Flecainide acetate for resistant arrhythmias in the young: Efficacy and pharmacokinetics

Abstract

Drug efficacy and pharmacokinetics were assessed in 63 patients, aged 5 days to 30 years (mean 8 years), who received flecainide acetate for control of resistant arrhythmias. Doses of flecainide ranged from 59 to 225 mg/m2 body surface area per day (mean 141) in divided doses every 8 to 12 h and serum trough levels ranged from 0.10 to 0.99 micrograms/ml (mean 0.36). Flecainide controlled or partially controlled arrhythmia in 53 (84%) of the 63 patients: 7 of 7 patients who had the permanent form of junctional reciprocating tachycardia, 12 of 13 who had an atrial ectopic tachycardia, 10 of 10 who had ventricular tachycardia and 18 of 25 patients who had reentrant supraventricular tachycardia. Five of seven patients who had the latter arrhythmia were unsuccessfully treated with flecainide. They had Wolff-Parkinson-White syndrome and developed asymptomatic, incessant, slower orthodromic reciprocating tachycardia while receiving the drug. Transient blurred vision was reported in three patients and two patients had transient hyperactivity. No significant hemodynamic side effects were seen in any patient. Twenty-five patients underwent oral pharmacokinetic investigation. Young infants (less than 1 year of age) had a mean plasma elimination half-life (t 1/2) approximating that (11 to 12 h) found in older children and healthy adults; children aged 1 to 12 years had a shorter mean t 1/2 of 8 h. Dosing schedules based on milligrams per square meter body surface area correlated better with plasma flecainide levels than did dosing based on milligrams per kilogram body weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacologic Management of Arrhythmias in Patients with Congenital Heart Disease

“…In contrast, PJRT is often refractory to antiarrhythmic therapy. Perry et al [51] reported good results with the use of flecainide in PJRT in patients without congenital heart disease. However, in the presence of congenital heart disease, the use of flecainide is controversial because of its potential for serious adverse effects.…”

Neonatal tachycardias: an update

“…[22][23][24][25][26][27][28] There must be concern about the proarrhythmic potential of these drugs in combination, but Price et al 29 found the combination of the two drugs to be safe and effective in refractory SVT in infants. It is important to note that flecainide solution currently has to be made up each week by the pharmacy.…”

Atrial tachycardia

“…The class IA, IC, and III drugs have direct effects on atrial electrophysiology and thus may prevent recurrence of atrial tachycardia. In reported studies [3][4][5][6][7], drug efficacy has ranged from 30% to 60%, but data on long-term success are scanty. Therefore, drug selection remains an empirical process based primarily on the side-effect and safety profiles of the various antiarrhythmic drugs.…”

“…Available therapies for atrial tachycardia include th use of antiarrhythmic drugs [1•,2••, [3][4][5][6][7], radiofrequency catheter ablation [8•,9••,10], and antiarrhythmic surgery [11•,12]. The initial treatment of choice has traditionally been antiarrhythmic drugs, but the efficacy of these drugs is modest at best and remains poorly defined.…”