Background: The incidence of postoperative nausea and vomiting (PONV) after intrathecal morphine is high. Ramosetron
is a 5-HT3 antagonist that has been shown to reduce PONV in general anesthesia. The objective of this study was to evaluate
the efficacy of Ramosetron in preventing PONV.
Material and Method: 165 patients undergoing elective gynecological surgery under spinal anesthesia were randomly
allocated to two groups: the Ramosetron group (0.1 mg orally, n = 82), and the placebo group (oral corn starch, n = 83). The
incidence of PONV, severity of nausea and use of rescue antiemetic during the first 24 hour after surgery were evaluated.
Results: The incidence of PONV was significantly lower in the Ramosetron group compared with the placebo group (24.4%
vs. 44.6%, number needed to treat (NNT) = 5.0). The severity of nausea was significantly lower in the Ramosetron group
compared with the placebo group (20.7% vs. 39.8%, NNT = 6.0) in the 24 hour period.
Conclusion: Oral Ramosetron 0.1 mg was more effective than placebo in PONV prevention and reduced the incidence of
moderate to severe nausea after intrathecal morphine in the first 24 hour after gynecological surgery.

Keywords: Ramosetron, Intrathecal morphine, Postoperative nausea and vomiting, Gynecological surgery