolol, acebutolol, esmolol

Side effects

Answer 20

Heart block; hypotension, brochospasm; bradycardia

Contraindicated in WPW

Decreases mortality in CHF.

Question 21

Sotalol, amiodarone, dofetilide, ibutelide, dronedarone

Drug class

Answer 21

Class III anti-arrhythmics

Question 22

Sotalol, amiodarone, dofetilide, ibutelide, dronedarone

Mechanism

Answer 22

K channel blockade = prolongs refractoriness

Question 23

Sotalol, amiodarone, dofetilide, ibutelide, dronedarone

Uses

Answer 23

Atrial fibrillation/flutter, paroxsymal supraventricular tachycardia, ventricular tachycardia

Question 24

Sotalol, amiodarone, dofetilide, ibutelide, dronedarone

Side effects

Answer 24

Torsades de Pointes; QT prolongation, bradycardia; pulmonary fibrosis, peripheral neuropathy, hepatic dysfunction, hypotension, brochospasm

Photosensitivity (blue-gray skin; numerous drug interactions; N & V w/ dronedarone

Question 25

Nifedipine, amlodipine, verapamil, diltiazam. Drug class

Answer 25

Class IV anti-arrhythmics - calcium chanel blockers

Question 26

Nifedipine, amlodipine, verapamil, diltiazam. Mechanism

Answer 26

Blockade of L-type calcium channels: slow SA & AV node activity; prolong AV refractoriness

Question 27

Nifedipine, amlodipine, verapamil, diltiazam. Uses

Answer 27

Prevent or terminate reentrant SVTs

Question 28

Nifedipine, amlodipine, verapamil, diltiazam. Side effects

Answer 28

Hypotension, bradycardia, constipation, dizziness Increased serum digoxin levels Contraindicated in WPW

Question 29

Adenosine Drug class

Answer 29

Anti-arrhythmic

Question 30

Adenosine Mechanism

Answer 30

Adenosine receptors in atrium, sinus node, AV node; activates K current, shortening AP, hyperpolarizing tissue, and slowing down automaticity and AV conduction

Question 31

Adenosine Uses

Answer 31

AF, paroxsymal supraventricular tachycardia

Question 32

Adenosine Side effects

Answer 32

Sedation, dyspnea, hypotension

Question 33

Digoxin Drug class

Answer 33

Anti-arrhythmic

Question 34

Digoxin Mechanism

Answer 34

Na/K pump inhibitor; slows AVN activity and conduction

Question 35

Digoxin Uses

Answer 35

Atrial fibrillation/flutter; chronic SVT; HF

Question 36

Digoxin Side effects

Answer 36

Nausea, cognitive dysfunction, blurred or yellow vision May cause DAD arrhythmias Low therapeutic index!

Question 37

Magnesium sulfate Drug class

Answer 37

Anti-arrhythmic

Question 38

Magnesium sulfate Uses

Answer 38

Prevents recurrent TdP and some digitalis-induced arrhythmias Alternative to amiodarone for shock-refractory cardiac arrest.