Prospective, randomized, double-blind, placebo-controlled comparison of metoclopramide and ondansetron for prevention of posttonsillectomy or adenotonsillectomy emesis

Effect of ondansetron and metoclopramide on postoperative nausea and vomiting in children undergoing tonsillectomy with or without adenoidectomy: a systematic review with meta-analysis

PURPOSE

Postoperative nausea and/or vomiting (PONV/POV) following tonsillectomy occurs in up to 89% of children without antiemetic prophylaxis. Prior systematic reviews have not evaluated the relative efficacy of ondansetron and metoclopramide for PONV/POV, including their adverse effects.

METHODS

A systematic search was conducted of five databases from their inceptions to June 19, 2024. Inclusion criteria were randomized controlled trials (RCTs) comparing ondansetron and metoclopramide in pediatric patients undergoing tonsillectomy or adenotonsillectomy. The primary outcome was incidence of PONV/POV. Secondary outcomes were length of hospital stay (LOS) and adverse events including postoperative extrapyramidal reactions and delayed hospital readmissions. Pooled risk ratios (RRs) or mean differences (MDs) and 95% confidence intervals (CIs) were calculated using random-effects meta-analysis. Adjusted RRs were calculated using random-effects meta-regression. Risk of bias and certainty of evidence were assessed using Cochrane RoB 2 and GRADE, respectively. This study was registered in PROSPERO (42,024,499,702).

RESULTS

Five RCTs met all inclusion criteria, consisting of 861 patients. Ondansetron significantly reduced risk of PONV/POV by almost 50% (RR 0.48 95% CI 0.31-0.75, moderate quality evidence), compared to metoclopramide. Intraoperative opioid dose did not impact the RR. Ondansetron also significantly shortened LOS (MD - 26.92 min 95% CI - 47.24 min to - 6.60 min, moderate quality evidence). Only two RCTs addressed readmission rates or extrapyramidal reactions, although no events occurred in either study.

CONCLUSION

Ondansetron is more effective than metoclopramide for PONV/POV prophylaxis, decreasing the risk of PONV/POV as well as LOS. Continued surveillance for adverse effects may be recommended when using either medication.

WITHDRAWN: Drugs for preventing postoperative nausea and vomiting

BACKGROUND

Drugs can prevent postoperative nausea and vomiting, but their relative efficacies and side effects have not been compared within one systematic review.

OBJECTIVES

The objective of this review was to assess the prevention of postoperative nausea and vomiting by drugs and the development of any side effects.

SEARCH METHODS

We searched The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2004), MEDLINE (January 1966 to May 2004), EMBASE (January 1985 to May 2004), CINAHL (1982 to May 2004), AMED (1985 to May 2004), SIGLE (to May 2004), ISI WOS (to May 2004), LILAC (to May 2004) and INGENTA bibliographies.

SELECTION CRITERIA

We included randomized controlled trials that compared a drug with placebo or another drug, or compared doses or timing of administration, that reported postoperative nausea or vomiting as an outcome.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted outcome data.

MAIN RESULTS

We included 737 studies involving 103,237 people. Compared to placebo, eight drugs prevented postoperative nausea and vomiting: droperidol, metoclopramide, ondansetron, tropisetron, dolasetron, dexamethasone, cyclizine and granisetron. Publication bias makes evidence for differences among these drugs unreliable. The relative risks (RR) versus placebo varied between 0.60 and 0.80, depending upon the drug and outcome. Evidence for side effects was sparse: droperidol was sedative (RR 1.32) and headache was more common after ondansetron (RR 1.16).

