II. Indications

  1. Maintenance of sinus rhythm
    1. Prevention of Paroxysmal Atrial Fibrillation and Atrial Flutter
    2. Prevention of Paroxysmal Supraventricular Tachycardia (PSVT)
  2. Atrial Fibrillation Cardioversion (Not FDA approved)
    1. See Intermittent Atrial Fibrillation Pill in the Pocket
    2. Flecainide is typically used for "pill in the pocket" management instead
    3. Time to Cardioversion: 3-8h
    4. Conversion Rate: 51-76%
    5. Chronic Efficacy: 50-60%

III. Contraindications

  1. Structural Heart Disease (e.g. Acute Myocardial Infarction, LV Dysfunction)
    1. Risk for lethal ventricular Arrhythmias and increased mortality
  2. Intraventricular conduction disorders (e.g. AV Node Block) without a Pacemaker
  3. Pulse generation disorders (e.g. Sick Sinus Syndrome) without a Pacemaker
  4. Hemodynamic instability
    1. Cardiogenic Shock
    2. Hypotension
    3. Bradycardia
  5. Severe COPD or bronchospastic disorders
  6. Uncorrected Electrolyte disorders (esp. Hypokalemia, Hyperkalemia, Hypomagnesemia)
  7. Brugada Syndrome
  8. Myasthenia Gravis
    1. Propafenone may precipitate Myasthenia Gravis symptoms

IV. Precautions

  1. Proarrhythmic
    1. Risk for ventricular Arrhythmias and mortality, esp. in structural heart disease (Acute Myocardial Infarction, LV Dysfunction)
    2. Combination with AV Nodal blocking medication (e.g. Metoprolol, Diltiazem) recommended
      1. Decreases risk of Atrial Flutter with 1:1 conduction (Heart Rate 300)
  2. Monitoring
    1. Electrolytes
      1. Correct Potassium and Magnesium before initiating Propafenone
    2. Blood Pressure Monitoring
    3. Electrocardiogram Monitoring
      1. Decrease dose if QRS Widening >20% over baseline or AV Block (second or third degree)

V. Mechanism

  1. See Class Ic Antiarrhythmic Drug
  2. Slows overall cardiac conduction
    1. Also prolongs refractory period within atria and ventricles
  3. Other effects
    1. Weak B adrenergic blocking effects
    2. Weak Calcium entry blocking effects

VI. Dosing: Adults

  1. Prevention of Paroxysmal Atrial Fibrillation, Atrial Flutter or PSVT (maintenance of sinus rhythm)
    1. Regular Release
      1. Start 150 mg orally every 8 hours
      2. May increase to 225 mg every 8 hours after 3 to 4 days
      3. Maximum 900 mg/day
    2. Sustained Release
      1. Start 225 mg sustained release orally every 12 hours
      2. May increase to 325 mg every 12 hours after 5 days
      3. Maximum 425 mg every 12 hours
  2. Cardioversion of acute Atrial Fibrillation
    1. See Intermittent Atrial Fibrillation Pill in the Pocket
    2. Weight <70 kg: 450 mg orally for single bolus dose
    3. Weight >70 kg: 600 mg orally for single bolus dose
  3. Hepatic Insufficiency
    1. Decrease dose 70 to 80%

VII. Adverse Effects

  1. Dysgeusia (altered Taste Sensation)
  2. Gastrointestinal
    1. Nausea
    2. Constipation

VIII. Safety

  1. Pregnancy Category C
  2. Unknown Safety in Lactation

IX. Pharmacokinetics

  1. Bioavailability
    1. Sustained Release 325 mg every 12 hours is equivalent to regular release 150 mg every 8 hours
  2. Slow metabolism in 10% of U.S. population (CYP2D6 deficiency)
    1. Risk of toxicity (esp during titration) with significantly prolonged Half-Life

X. Drug Interactions

  1. Avoid with Amiodarone, Quinidine
  2. CNS side effects when combined with Lidocaine
  3. Increases plasma levels of other drugs
    1. Propranolol (and other Beta Blockers)
    2. Digoxin (increases levels >35%)
    3. Warfarin
      1. Monitor INR
  4. Other drugs that increase Propafenone levels
    1. Cimetidine
    2. Fluoxetine
    3. Orlistat
    4. Ritonavir
    5. CYP2D6 Inhibitors
      1. Desipramine
      2. Paroxetine
      3. Sertraline
    6. CYP3A4 Inhibitors
      1. Ketoconazole
      2. Saquinavir
      3. Erythromycin
  5. Other drugs that decrease Propafenone levels
    1. Rifampin

XII. References

  1. Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 78-9
  2. Hamilton (2020) Tarascon Pocket Pharmacopoeia

Images: Related links to external sites (from Bing)

Related Studies

Cost: Medications

propafenone (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
PROPAFENONE HCL 150 MG TABLET Generic $0.13 each
PROPAFENONE HCL 225 MG TAB Generic $0.22 each
PROPAFENONE HCL 300 MG TAB Generic $0.46 each
PROPAFENONE HCL ER 225 MG CAP Generic $0.88 each
PROPAFENONE HCL ER 325 MG CAP Generic $0.96 each