Flecainide

Aka: Flecainide, Tambocor

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II. Mechanism

  1. Class Ic Antiarrhythmic Drug
  2. Blocks cardiac Sodium channels
  3. Slows overall cardiac conduction velocity
    1. Electrocardiogram demonstrates an increase over baseline in PR Interval, QRS Duration, QT Interval
  4. Decreases cardiac contractility
  5. Decreases both ectopic and SA Node automaticity
  6. Prolongs refractory period in His bundle and Purkinje Fibers, ventricle and accessory pathways

III. Indications

  1. Life Threatening ventricular Arrhythmia (without structural heart disease)
  2. Atrial Fibrillation Chemical Cardioversion
  3. Atrial Fibrillation Rhythm Control (maintenance of sinus rhythm)
  4. Recurrent Paroxysmal Supraventricular Tachycardia (PSVT)
  5. Intermittent Atrial Fibrillation Pill in the Pocket

IV. Contraindications

  1. Structural heart disease (e.g. prior Myocardial Infarction)
  2. Cardiogenic Shock
  3. Sick Sinus Syndrome
  4. Second or third degree AV Block (without Pacemaker)
  5. QTc Prolongation
  6. History of Torsades de Pointes

V. Efficacy

  1. Atrial Fibrillation Cardioversion
    1. Time to Cardioversion: 3-8 hours
    2. Conversion Rate: 68-91%
    3. Chronic Efficacy: 40-74%

VI. Precautions

  1. Proarrythmic
    1. Higher mortality in history of Myocardial Infarction and non-life threatening ventricular Arrhythmia
      1. Seen with other Class Ic Antiarrhythmic Drug
    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. Narrow therapeutic range
  3. Correct Potassium abnormalities (Hypokalemia, Hyperkalemia) before administration
  4. Exercise caution in decreased Renal Function
  5. Risk of toxicity (esp. in renal dysfunction)
    1. Acute ingestion >1 gram
    2. Chronic dosing error
  6. Indications to discontinue
    1. Electrocardiogram (EKG) Changes
      1. QRS Widening >20%
      2. Second or third degree AV Block

VII. Dosing

  1. Background
    1. Consider starting medication while on telemetry in hospital
  2. Life Threatening ventricular Arrhythmia (without structural heart disease)
    1. Start 100 mg orally every 12 hours
      1. Start at 50 mg orally every 12 hours if Creatinine Clearance <35 ml/min
    2. Increase by up to 50 mg twice daily every 4 days
    3. Maximum: 400 mg/day
  3. Atrial Fibrillation Rhythm Control (maintenance of sinus rhythm)
    1. Start 50 mg orally every 12 hours
    2. Increase by up to 50 mg twice daily every 4 days
    3. Maximum: 300 mg/day
  4. Intermittent Atrial Fibrillation Pill in the Pocket (home use)
    1. Take one 200 to 300 mg tablet orally at onset of Atrial Fibrillation
  5. Atrial Fibrillation Chemical Cardioversion
    1. Load: 300 mg orally single bolus dose
    2. Maintenance: 50-150 mg orally twice daily (see rhythm control dose titration as above)

VIII. Pharmacokinetics

  1. Oral Bioavailability: 90%
    1. However absorption is highly variable between patients
  2. Peak: 3 hours after ingestion
  3. Volume of Distribution (Vd): 8 to 9 L/kg (high)
    1. Not dialyzable
  4. Half-Life: 12 to 24 hours
    1. Steady state level reached 4 days after starting or dose change
  5. Trough Level target: 0.2 to 1 mcg/ml
  6. Metabolism: Hepatic
    1. Up to 10% of patients metabolize Flecainide four fold slower than other patients
  7. Renal excretion: 30% unchanged

IX. Adverse Effects

  1. See Flecainide Overdose
  2. See precautions above
  3. Neurologic
    1. Dizziness
    2. Visual Disturbance
    3. Headache
  4. Dyspnea
  5. Nausea or Vomiting
  6. Tremor
  7. Fatigue
  8. Paresthesias

X. Drug Interactions

  1. Avoid other Antiarrhythmic use in combination (except on cardiology Consultation)
  2. Flecainide increases the serum level of other medications
    1. Digoxin (>13 fold increase)
  3. Other medications that increase Flecainide levels
    1. Amiodarone
      1. Decrease Flecainide dose by 50% if used in combination with Amiodarone
    2. Cimetidine
    3. Quinidine

XI. Safety

  1. Avoid in Lactation
  2. Pregnancy Category C

XII. Resources

  1. Flecainide Tablet (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5a12889a-52ce-4dc4-9240-22d126f071ac
  2. Flecainide (Stat Pearls)
    1. https://www.ncbi.nlm.nih.gov/books/NBK542291/

XIII. References

  1. Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 78-9
  2. Andrikopoulos (2015) World J Cardiol 7(2):76-85 +PMID: 25717355 [PubMed]

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Related Studies

Cost: Medications

flecainide (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
FLECAINIDE ACETATE 100 MG TAB Generic $0.21 each
FLECAINIDE ACETATE 150 MG TAB Generic $0.37 each
FLECAINIDE ACETATE 50 MG TAB Generic $0.13 each
FPNotebook does not benefit financially from showing this medication data or their pharmacy links. This information is provided only to help medical providers and their patients see relative costs. Insurance plans negotiate lower medication prices with suppliers. Prices shown here are out of pocket, non-negotiated rates. See Needy Meds for financial assistance information. GoodRx is another tool for finding lower drug prices.

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