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Effect of Ondansetron on QT Interval in Patients Cared for in the PICU
Sangita Trivedi1, Brenda Schiltz, Rakesh Kanipakam
11Division of Pediatric Critical Care, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN. 2Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN. 3Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, MN. 4Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN.
Insights
Ondansetron administration in pediatric intensive care units (PICUs) is frequently associated with QT interval prolongation. Electrolyte abnormalities and organ dysfunction are key risk factors for prolonged QT intervals in these patients.
Area of Science:
- Pediatric critical care medicine
- Clinical pharmacology
- Cardiology
Background:
- Limited evidence exists on ondansetron's effect on QT intervals in pediatric intensive care unit (PICU) patients.
- Ondansetron is commonly used for nausea and vomiting in pediatric populations.
Purpose of the Study:
- To evaluate the impact of ondansetron on the corrected QT (QTc) interval in patients within a medical/surgical PICU.
- To identify risk factors associated with QTc interval prolongation after ondansetron administration.
Main Methods:
- Retrospective cohort study involving consecutive enrollment of patients under 8 years old who received ondansetron.
- Exclusion criteria included pre-existing cardiac conditions or concurrent use of proarrhythmic agents.
- QTc intervals were analyzed before and after ondansetron administration.
Main Results:
- Ondansetron administration was associated with QTc prolongation in 29% (460-500 ms) and 11% (>500 ms) of events.
- Higher baseline QTc intervals were noted in patients who experienced significant prolongation.
- Multivariate analysis identified electrolyte abnormalities and organ dysfunction as significant risk factors for QTc prolongation.
Conclusions:
- Prolonged QT intervals are common in PICU patients receiving ondansetron.
- Electrolyte abnormalities and organ dysfunction are significant risk factors for ondansetron-induced QTc prolongation.
- Identifying high-risk patients can aid in preventing arrhythmias.
Objectives:
There is no evidence regarding the effect of ondansetron on the QT interval in pediatric patients in the ICU. This study aimed to describe the effect of ondansetron on the corrected QT interval in patients cared for in the PICU.
Design:
Retrospective cohort, consecutive enrollment study.
Setting:
Single-center, tertiary-level, medical/surgical PICU.
Patients:
All patients less than 8 years old who received ondansetron over an 11-month period were included. Exclusion criteria were atrial arrhythmia, bundle-branch block, known congenital long QT syndrome, and concomitant administration of proarrhythmic antiarrhythmic agents.
Interventions:
None.
Measurements And Main Results:
Overall, 210 doses of ondansetron were administered to 107 patients, with a mean age 10.5 ± 4.8 years; 49% were men. Corrected QT interval increased to 460-500 ms in 29% and to more than 500 ms in 11% of events of ondansetron administration. The mean baseline corrected QT interval even before ondansetron administration was higher for these groups (460-500 and > 500 ms; 457 ± 33 and 469 ± 45, respectively; p ≤ 0.05). In multivariate analysis, both groups were associated significantly with underlying electrolyte abnormalities (odds ratio, 2.2; 95% CI, 1.1-4.4 and odds ratio, 5.1; 95% CI, 1.8-15.7, respectively); the group with corrected QT interval more than 500 ms was also significantly associated with organ dysfunction (odds ratio, 3.2; 95% CI, 1.1-9.4). As the numbers of risk factors increased from only ondansetron to three additional QT aggravating factors (electrolyte abnormalities, administration of other QT-prolonging drugs, and organ dysfunction), the likelihood of being associated with corrected QT interval more than 500 ms increased.
Conclusions:
Prolonged QT interval is observed commonly in PICUs following the administration of ondansetron. Underlying risk factors, such as electrolyte abnormalities and organ dysfunction, seem to pose the highest risk of prolongation of QT interval in these patients. The awareness of prevalent risk factors for increased corrected QT interval may help identify patients at high risk for arrhythmias.
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