AUTHORS' CONCLUSIONS

Either nausea or vomiting is reported to affect, at most, 80 out of 100 people after surgery. If all 100 of these people are given one of the listed drugs, about 28 would benefit and 72 would not. Nausea and vomiting are usually less common and, therefore, drugs are less useful. For 100 people, of whom 30 would vomit or feel sick after surgery if given placebo, 10 people would benefit from a drug and 90 would not. Between one to five patients out of every 100 people may experience a mild side effect, such as sedation or headache, when given an antiemetic drug. Collaborative research should focus on determining whether antiemetic drugs cause more severe, probably rare, side effects. Further comparison of the antiemetic effect of one drug versus another is not a research priority.

Randomized, double-blind study comparing the efficacy of moderate-dose metoclopramide and ondansetron for the prophylactic control of postoperative vomiting in children after tonsillectomy

BACKGROUND

Postoperative vomiting (POV) is a major cause of morbidity after tonsillectomy in children. It has been well established that anti-serotinergic agents are effective for the prophylactic control of POV in this patient group. It has been suggested that at moderate doses (0.5 mg kg(-1)), metoclopramide is also an effective agent. No study has been performed comparing the efficacy of an anti-serotinergic agent and moderate-dose metoclopramide.

METHODS

A total of 557 children undergoing tonsillectomy with or without adenoidectomy were randomly allocated to receive either ondansetron 0.1 mg kg(-1) or metoclopramide 0.5 mg kg(-1). All received a standardized muscle-relaxant anaesthetic and dexamethasone 0.1 mg kg(-1). The primary outcome was any vomit in the immediate postoperative period. Comparisons were made of the proportion in each group reaching the primary outcome and the time until their first vomit. The study was designed to detect equivalence.

RESULTS

The incidence of vomiting in the group receiving ondansetron (25.3%) was 12% lower (95% CI 4.4-19.7) than those in metoclopramide (37.3%). The time until first vomit was significantly longer in the group receiving ondansetron (hazard ratio 0.61, 95% CI 0.45-0.82).

CONCLUSIONS

Although the incidence of vomiting was similar, when these results are compared with a pre-specified zone of equivalence of 0-15%, it cannot be concluded that the effect of metoclopramide is equivalent to ondansetron. Survival analysis indicated that those in the metoclopramide group vomited substantially earlier. It is concluded, therefore, that ondansetron 0.1 mg kg(-1) is a superior drug to metoclopramide 0.5 mg kg(-1) for the prophylactic control of POV in children undergoing tonsillectomy.

Acute gastroenteritis in children: role of anti-emetic medication for gastroenteritis-related vomiting

Acute gastroenteritis is associated with significant morbidity in developed countries and each year is the cause of death of several million children in developing countries. Acute gastroenteritis is usually self-limiting. Oral rehydration therapy (ORT) is effective and successful in the majority of patients. Vomiting is common at the outset of viral gastroenteritis and can limit the effectiveness of ORT. Treatment with newer anti-emetic medications has been reported to facilitate ORT and to minimize the risk of dehydration and the need for intravenous hydration and hospitalization. The role of anti-emetic medications in the treatment of gastroenteritis-related vomiting is not clear. Some physicians agree with the use of anti-emetic medications because vomiting is unpleasant and distressing for the child and parents alike, and because vomiting can increase the likelihood of dehydration, electrolyte imbalance, and the need for intravenous hydration or hospitalization. Several surveys have shown that anti-emetic medications are commonly prescribed in the treatment of pediatric gastroenteritis and that adverse events are uncommon. Efficacy studies of the newer anti-emetic medications are now available and reveal that some are effective and help facilitate ORT. Other physicians disagree with the use of anti-emetic medications because acute gastroenteritis is a self-limiting condition, vomiting might help rid the body of toxic substances, there was previously a relative lack of published evidence of clinical benefit, and there are potential adverse events associated with the use of an anti-emetic medication. Anti-emetic medications that are currently available include ondansetron, granisetron, tropisetron, dolasetron, ramosetron, promethazine, dimenhydrinate, metoclopramide, domperidone, droperidol, prochlorperazine, and trimethobenzamide. Randomized, placebo-controlled trials suggest that ondansetron is efficacious and superior to other anti-emetic medications in the treatment of gastroenteritis-related vomiting. A recent double-blind clinical trial showed that a single oral dose of ondansetron reduces gastroenteritis-related vomiting and facilitates ORT without significant adverse events. Ondansetron shows promise as a first-line anti-emetic, and judicious use of this agent might increase the success of ORT, minimize the need for intravenous therapy and hospitalization, and reduce healthcare costs. Ondansetron should be considered in situations where vomiting hinders ORT, but a larger randomized, placebo-controlled trial is necessary before the medication can be routinely recommended for the treatment of gastroenteritis-related vomiting in children.

