What is the mechanism of action of antiarrhythmic drugs?
Christopher Pierce
Updated on February 27, 2026
Antiarrhythmic agents act by blocking the membrane sodium, potassium, and calcium channels, but no agent has exclusive action on a given type of channel. Arrhythmias resulting from reentry form the largest group of clinically significant arrhythmias. Most arrhythmias result from depressed sodium channel function.
What is the primary mechanism of action of Class 4 antiarrhythmic drugs?
Class IV agents are slow non-dihydropyridine calcium channel blockers. They decrease conduction through the AV node, and shorten phase two (the plateau) of the cardiac action potential. They thus reduce the contractility of the heart, so may be inappropriate in heart failure.
What are the classes of antiarrhythmic drugs give examples?
Overview
| Classes of antiarrhythmic drugs | |
|---|---|
| Class | Examples |
| Class IB antiarrhythmics | Lidocaine Mexiletine Phenytoin |
| Class IC antiarrhythmics | Flecainide Propafenone |
| Class II antiarrhythmic drugs | Metoprolol Esmolol (short acting) Propranolol Atenolol Timolol Carvedilol Sotalol |
How do class antiarrhythmic drugs work?
Class Ia antiarrhythmic drugs Class Ia drugs block repolarizing potassium channels, prolonging the refractory periods of fast-channel tissues. On the ECG, this effect is reflected as QT-interval prolongation even at normal rates. . The primary indications are supraventricular and ventricular tachycardias.
Can amlodipine cause arrhythmia?
dizziness. hot or warm feeling in your face (flushing) irregular heart rate (arrhythmia) very fast heart rate (palpitations)
What are the side effects of antiarrhythmic drugs?
The thing that is especially concerning about antiarrhythmic drugs is their unique toxicity, which often makes them difficult and relatively risky to administer and to take. The usual kinds of side effects seen with many drugs, such as allergies, insomnia, gastrointestinal disturbances, etc.
Is metoprolol an antiarrhythmic?
Metoprolol and amiodarone are common antiarrhythmic drugs used in clinics throughout the world. The taste and smell alterations induced by antiarrhythmic drugs remain uncommon throughout the world, with less than 10 reported cases. Patient concerns:
Is digoxin an antiarrhythmic medication?
Digoxin is used to treat atrial fibrillation and heart failure. Digoxin belongs to a class of drugs called antiarrhythmics. It works by slowing your heart rate down and improving the way your ventricles are filled with blood. Your ventricles are two of the four chambers of your heart. Digoxin oral tablet does not cause drowsiness.
Is atenolol an antiarrhythmic medication?
In nine patients atenolol was the first antiarrhythmic drug given. In 15 of the 22 patients (68%) therapy with atenolol was considered successful. The average effective dose of atenolol in these 15 patients was 1.2 +/- 0.3 mg/kg/day.
