Propafenone (Rythmol) to Control Heart Rhythm

Unless otherwise noted, the following information about propafenone (Rythmol®) comes from the package insert.1


Propafenone is an antiarrhythmic used to maintain a normal sinus rhythm in those with paroxysmal afib and no structural heart disease (such as problems with the heart valves). It is not recommended for those with permanent afib or atrial flutter.

How to Use

Propafenone comes in two forms: immediate-release pills (taken once every eight hours) and extended-release pills (taken once every 12 hours). Your doctor will determine the correct dose for you. It may also be taken as needed, called “pill-in-the-pocket,”  to restore normal sinus rhythm when afib symptoms appear.


Propafenone should only be used in the event of a life-threatening arrhythmia. It should not be used for:

  • Those with significant kidney or liver disease, cardiovascular disease, certain types of heart failure, or asthma.
  • For cardioversion of atrial flutter.

Common Side Effects

These are common side effects of propafenone. If these conditions persist or get worse, talk with your doctor.

  • Unusual taste
  • Nausea and/or vomiting
  • Dizziness
  • Constipation

Serious Side Effects

Contact your doctor immediately if you experience any of these serious side effects while taking propafenone.

  • Excessive or prolonged diarrhea
  • Sweating
  • Vomiting
  • Loss of appetite or thirst

Drug Interactions

Tell your doctor about any over-the-counter drugs or supplements you take.

These drugs should be avoided when taking propafenone:

  • Certain other antiarrhythmic medications, including quinidine and amiodarone
  • Desipramine, paroxetine, ritonavir, sertraline, ketoconazole, erythromycin, or saquinavir

Don’t drink grapefruit juice while taking this drug, as it may affect its potency.


The various guidelines have specific recommendations related to propafenone.

  • US guidelines (AHA/ACC/HRS) say propafenone may be considered for rhythm control in patients without structural heart disease.2
  • European guidelines (ESC) recommend propafenone for long-term rhythm control in those with afib who have normal left ventricle function and no structural heart disease.3
  • Canadian guidelines (CCS) leave the choice of which antiarrhythmic to use for maintaining rhythm control up to the physician based on patient characteristics.4