Management of postoperative nausea and vomiting in children

Postoperative nausea and vomiting (PONV) continues to be a frequent and important cause of morbidity in children. Postoperative vomiting (POV) is more commonly studied in children than postoperative nausea because of a child's inability to effectively express distress after experiencing nausea. POV is problematic in children and is one of the leading postoperative complaints from parents and the leading cause of readmission to the hospital. POV occurs twice as frequently in children as in adults, increasing until puberty and then decreasing to adult incidence rates. Gender differences are not seen before puberty. POV remains a main cause of morbidity in children because severe vomiting can be associated with dehydration, postoperative bleeding, pulmonary aspiration, and wound dehiscence. While children have an increased potential for dehydration and the resulting physiologic impairments, other associated results such as a delay in hospital discharge or an overnight or longer hospital admission also must be considered. The two most common emetogenic surgical procedures evaluated in children are strabismus repair and adenotonsillectomy. The approach to the management of PONV and POV in children is similar to that in adults. However, as the rate of POV is more frequent in children than in adults, more children are candidates for antiemetic prophylaxis. The management approach is multifactorial and involves proper preoperative preparation, risk stratification, rational selection of antiemetic prophylaxis, choice of anesthesia technique, and a plan for postoperative antiemetic therapy. It is important to identify children at moderate-to-high risk for POV as prophylactic antiemetic therapy is useful in these children. Antiemetics of choice for POV in children include dexamethasone, dimenhydrinate, perphenazine, ondansetron, dolasetron, granisetron, and tropisetron. The serotonin (5-hydroxytryptamine; 5-HT(3)) antagonists are the antiemetic drugs of first choice for POV prophylaxis in children because as a group they have greater efficacy for preventing vomiting than nausea. The 5-HT(3) antagonists can be effectively combined with dexamethasone with an increase in efficacy. If possible, regional anesthesia should be considered. For those undergoing general anesthesia, the baseline POV risk should be reduced. Children at moderate-to-high PONV risk should receive combination therapy with two or three prophylactic antiemetics from different antiemetic drug classes. Reference to and the use of PONV guidelines and management algorithms help improve cost-effective postoperative care.

Prophylaxis of postoperative vomiting in children undergoing tonsillectomy: a systematic review and meta-analysis

Postoperative vomiting (POV) remains one of the commonest causes of significant morbidity after tonsillectomy in children. A variety of prophylactic anti-emetic interventions have been reported, but there has only been a limited systematic review in this patient group. A systematic search was performed by using Cochrane Controlled Trials Register, MEDLINE and EMBASE to identify double-blind, randomized, placebo-controlled trials of prophylactic anti-emetic interventions in children undergoing tonsillectomy, with or without adenoidectomy. The outcome of interest was POV in the first 24 h. Summary estimates of the effect of each prophylactic anti-emetic strategy were derived using fixed effect meta-analysis. Where appropriate, dose-response effects were estimated using logistic regression and 22 articles were identified. Good evidence was found for the prophylactic anti-emetic effect of dexamethasone [odds ratio (OR) 0.23, 95% CI 0.16-0.33], and the serotinergic antagonists ondansetron (OR 0.36, 95% CI 0.29-0.46), granisetron (OR 0.11, 95% CI 0.06-0.19), tropisetron (OR 0.15, 95% CI 0.06-0.35) and dolasetron (OR 0.25, 95% CI 0.1-0.59). Metoclopramide was also found to be efficacious (OR 0.51, 95% CI 0.34-0.77). There is not sufficient evidence to suggest that dimenhydrinate, perphenazine or droperidol, in the doses studied, are efficacious, nor were gastric aspiration or acupuncture. In conclusion, dexamethasone and the anti-serotinergic agents appear to be the most effective agents for the prophylaxis for POV in children undergoing tonsillectomy.

