The effect of metilpheniydate, risperidone and combination therapy on ECG in children with attention-deficit hyperactivity disorder.

Introduction: This study is to investigate ventricular repolarization on electrocardiogram (ECG) in a pediatric population receiving methylphenidate (MPH), risperidone (RIS) and combined therapy.

Methods: A total of 215 patients between 6 and 12years with ADHD/conduct disorder receiving methylphenidate, risperidone and combined therapy for minimum 3months and an untreated ADHD group (n=76) was consecutively included in the study. Twelve lead ECG parameters including mean QT, QTc, T-peak to T-end (TpTe) intervals, TpTe dispersion and TpTe/QT ratio were compared.

Results: QT interval, and QTc, TpTe interval, TpTe dispersion and TpTe/QTc ratio values for groups receiving RIS, MPH and combined therapy were found to be significantly higher than other groups. Moreover, in the combined therapy group TpTe and TpTe/QTc values were higher than the single drug administration groups (p<0.05). TpTe and TpTe/QT ratio was significantly higher in the RIS group compared to that of the MPH group.

Conclusion: These results suggested that combined therapy of these drugs had a more prominent impact on the T wave and RIS could be strongly associated with it.