Background: Postoperative nausea and vomiting can be a serious issue in reducing caloric intake for patients in the early stage after surgery. In Japan, ondansetron injection is now approved by insurance as a countermeasure against postoperative nausea and vomiting, but the number of reports on its effects regarding caloric intake is limited in the early stage following surgery, and opinions about the effects are divided. Thus, we examined how the effects of ondansetron administration during surgery influence caloric intake starting the day after surgery.
Methods: We examined 65 patients who received a 4mg injection of ondansetron during gynecological surgery under epidural anesthesia, in comparison to 51 patients who did not receive any antiemetic. Our study was to compare the amount of caloric intake the day after surgery.
Results: The patient group who received an ondansetron injection showed higher caloric intake (1364.1 ± 55.9 vs 1188.3 ± 63.1 kcal; ANCOVA, p = 0.045). A significant increase in caloric intake was observed in patients with an Apfel Score of 3 (807 ± 62 vs 593 ± 76 kcal; p = 0.031).
Conclusions: Our study indicated that ondansetron administration during gynecological surgery may have a positive effect on increasing postoperative caloric intake one day after surgery.
Keywords: Caloric intake; Ondansetron; Postoperative nausea and vomiting.
© 2026. The Author(s).