Drugs for preventing postoperative nausea and vomiting

BACKGROUND

Drugs can prevent postoperative nausea and vomiting, but their relative efficacies and side effects have not been compared within one systematic review.

OBJECTIVES

The objective of this review was to assess the prevention of postoperative nausea and vomiting by drugs and the development of any side effects.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2004), MEDLINE (January 1966 to May 2004), EMBASE (January 1985 to May 2004), CINAHL (1982 to May 2004), AMED (1985 to May 2004), SIGLE (to May 2004), ISI WOS (to May 2004), LILAC (to May 2004) and INGENTA bibliographies.

SELECTION CRITERIA

We included randomized controlled trials that compared a drug with placebo or another drug, or compared doses or timing of administration, that reported postoperative nausea or vomiting as an outcome.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted outcome data.

MAIN RESULTS

We included 737 studies involving 103,237 people. Compared to placebo, eight drugs prevented postoperative nausea and vomiting: droperidol, metoclopramide, ondansetron, tropisetron, dolasetron, dexamethasone, cyclizine and granisetron. Publication bias makes evidence for differences among these drugs unreliable. The relative risks (RR) versus placebo varied between 0.60 and 0.80, depending upon the drug and outcome. Evidence for side effects was sparse: droperidol was sedative (RR 1.32) and headache was more common after ondansetron (RR 1.16).

AUTHORS' CONCLUSIONS

Either nausea or vomiting is reported to affect, at most, 80 out of 100 people after surgery. If all 100 of these people are given one of the listed drugs, about 28 would benefit and 72 would not. Nausea and vomiting are usually less common and, therefore, drugs are less useful. For 100 people, of whom 30 would vomit or feel sick after surgery if given placebo, 10 people would benefit from a drug and 90 would not. Between one to five patients out of every 100 people may experience a mild side effect, such as sedation or headache, when given an antiemetic drug. Collaborative research should focus on determining whether antiemetic drugs cause more severe, probably rare, side effects. Further comparison of the antiemetic effect of one drug versus another is not a research priority.

Antiemetic use in pediatric gastroenteritis: a national survey of emergency physicians, pediatricians, and pediatric emergency physicians

The objective of this study was to review the use of antiemetics for pediatric gastroenteritis and to determine prescribing patterns of physicians. A mailed cross-sectional survey instrument was sent to randomly selected board-certified emergency medicine, pediatric, and pediatric emergency medicine specialists. A total of 1665 surveys were mailed, with 593 completed surveys returned (35.6% response rate). A majority of responders (60.9%) reported using antiemetics for pediatric gastroenteritis at least once in the past year, with a greater than 50% usage for all three specialty groups. Promethazine was the most commonly used antiemetic in all specialties, and per rectum the most common route of administration. Adverse reactions following a single dose of antiemetic were most frequently reported with prochlorperazine. The most common reason for antiemetic use was to prevent further dehydration. The most common concern regarding antiemetic use was potential for side effects. Occasional antiemetic use appears to be a common practice in treating pediatric gastroenteritis, regardless of specialty. Given the absence of literature on efficacy or safety, these drugs should be used only with careful consideration to potential side effects.

