Complete dosing information for Flecainide acetate
Medical guidance required: Dosing information here is for educational purposes. Your healthcare provider will determine the appropriate dose based on your specific condition, kidney function, other medications, and medical history. Never adjust your dose without consulting your doctor or pharmacist.
For PSVT and paroxysmal atrial fibrillation/flutter (patients without structural heart disease): start 50 mg orally every 12 hours; increase in increments of 50 mg twice daily every 4 days until effective. Maximum recommended dose for supraventricular arrhythmias is 300 mg/day. For sustained ventricular tachycardia: initiate in hospital at 100 mg every 12 hours; increase by 50 mg twice daily every 4 days as needed; most patients respond to 150 mg every 12 hours or less, and doses above 400 mg/day are rarely needed. Allow at least 4 days between dose increases because of the long half-life and slow approach to steady state. When used as 'pill-in-the-pocket' cardioversion of recent-onset AF, a single oral dose of 200-300 mg may be given to appropriate, previously evaluated patients.
Not FDA-approved for use in children, but used by pediatric cardiologists. Initiate in hospital with continuous monitoring. Infants under 6 months: about 50 mg/m2 body surface area per day in divided doses. Children over 6 months: starting around 100 mg/m2 per day; maximum recommended 200 mg/m2 per day. Milk-based feeds can reduce absorption in neonates, so dosing should be timed consistently relative to feeds.
Reduce dose in significant renal impairment. With creatinine clearance 35 mL/min/1.73 m2 or less, a starting dose of 100 mg once daily (or 50 mg twice daily) is recommended, with slower titration and plasma level monitoring. Less severe renal disease may require modest dose reduction; monitor closely.
Flecainide is extensively metabolized by the liver, so significant hepatic impairment markedly slows clearance and can cause accumulation. Use is generally not recommended in significant liver disease unless benefits clearly outweigh risks; if used, reduce the dose, lengthen titration intervals, and monitor plasma flecainide levels.