Effect on growth of children with cardiac dysrhythmias treated with amiodarone.

We report the results of treatment with amiodarone in nine children with dysrhythmias resistant to conventional drugs, namely, one with ventricular tachycardia, two with atrial tachycardia, one with junctional tachycardia, three with reciprocal rhythm tachycardia, and two with Wolff-Parkinson-White syndrome. The initial dose was 800 mg/1.73 m2, administered for two weeks, followed by half the dose for five days a week. The duration of the treatment varied from nine months to 19 months (mean duration, 13 months). Patients were followed up for a period ranging between nine and 33 months (mean period, 17 months). A complete remission was obtained in 56% of patients and partial success in 46%. The following side effects were detected: photosensitization in two; effect on weight, height, growth velocity, and thyroid hormones in three, six, five, and six, respectively; and acceleration in bone age in three. These effects were observed from two to nine months after the beginning of treatment. They persisted for 5-18 months after treatment had been suspended. The main side effect of amiodarone in children is presumably initial hypothyroidism, followed by a biological hyperthyroid reaction. For these reasons we suggest that amiodarone should be restricted as an alternative drug for resistant critical dysrhythmias and be used only for a limited period of two years.