II. Mechanism

III. Medications: Class I - Sodium Channel Blockade

  1. Background
    1. Unlike other Antiarrhythmic classes, Class I agents have minimal effect on SA Node automaticity
  2. Class Ia: Lengthens Action Potential duration
    1. Quinidine
    2. Procainamide (Pronestyl)
    3. Disopyramide (Norpace)
    4. Amiodarone (also Class II, III, IV)
    5. Several non-classic Antiarrhythmics have Class Ia activity (e.g. Imipramine, a Tricyclic Antidepressant)
  3. Class Ib: Shortens Action Potential duration
    1. Lidocaine (Xylocaine)
    2. Tocainide (Tonocard)
    3. Mexiletine (Mexitil)
    4. Phenytoin (Dilantin)
  4. Class Ic: Slows conduction
    1. Precautions
      1. Increased proarrhythmia risk and risk of Sudden Cardiac Death
      2. Avoid in structural heart disease, Coronary Artery Disease and Left Ventricular Hypertrophy
      3. Must use with concurrent AV Nodal Blocking agent (e.g. Beta Blocker)
    2. Flecainide (Tambocor)
    3. Encainide (Enkaid)
    4. Propafenone (Rythmol)

IV. Medications: Class II - Beta Blocker

  1. Propranolol
  2. Metoprolol
  3. Atenolol
  4. Carvedilol (Coreg)
  5. Esmolol (Brevibloc)
  6. Sotalol (also Class III)
  7. Amiodarone (also Class Ia, III, IV)

V. Medications: Class III - Blocks potassiun channels, prolongs repolarization

  1. Bretylium (Bretylol)
  2. Sotalol
  3. Amiodarone (also Class Ia, II, IV)
  4. Dofetilide (Tikosyn)
  5. Dronedarone (Multaq)

VI. Medications: Class IV - Calcium Channel Blocker, blocks slow Calcium channel inward current

  1. Verapamil (Calan)
  2. Diltiazem (Cardizem)
  3. Nifedipine
  4. Amiodarone (also Class Ia, II, III)

VII. References

  1. Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 83
  2. Helton (2015) Am Fam Physician 92(9): 793-800 [PubMed]

Images: Related links to external sites (from Bing)

Related Studies