Comparison of ramosetron with ondansetron for prevention of postoperative nausea and vomiting in patients undergoing gynaecological surgery

Ramosetron is a new selective 5-hydroxytryptamine type 3 (5-HT3) receptor antagonist that reportedly has more potent antiemetic effects compared with other 5-HT3 receptor antagonists. The purpose of this study was to evaluate the efficacy of ramosetron for the prevention of postoperative nausea and vomiting (PONV) with that of ondansetron or placebo in high-risk patients undergoing gynaecological surgery. In this prospective, randomized, double-blinded, placebo-controlled study, 162 healthy patients who were undergoing gynaecological operation under general anaesthesia using sevoflurane were enrolled. Patients were divided into three groups: the ramosetron group (0.3 mg i.v.; n=54), the ondansetron group (8 mg i.v.; n=54), and the placebo group (normal saline i.v.; n=54). The treatments were given before the end of surgery. The incidence of PONV, severity of nausea, and the use of rescue antiemetic requirements during the first 24 h after surgery were evaluated. The incidence of nausea was lower in the ramosetron (50%) and ondansetron (44%) groups compared with the placebo group (69%) (P < 0.05). In addition, the incidence of vomiting was lower in both the ramosetron (17%) and the ondansetron (20%) groups than in the placebo group (44%) during the first 24 h after surgery (P < 0.05). The visual analogue scale score for nausea was also lower in the ramosetron and ondansetron groups compared with the placebo group (P < 0.05). The proportion of patients requiring rescue antiemetics was significantly lower with ramosetron (15%) when compared with the placebo group (41%) during the 24 h after surgery (P < 0.05). However, there were no significant differences in the incidence of nausea and vomiting, severity of nausea, and required rescue PONV between the ramosetron and the ondansetron groups. Ramosetron 0.3 mg i.v. was as effective as ondansetron 8 mg i.v. in decreasing the incidence of PONV and reducing nausea severity in female patients during the first 24 h after gynaecological surgery.