Antiarrhythmics are drugs used to suppress cardiac arrhythmias (abnormal heart rhythms), e.g. atrial fibrillation, atrial flutter, ventricular tachycardia, and ventricular fibrillation.

• Class 1, which intefere w/ the sodium Na+ channel. Examples include:
  • Class 1a:
    • Quinidine
    • Procainamide
    • Disopyramide
  • Class 1b:
    • Lidocaine
    • Phenytoin
    • Mexiletine
    • Tocainide
  • Class 1c:
    • Encainide
    • Flecainide
    • Propafenone
    • Moricizine
• Class 2, which are anti-sympathetics agents, mostly, beta blockers. Examples include:
  • Carvedilol
  • Propranolol
  • Esmolol
  • Timolol
  • Metoprolol
  • Atenolol
  • Bisoprolol
• Class 3, which affect potassium K+ efflux. Examples include:
  • Amiodarone, which despite relatively common side effects, is used to Tx arrhythmias otherwise difficult to Tx w/ drugs
  • Sotalol
  • Ibutilide
  • Dofetilide
  • Dronedarone
  • E-4031
• Class 4, which affect calcium channels and the AV node. Examples include:
  • Verapamil
  • Diltiazem
• Class 5, which work by other or unknown mechanisms. Examples include:
  • Adenosine
  • Digoxin
  • Magnesium sulfate