The triangular test to assess the efficacy of metoclopramide in gastroesophageal reflux

Pediatric Gastroesophageal Reflux Clinical Practice Guidelines: Joint Recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition

This document serves as an update of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) 2009 clinical guidelines for the diagnosis and management of gastroesophageal reflux disease (GERD) in infants and children and is intended to be applied in daily practice and as a basis for clinical trials. Eight clinical questions addressing diagnostic, therapeutic and prognostic topics were formulated. A systematic literature search was performed from October 1, 2008 (if the question was addressed by 2009 guidelines) or from inception to June 1, 2015 using Embase, MEDLINE, the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Clinical Trials. The approach of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) was applied to define and prioritize outcomes. For therapeutic questions, the quality of evidence was also assessed using GRADE. Grading the quality of evidence for other questions was performed according to the Quality Assessment of Studies of Diagnostic Accuracy (QUADAS) and Quality in Prognostic Studies (QUIPS) tools. During a 3-day consensus meeting, all recommendations were discussed and finalized. In cases where no randomized controlled trials (RCT; therapeutic questions) or diagnostic accuracy studies were available to support the recommendations, expert opinion was used. The group members voted on each recommendation, using the nominal voting technique. With this approach, recommendations regarding evaluation and management of infants and children with GERD to standardize and improve quality of care were formulated. Additionally, 2 algorithms were developed, 1 for infants <12 months of age and the other for older infants and children.

The Safety of Metoclopramide in Children: A Systematic Review and Meta-Analysis

INTRODUCTION

Metoclopramide is recommended for adults with breakthrough or refractory chemotherapy-induced nausea and vomiting (CINV) and for CINV prophylaxis in children. The drug regulatory agencies of Canada and the EU have revised the labelling of metoclopramide to contraindicate its use in children aged <1 year and to caution against its use in children aged <5 years and its duration of use beyond 5 days.

OBJECTIVE

This review describes the safety of metoclopramide in children when given for any indication.

METHODS

We conducted electronic searches in MEDLINE and Embase as of 9 March 2015. All studies in English reporting adverse effects associated with the use of metoclopramide in children (aged ≤18 years) were included. Adverse effects that had a cumulative incidence of at least 1 % and were reported in prospective studies were synthesized.

RESULTS

A total of 108 (57 prospective) studies involving 2699 patients (2745 metoclopramide courses) were included. The most common adverse effects reported in prospective studies of metoclopramide in children were extrapyramidal symptoms (EPS; 9 %, 95 % confidence interval [CI] 5-17), diarrhea (6 %, 95 % CI 4-9), and sedation (multiple-dose studies: 6 %, 95 % CI 3-12). Dysrhythmia, respiratory distress/arrest, neuroleptic malignant syndrome, and tardive dyskinesia were rarely associated with metoclopramide use.

LIMITATIONS

The definitions of adverse effects reported in the included studies were heterogeneous, and the risk of bias in most studies was moderate.

CONCLUSIONS

The most commonly reported adverse effects associated with the use of metoclopramide in children-EPS, diarrhea, and sedation-were reversible and of no long-term significance. Adverse effects that were life threatening or slow to resolve were rarely associated with its use in children.

Variations in Definitions and Outcome Measures in Gastroesophageal Reflux Disease: A Systematic Review

CONTEXT

Gastroesophageal reflux (GER) is defined as GER disease (GERD) when it leads to troublesome symptoms and/or complications. We hypothesized that definitions and outcome measures in randomized controlled trials (RCTs) on pediatric GERD would be heterogeneous.

OBJECTIVES

Systematically assess definitions and outcome measures in RCTs in this population.

DATA SOURCES

Data were obtained through Cochrane, Embase, Medline, and Pubmed databases.

STUDY SELECTION

We selected English-written therapeutic RCTs concerning GERD in children 0 to 18 years old.

DATA EXTRACTION

Data were tabulated and presented descriptively. Each individual parameter or set of parameters with unique criteria for interpretation was considered a single definition for GER(D). Quality was assessed by using the Delphi score.

RESULTS

A total of 2410 unique articles were found; 46 articles were included. Twenty-six (57%) studies defined GER by using 25 different definitions and investigated 25 different interventions. GERD was defined in 21 (46%) studies, all using a unique definition and investigating a total of 23 interventions. Respectively 87 and 61 different primary outcome measures were reported by the studies in GER and GERD. Eight (17%) studies did not report on side effects. Of the remaining 38 (83%) studies that did report on side effects, 18 (47%) included this as predefined outcome measure of which 4 (22%) as a primary outcome measure. Sixteen studies (35%) were of good methodological quality.

