Propafenone

Administration

  • Type:Antiarrhythmics
  • Dosage Forms: Oral cap, Oral tablet
  • Routes of Administration: PO
  • Common Trade Names: Rhythmol

Adult Dosing

Sustained Ventricular Tachycardia

  • 150 mg PO q 8 hrs
  • Dosage may be increased at 3-4 days to 225 mg PO q 8 hrs
  • Max dosage: 300 mg PO q 8 hrs

New Onset Atrial fibrillation

  • 450 to 600 mg PO as a single dose

Sinus Rhythm Maintenance in Atrial fibrillation or Atrial flutter

  • See sustained VT dosing

PSVT Prophylaxis in AVRT including WPW

  • 300 mg q 8 hrs for 48 hrs (max 900 mg q 8 hrs)
  • Limited data regarding dosing

Pediatric Dosing

PSVT Prophylaxis in AVRT including WPW

  • 8 to 10 mg/kg/day PO in 3 divided doses.
  • Increase by 2 to 3 mg/kg/day every 2 to 3 days
  • Max 15 mg/kg/day PO in 3 divided doses.

Special Populations

Pregnancy Rating

  • No assigned FDA category
  • No associated risk of miscarriage, birth defects, or adverse maternal or fetal outcomes with this drug

Lactation risk

  • Dosages up to 900mg/day not expected to cause adverse effects in breast fed infants

Renal Dosing

  • Adult: No dosage adjustment needed
  • Pediatric: No dosage adjustment needed

Hepatic Dosing

  • Adult: Administer 20-30% of normal IR dose and monitor closely; consider dose reduction if administering ER dose
  • Pediatric: No specified guidelines

Contraindications

  • Allergy to class/drug
  • Significant QRS widening
  • High Grade Heart Block
  • Heart Failure
  • Left Ventricular Dysfunction
  • Bradycardia
  • Cardiogenic Shock
  • Electrolyte Imbalance
  • Hypotension
  • Sick Sinus Syndrome
  • Long QT Syndrome
  • Brugada Syndrome
  • Renal failure (relative)
  • Hepatic failure (relative)
  • Asthma
  • COPD
  • Bronchospasm
  • SLE

Adverse Reactions[1]

Serious

  • Cardiac arrhythmia (2%-10%; new or worsened)
  • Cardiac failure (1%-4%)

Common

  • Unusual Taste (3%-23%)
  • Dizziness (4%-15%)
  • Nausea/Vomiting (<11%)

Pharmacology[2]

  • Half-life: Extensive metabolizers: 2-10 hours; Poor metabolizers: 10-32 hours
  • Metabolism: Hepatic via CYP2D6, CYP3A4 and CYP1A2
  • Excretion: Urine (<1% unchanged; remainder as glucuronide or sulfate conjugates); feces

Mechanism of Action[3]

  • Class 1c antiarrhythmic agent w/ local anesthetic properties
  • Blocks the fast inward sodium current, slowing the rate of increase of the action potential.
  • Prolongs conduction/refractoriness in myocardium, reduces spontaneous automaticity, and exhibits some beta-blockade activity

Comments

See Also

References

  1. Drugs.com. 2021. Propafenone (Professional Patient Advice) - Drugs.com. [online] Available at: <https://www.drugs.com/ppa/propafenone.html> [Accessed 25 June 2021]
  2. Drugs.com. 2021. Propafenone (Professional Patient Advice) - Drugs.com. [online] Available at: <https://www.drugs.com/ppa/propafenone.html> [Accessed 25 June 2021]
  3. Drugs.com. 2021. Propafenone (Professional Patient Advice) - Drugs.com. [online] Available at: <https://www.drugs.com/ppa/propafenone.html> [Accessed 25 June 2021]