The post-operative anti-emetic efficacy of 4 and 8 mg of ondansetron in adult patients with and without a previous history of motion sickness (PHMS) was assessed by meta-analysis. MEDLINE and EMBASE databases were searched for randomized placebo-controlled trials evaluating the anti-emetic effectiveness of ondansetron in a 24-h period. In the 49 studies found, a further selection was with respect to those studies that noted the patient's previous history of motion sickness. Twelve trials involving 2122 patients; 446 previous history of motion sickness(+)patients and 1676 previous history of motion sickness(−) patients met the selection criteria. The dose of 4 mg ondansetron was 71.5% more effective in previous history of motion sickness(+) than in previous history of motion sickness(−) patients. For the 8 mg dose, the odds ratios (95% CI) were: previous history of motion sickness(+)=3.11 (1.40–6.93) and previous history of motion sickness(−)=2.08 (1.35–3.21). The calculated number needed to treat was also more favourable in previous history of motion sickness(+) patients for both doses of ondansetron,demonstrating a higher effectiveness in this subgroup of patients.

This study evaluates the prophylactic anti-emetic efficacy of granisetron, droperidol and metoclopramide, for the prevention of post-operative nausea and vomiting in female patients undergoing elective laparoscopic cholecystectomy. The patients were randomly assigned to one of four groups (n=30 for each group): granisetron 3 mg, droperidol 1.25 mg, metoclopramide 10 mg and placebo (saline). These medications were given immediately before the induction of anaesthesia. During the first 24 h after an-aesthesia, the incidence of post-operative nausea and vomiting was 13, 30, 33 and 37% after administration of granisetron, droperidol, metoclopramide and placebo, respectively (P>0.05, overall Fisher's exact probability test). No clinically important adverse effects were observed in either group. Our results suggest that granisetron is a better anti-emetic than droperidol or metoclopramide for the prevention of post-operative nausea and vomiting after laparoscopic cholecystectomy when compared with a placebo.