Clinical trial: oral ondansetron for reducing vomiting secondary to acute gastroenteritis in children--a double-blind randomized study

Impact of Ondansetron Prescription on Return Emergency Department Visits Among Children with Acute Gastroenteritis

OBJECTIVES

The objective of this study was to determine if providing ondansetron prescription to children with acute gastroenteritis seen in the emergency department (ED) is associated with reduced unscheduled ED revisits.

METHODS

This was a retrospective comparative cohort study conducted in a tertiary urban pediatric ED. We evaluated otherwise healthy children 6 months to 18 years old who presented to the ED between 2010 and 2015 and were discharged home with acute gastroenteritis diagnosis. Illness severity was determined using dehydration score, emergency severity index, and presenting symptoms. The incidence of unscheduled 72-hour ED revisit among patients discharged home with ondansetron prescription was compared with those without a prescription.

RESULTS

Of the 11,785 eligible patients, 35.5% (N = 4,187) of patients were discharged home with ondansetron prescription. After adjustment for emergency severity index, age, insurance source, race, time of index visit registration, intravenous fluid use, and ED-administered ondansetron, there were no differences in the rates of ED revisit (adjusted odds ratio [aOR] = 1.12 [0.92, 1.33]) or admission after ED revisit (aOR = 0.81 [0.51, 1.27]) among children with versus without ondansetron prescription. No difference was found in the proportion of alternative diagnoses among returning patients with versus without ondansetron prescription (aOR = 0.56 [0.20, 1.59]).

CONCLUSIONS

There was no association between ondansetron prescription and ED revisit among children seen in the ED with suspected acute gastroenteritis. In the appropriate setting, however, physicians may consider prescribing ondansetron for symptom control in conjunction with careful discharge instructions.

Cost-effectiveness of oral ondansetron for children with acute gastroenteritis in primary care: a randomised controlled trial

BACKGROUND

Acute gastroenteritis is a common childhood condition with substantial medical and indirect costs, mostly because of referral, hospitalisation, and parental absence from work.

AIM

To determine the cost-effectiveness of adding oral ondansetron to care as usual (CAU) for children with acute gastroenteritis presenting to out-of-hours primary care (OOH-PC).

DESIGN AND SETTING

A pragmatic randomised controlled trial from December 2015 to January 2018, at three OOHPC centres in the north of the Netherlands (Groningen, Zwolle, and Assen) with a follow-up of 7 days.

METHOD

Children were recruited at the OOH-PC and parents kept a parental diary. Inclusion criteria were: aged 6 months-6 years; diagnosis of acute gastroenteritis; at least four reported episodes of vomiting 24 hours before presentation, at least one of which was in the 4 hours before presentation; and written informed consent from both parents. Children were randomly allocated at a 1:1 ratio to either CAU (oral rehydration therapy) or CAU plus one dose of 0.1 mg/kg oral ondansetron.

RESULTS

In total, 194 children were included for randomisation. One dose of oral ondansetron decreased the proportion of children who continued vomiting within the first 4 hours from 42.9% to 19.5%, (a decrease of 54.5%), with an odds ratio of 0.4 (95% confidence interval [CI] = 0.2 to 0.7; number needed to treat: four). Total mean costs in the ondansetron group were 31.2% lower (€488 [£420] versus €709 [£610]), and the total incremental mean costs for an additional child free of vomiting in the first 4 hours was -€9 (£8) (95% CI = -€41 [£35] to €3 [£3]).

CONCLUSION

A single oral dose of ondansetron for children with acute gastroenteritis, given in OOH-PC settings, is both clinically beneficial and cost-effective.

