Effects of prophylactic ramosetron and ondansetron on corrected QT interval during general anesthesia

Study ObjectiveTo evaluate whether ramosetron increases the corrected QT (QTc) interval.DesignProspective, randomized, controlled study.SettingOperating room.Patients135 patients undergoing elective laparoscopic cholecystectomy.InterventionPatients were allocated to three groups to receive ondansetron 4 mg (Group O4), ramosetron 0.3 mg (Group R), or ondansetron 8 mg (Group O8). The study drugs were administered intravenously approximately 15 minutes before the end of surgery.MeasurementThe QT interval for 10 minutes after administration was recorded. The QTc interval was calculated according to the Fridericia (QTcF) formula. The primary outcome was the QTcF interval among the three groups during the 10 minutes after administration of the study drugs.Main ResultsThe QTcF interval was not significantly prolonged after administration of ondansetron 4 mg and ramosetron. It was significantly increased from one minute after administration until 7 minutes after ondansetron 8 mg (Group O8). The QTcF interval was significantly longer in Group O8 at 1, 2, 3, 4, and 5 minutes.ConclusionsThe prophylactic administration 0.3 mg of ramosetron does not increase the QTc interval. Ondansetron 8 mg increases the QTc interval more so than 4 mg of ondansetron.