Ondansetron: a review of its use as an antiemetic in children

Ondansetron, a selective serotonin (5-hydroxytryptamine; 5-HT) 5-HT3 receptor antagonist, is an antiemetic agent available for use in adults and children. In children receiving ondansetron (multiple 5 mg/m2 or 0.15 mg/kg intravenous and/or oral doses) in addition to chemotherapy in 2 large (n > 100) non-comparative analyses, < or =2 emetic episodes were observed in 33 and 40% of cisplatin recipients, 48 and 68% of ifosfamide recipients, and 70 and 72% of patients receiving other chemotherapeutic regimens. In comparative trials, ondansetron was significantly more effective at reducing nausea and vomiting than metoclopramide or chlorpromazine (both combined with dexamethasone), although the incidence of delayed symptoms were similar between children receiving ondansetron and metoclopramide. In addition, dexamethasone significantly improved the antiemetic efficacy of ondansetron in 1 randomised trial. When used in children undergoing conditioning therapy (including total body irradiation) prior to bone marrow transplantation, ondansetron was significantly better at controlling nausea and vomiting than combined perphenazine and diphenhydramine therapy. In dose-ranging and large placebo-controlled trials, intravenous (0.075 to 0.15 mg/kg) or oral (0.1 mg/kg) ondansetron was significantly more effective than placebo in preventing emesis in children undergoing surgery associated with a high risk of postoperative nausea and vomiting (PONV) including tonsillectomy or strabismus repair. In comparative studies, intravenous administration of ondansetron 0.1 to 0.15 mg/kg was significantly superior to droperidol 0.02 to 0.075 mg/kg or metoclopramide 0.2 to 0.25 mg/kg in preventing emesis in children undergoing various surgical procedures. In comparison with other antiemetics, including prochlorperazine and dimenhydrinate, ondansetron generally showed greater prophylactic antiemetic efficacy. Ondansetron combined with dexamethasone was significantly more effective than ondansetron or dexamethasone alone, as was the combination of ondansetron with a propofol-based anaesthetic compared with either agent alone. Ondansetron is generally well tolerated in children, rarely necessitating treatment withdrawal. The most frequently reported adverse events were mild to moderate headache, constipation and diarrhoea in patients receiving chemotherapy. Wound problems, anxiety, headache, drowsiness and pyrexia were reported most frequently in patients postsurgery.

CONCLUSIONS

Ondansetron has shown good efficacy in the prevention of acute nausea and vomiting in children receiving moderately or highly emetogenic chemotherapy and/or irradiation, particularly when combined with dexamethasone. In the chemotherapy setting, ondansetron is significantly better than metoclopramide and chlorpromazine and has a more favourable tolerability profile. In children undergoing surgery, ondansetron demonstrated superior prophylactic antiemetic efficacy compared with placebo, droperidol and metoclopramide, and was relatively free of adverse events. Ondansetron is thus an effective first-line antiemetic in children undergoing chemotherapy, radiotherapy and surgery.

Comparative efficacy and safety of ondansetron, droperidol, and metoclopramide for preventing postoperative nausea and vomiting: a meta-analysis

Postoperative nausea and vomiting are important causes of morbidity after anesthesia and surgery. We performed a meta-analysis of published, randomized, controlled trials to determine the relative efficacy and safety of ondansetron, droperidol, and metoclopramide for the prevention of postoperative nausea and vomiting. We performed a literature search of English references using both the MEDLINE database and a manual search. Double-blinded, randomized, controlled trials comparing the efficiency of the prophylactic administration of ondansetron, droperidol, and/or metoclopramide therapy during general anesthesia were included. A total of 58 studies were identified, of which 4 were excluded for methodological concerns. For each comparison of drugs, a pooled odds ratio (OR) with a 95% CI was calculated using a random effects model. Ondansetron (pooled OR 0.43, 95% CI 0.31, 0.61; P < 0.001) and droperidol (pooled OR 0.68, 95% CI 0.54, 0.85; P < 0.001) were more effective than metoclopramide in preventing vomiting. Ondansetron was more effective than droperidol in preventing vomiting in children (pooled OR 0.49; P = 0.004), but they were equally effective in adults (pooled OR 0.87; P = 0.45). The overall risk of adverse effects was not different among drug combinations. We conclude that ondansetron and droperidol are more effective than metoclopramide in reducing postoperative vomiting.