A pragmatic randomized controlled trial of multi-dose oral ondansetron for pediatric gastroenteritis (the DOSE-AGE study): statistical analysis plan

Background

Acute gastroenteritis is a leading cause of emergency department visits and hospitalizations among children in North America. Oral-rehydration therapy is recommended for children with mild-to-moderate dehydration, but children who present with vomiting are frequently offered intravenous rehydration in the emergency department (ED). Recent studies have demonstrated that the anti-emetic ondansetron can reduce vomiting, intravenous rehydration, and hospitalization when administered in the ED to children with dehydration. However, there is little evidence of additional benefit from prescribing ondansetron beyond the initial ED dose. Moreover, repeat dosing may increase the frequency of diarrhea. Despite the lack of evidence and potential adverse side effects, many physicians across North America provide multiple doses of ondansetron to be taken following ED disposition. Thus, the Multi-Dose Oral Ondansetron for Pediatric Gastroenteritis (DOSE-AGE) trial will evaluate the effectiveness of prescribing multiple doses of ondansetron to treat acute gastroenteritis-associated vomiting. This article specifies the statistical analysis plan (SAP) for the DOSE-AGE trial and was submitted before the outcomes of the study were available for analysis.

Methods/design

The DOSE-AGE study is a phase III, 6-center, placebo-controlled, double-blind, parallel design randomized controlled trial designed to determine whether participants who are prescribed multiple doses of oral ondansetron to administer, as needed, following their ED visit have a lower incidence of experiencing moderate-to-severe gastroenteritis, as measured by the Modified Vesikari Scale score, compared with a placebo. To assess safety, the DOSE-AGE trial will investigate the frequency and maximum number of diarrheal episodes following ED disposition, and the occurrence of palpitations, pre-syncope/syncope, chest pain, arrhythmias, and serious adverse events. For the secondary outcomes, the DOSE-AGE trial will investigate the individual elements of the Modified Vesikari Scale score and caregiver satisfaction with the therapy.

Discussion

The DOSE-AGE trial will provide evidence on the effectiveness of multiple doses of oral ondansetron, taken as needed, following an initial ED dose in children with acute gastroenteritis-associated vomiting. The data from the DOSE-AGE trial will be analyzed using this SAP. This will reduce the risk of producing data-driven results and bias in our reported outcomes. The DOSE-AGE study was registered on ClinicalTrials.gov on February 22, 2019.

Trial registration

ClinicalTrials.gov NCT03851835. Registered on 22 February 2019.

Effect of ondansetron on vomiting associated with acute gastroenteritis in a developing country: a meta-analysis

In high-income countries. ondansetron is an effective antiemetic in children with gastroenteritis, but data from low- and middle-income countries are sparse. This study aimed to evaluate evidences of the effectiveness of ondansetron in preventing vomiting and reducing the use of intravenous fluids in children with gastroenteritis in developing countries. A total of nine randomized controlled trials (RCTs) involving 2313 participants met the inclusion criteria. Compared with placebo, ondansetron reduced the use of intravenous rehydration (three RCTs, n = 1126, relative risk (RR) 0.60, 95% confidence interval (CI) 0.38-0.95, no significant heterogeneity, I² = 43%), the risk of failure of oral rehydration therapy among children with gastroenteritis-associated vomiting and dehydration (four RCTs, n = 1370, RR 0.58, 95% CI 0.43-0.79; no significant heterogeneity was found, I² = 39%) and risk of hospitalization (2 RCTs, n = 264, RR 0.25, 95% CI 0.09-0.73, no heterogeneity, I² = 0).Conclusions: Compared with placebo, ondansetron reduced the use of intravenous fluids in children with gastroenteritis and dehydration. It has no effect on children with gastroenteritis who do not present with dehydration in developing countries. While ondansetron is effective in controlling vomiting and reducing the rate of hospitalization, there is no evidence that it is effective in reducing the rate of readmission. What is Known: • In high-income countries, ondansetron can reduce the use of intravenous fluids in children with gastroenteritis and dehydration. • No systematic review and meta-analysis of randomized controlled trials were done in a developing country setting. What is New: • In developing countries, ondansetron reduces the use of intravenous fluids in children with gastroenteritis and dehydration. • It has no effect on children with gastroenteritis but without dehydration.

