🍂
FALL INTO SAVINGS SAVE UP TO 25%
Medicine (MD/DO)
/
Courses
/
Pharmacology
/
Antiarrhythmic Agents
/
Class IA Antiarrhythmics (Na+ Channel Blockers)

Class 1A Antiarrhythmic Drugs: Mnemonic

Master antiarrhythmic drugs with Picmonic! Our engaging characters and stories make learning fun and interactive. Watch this video to remember key concepts and drug classifications.

DOWNLOAD PDF
Class IA Antiarrhythmics (Na+ Channel Blockers)

Class IA Antiarrhythmics (Na+ Channel Blockers)

(1) Wand A-apple Ant-tie-arrhythmia-drummer (Salt Shaker Channel Blocked)
Picmonic

Class IA Antiarrhythmics are used to treat arrhythmias through blockage of Na+ channels, prolonging action potentials, and are effective for both atrial and ventricular arrhythmias. These can also be used for reentrant and ectopic supraventricular and ventricular tachycardia, as well Wolff-Parkinsons-White syndrome. These affect the rhythm by increasing action potential duration (AP), effective refractory period (ERP) and QT interval.

Commonly used Class IA antiarrhythmic drugs include disopyramide, procainamide, which has been known to cause drug-induced lupus, and quinidine, which can cause cinchonism.

Shared side effects of this drug class include thrombocytopenia and torsades de pointes.

9 KEY FACTS
INDICATIONS
Arrhythmias
Broken Arrhythmia-drum

These drugs are used to treat arrhythmias, especially, ventricular tachycardia and reentrant and ectopic supraventricular arrhythmias, such as Wolff-Parkinson-White syndrome.

MECHANISM OF ACTION
Increase AP, ERP, and QT interval.
Up-arrow Action-clapper-P, Ear-P, Elongated QT-heart

These drugs increase AP (action potential) duration, ERP (effective refractory period), and QT interval.

DRUGS
Disopyramide
Disco-pyramid

Disopyramide is similar in action to quinidine, and has the longest half life of drugs in this class. It is indicated for ventricular arrhythmias, but has pronounced anticholinergic side effects, and can possibly worsen heart block and cause severe heart failure.

Procainamide
Pro-cane

Procainamide is similar in action to quinidine, but has less GI side effects and is safer to be used intravenously.

Drug-induced Lupus
Loopy Pill-butterfly

Procainamide may often lead to drug induced lupus, an autoimmune disease which can be catalyzed by medication. Patients with drug-induced lupus typically show anti-histone antibodies.

Quinidine
Queen-dine

Quinidine is indicated for supraventricular and ventricular arrhythmias, and also may be used for prevention. It causes a state-dependant block, meaning at higher heart rates, the block increases, while at lower heart rates, the block decreases.

Cinchonism
Sing-cone

Cinchonism is an adverse effect of quinidine use, which presents as dizziness, ringing in the ears, and diarrhea.

SHARED SIDE EFFECTS
Thrombocytopenia
Trombone-side-toe-peanut

Thrombocytopenia may be induced with quinidine, possibly due to the destruction of platelets by antibodies developed in response to protein-quinine complexes in the circulation.

Torsades de Pointes
Tortoise with Points

Torsades de Pointes can quickly transform into ventricular fibrillation, which may lead to sudden death in minutes. Torsades is a ventricular tachycardia which presents with shifting sinusoid waveforms on ECG. It may occur due to the increase in QT interval associated with this drug class.

DOWNLOAD PDF

Recommended Picmonics

picmonic thumbnail
Class I Antiarrhythmics (Na+ Channel Blockers) Overview
picmonic thumbnail
Class IB Antiarrhythmics (Na+ Channel Blockers)
picmonic thumbnail
Class IC Antiarrhythmics (Na+ Channel Blockers)
picmonic thumbnail
Class III Antiarrhythmics (K+ Channel Blockers)
picmonic thumbnail
Class IV Antiarrhythmics (Ca2+ Channel Blockers)

Take the Class IA Antiarrhythmics (Na+ Channel Blockers) Quiz

Test your antiarrhythmic knowledge with Picmonic's rapid review quizzes. Our multiple-choice questions cover Class 1A drugs and more.

Why Med Students Love Picmonic

Our Story Mnemonics Increase Mastery and Retention

Memorize facts with phonetic mnemonics

Unforgettable characters with concise but impactful videos (2-4 min each)

Memorize facts with phonetic mnemonics

Ace Your Medicine (MD/DO) Classes & Exams with Picmonic:

Over 1,960,000 students use Picmonic’s picture mnemonics to improve knowledge, retention, and exam performance.

Choose the #1 Medicine (MD/DO) student study app.

Picmonic for Medicine (MD/DO) covers information that is relevant to your entire Medicine (MD/DO) education. Whether you’re studying for your classes or getting ready to conquer the USMLE Step 1, USMLE Step 2 CK, COMLEX Level 1, or COMLEX Level 2, we’re here to help.

Works better than traditional Medicine (MD/DO) flashcards.

Research shows that students who use Picmonic see a 331% improvement in memory retention and a 50% improvement in test scores.