LONG-TERM EFFICACY AND TOLERANCE OF AMIODARONE IN CHILDREN

The authors reviewed the files of 37 patients under 15 years of age (22 boys and 15 girls) in order to study the long-term efficacy and tolerance of amiodarone therapy. The mean age of the patients at the time of initiation of amiodarone was 6.2 +/- 4.7 years. Amiodarone was prescribed at a loading dose of 500 mg/m2 and at a maintenance dose of 250 mg/m2. This drug was prescribed in second intention in 29/37 patients and as monotherapy in 15/37 patients. The treated arrhythmias were supraventricular in 25 patients (atrial: 10; junctional: 15) and ventricular in 12 patients. Underlying cardiac disease was present in 21/37 patients (57%) and the arrhythmias were postoperative in 14/37 cases (38%). Efficacy and tolerance of amiodarone were estimated on clinical and biological data, the results of Holter monitoring, ophthalmological slit-lamp examination and thyroid function tests. The average duration of therapy was 4 +/- 3 years. The efficacy of amiodarone was judged to be good in 59% and satisfactory in 38% of cases. Secondary effects and complications included: corneal deposits: 14 cases (38%); skin pigmentation: 1 case; photosensitivity: 10 cases (27%). There was a high incidence of thyroid disorders: 7 cases (19%) with 4 cases of biological or clinical hyperthyroidism and 3 cases of clinical or biological hypothyroidism. These abnormalities of thyroid function led to the interruption of amiodarone in 6 cases which resolved without sequellae. The efficacy of amiodarone in these patients was comparable to that of previously published series (about 90%). On the other hand, the incidence of secondary effects and of thyroid dysfunction in particular, is high but can be compared with the only other serie in the literature with a similar follow-up to this one (40 months). In conclusion, amiodarone is particularly efficacious in the treatment of supraventricular and ventricular arrhythmias in children. But long-term therapy is quite often complicated by thyroid dysfunction (19%). It usually disappears without sequellae when the treatment is stopped but this shows that amiodarone treatment should be reserved for severe arrhythmias, resistant to other antiarrhythmic agents, and needs a regular biological follow-up of thyroid function (every 4 to 6 months).