Question

Which of the following is wrongly matched combination of anti-arrhythmic drugs and their class?

• A. Lidocaine - IB
• B. Disopyramide - II
• C. Diltiazem - IV
• D. Amiodarone - III

Answer 1

The Correct Option is B

The question asks to find the wrongly matched combination of anti-arrhythmic drugs and their class from the given options. To solve this, we need to have a clear understanding of the classification of anti-arrhythmic drugs.

Anti-arrhythmic drugs are classified into four main classes based on their mechanism of action as per the Vaughan-Williams classification:

• Class I: Sodium channel blockers. Subdivided into IA, IB, and IC.
  • IA: Quinidine, Procainamide, Disopyramide
  • IB: Lidocaine, Mexiletine
  • IC: Flecainide, Propafenone
• Class II: Beta blockers.
• Class III: Potassium channel blockers.
  • Amiodarone, Sotalol
• Class IV: Calcium channel blockers.
  • Diltiazem, Verapamil

Now, let's analyze the given options: 

1. Lidocaine - IB: Correctly matched. Lidocaine is a Class IB anti-arrhythmic drug.
2. Disopyramide - II: Incorrectly matched. Disopyramide is a Class IA anti-arrhythmic drug, not Class II. Class II refers to beta blockers.
3. Diltiazem - IV: Correctly matched. Diltiazem is a Class IV anti-arrhythmic drug as it is a calcium channel blocker.
4. Amiodarone - III: Correctly matched. Amiodarone is a Class III anti-arrhythmic drug as it blocks potassium channels.

Conclusion: The option "Disopyramide - II" is wrongly matched as Disopyramide actually belongs to Class IA. Therefore, the correct answer is Disopyramide - II.