The Effect of Different Doses of Ondansetron in Reducing Injection Pain of Etomidate: A Double-Blind Randomized Clinical Trial

Abstract

Background: Etomidate is an anesthetic induction medicine that is the first choice, particularly in elderly and cardiovascular patients, due to its favorable hemodynamic stability. There are some complications with etomidate administration nevertheless. Created pain during the injection, for instance, may be bothering. Methods: 60 patients who were candidates for general anesthesia with Etomidate were divided into 3 groups randomly. After infusing 300 ml of normal saline for each patient, 2 minutes before induction, Ondansetron 8mg, Ondansetron 4mg, and normal saline were administered to groups first, second, and third, respectively. Then Etomidate was given to all patients in the form of 10 ml ampoules containing 20 mg of Etomidate equally. The pain score was rated using the FPRS criterion, which is from 0 to 10. Collected data were analyzed and interpreted. Results: The factor of sex wasn’t an effective element in the level of pain, but height (p = 0.034) and age affected this level; patients who were in their seventh decade of life had no complaints (59.4). There was no significant difference in the mean arterial blood pressure, the mean heart rate, and the mean arterial oxygen saturation between the three groups. The level of pain was considerably different in the study groups (p = 0.000), and the 8 mg ondansetron group had the lowest pain. Conclusion: Ondansetron can reduce the injection pain of Etomidate, and the greatest effect is related to the 8 mg dose of Ondansetron. Copyright © 2025 Tehran University of Medical Sciences.