Efficacy and safety of intravenous amiodarone for incessant tachycardias in infants.

UNLABELLED: Amiodarone is an effective anti-arrhythmic agent for the treatment of supraventricular and ventricular tachycardias. The safety and efficacy of intravenous amiodarone has been described in adults and children but only to a limited extent in infants. The purpose of this study was to evaluate the safety and efficacy of intravenous amiodarone in infants. Between February 1994 and June 2001, 23 infants with a median age of 8 days (range 1-300 days) with life-threatening incessant tachycardias (17 supraventricular, 6 ventricular) were treated with intravenous amiodarone as single anti-arrhythmic agent. At presentation, 22 infants were haemodynamically unstable. Amiodarone was given as an intravenous loading dose of 5 mg/kg over 1 h followed by an intravenous maintenance dose of 5 micro g/kg per min with stepwise increase up to 25 micro g/kg per min until arrhythmia control or side-effects occurred. Amiodarone was effective in 19 infants, partially effective in three and ineffective in one infant. The median time until arrhythmia control was 24 h (range 1-96 h) and the median maintenance dosage 15 micro g/kg per min (range 5-26 micro g/kg per min). Electrophysiological side-effects necessitating dose reduction comprised of sinus bradycardia in two patients. Hypotension in one patient resolved after dose diminution. Neurological side-effects consisted of choreatic movements in one infant, which resolved over time. Amiodarone administration was stopped in one patient with elevated liver enzymes.
CONCLUSION: intravenous amiodarone is a safe and effective therapy for life-threatening incessant tachycardias in infants.