Unit 4-Antiarrhythmics Flashcards
Quinidine, procainamide, disopyramide
Drug class
Class IA anti-arrhythmics
Quinidine, procainamide, disopyramide
Mechanism
Block inward potassium rectifying channel (slow rate) at normal concentrations; blocks sodium channels (fast rate) at high concentrations
Quinidine, procainamide, disopyramide
Uses
Atrial fibrillation/flutter, paroxsymal supraventricular tachycardia, ventricular tachycardia
Quinidine, procainamide, disopyramide
Side effects
QT prolongation; TdP arrhythmias; heart block; hypotension; lupus-like syndrome
GI symptoms; cinchonism, hepatitis, & thrombocytopenia w/ quinidine; anticholinergic effects w/ disopyramide
Lidocaine, mexiletine
Drug class
Class IB anti-arrhythmics
Lidocaine, mexiletine
Mechanism
Block sodium channels in inactivated state mostly; no action on atrial tissue
Lidocaine, mexiletine
Uses
Digitalis toxicity
Lidocaine, mexiletine
Side effects
Tremor; nausea; seizures; local anesthetic action
GI toxicity w/ mexiletine
Flecainide, propafenone, moricizine
Drug class
Class IC anti-arrhythmics
Flecainide, propafenone, moricizine
Mechanism
Sodium channel blockers (most potent in class I), acting as negative ionotrope
Flecainide, propafenone, moricizine
Uses
Atrial fibrillation/flutter, paroxsymal supraventricular tachycardia, ventricular tachycardia
Flecainide, propafenone, moricizine
Side effects
Worsened heart failure, proarrhythmia in ischemic tissue, increased mortality
Blurred vision w/ flecainide; sinus bradycardia & brochospasm w/ propafenone
Propanolol, carvedilol.
Drug class
Class II anti-arrhythmics - beta blockers (non-selective)
Propanolol, carvedilol
Mechanism
Blocks beta-adrenergic receptors; decrease SA, AV node activity (phase 4 depolarization)
Propanolol, carvedilol.
Uses
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
Propanolol, carvedilol.
Side effects
Heart block; hypotension, brochospasm; bradycardia
Contraindicated in WPW
Decreases mortality in CHF.
Metoprolol, acebutolol, esmolol
Drug class
Class II anti-arrhythmics - beta blockers (selective)
Metoprolol, acebutolol, esmolol
Mechanism
Blocks beta-adrenergic receptors; decrease SA, AV node activity (phase 4 depolarization)
Metoprolol, acebutolol, esmolol
Uses
Control of ventricular rate in atrial fibrillation/flutter; long-term suppression of SVTs; PVCs
Metoprolol, acebutolol, esmolol
Side effects
Heart block; hypotension, brochospasm; bradycardia
Contraindicated in WPW
Decreases mortality in CHF.
Sotalol, amiodarone, dofetilide, ibutelide, dronedarone
Drug class
Class III anti-arrhythmics
Sotalol, amiodarone, dofetilide, ibutelide, dronedarone
Mechanism
K channel blockade = prolongs refractoriness
Sotalol, amiodarone, dofetilide, ibutelide, dronedarone
Uses
Atrial fibrillation/flutter, paroxsymal supraventricular tachycardia, ventricular tachycardia
Sotalol, amiodarone, dofetilide, ibutelide, dronedarone
Side effects
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
Nifedipine, amlodipine, verapamil, diltiazam.
Drug class
Class IV anti-arrhythmics - calcium chanel blockers
Nifedipine, amlodipine, verapamil, diltiazam.
Mechanism
Blockade of L-type calcium channels: slow SA & AV node activity; prolong AV refractoriness
Nifedipine, amlodipine, verapamil, diltiazam.
Uses
Prevent or terminate reentrant SVTs
Nifedipine, amlodipine, verapamil, diltiazam.
Side effects
Hypotension, bradycardia, constipation, dizziness
Increased serum digoxin levels
Contraindicated in WPW
Adenosine
Drug class
Anti-arrhythmic
Adenosine
Mechanism
Adenosine receptors in atrium, sinus node, AV node; activates K current, shortening AP, hyperpolarizing tissue, and slowing down automaticity and AV conduction
Adenosine
Uses
AF, paroxsymal supraventricular tachycardia
Adenosine
Side effects
Sedation, dyspnea, hypotension
Digoxin
Drug class
Anti-arrhythmic
Digoxin
Mechanism
Na/K pump inhibitor; slows AVN activity and conduction
Digoxin
Uses
Atrial fibrillation/flutter; chronic SVT; HF
Digoxin
Side effects
Nausea, cognitive dysfunction, blurred or yellow vision
May cause DAD arrhythmias
Low therapeutic index!
Magnesium sulfate
Drug class
Anti-arrhythmic
Magnesium sulfate
Uses
Prevents recurrent TdP and some digitalis-induced arrhythmias
Alternative to amiodarone for shock-refractory cardiac arrest.