Single-dose of ondansetron for vomiting in children and adolescents with acute gastroenteritis-an updated systematic review and meta-analysis

This review aimed to meta-analyze evidence of efficacy and safety of one single dose of ondansetron for vomiting in children and adolescents with acute gastroenteritis. Database searches of MEDLINE (PubMed), Scopus (Elsevier), Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov up to November 2019 were performed. Only randomized clinical trials versus placebo were considered. Fixed and random effect models were used for the analyses of pooled data. Thirteen randomized clinical trials (2146 patients) were finally included. One single dose of ondansetron showed to produce (1) higher chance of vomiting cessation within 8 h (RR 1.41, 95% CI 1.19-1.68; low-quality evidence); (2) lower chances of oral rehydration therapy failure (RR 0.43, 95% CI 0.34-0.55; high-quality evidence), intravenous hydration needs (RR 0.44, 95% CI 0.34-0.57; high-quality evidence), and hospitalization rates within 8 h (RR 0.49, 95% CI 0.32-0.75; high-quality evidence); and (3) no statistically significant differences in return visits to emergency department (RR 1.14, 95% CI 0.74-1.76; high-quality evidence) compared with placebo. Further studies are necessary to better assess long term efficacy and safety of ondansetron in this context.Conclusions: Mixed evidence was found via few studies about the efficacy and safety of a single dose of ondansetron in the pediatric population.What is known:• Ondansetron use for vomiting in pediatric acute gastroenteritis is increasing worldwide.• Actual convictions come from studies evaluating one and more than one dose of the drug.What is new:• This is the first review to collect data about the effects of one single dose of ondansetron on strong and temporally homogeneous clinical outcomes.• This study supports the use of one dose of ondansetron in pediatric acute gastroenteritis.• Further studies are necessary to assess its long-term efficacy and safety.

Multi-dose Oral Ondansetron for Pediatric Gastroenteritis: study Protocol for the multi-DOSE oral ondansetron for pediatric Acute GastroEnteritis (DOSE-AGE) pragmatic randomized controlled trial

BACKGROUND

There are limited treatment options that clinicians can provide to children presenting to emergency departments with vomiting secondary to acute gastroenteritis. Based on evidence of effectiveness and safety, clinicians now routinely administer ondansetron in the emergency department to promote oral rehydration therapy success. However, clinicians are also increasingly providing multiple doses of ondansetron for home use, creating unquantified cost and health system resource use implications without any evidence to support this expanding practice.

METHODS/DESIGN

DOSE-AGE is a randomized, placebo-controlled, double-blinded, six-center, pragmatic clinical trial being conducted in six Canadian pediatric emergency departments (EDs). In September 2019 the study began recruiting children aged 6 months to 18 years with a minimum of three episodes of vomiting in the 24 h preceding enrollment, <72 h of gastroenteritis symptoms and who were administered a dose of ondansetron during their ED visit. We are recruiting 1030 children (1:1 allocation via an internet-based, third-party, randomization service) to receive a 48-h supply (i.e., six doses) of ondansetron oral solution or placebo, administered on an as-needed basis. All participants, caregivers and outcome assessors will be blinded to group assignment. Outcome data will be collected by surveys administered to caregivers 24, 48 and 168 h following enrollment. The primary outcome is the development of moderate-to-severe gastroenteritis in the 7 days following the ED visit as measured by a validated clinical score (the Modified Vesikari Scale). Secondary outcomes include duration and frequency of vomiting and diarrhea, proportions of children experiencing unscheduled health care visits and intravenous rehydration, caregiver satisfaction with treatment and safety. A preplanned economic evaluation will be conducted alongside the trial.

DISCUSSION

Definitive data are lacking to guide the clinical use of post-ED visit multidose ondansetron in children with acute gastroenteritis. Usage is increasing, despite the absence of supportive evidence. The incumbent additional costs associated with use, and potential side effects such as diarrhea and repeat visits, create an urgent need to evaluate the effect and safety of multiple doses of ondansetron in children focusing on post-emergency department visit and patient-centered outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03851835. Registered on 22 February 2019.

Antiemetics in Children With Acute Gastroenteritis: A Meta-analysis

CONTEXT

Several antiemetics have been used in children with acute gastroenteritis. However, there is still controversy over their use.

OBJECTIVE

To determine the effectiveness and safety of antiemetics for controlling vomiting in children with acute gastroenteritis.

DATA SOURCES

Medline, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, Latin America and the Caribbean Literature on Health Sciences, and gray literature, until December 2018.