IMPLICATIONS

We performed a systematic review of published, randomized, controlled trials to determine the relative efficacy and safety of ondansetron, droperidol, and metoclopramide for preventing postoperative nausea and vomiting. Ondansetron and droperidol were more effective than metoclopramide in reducing postoperative vomiting. The overall risk of adverse effects did not differ.

Ondansetron with propofol reduces the incidence of emesis in children following tonsillectomy

PURPOSE

This study tested the hypothesis that the antiemetic effects of a combination of ondansetron and propofol were superior to propofol alone in children undergoing tonsillectomy surgery.

METHODS

A prospective, randomized, double-blind, placebo-controlled study design was employed. Young children underwent mask induction with halothane, nitrous oxide and oxygen and then had i.v. access established: older children had i.v. induction with propofol. All patients received 0.3 mg x kg(-1) mivacurium and 2-4 microg x kg(-1) fentanyl i.v. and 30 mg x kg(-1) acetaminophen pr to a maximum dose of 650 mg. Following induction, patients received either 100 microg x kg(-1) ondansetron or placebo. Anaesthesia was maintained with 120-140 microg x kg(-1) x min(-1) propofol, nitrous oxide and oxygen to maintain vital signs within 20% of baseline. After surgery, in all patients the tracheas were extubated in the operating room without use of neuromuscular reversing agents. Episodes of emesis were recorded by PACU nurses for four to six hours. A telephone interview on the following day was also used for data recovery. Groups were compared in relation to age using the Mann-Whitney test, and with respect to sex and number of episodes of vomiting using the Fisher Exact Test.

RESULTS

Three of the 45 patients who received ondansetron vomited (6.7%), whereas 10 of the 45 patients who received placebo vomited (22.2%). (P = 0.035)

CONCLUSION

Ondansetron in a dose of 100 microg x kg(-1), when combined with propofol for children undergoing tonsillectomy reduced the incidence of postoperative vomiting to very low levels.

Ondansetron in the prophylaxis of postoperative vomiting: a meta-analysis

STUDY OBJECTIVES

To assess the efficacy of ondansetron and the incidence of headache when used as prophylaxis for postoperative vomiting.

DATA SOURCES

Studies were identified using MEDLINE (January 1990 to July 1997) with the key words: "vomiting," "ondansetron," and "surgery" and/or "anesthesia."

STUDY SELECTION

All prospectively randomized trials in which ondansetron and placebo had been administered for prevention of postoperative vomiting.

DATA EXTRACTION

Data on patient numbers, gender and ages, drug dosage, outcomes (incidence of vomiting and incidence of headache), time of outcome (up to 8 hrs or up to 48 hrs postoperatively), and baseline risk for vomiting according to type of surgical intervention were extracted.

MAIN RESULTS

48 trials involving 12,078 patients (10,390 adults and 1688 children) met the selection criteria. No evidence was found that the drug became more effective at doses larger than 4 mg. The dose of 8 mg was not statistically demonstrated to be superior (p = 0.558), while that of 1 mg was barely effective. The meta-analysis indicated that when the incidence of vomiting is elevated (e.g., the combined average of the placebo groups of 48%), on the statistical (i.e., hypothetical) grounds of six patients being treated with 4 mg of ondansetron, one will not vomit due to the treatment and, of the rest, two patients would have vomited despite the treatment and three patients would not have vomited anyway. The overall incidence of headache was 7.05% in ondansetron groups versus 6.16% in placebo groups.

CONCLUSIONS

While ondansetron is an effective antiemetic with minimal adverse effects, the data obtained on the numbers needed to be treated calculation for prophylaxis of postoperative vomiting should be considered in future cost-effective strategies of postoperative management.