Hoffman RJ, et al. - Well-documentation was identified of potential for ondansetron to cause QT prolongation and fatal dysrhythmia. In this study, authors planned to assess the effect of a standardized dose of intravenous ondansetron on the QTc duration of children under 14 years of age treated for gastroenteritis-associated vomiting in a pediatric ED. 0.15 mg/kg of intravenous ondansetron in these children resulted in no prolongation of QTcB or QTcF measured 15 min after administration, nor at later times.