Effect of intravenous odansetron in hospitalized patients on measured QTC interval
Kruchko DH, Ehrenpreis ED, Broy C. Effect of intravenous odansetron in hospitalized patients on measured QTC interval. World Journal of Pharmacy and Pharmaceutical Sciences. May 2020; 9(5):1-10.
Introduction: Ondansetron is commonly used in hospitalized patients to treat nausea and vomiting. Ondansetron is a known QT-prolonging medication, but its effect on QTc in hospitalized patients has not been fully established. Objective: Evaluation of changes in corrected QT intervals (QTc) on followup EKGs after the administration of ondansetron plus or minus the co-administration of a QT-prolonging medication.
Methods: This was a single-institution, retrospective study utilizing electronic medical records from January 2017 - December 2017. All adult patients who had an initial EKG during the hospitalization prior to receiving intravenous ondansetron and a subsequent EKG performed within six hours of the administration of ondansetron were included. Patients were then separated into Group I, (receiving a QT-prolonging medication at the time of ondansetron administration), and Group II, (not receiving an additional QT-prolonging medication at the time of ondansetron administration). Group III consisted of randomized group of age and sex-matched controls.
Results: A total of 55 inpatients met our patient inclusion criteria, (17 patients in Group I and 38 patients in Group II). Mean change in QTc were +10.3ms in Group I (p = 0.21), +2.2ms in Group II (p = 0.0001), and 3.5ms in Group III (p = 0.13). Follow up QTc >500ms was seen in 4/17 (24%) patients in Group I, 4/38 (11%) patients in Group II and 3/100 patients in Group III (3%). Compared to Group III, OR for the development of QTc >500ms in Group I was 10.8 (95% CI 2.1-54.1, p <0.01).
Conclusion: Patients receiving ondansetron with another QT-prolonging medication (Group I), are at risk of having a QTc over 500ms on their follow up EKG. Hospitalized patients that receive IV ondansetron co-administered with another QT-prolonging drug require close monitoring to avoid the development of arrhythmias.