STUDY SELECTION

We selected randomized clinical trials comparing metoclopramide, ondansetron, domperidone, dexamethasone, dimenhydrinate, and granisetron.

DATA EXTRACTION

Two reviewers independently screened abstracts and full texts, extracted the data, and assessed the risk of bias. We performed pairwise and network meta-analysis using the random-effects model.

RESULTS

Twenty-four studies were included (3482 children). Ondansetron revealed the largest effect in comparison to placebo for cessation of vomiting (odds ratio = 0.28 [95% credible interval = 0.16 to 0.46]; quality of evidence: high) and for hospitalization (odds ratio = 2.93 [95% credible interval = 1.69 to 6.18]; quality of evidence: moderate). Ondansetron was the only intervention that reduced the need for intravenous rehydration and the number of vomiting episodes. When considering side effects, dimenhydrinate was the only intervention that was worse than placebo.

LIMITATIONS

Most treatment comparisons had low- or very low-quality evidence, because of risk of biases and imprecise estimates.

CONCLUSIONS

Ondansetron is the only intervention that revealed an effect on the cessation of vomiting, on preventing hospitalizations, and in reducing the need for intravenous rehydration. Ondansetron was also considered a safe intervention.

Ondansetron Prescription for Home Use in a Pediatric Emergency Department

OBJECTIVES

Ondansetron has been shown to decrease admission rate and the need for intravenous fluids among pediatric emergency department (ED) patients with acute gastroenteritis, but there is limited evidence regarding its use after ED discharge. This study describes prescribing patterns for ondansetron and assesses the effects of ondansetron home prescription on rate of return.

METHODS

Data were gathered from the electronic health record on 2 separate but overlapping groups of patients seen in a pediatric ED from 2012 to 2014. The Gastroenteritis Group included all patients with a discharge diagnosis of gastroenteritis by International Classification of Diseases, Ninth Revision, code. The All Ondansetron Group included any child prescribed ondansetron at discharge. Patterns of ondansetron use and 3- and 7-day ED return rate were assessed for both groups. Discharge diagnosis was evaluated for the All Ondansetron Group.

RESULTS

A total of 996 patients with acute gastroenteritis were identified during the study period. Of these, 76% received ondansetron in the ED, and 71% were discharged with prescriptions for ondansetron. Seven-day ED return rates were similar between groups (6% with prescription, 5% without, P = 0.66). A total of 2287 patients received home prescriptions for ondansetron. Fifty-four percent of these patients' discharge diagnoses were classed as gastrointestinal complaints, 14% other infectious conditions, 9% respiratory, and 4% injuries. Their return rate was 6%. There was wide variation in the number of doses prescribed.

CONCLUSIONS

Home-use ondansetron is widely prescribed in this urban academic pediatric ED for a variety of indications, without effect on 3- or 7-day ED return. Further prospective studies are necessary to determine the efficacy of this practice.

Bromopride, metoclopramide, or ondansetron for the treatment of vomiting in the pediatric emergency department: a randomized controlled trial

OBJECTIVE

To compare the effectiveness of a single intramuscular dose of bromopride, metoclopramide, or ondansetron for treating vomiting.

METHODS

Randomized controlled trial including children 1-12 years of age presenting with acute vomiting at the pediatric emergency department.

OUTCOMES

Number of children that stopped vomiting at one, six, and 24h following treatment; episodes of diarrhea; acceptance of oral liquids; intravenous rehydration; return to hospital and side effects.

RESULTS

There were 175 children who completed the study. Within the first hour after treatment, all drugs were equally effective, with ondansetron preventing vomiting in 100%, bromopride in 96.6%, and metoclopramide in 94.8% of children (p=0.288). Within six hours, ondansetron was successful in preventing vomiting in 98.3% of children, compared to bromopride and metoclopramide, which were successful in 91.5% and 84.4% of patients, respectively (p=0.023). Within 24h, ondansetron was superior to both other agents, as it remained efficacious in reducing vomiting in 96.6% of children, as opposed to 67.8% and 67.2% with bromopride and metoclopramide, respectively (p=0.001). The ondansetron group showed better acceptance of oral liquids (p=0.05) when compared to the bromopride and metoclopramide. The ondansetron group did not show any side effects in 75.9% of cases, compared to 54.2% and 53.5% in the bromopride and metoclopramide groups, respectively. Somnolence was the most common side effect.