LIMITATIONS

Only English-written studies were included.

CONCLUSIONS

Inconsistency and heterogeneity exist in definitions and outcome measures used in RCTs on pediatric GER and GERD; therefore, we recommend the development of a core outcome set.

Use and Safety of Erythromycin and Metoclopramide in Hospitalized Infants

OBJECTIVE

Prokinetic medications are used in premature infants to promote motility and decrease time to full enteral feeding. Erythromycin and metoclopramide are the most commonly used prokinetic medications in the neonatal intensive care unit (NICU), but their safety profile is not well defined.

METHODS

We conducted a large retrospective cohort study using data from 348 NICUs managed by the Pediatrix Medical Group. All of the infants exposed to ≥1 dose of erythromycin, metoclopramide, or both, from a cohort of 8,87,910 infants discharged between 1997 and 2012 were included. We collected laboratory and clinical information while infants were exposed to erythromycin or metoclopramide and described the frequency of laboratory abnormalities and clinical adverse events (AEs).

RESULTS

Metoclopramide use increased from 1997 to 2005 and decreased from 2005 to 2012, whereas erythromycin use remained stable. Erythromycin use was most often associated with a diagnosis of feeding problem (40%), whereas metoclopramide was most often associated with a diagnosis of gastroesophageal reflux (59%). The most common laboratory AE during exposure to erythromycin or metoclopramide was hyperkalemia (8.6/1000 infant days on erythromycin and 11.0/1000 infant days on metoclopramide). Incidence of pyloric stenosis was greater with erythromycin than with metoclopramide (10/1095, 0.9% vs 76/19,001, 0.4%; P = 0.01), but odds were not significantly increased after adjusting for covariates (odds ratio 0.52, 95% confidence interval [CI] 0.26-1.02, P = 0.06). More infants experienced an AE while treated with metoclopramide than with erythromycin (odds ratio 1.21, 95% CI 1.03-1.43).

CONCLUSIONS

Metoclopramide was associated with increased risk of AEs compared with erythromycin. Studies are needed to confirm safety and effectiveness of both the drugs in infants.

Pharmacological treatment of children with gastro-oesophageal reflux

BACKGROUND

Gastro-oesophageal reflux (GOR) is a common disorder, characterised by regurgitation of gastric contents into the oesophagus. GOR is a very common presentation in infancy in both primary and secondary care settings. GOR can affect approximately 50% of infants younger than three months old (Nelson 1997). The natural history of GOR in infancy is generally that of a functional, self-limiting condition that improves with age; < 5% of children with vomiting or regurgitation continue to have symptoms after infancy (Martin 2002). Older children and children with co-existing medical conditions can have a more protracted course. The definition of gastro-oesophageal reflux disease (GORD) and its precise distinction from GOR are debated, but consensus guidelines from the North American Society of Gastroenterology, Hepatology and Nutrition (NASPGHAN-ESPGHAN guidelines 2009) define GORD as 'troublesome symptoms or complications of GOR.'

OBJECTIVES

This Cochrane review aims to provide a robust analysis of currently available pharmacological interventions used to treat children with GOR by assessing all outcomes indicating benefit or harm.

SEARCH METHODS

We sought to identify relevant published trials by searching the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 5), MEDLINE and EMBASE (1966 to 2014), the Centralised Information Service for Complementary Medicine (CISCOM), the Institute for Scientific Information (ISI) Science Citation Index (on BIDS-UK General Science Index) and the ISI Web of Science. We also searched for ongoing trials in the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com).Reference lists from trials selected by electronic searching were handsearched for relevant paediatric studies on medical treatment of children with gastro-oesophageal reflux, as were published abstracts from conference proceedings (published in Gut and Gastroenterology) and reviews published over the past five years.No language restrictions were applied.

SELECTION CRITERIA

Abstracts were reviewed by two review authors, and relevant RCTs on study participants (birth to 16 years) with GOR receiving a pharmacological treatment were selected. Subgroup analysis was considered for children up to 12 months of age, and for children 12 months to 16 years of age, and for those with neurological impairment.

DATA COLLECTION AND ANALYSIS

Trials were critically appraised and data collected by two review authors. Risk of bias was assessed. Meta-analysis data were independently extracted by two review authors, and suitable outcome data were analysed using RevMan.

