LONG-TERM EFFICACY AND TOLERANCE OF AMIOD ARONE IN CHILDREN

The authors reviewed the files of 37 patients under 15 years of age (2 2 boys and 15 girls) in order to study the long-term efficacy and tole rance of amiodarone therapy. The mean age of the patients at the time of initiation of amiodarone was 6.2 +/- 4.7 years. Amiodarone was pres cribed 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 su praventricular in 25 patients (atrial: 10; junctional: 15) and ventric ular in 12 patients. Underlying cardiac disease was present in 21/37 p atients (57%) and the arrhythmias were postoperative in 14/37 cases (3 8%). Efficacy and tolerance of amiodarone were estimated on clinical a nd biological data, the results of Holter monitoring, ophthalmological slit-lamp examination and thyroid function tests. The average duratio n 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 pig mentation: 1 case; photosensitivity: 10 cases (27%). There was a high incidence of thyroid disorders: 7 cases (19%) with 4 cases of biologic al or clinical hyperthyroidism and 3 cases of clinical or biological h ypothyroidism. These abnormalities of thyroid function led to the inte rruption of amiodarone in 6 cases which resolved without sequellae. Th e efficacy of amiodarone in these patients was comparable to that of p reviously published series (about 90%). On the other hand, the inciden ce of secondary effects and of thyroid dysfunction in particular, is h igh but can be compared with the only other serie in the literature wi th a similar follow-up to this one (40 months). In conclusion, amiodar one is particularly efficacious in the treatment of supraventricular a nd 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 a miodarone treatment should be reserved for severe arrhythmias, resista nt to other antiarrhythmic agents, and needs a regular biological foll ow-up of thyroid function (every 4 to 6 months).