What is the appropriate dosing for Flecainide (anti-arrhythmic medication)?

From the Guidelines

Flecainide should be dosed at 200 to 300 mg orally for adults with atrial fibrillation, with careful monitoring for potential adverse effects such as hypotension and atrial flutter with high ventricular rate. The dosage may vary depending on the individual patient's condition and response to the medication. According to the guidelines outlined in the study 1, the recommended dose of flecainide for pharmacological cardioversion of atrial fibrillation is 200 to 300 mg orally.

When initiating flecainide therapy, it is essential to monitor the patient's ECG to watch for signs of potential proarrhythmia, such as QRS widening, which should not exceed 25% of baseline 2. Additionally, flecainide should be used with caution in patients with underlying organic heart disease involving abnormal ventricular function, as it may increase the risk of ventricular arrhythmias 1.

The study 3 also provides guidance on the suggested doses and main caveats for commonly used antiarrhythmic drugs, including flecainide. It recommends a dose of 100-200 mg twice daily for flecainide, with contraindications including creatinine clearance <50 mg/mL, coronary artery disease, and reduced LV ejection fraction.

In terms of potential adverse effects, flecainide may cause hypotension, atrial flutter with high ventricular rate, and other arrhythmias 1. Therefore, careful monitoring and dose adjustments are necessary to minimize the risk of these adverse effects.

Overall, the recommended dose of flecainide for adults with atrial fibrillation is 200 to 300 mg orally, with careful monitoring and dose adjustments as needed to minimize the risk of potential adverse effects.

From the FDA Drug Label

For patients with PSVT and patients with PAF the recommended starting dose is 50 mg every 12 hours. Flecainide doses may be increased in increments of 50 mg bid every four days until efficacy is achieved For PAF patients, a substantial increase in efficacy without a substantial increase in discontinuations for adverse experiences may be achieved by increasing the flecainide dose from 50 mg to 100 mg bid. The maximum recommended dose for patients with paroxysmal supraventricular arrhythmias is 300 mg/day. For sustained VT the recommended starting dose is 100 mg every 12 hours This dose may be increased in increments of 50 mg bid every four days until efficacy is achieved. Most patients with sustained VT do not require more than 150 mg every 12 hours (300 mg/day), and the maximum dose recommended is 400 mg/day

The recommended starting dose of flecainide is:

• 50 mg every 12 hours for patients with PSVT and PAF 4
• 100 mg every 12 hours for patients with sustained VT 4 The maximum recommended dose is:
• 300 mg/day for patients with paroxysmal supraventricular arrhythmias 4
• 400 mg/day for patients with sustained VT 4 Dose increases should be made no more frequently than once every four days, in increments of 50 mg bid 4

From the Research

Flecainide Dosing

• The initial flecainide dose can be 100 mg twice daily, with possible increases by 50 mg bid every 4 days to a maximum of 200 mg twice daily 5.
• Flecainide was initially prescribed at a dose of 200 mg twice daily, but due to early toxicity, the dosage was reduced to 100 mg twice daily 6.
• The mean dose of flecainide used in a study was 1.5 +/- 0.1 mg/kg, with a range of 100-300 mg/day 6, 7.
• Flecainide dosing can be adjusted based on the patient's response to treatment, with a goal of achieving optimal efficacy while minimizing side effects 5, 6, 7.

Efficacy and Safety

• Flecainide appears to be safe and effective for treating patients with supraventricular arrhythmias, including paroxysmal supraventricular tachycardia (PSVT), paroxysmal atrial fibrillation/flutter (PAF), and chronic atrial fibrillation (CAF) 5.
• The efficacy of flecainide is lowest and side effects are most frequent in patients with CAF, particularly those with structural heart disease 5, 7.
• Flecainide can cause cardiac adverse experiences, including proarrhythmic events, new or worsened congestive heart failure, and sinus pauses 5.
• Noncardiac adverse experiences, such as abnormal vision, dizziness, and headaches, are common with flecainide therapy 5.

Special Populations

• In children, flecainide is used as a second-line agent for treating supraventricular arrhythmias, with a high efficacy rate and a low risk of adverse events in otherwise healthy patients 8.
• However, children with underlying cardiac disease may have an increased risk of adverse events and rhythm-related side effects during flecainide initiation 8.
• In patients without structural heart disease, routine exercise testing to detect rate-related QRS widening is not warranted 9.