Comparison of prophylactic anti-emetic effects of ramosetron between single bolus administration and continuous infusion following bolus administration

ABSTRACT

BACKGROUND: The authors hypothesized that the continuous infusion of ramosetron 0.15 mg following a 0.15 mg bolus administration would maintain higher 5-hydroxytryptamine type 3 receptor occupancy levels and be more effective in preventing postoperative nausea and vomiting (PONV) than a 0.3 mg single bolus administration. We conducted a study to compare the efficacy of single bolus ramosetron administration with the combination of continuous infusion following intravenous bolus administration for PONV prophylaxis. METHODS: One hundred and fifty female patients undergoing thyroidectomy were allocated randomly to one of three groups to receive a placebo (Group 1, n = 49), 0.3 mg of IV ramosetron (Group 2, n = 53), or the continuous infusion of 0.15 mg ramosetron following a bolus administration of 0.15 mg of ramosetron (Group 3, n = 48). Anesthesia was maintained with sevoflurane and N2O. The incidence of PONV, nausea severity, and use of rescue antiemetics during the postoperative 24 hours were recorded. RESULTS: Group 1 showed higher incidences of PONV during the postoperative 24 hour than Group 2 (81% vs. 58%, P = 0.02) and Group 3 (81% vs. 48%, P < 0.01), but there was no difference between Groups 2 and 3 (P = 0.39). The use of rescue antiemetics was significantly lower in Groups 2 and 3 than Group 1 during the postoperative 6 to 24 hours. CONCLUSIONS: There were no significant differences of incidence and severity of PONV between ramosetron 0.3 mg single bolus administration and the combination of ramosetron infusion after 0.15 mg bolus administration.