The Effects of Cisapride on Ventricular Repolarization in Children

Life-threatening ventricular dysrhythmias mainly attributed to QTc prolongation have been reported in adults and children using cisapride, a prokinetic agent that facilitates gastrointestinal motility. Recent adult and pediatric case reports have suggested an association of malignant ventricular dysrhythmias with administration of cisapride in conjunction with drugs that inhibit its cytochrome P-450 metabolism. Therefore, we prospectively studied infants and children receiving cisapride without any concomitant drug, to analyze the time-related effects of cisapride on ventricular repolarization. Standard ı2- lead resting ECGs were obtained from 20 patients (mean age: 6.ı±4.ı years) before cisapride (0.8-1.2 mg/kg per day) therapy, and after 3rd, 71h days and ı month of therapy. The corrected QT interval (QTc), dispersion of QT and QTc (QTD, QTcD) were calculated. Data from these study patients were compared with a control group of 372 normal chil dren. There were no elinical adverse effects inciurling palpitations, presyncope and syncope reported during the study. Baseline QTc, QTD and QTcD measurements were not different from control group. Mean QTc values at 7th day and 1 month of cisapride therapy were significantly higher from the control group (p< O.Oı and< O.OOı , respectively). Mean QTc at 7th day and ı month of therapy were also found sig- nificantly higher than that of baseline value (p< 0.05, and < 0.01, respectively). Mean QTD and mean QTcD values during the cisapride treatment were not different from baseline values and controls. The results of this study suggest that cisapride treatment may cause prolongation of ventricular repolarization without causing increased heterogeneity of repolarization (QT dispersion). However, elinical significance of this prolongation is unclear, because all the patients in this study group have been asymptomatic without signs of dysrhythmia.