CONCLUSIONS

A single dose of ondansetron is superior to bromopride and metoclopramide in preventing vomiting six hours and 24h following treatment. Oral fluid intake after receiving medication was statistically better with Ondansetronwhile also having less side effects compared to the other two agents.

2017 Infectious Diseases Society of America Clinical Practice Guidelines for the Diagnosis and Management of Infectious Diarrhea

These guidelines are intended for use by healthcare professionals who care for children and adults with suspected or confirmed infectious diarrhea. They are not intended to replace physician judgement regarding specific patients or clinical or public health situations. This document does not provide detailed recommendations on infection prevention and control aspects related to infectious diarrhea.

Ondansetron treatment reduces rotavirus symptoms-A randomized double-blinded placebo-controlled trial

Background

Rotavirus and norovirus cause acute gastroenteritis with severe diarrhoea and vomiting, symptoms that may lead to severe dehydration and death. The objective of this randomized double-blinded placebo-controlled study was to investigate whether ondansetron, a serotonin receptor antagonist could attenuate rotavirus- and norovirus-induced vomiting and diarrhoea, which would facilitate oral rehydration and possibly accelerate recovery and reduce need for hospitalization.

Methods

Children with acute gastroenteritis, aged 6 months to 16 years where enrolled (n = 104) and randomized to one single oral dose (0.15mg/kg) of ondansetron (n = 52) or placebo (n = 52). The number of diarrhoea and vomiting episodes during the 24 hours following treatment was reported as well as the number of days with symptoms. Pathogens in faeces were diagnosed by real-time PCR. Outcome parameters were analyzed for rotavirus- and norovirus-positive children.

Results

One dose of oral ondansetron reduced duration of rotavirus clinical symptoms (p = 0.014), with a median of two days. Furthermore, ondansetron reduced diarrhea episodes, most pronounced in children that had been sick for more than 3 days before treatment (p = 0.028).

Conclusion

Ondansetron may be a beneficial treatment for children with rotavirus gastroenteritis.

Trial registration

European Clinical Trial Database EudraCT 2011-005700-15.

Ondansetron Oral Dissolve Tab vs. Oral Solution in Children Presenting to the Emergency Department with Gastroenteritis

BACKGROUND

Ondansetron is often used in the emergency department (ED) to promote oral rehydration in children with acute gastroenteritis (AGE), yet medication solutions administered orally may be poorly tolerated in this population.

OBJECTIVES

We compared the tolerability of ondansetron oral dissolve tab (ODT) to oral solution (OS) in children presenting to the ED with AGE.

METHODS

Using alternate-day controlled clinical trial design, children aged 3 months to 10 years received either ondansetron ODT or OS. Our primary outcome was early vomiting (within 15 min of drug administration). The secondary outcome was intravenous (i.v.) fluid administration.

RESULTS

There were 462/534 eligible children who met study criteria. Demographics, severity, and duration of illness were similar between groups. Using intention-to-treat analysis, early vomiting occurred in 8/209 ODT vs. 19/253 OS children (3.8% vs. 7.5%; odds ratio [OR] 0.49; 95% confidence interval [CI] 0.18-1.21). Using as-treated analysis, 6/222 (2.7%) children receiving ODT experienced early vomiting, compared with 21/221 (9.5%) of the OS group (OR 0.26; 95% CI 0.09-0.70). The proportion of children discharged without i.v. fluids was not different (intention-to-treat: ODT = 91.4% (191/209), OS = 94.1% (238/253), OR 1.49, 95% CI 0.69-3.28; as-treated: ODT = 92.3% (205/222), OS = 93.2% (206/221), OR 0.88, 95% CI 0.40-1.93).

