Effect of Intravenous Ondansetron on the QT Interval of Patients' Electrocardiograms.
OBJECTIVE
Ondansetron improves the success of oral rehydration in children with gastroenteritis. In postoperative adults, ondansetron has been shown to prolong the corrected QT (QTc). The aim of the study was to evaluate the effect of ondansetron on the QT at peak effect and at 1-hour postpeak effect in pediatric patients.


METHODS
This was an observational study looking at patients aged 6 months to 18 years receiving intravenous ondansetron for nausea, vomiting, or the inability to take fluids in the emergency department. Patients had electrocardiogram performed at baseline, at ondansetron's peak effect, and 1 hour postpeak effect. A paired samples Student t test compared QTc change at peak effect to zero. Peak effect of intravenous ondansetron is 3 minutes.


RESULTS
One hundred patients were included. Fifty-five percent of patients were female with a mean age of 8.3 years. The mean (range) baseline QTc was 435 (388 to 501) milliseconds. The mean (range) change in QTc at peak effect of ondansetron was 3 (-40 to 65) milliseconds (P = 0.072). The change in QTc 1-hour postpeak effect of ondansetron was 3 (-43 to 45) milliseconds (P = 0.082). No change at peak effect or 1-hour postpeak effect was clinically significant.


CONCLUSIONS
Ondansetron does not affect the QTc of pediatric patients receiving the medication for nausea, vomiting, or inability to take fluids in the emergency department. No changes in the QTc are clinically significant. To date, there have been no studies evaluating the effect of ondansetron in this acutely ill population; therefore, a larger study should be completed to confirm these data.
Sarah Kline
SK
Krammes
Todd
T
Jacobs
John M
JM
Clark
R Esther
RE
Lutes
D000293:Adolescent; D000932:Antiemetics / Q000009:adverse effects* / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography / Q000187:drug effects*; D005260:Female; D006801:Humans; D007223:Infant; D008133:Long QT Syndrome / Q000139:chemically induced* / Q000453:epidemiology; D008297:Male; D017294:Ondansetron / Q000009:adverse effects* / Q000627:therapeutic use; D010865:Pilot Projects; D014839:Vomiting / Q000188:drug therapy
D000932:Antiemetics; D017294:Ondansetron