SummaryThe efficacy, safety and resource implications of a single intravenous dose of ondansetron (0.1 mg·kg −1 , maximum 4 mg) were assessed in a multinational, multicentre, randomized, double-blind, placebocontrolled trial of 427 children aged 1-12 years, undergoing tonsillectomy with/without adenoidectomy. Emesis (retching and/or vomiting) and nausea were analysed separately. Significantly more ondansetron-treated children had no episodes of emesis (127/212 (60%) vs 100/215 (47%); P=0.004) and experienced no postoperative nausea (135/211 (64%) vs 108/213 (51%); P=0.004) in the first 24 h. Ondansetron also reduced the number of emetic episodes (P<0.001), the time to the first emetic episode (P<0.001) and overall nausea severity (P=0.003). Significantly fewer ondansetron-treated children were rescued or withdrawn from the study (5% vs 10%; P=0.042). Fewer ondansetron-treated patients required nursing intervention (34% vs 45%; P=0.007) and the average intervention time was significantly shorter (4.6 vs 8.1 minutes; P=0.001). Resources used to manage PONV were significantly reduced by ondansetron (43% vs 57%; P=0.014).

SummaryIn two placebo-controlled, double-blind, multicentre 0.007; nausea p Key wordsPharmacology; ondansetron, oral formulation. Complications; nausea and vomiting. Receptors; 5-HT3. Vomiting; antiemetics, prophylaxis.Postoperative nausea and vomiting (PONV) are among the most common complications that occur after surgery performed under general anaesthesia, with female patients being particularly susceptible [ 11. Other factors, including a previous history of PONV and the site of surgery, are thought to influence the occurrence of these problems [2].In two earlier studies, a three-dose oral regimen of ondansetron 8 mg has been shown to be effective and well tolerated in preventing PONV [3,4]. A single dose of intravenous ondansetron 4 mg has also been shown to be effective and well tolerated in preventing and treating established PONV [5,6]. Two further studies were undertaken to examine whether a single oral dose of ondansetron would be effective in preventing PONV both in patients with and without a previous history of PONV undergoing gynaecological and non-gynaecological surgery. The studies also aimed to identify the optimum dose of ondansetron in terms of efficacy and safety. MethodBoth studies were double-blind, placebo-controlled, and multicentre, with one being performed in 34 centres across nine European countries

Ondansetron 4 mg was compared with metoclopramide 10 mg for prevention of post-operative nausea and emesis in in-patients undergoing major gynaecological surgery in this double-blind, randomized, placebo-controlled, multicentre study. A total of 1044 patients received a single intravenous (i.v.) injection of study medication immediately before induction of anaesthesia. Nausea and emesis were assessed over the 24 h post-operative period. Significantly more patients who received ondansetron experienced no emetic episodes (44%) compared with those who received metoclopramide (37%, P = 0.049) or placebo (25%, P < 0.001). No nausea was experienced by significantly more patients who received ondansetron (32%) than with patients who received metoclopramide (24%, P = 0.009) or placebo (16%, P < 0.001). In addition, fewer emetic episodes, less severe nausea and a reduced need for rescue antiemetics were also observed with ondansetron (P < 0.05 vs. metoclopramide and placebo). Metoclopramide and placebo-treated patients were also 1.5 times (95% Cl 1.5-4.2) and 2.5 times (95% Cl 1.1-2.0) more likely, respectively, to experience nausea post-operatively. Overall, ondansetron was the most effective antiemetic in this patient population.

tron (32%) than with patients who received metoclopramide (24%, P=0.009) or placebo (16%, P<0.001). Ondansetron 4 mg was compared with me-In addition, fewer emetic episodes, less severe nausea toclopramide 10 mg for prevention of post-operative and a reduced need for rescue antiemetics were also nausea and emesis in in-patients undergoing major observed with ondansetron (P<0.05 vs. megynaecological surgery in this double-blind, rantoclopramide and placebo). Metoclopramide and domized, placebo-controlled, multicentre study. A placebo-treated patients were also 1.5 times (95% CI total of 1044 patients received a single intravenous 1.5-4.2) and 2.5 times (95% CI 1.1-2.0) more likely, (i.v.) injection of study medication immediately before respectively, to experience nausea post-operatively. induction of anaesthesia. Nausea and emesis were Overall, ondansetron was the most effective antiassessed over the 24 h post-operative period. Sigemetic in this patient population. nificantly more patients who received ondansetron experienced no emetic episodes (44%) compared with

Nausea and vomiting are significant side effects in bone marrow transplant (BMT) patients who receive high-dose preparative regimens. Higher than conventional ondansetron doses and continuous infusion might improve emetic control, because of the high doses and combinations of chemotherapy (CT) used in this setting. Our objective was to conduct a prospective, randomized study comparing two different administration methods of high-dose ondansetron during a BMT preparative regimen in breast cancer patients. Patients were eligible if they were nonpregnant women over 18 but under 65 years of age, undergoing highly emetogenic CT in preparation for autologous BMT. All patients received ondansetron as an intermittent (INT = 24 mg i.v. q 12 h/day) or continuous intravenous infusion (CIV = 8 mg i.v. loading dose followed by a continuous infusion of 2 mg/h per day). A total of 66 patients were enrolled in the study (n = 34, INT; n = 32, CIV). There was no statistical difference between treatment groups in the worst grade of emesis for the entire study period (P = 0.49). Greater than 90% of all patients were graded as failures (> or = 5 emetic episodes or need for rescue antiemetics). Complete control (no vomiting episodes) and complete plus major control (1-2 emetic episodes) per day ranged from 8% to 85% and 11% to 91%, respectively. There was no significant difference between the treatment arms in: grade of emesis, episodes of vomiting and retching, nausea scores, and mean number of rescue medications administered. There were no differences in efficacy when high-dose ondansetron was given as CIV or INT for the control of nausea and vomiting in breast cancer patients undergoing high-dose CT for autologous BMT. Ondansetron alone was not adequate to provide sustained control of CT-induced nausea and vomiting over the entire 5-day study period. A combination of antiemetics targeting various mechanisms of CT-induced nausea and vomiting may be necessary to improve response rates.