CONCLUSIONS

Using a conservative intention-to-treat analysis, we found that children presenting to an ED with AGE did not have statistically less early vomiting with ondansetron ODT as compared with OS. However, our as-treated analysis demonstrates that children receiving ondansetron ODT experienced early vomiting approximately one-third as often as those receiving OS. The rate of i.v. fluid administration was no different between groups regardless of the type of analysis used.

Systematic review with meta-analysis: ondansetron for vomiting in children with acute gastroenteritis

BACKGROUND

Vomiting in children with acute gastroenteritis is a common symptom, and it is considered to be the main cause of failure of oral rehydration therapy.

AIM

To systematically update evidence on the effects of ondansetron (5-HT3 serotonin antagonist) for vomiting in children with acute gastroenteritis.

METHODS

The Cochrane Library, MEDLINE and EMBASE databases were searched up to April 2016, with no language restrictions, for randomised controlled trials (RCTs). Reference lists of reviews and included studies were examined.

RESULTS

Ten RCTs involving 1215 participants were included. Treatment with ondansetron compared with placebo increased the chance for vomiting cessation up to 1 h after drug administration, relative risk, RR, 1.49 (95% confidence interval 1.17-1.89), but there was no difference between the groups after 4, 24 and 48 h. Treatment with ondansetron compared with placebo reduced the risk of failure of oral rehydration therapy, RR 0.5 (0.37-0.69), increased the intake of oral rehydration solution in 1 h and 4 h, mean difference: 43 mL/1 h (15.5-70.5), and 91 mL/4 h (35-147), respectively, reduced the risk of hospitalisation, RR 0.53 (0.29-0.97), and reduced the need for intravenous rehydration, RR 0.45 (0.31-0.63); however, it had no effect on the need for return visits to the emergency department, RR 1.14 (0.72-1.8). Adverse effects were similar in both groups.

CONCLUSIONS

Compared with placebo, ondansetron administration for vomiting in children with acute gastroenteritis can improve the efficacy of oral rehydration therapy.

Randomized study of ondansetron versus domperidone in the treatment of children with acute gastroenteritis

Background

Acute gastroenteritis (AGE) is a common condition among children that is frequently accompanied by vomiting. Symptomatic control of vomiting is important as it improves patient’s general condition and reduces the need for intravenous therapy and hospitalization. Antiemetic agents including ondansetron and domperidone are used to provide symptomatic relief but the existing studies do not provide enough evidence of better efficacy for one over another.

Methods

Seventy-six Thai children under the age of 15 with AGE were randomized to receive either ondansetron or domperidone. The primary outcome of the study was the proportion of the patients in each group who had no episode of vomiting 24 hours after the start of treatment.

Results

Primary outcome was met in 62% of patients in ondansetron group and 44% of patients in domperidone group (P = 0.16). Patients in domperidone group received more doses of the drug within 24 hours after the start of the treatment compared to ondansetron group (P = 0.01). No adverse effect was observed in any of the two groups.

Conclusions

Ondansetron can be considered a safe comparable alternative to commonly-used domperidone in Thai children who suffer from symptoms of gastroenteritis. Larger clinical trials are needed to further explore the effectiveness of the two medications.

The effect of antiemetics in childhood gastroenteritis

Introduction

Diarrheal diseases are the second leading cause of childhood morbidity and mortality in developing countries and an important cause of malnutrition. An estimated 0.75 million children below 5 years of age die from diarrhea. Vomiting associated with acute gastroenteritis (AGE) is a distressing symptom and limits the success of oral rehydration in AGE leading to an increased use of intravenous rehydration, prolonged emergency department stay and hospitalization. In this review we estimate the effect of antiemetics in gastroenteritis in children.

Methods

We conducted a systematic review of all the efficacy and effectiveness studies. We used a standardized abstraction and grading format and performed meta-analyses for all outcomes with more than two studies. The estimated effect of antiemetics was determined by applying the standard Child Health Epidemiology Reference Group (CHERG) rules.

Results

We included seven studies in the review. Antiemetics significantly reduced the incidence of vomiting and hospitalization by 54%. Antiemetics also significantly reduced the intravenous fluid requirements by 60%, while it had a non-significant effect on the ORT tolerance and revisit rates.

