The effect of oral ondansetron in the prevention of postoperative nausea and vomiting after major gynaecological surgery performed under general anaesthesia

Abstract

SummaryThe efficacy and safety of ondansetron in preventing postoperative nausea and vomiting.fol1owing Postoperative nausea and vomiting are complications in 20% to 40% of general anaesthesia cases [I]. Women undergoing gynaecological surgery are particularly at risk of experiencing these problems. In the absence of any antiemetic treatment, the incidence of nausea and vomiting after gynaecological surgery can range from 58% to 80% [2, 31. Ondansetron is a selective antagonist of 5-hydroxytryptamine type 3 (5HTJ receptors, with little or no clinically relevant effects on dopamine or other receptors. Initial studies in the guinea-pig [4] showed that a dose of 0.001 mg.kg-l given by intraperitoneal injection had a positive effect on gastric kinetics equivalent to that of 5 mg.kg-' metoclopramide. Furthermore, ondansetron is an effective antiemetic in patients receiving cancer chemotherapy [5, 61 or radiotherapy [7].Recent studies have evaluated the efficacy of intravenously administered ondansetron 8 mg in the prevention and treatment of postoperative nausea [8-1 I], and also orally administered ondansetron 16 mg in the prevention of postoperative nausea and vomiting [12].In this present study, the antiemetic effect of ondansetron in the prevention of postoperative nausea and vomiting was investigated in patients undergoing major gynaecological surgery.

Single oral dose ondansetron in the prevention of postoperative nausea and emesis

“…The percentage of patients in the total populations who experienced no emesis with placebo (European study 26%; US study 32%) and ondansetron 16mg (European study 54%; US study 52%), and the percentage of patients who experienced no nausea with placebo (European study 22%; US study 19%) and ondansetron 16mg (European study 42%; US study 34%) were also similar. The percentage increase in complete response across both these single dose studies with ondansetron 16mg for nausea (15-20%) and emesis (20-28%) was comparable with results observed in the previous studies with three oral doses of ondansetron 8 mg for nausea (1% 24%) and vomiting (23-26%) [3,4]. Even though the terminal plasma half-life of ondansetron is approximately 3 h [7], the efficacy of a single oral dose of ondansetron was comparable to the three oral dose regimen over the same time period.…”

“…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].…”

Oral ondansetron decreases vomiting after tonsillectomy in children

“…However, oral ondansetron is available at two-thirds of the price of the parenteral form and is effective in adults. 7 The purpose of this double-blind, placebo-controlled, randomized study was to determine the effect of oral ondansetron on vomiting after outpatient paediatric tonsillectomy.…”

Additive anti-emetic efficacy of prophylactic ondansetron with droperidol in out-patient gynecological laparoscopy

“…9 However, both ondansetron and droperidol have limited efficacy in decreasing the incidence of PONV. Ondansetron lowers the PONV incidence range to 20 to 45 % [10][11][12] and only has minor transient side effects. 13,14 Droperidol lowers the PONV incidence range to 22 to 60% 15,16 and is associated with sedation, hypotension, and extrapyramidal reactions.…”