MAIN RESULTS

A total of 24 studies (1201 participants) contributed data to the review. The review authors had several concerns regarding the studies. Pharmaceutical company support for manuscript preparation was a common feature; also, because common endpoints were lacking, study populations were heterogenous and variations in study design were noted, individual drug meta-analysis was not possible.Moderate-quality evidence from individual studies suggests that proton pump inhibitors (PPIs) can reduce GOR symptoms in children with confirmed erosive oesophagitis. It was not possible to demonstrate statistical superiority of one PPI agent over another.Some evidence indicates that H₂antagonists are effective in treating children with GORD. Methodological differences precluded performance of meta-analysis on individual agents or on these agents as a class, in comparison with placebo or head-to-head versus PPIs, and additional studies are required.RCT evidence is insufficient to permit assessment of the efficacy of prokinetics. Given the diversity of study designs and the heterogeneity of outcomes, it was not possible to perform a meta-analysis of the efficacy of domperidone.In younger children, the largest RCT of 80 children (one to 18 months of age) with GOR showed no evidence of improvement in symptoms and 24-hour pH probe, but improvement in symptoms and reflux index was noted in a subgroup treated with domperidone and co-magaldrox(Maalox(®) ). In another RCT of 17 children, after eight weeks of therapy. 33% of participants treated with domperidone noted an improvement in symptoms (P value was not significant). In neonates, the evidence is even weaker; one RCT of 26 neonates treated with domperidone over 24 hours showed that although reflux frequency was significantly increased, reflux duration was significantly improved.Diversity of RCT evidence was found regarding efficacy of compound alginate preparations(Gaviscon Infant(®) ) in infants, although as a result of these studies, Gaviscon Infant(®) was changed to become aluminium-free and has been assessed in its current form in only two studies since 1999. Given the diversity of study designs and the heterogeneity of outcomes, as well as the evolution in formulation, it was not possible to perform a meta-analysis on the efficacy of Gaviscon Infant(®) . Moderate evidence indicates that Gaviscon Infant(®) improves symptoms in infants, including those with functional reflux; the largest study of the current formulation showed improvement in symptom control but was limited by length of follow-up.No serious side effects were reported.No RCTs on pharmacological treatments for children with neurodisability were identified.

AUTHORS' CONCLUSIONS

Moderate evidence was found to support the use of PPIs, along with some evidence to support the use of H₂ antagonists in older children with GORD, based on improvement in symptom scores, pH indices and endoscopic/histological appearances. However, lack of independent placebo-controlled and head-to-head trials makes conclusions as to relative efficacy difficult to determine. Further RCTs are recommended. No robust RCT evidence is available to support the use of domperidone, and further studies on prokinetics are recommended, including assessments of erythromycin.Pharmacological treatment of infants with reflux symptoms is problematic, as many infants have GOR, and little correlation has been noted between reported symptoms and endoscopic and pH findings. Better evidence has been found to support the use of PPIs in infants with GORD, but heterogeneity in outcomes and in study design impairs interpretation of placebo-controlled data regarding efficacy. Some evidence is available to support the use of Gaviscon Infant(®) , but further studies with longer follow-up times are recommended. Studies of omeprazole and lansoprazole in infants with functional GOR have demonstrated variable benefit, probably because of differences in inclusion criteria.No robust RCT evidence has been found regarding treatment of preterm babies with GOR/GORD or children with neurodisabilities. Initiation of RCTs with common endpoints is recommended, given the frequency of treatment and the use of multiple antireflux agents in these children.

Small sample approach, and statistical and epidemiological aspects

In this chapter, the design of pharmacokinetic studies and phase III trials in children is discussed. Classical approaches and relatively novel approaches, which may be more useful in the context of drug research in children, are discussed. The burden of repeated blood sampling in pediatric pharmacokinetic studies may be overcome by the population pharmacokinetics approach using nonlinear mixed effect modeling as the statistical solution to sparse data. Indications and contraindications for phase III trials are discussed: only when there is true "equipoise" in the medical scientific community, it is ethical to conduct a randomized clinical trial. The many reasons why a pediatric trial may fail are illustrated with examples. Inadequate sample sizes lead to inconclusive results. Twelve classical strategies to minimize sample sizes are discussed followed by an introduction to group sequential design, boundaries design, and adaptive design. The evidence that these designs reduce sample sized between 35 and 70% is reviewed. The advantages and disadvantages of the different approaches are highlighted to give the reader a broad idea of the design types that can be considered. Finally, working with DMCs during the conduct of trials is introduced. The evidence regarding DMC activities, interim analysis results, and early termination of pediatric trials is presented. So far reporting is incomplete and heterogeneous, and users of trial reports may be misled by the results. A proposal for a checklist for the reporting of DMC issues, interim analyses, and early stopping is presented.