Conclusion

Antiemetics are effective for the management of gastroenteritis in children and have the potential to decrease morbidity and mortality burden due to diarrhea, when introduced and scaled up.

Management of a child with vomiting

Vomiting is a protective reflex that results in forceful ejection of stomach contents up to and out of the mouth. It is a common complaint and may be the presenting symptom of several life-threatening conditions. It can be caused by a variety of organic and nonorganic disorders; gastrointestinal (GI) or outside of GI. Acute gastritis and gastroenteritis (AGE) are the leading cause of acute vomiting in children. Important life threatening causes in infancy include congenital intestinal obstruction, atresia, malrotation with volvulus, necrotizing enterocolitis, pyloric stenosis, intussusception, shaken baby syndrome, hydrocephalus, inborn errors of metabolism, congenital adrenal hypoplasia, obstructive uropathy, sepsis, meningitis and encephalitis, and severe gastroenteritis, and in older children appendicitis, intracranial mass lesion, diabetic ketoacidosis, Reye's syndrome, toxic ingestions, uremia, and meningitis. Initial evaluation is directed at assessment of airway, breathing and circulation, assessment of hydration status and red flag signs (bilious or bloody vomiting, altered sensorium, toxic/septic/apprehensive look, inconsolable cry or excessive irritability, severe dehydration, concern for symptomatic hypoglycemia, severe wasting, Bent-over posture). The history and physical examination guides the approach in an individual patient. The diverse nature of causes of vomiting makes a "routine" laboratory or radiologic screen impossible. Investigations (Serum electrolytes and blood gases,renal and liver functions and radiological studies) are required in any child with dehydration or red flag signs, to diagnose surgical causes. Management priorities include treatment of dehydration, stoppage of oral fluids/feeds and decompression of the stomach with nasogastric tube in patients with bilious vomiting. Antiemetic ondansetron(0.2 mg/kg oral; parenteral 0.15 mg/kg; maximum 4 mg) is indicated in children unable to take orally due to persistent vomiting, post-operative vomiting, chemotherapy induced vomiting, cyclic vomiting syndrome and acute mountain sickness.

Antiemetics for reducing vomiting related to acute gastroenteritis in children and adolescents

BACKGROUND

Vomiting is a common manifestation of acute gastroenteritis in children and adolescents. When untreated it can be a hindrance to oral rehydration therapy, which is the cornerstone in the management of acute gastroenteritis. Evidence is needed concerning the safety and efficacy of antiemetic use for vomiting in acute gastroenteritis in children.

OBJECTIVES

To assess the safety and effectiveness of antiemetics on gastroenteritis induced vomiting in children and adolescents.

SEARCH STRATEGY

We searched the Cochrane Upper Gastrointestinal and Pancreatic Diseases Group Trials Register comprising references identified from comprehensive electronic database searches and hand searches of relevant journals and abstract books of conferences.The search was re-run and is up to date as on 20 July 2010.

SELECTION CRITERIA

Randomized controlled trials comparing antiemetics with placebo or no treatment, in children and adolescents under the age of 18, for vomiting due to gastroenteritis.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

We included seven trials involving 1,020 participants. Mean time to cessation of vomiting in one study was 0.34 days less with dimenhydrinate suppository compared to placebo (P value = 0.036). Pooled data from three studies comparing oral ondansetron with placebo showed: a reduction in the immediate hospital admission rate (RR 0.40, NNT 17, 95% CI 10 to 100) but no difference between the hospitalization rates at 72 hours after discharge from the Emergency Department (ED); a reduction in IV rehydration rates both during the ED stay (RR 0.41, NNT 5, 95% CI 4 to 8), and in follow-up to 72 hours after discharge from the ED stay (worst-best scenario for ondansetron RR 0.57, NNT 6, 95% CI 4 to 13) and an increase in the proportion of patients with cessation of vomiting (RR 1.34, NNT 5, 95% CI 3 to 7)). No significant difference was noted in the revisit rates or adverse events, although diarrhea was reported as a side effect in four of the five ondansetron studies. In one study the proportion of patients with cessation of vomiting in 24 hours was (58%) with IV ondansetron, (17%) placebo and (33%) in the metoclopramide group (P value = 0.039).

