NAPLEX (North American Pharmacist Licensure Examination) Practice Exam

Which class of antiarrhythmics is primarily used for rate control in A-Fib?

1. Class 1

2. Class 2

3. Class 3

4. Class 4

The correct answer is: Class 2

Antiarrhythmic drugs are categorized into four main classes Class 1, 2, 3, and 4. While all classes have applications in treating different cardiac arrhythmias, Class 2 antiarrhythmics primarily work to control heart rate in atrial fibrillation (A-Fib). Class 1 antiarrhythmics mainly target the sodium channels in the heart, making them more suitable for treating ventricular arrhythmias. Class 3 antiarrhythmics have a broader range of effects on potassium channels and are used for both rate control and rhythm control in A-Fib. Class 4 antiarrhythmics primarily block calcium channels and are often used for treating supraventricular tachycardias (SVTs) such as atrial flutter. Overall, Class 2 antiarrhythmics, such as beta blockers or calcium channel blockers, are the preferred choice for rate control in A-Fib due to their specific mechanism of action.