WITHDRAWN: Metoclopramide, thickened feedings, and positioning for gastro-oesophageal reflux in children under two years

BACKGROUND

Gastro-esophageal reflux (GER) is the refluxing of gastric contents into the esophagus. Fifty per cent of all infants 0 to 3 months regurgitate at least once a day. This drops to 5% once infants are 10 to 12 months old. Three per cent of parents of 10 to 12 month old infants view this as a problem.

OBJECTIVES

To investigate the effectiveness of thickened feeds, positioning, and metoclopramide as compared to placebo in improving the outcome of GER in developmentally normal infants aged one month to two years.

SEARCH STRATEGY

Trials were identified by searching Cochrane Central Register of Controlled Trials (The Cochrane Library 2003), MEDLINE (January 1966 to 23 January 2003), EMBASE (January 1985 to 27 January 2003), and reference lists of articles. Searches in all databases were updated in April 2009.

SELECTION CRITERIA

Randomised studies (parallel or cross over) which evaluated thickened feeds, positional alternations or metoclopramide for the treatment of GER in children between the age of one month and two years who were developmentally normal.

DATA COLLECTION AND ANALYSIS

All three reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

MAIN RESULTS

Twenty trials involving 771 children met the inclusion criteria: eight dealt with thickened feeds, five with positioning, and seven with metoclopramide. Few comparisons could be made, and so summary measures were often made with two or three studies. Thickened feeds reduce the regurgitation severity score (standardized mean difference (SMD) -0.94;95% confidence interval -1.35 to -0.52), as well as the frequency of emesis (SMD -0.91; confidence interval -1.22 to -0.61). The reflux index was not reduced (weighted mean difference (WMD) 0.48%; 95% confidence interval -3.27 to 4.23). All five positioning studies utilized esophageal pH monitoring as their outcome measure. Elevating the head of the crib for treating reflux in the supine position is not justifiable. The seven metoclopramide studies used a variety of outcomes. Compared to placebo, metoclopramide appears to reduce daily symptoms ( SMD -0.73; 95% confidence interval -1.16 to -0.30), and reduce the reflux index (WMD -2.80%; 95% confidence interval -5.58 to -0.01). It does increase side effects.

AUTHORS' CONCLUSIONS

Thickened feeds are helpful in reducing the symptoms of GER. Elevating the head of the crib in the supine position does not have any effect. Metoclopramide may have some benefit in comparison to placebo in the symptomatic treatment for GER, but that must be weighed against possible side effects. .

Revisão sistemática e metanálise do uso de procinéticos no refluxo gastroesofágico e na doença do refluxo gastroesofágico em Pediatria

OBJETIVO: Avaliar, por meio de revisão sistemática e metanálise, estudos randomizados que comparam os procinéticos domperidona, bromoprida, metoclopramida e betanecol ao placebo no tratamento do refluxo gastroesofágico (RGE) e da doença do refluxo gastroesofágico (DRGE) em crianças. MÉTODOS: BUsca bibliográfica de ensaios clínicos randomizados (Medline, EMBASE, Biological Abstracts, ISI/Web of Science, CINAHL, Lilacs e Cochrane). O desfecho primário foi eficácia na modificação dos sintomas de refluxo, conforme definição de autores das fontes primárias. Outras variáveis de interesse foram: complicações relacionadas ao RGE, alterações nos exames laboratoriais de controle, qualidade de vida, eventos adversos e abandono do tratamento. RESULTADOS: Foram incluídos quatro estudos com domperidona, dois com metoclopramida, um com betanecol. Nenhum estudo com bromoprida foi localizado. O risco de não resposta ao tratamento foi significativamente menor para os procinéticos quando comparados ao placebo (RR 0,35; IC95% 0,14-0,88). A vantagem terapêutica individual em relação ao placebo se manteve para a domperidona (n=126; RR 0,27; IC95% 0,14-0,52; NNT 3; I2 0%) e betanecol (n=44, RR 0,19, IC95% 0,05-0,55, NNT 2), mas não para metoclopramida (n=71; RR 0,63; IC95% 0,07-5,71, I2 92,2%). CONCLUSÕES: A evidência para o uso de procinéticos no RGE e na DRGE em crianças é limitada, pois os poucos estudos são ensaios preliminares de resposta em curto prazo e com limitações metodológicas.

Efficient ways exist to obtain the optimal sample size in clinical trials in rare diseases

OBJECTIVE

Recruitment of pediatric patients in randomized clinical trials is hampered by the rarity of many conditions and by ethical constraints. The objective of this paper is to give an overview of design options to obtain a statistically valid result while including a minimum number of subjects.

