No abstract

A total of 1442 patients who had major gynaecological surgery were recruited into three multicentre studies using a standard general anaesthetic technique in order to assess the efficacy of various doses of orally administered ondansetron in the prevention of postoperative nausea and vomiting. A total of 1257 patients were included in this analysis: 420 received oral formulations of placebo and 212, 296 and 329 received ondansetron 1, 8 and 16 mg, respectively. The following factors were measured in these studies and were considered to have a possible influence on the proportion of patients experiencing postoperative nausea and vomiting: age of patient; volatile anaesthetic; intraoperative dose of fentanyl; postoperative dose of morphine; country; anaesthesia duration; neuromuscular blocker; neuromuscular block antagonist; premedicant; recovery time; type of surgery; antiemetic treatment; body weight. Using a process of elimination based on logistic regression techniques, the factors found to be the most important influences on the frequencies of nausea and vomiting were antiemetic treatment, type of surgery, neuromuscular blocker, country, volatile anaesthetic and age. A statistically significant interaction between type of surgery and age was observed. Adjusted probabilities of nausea and vomiting were obtained from the model, including all the above factors, together with the type of surgery by age interaction. Ondansetron 8 mg showed the smallest adjusted probability of nausea (0.54) and vomiting (0.34) and placebo the greatest (nausea 0.75, vomiting 0.61). A similar pattern of adjusted probabilities over neuromuscular blocking agents was seen for nausea and vomiting, with the greatest occurring in patients receiving pancuronium (nausea 0.74, vomiting 0.57) and the least in patients receiving alcuronium (nausea 0.59, vomiting 0.38).(ABSTRACT TRUNCATED AT 250 WORDS)

Background: In patients with pruritus of cholestasis, response to conventional drug treatment may be unsatisfactory. Activation of 5-hydroxytryptamine receptors on dermal sensory nerve-endings plays a role in the perception of pruritus. The 5-hydroxytryptamine 3 receptor antagonist, ondansetron, has been used in the treatment of pruritus of cholestasis, but there are few controlled data. Aim: To determine whether ondansetron is effective in treating the pruritus of cholestasis. Methods: A total of 19 patients with resistant pruritus were randomized, double blind, to receive either on-

This double-blind, parallel-group, multicenter study compared the efficacy and safety of intravenous (i.v.) ondansetron with oral syrup ondansetron plus oral dexamethasone in the prevention of nausea and emesis in pediatric patients receiving moderately/highly emetogenic chemotherapy. On each day of chemotherapy, patients were administered ondansetron 5 mg/m2 i.v. and placebo syrup orally (n = 215) or ondansetron 8 mg syrup orally and placebo i.v. (n = 223) plus dexamethasone 2-4 mg p.o. Ondansetron 4 mg syrup p.o. was administered twice daily for 2 days following the cessation of chemotherapy. Complete or major control of emesis was obtained in 89% patients in the i.v. group and 88% patients in the oral syrup group during the worst day of chemotherapy treatment (90% CI: -6, 4) and in 85% and 82% patients, respectively, during the worst day of the study period (90% CI: -8, 3). Intravenous or oral syrup ondansetron plus dexamethasone was well tolerated and effective in preventing chemotherapy-induced emesis in pediatric patients.

In a placebo-controlled, double-blind study, we have compared the efficacy of ondansetron 16 mg, 8 mg and 1 mg administered 8-hourly for prevention of postoperative nausea and vomiting. We studied 995 patients undergoing major gynaecological surgery; 982 were included in the analysis. Study medication was administered 1 h before induction of anaesthesia and second and third doses were given 8 and 16 h after the first. The treatment groups were similar for patient characteristics, surgical procedures, anaesthetics administered and opioids given. The frequency of nausea was 75%, 70%, 56% and 55% after placebo and ondansetron 1 mg, 8 mg and 16 mg, respectively; the corresponding frequencies of vomiting were 60%, 55%, 37% and 37%. Ondansetron 8 mg was as effective as 16 mg and both resulted in significant reductions in nausea and vomiting compared with placebo and ondansetron 1 mg (P less than 0.001).