Propafenone (Rythmol) Considerations for Use*

US/FDA Approved Indications: Heart Rhythm Control for Atrial Fibrillation

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Black Box Warning* Proarrhythmic; only administer by trained personnel with continuous ECG monitoring, capable of identifying and treating acute ventricular arrhythmias. Potentially fatal ventricular arrhythmias may occur with/without QT prolongation and can lead to torsade de pointes.

Mechanism of Action

Depresses phase 0 depolarization significantly, slows cardiac conduction significantly (Class 1C).


Cardioversion: 600 mg PO x 1

Maintenance: 150 to 300 mg PO every 8 hrs, or sustained release 225 to 425 mg every 12 hrs

Hepatic Impairment: Give approximately 20-30% of the normal oral dosage for immediate - release tablets.

Renal Impairment: No adjustments needed

  • Asthma, acute bronchospasm
  • AV block
  • Bradycardia
  • cardiogenic shock
  • decompensated heart failure
  • electrolyte imbalance
  • sick sinus syndrome
  • Major Side Effects

    QT prolongation, torsades de pointes

    Dosage forms and Strengths

    150, 225, 300 mg immediate release tablets
    225, 325, 425 mg extended-release capsules

    Special Notes

    Do not use in patients with ischemic heart disease or LV dysfunction; increases risk of proarrhthmia.

    Additional AV nodal blocking agent may be required to maintain rate control when AF recurs.

    Potassium and magnesium levels should be within normal range prior to initiating and during therapy.

    Has many drug interactions.


    Report angina or signs/symptoms of congestive heart failure, new or worsened arrhythmias, or other cardiac dysfunction.

    Consult with a healthcare provider prior to new drug use (including OTC and herbals).

    * Refer to prescribing information for more complete information.
    †Dosages given in the table may differ from those recommended by the manufacturers.


    1. American College of Cardiology (ACC), American Heart Association (AHA), and the European Society of Cardiology (ESC). ACC/AHA/ESC 2006 Guidelines for the Management of Patients with Atrial Fibrillation. Washington, DC: American College of Cardiology.
    2. Heart Rhythm Society. AF360 Pocket Guide: Practical Rate and Rhythm Management of Atrial Fibrillation. 2010, Washington, DC: Heart Rhythm Society.
    3. Tarascon Pocket Pharmacopoeia® 2012.