STUDY DESIGN AND SETTING

Overview and discussion of several approaches to conduct valid randomized clinical trials in rare diseases and vulnerable populations.

RESULTS

Sequential designs have been developed as efficient ways to evaluate accumulating information from a clinical trial, thereby reducing the average size of trials. Different sequential procedures exist, including group sequential designs, boundaries designs, and adaptive designs. The sample size attained at the end of the trial is unknown at the start. The sample size for a given set of alpha, beta, and effect size may turn out to be larger than with a classical fixed sample size approach. Simulations have shown that on average, sample sizes are smaller.

CONCLUSION

There are several possibilities to optimize the number of subjects in a clinical trial. The rarity of many disorders in children and the ethical requirements in this patient population should not obstruct the performance of well-designed research to support clinical decision making.

Metoclopramide for the treatment of gastroesophageal reflux disease in infants: a systematic review

OBJECTIVES

Metoclopramide is a commonly used drug to treat gastroesophageal reflux disease in infants. Given its widespread use and growing concern about toxicity in this population, we conducted a systematic review of metoclopramide for the treatment of gastroesophageal reflux disease in infants.

METHODS

We performed a systematic search of PubMed and bibliographies of relevant review articles. We included cohort, case-control, and intervention studies of the efficacy, effectiveness, or toxicity of metoclopramide therapy for gastroesophageal reflux disease in infants. We excluded case reports, case series, review articles, and abstracts.

RESULTS

Twelve articles met our inclusion criteria. Of these, 11 were prospective trials, and 5 were randomized, blinded clinical trials. Study size ranged from 6 to 77 patients. Eight studies showed patient improvement with metoclopramide in at least 1 measured outcome; 1 study showed worsening symptoms with metoclopramide. Of the 5 randomized, blinded trials, 2 showed no effect of metoclopramide on any outcome, and 2 showed a significant placebo effect. Four studies commented on adverse effects of therapy, with irritability being the most frequently reported potential adverse effect of therapy. Other reported adverse effects included dystonic reactions, drowsiness, oculogyric crisis, emesis, and apnea. Among studies, there was marked heterogeneity in the patient populations, dosing, and outcomes studied. Therefore, a meta-analysis was not performed. We both agreed on a US Preventive Service Task Force rating of "poor" for the level of evidence, leading to an "inconclusive" recommendation for the safety and efficacy of metoclopramide in infants.

CONCLUSIONS

The current literature is insufficient to either support or oppose the use of metoclopramide for gastroesophageal reflux disease in infants. In the future, large blinded randomized clinical trials are needed to determine the efficacy and toxicity of metoclopramide in this population.

A 25-year review of sequential methodology in clinical studies

This paper explores the theoretical developments and subsequent uptake of sequential methodology in clinical studies in the 25 years since Statistics in Medicine was launched. The review examines the contributions which have been made to all four phases into which clinical trials are traditionally classified and highlights major statistical advancements, together with assessing application of the techniques. The vast majority of work has been in the setting of phase III clinical trials and so emphasis will be placed here. Finally, comments are given indicating how the subject area may develop in the future.

Impact of a mis-specification of the response rate under standard treatment in sequential clinical trials

Phase III trials are aimed at assessing whether new treatments have superior efficacy than standards. Sequential methods, such as the single triangular test (STT) and the double triangular test (DTT), allow for early stopping of such trials. They use stopping boundaries which depend, for a binary endpoint, on pi(0) and pi(1) (response rates under standard and new treatment, respectively) and alpha and beta (type I and II errors, respectively). Thus, a wrong estimation of pi(0) at planning phase might have an influence on their statistical properties. We assessed the extent of this influence by simulations regarding alpha, 1--beta, and average sample number (ASN) and compared the two methods with the one-sided and two-sided single-stage designs (SSD). There was no influence on alpha for any test and the power achieved by the one-sided or two-sided SSD was moderately affected by a wrong estimation of pi(0). However, important drifts (whose magnitude depended on chosen design) were observed for sequential methods concerning power and ASN in case of moderate under- or overestimation of pi(0) (+/-20% compared with its 'true' value). For example, when 'true' values of pi(0) and pi(1) are 0.30 and 0.40, respectively, using design values of 0.10 and 0.20, the power is 0.57 and 0.50 for the STT and DTT, respectively, instead of 0.95. When 'true' values of pi(0) and pi(1) are 0.10 and 0.20, respectively, using design values of 0.30 and 0.40, the ASN under H(0) is 1,309 and 2,019 for the STT and DTT, respectively, instead of 392 and 601, respectively, using the right design. