II. Indications
- Maintenance of sinus rhythm
- Prevention of Paroxysmal Atrial Fibrillation and Atrial Flutter
- Prevention of Paroxysmal Supraventricular Tachycardia (PSVT)
-
Atrial Fibrillation Cardioversion (Not FDA approved)
- See Intermittent Atrial Fibrillation Pill in the Pocket
- Flecainide is typically used for "pill in the pocket" management instead
- Time to Cardioversion: 3-8h
- Conversion Rate: 51-76%
- Chronic Efficacy: 50-60%
III. Contraindications
- Structural Heart Disease (e.g. Acute Myocardial Infarction, LV Dysfunction)
- Risk for lethal ventricular Arrhythmias and increased mortality
- Intraventricular conduction disorders (e.g. AV Node Block) without a Pacemaker
- Pulse generation disorders (e.g. Sick Sinus Syndrome) without a Pacemaker
- Hemodynamic instability
- Severe COPD or bronchospastic disorders
- Uncorrected Electrolyte disorders (esp. Hypokalemia, Hyperkalemia, Hypomagnesemia)
- Brugada Syndrome
-
Myasthenia Gravis
- Propafenone may precipitate Myasthenia Gravis symptoms
IV. Precautions
- Proarrhythmic
- Risk for ventricular Arrhythmias and mortality, esp. in structural heart disease (Acute Myocardial Infarction, LV Dysfunction)
- Combination with AV Nodal blocking medication (e.g. Metoprolol, Diltiazem) recommended
- Decreases risk of Atrial Flutter with 1:1 conduction (Heart Rate 300)
- Monitoring
- Electrolytes
- Blood Pressure Monitoring
- Electrocardiogram Monitoring
- Decrease dose if QRS Widening >20% over baseline or AV Block (second or third degree)
V. Mechanism
- See Class Ic Antiarrhythmic Drug
- Slows overall cardiac conduction
- Also prolongs refractory period within atria and ventricles
- Other effects
- Weak B adrenergic blocking effects
- Weak Calcium entry blocking effects
VI. Dosing: Adults
- Prevention of Paroxysmal Atrial Fibrillation, Atrial Flutter or PSVT (maintenance of sinus rhythm)
- Regular Release
- Start 150 mg orally every 8 hours
- May increase to 225 mg every 8 hours after 3 to 4 days
- Maximum 900 mg/day
- Sustained Release
- Start 225 mg sustained release orally every 12 hours
- May increase to 325 mg every 12 hours after 5 days
- Maximum 425 mg every 12 hours
- Regular Release
- Cardioversion of acute Atrial Fibrillation
- See Intermittent Atrial Fibrillation Pill in the Pocket
- Weight <70 kg: 450 mg orally for single bolus dose
- Weight >70 kg: 600 mg orally for single bolus dose
- Hepatic Insufficiency
- Decrease dose 70 to 80%
VII. Adverse Effects
- Dysgeusia (altered Taste Sensation)
- Gastrointestinal
VIII. Safety
- Pregnancy Category C
- Unknown Safety in Lactation
IX. Pharmacokinetics
-
Bioavailability
- Sustained Release 325 mg every 12 hours is equivalent to regular release 150 mg every 8 hours
- Slow metabolism in 10% of U.S. population (CYP2D6 deficiency)
- Risk of toxicity (esp during titration) with significantly prolonged Half-Life
X. Drug Interactions
- Avoid with Amiodarone, Quinidine
- CNS side effects when combined with Lidocaine
- Increases plasma levels of other drugs
- Propranolol (and other Beta Blockers)
- Digoxin (increases levels >35%)
- Warfarin
- Monitor INR
- Other drugs that increase Propafenone levels
- Other drugs that decrease Propafenone levels
XI. Resources
- Propafenone Tablet (DailyMed)
XII. References
- Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 78-9
- Hamilton (2020) Tarascon Pocket Pharmacopoeia
Images: Related links to external sites (from Bing)
Related Studies
| 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 |