AUTHORS' CONCLUSIONS

Oral ondansetron increased the proportion of patients who had ceased vomiting and reduced the number needing intravenous rehydration and immediate hospital admission. Intravenous ondansetron and metoclopramide reduced the number of episodes of vomiting and hospital admission, and dimenhydrinate as a suppository reduced the duration of vomiting.

Rotavirus stimulates release of serotonin (5-HT) from human enterochromaffin cells and activates brain structures involved in nausea and vomiting

Rotavirus (RV) is the major cause of severe gastroenteritis in young children. A virus-encoded enterotoxin, NSP4 is proposed to play a major role in causing RV diarrhoea but how RV can induce emesis, a hallmark of the illness, remains unresolved. In this study we have addressed the hypothesis that RV-induced secretion of serotonin (5-hydroxytryptamine, 5-HT) by enterochromaffin (EC) cells plays a key role in the emetic reflex during RV infection resulting in activation of vagal afferent nerves connected to nucleus of the solitary tract (NTS) and area postrema in the brain stem, structures associated with nausea and vomiting. Our experiments revealed that RV can infect and replicate in human EC tumor cells ex vivo and in vitro and are localized to both EC cells and infected enterocytes in the close vicinity of EC cells in the jejunum of infected mice. Purified NSP4, but not purified virus particles, evoked release of 5-HT within 60 minutes and increased the intracellular Ca²⁺ concentration in a human midgut carcinoid EC cell line (GOT1) and ex vivo in human primary carcinoid EC cells concomitant with the release of 5-HT. Furthermore, NSP4 stimulated a modest production of inositol 1,4,5-triphosphate (IP₃), but not of cAMP. RV infection in mice induced Fos expression in the NTS, as seen in animals which vomit after administration of chemotherapeutic drugs. The demonstration that RV can stimulate EC cells leads us to propose that RV disease includes participation of 5-HT, EC cells, the enteric nervous system and activation of vagal afferent nerves to brain structures associated with nausea and vomiting. This hypothesis is supported by treating vomiting in children with acute gastroenteritis with 5-HT₃ receptor antagonists.

Rotavirus (RV) can cause severe dehydration and is a leading cause of childhood deaths worldwide. While most deaths occur due to excessive loss of fluids and electrolytes through vomiting and diarrhoea, the pathophysiological mechanisms that underlie this life-threatening disease remain to be clarified. Our previous studies revealed that drugs that inhibit the function of the enteric nervous system can reduce symptoms of RV disease in mice. In this study we have addressed the hypothesis that RV infection triggers the release of serotonin (5-hydroxytryptamine, 5-HT) from enterochromaffin (EC) cells in the intestine leading to activation of vagal afferent nerves connected to brain stem structures associated with vomiting. RV activated Fos expression in the nucleus of the solitary tract of CNS, the main target for incoming fibers from the vagal nerve. Both secreted and recombinant forms of the viral enterotoxin (NSP4), increased intracellular Ca²⁺ concentration and released 5-HT from EC cells. 5-HT induced diarrhoea in mice within 60 min, thereby supporting the role of 5-HT in RV disease. Our study provides novel insight into the complex interaction between RV, EC cells, 5-HT and nerves.

Acute gastroenteritis: from guidelines to real life

Acute gastroenteritis is a very common disease. It causes significant mortality in developing countries and significant economic burden to developed countries. Viruses are responsible for approximately 70% of episodes of acute gastroenteritis in children and rotavirus is one of the best studied of these viruses. Oral rehydration therapy is as effective as intravenous therapy in treating mild to moderate dehydration in acute gastroenteritis and is strongly recommended as the first line therapy. However, the oral rehydration solution is described as an underused simple solution. Vomiting is one of the main reasons to explain the underuse of oral rehydration therapy. Antiemetics are not routinely recommended in treating acute gastroenteritis, though they are still commonly prescribed. Ondansetron is one of the best studied antiemetics and its role in enhancing the compliance of oral rehydration therapy and decreasing the rate of hospitalization has been proved recently. The guidelines regarding the recommendation on antiemetics have been changed according to the evidence of these recent studies.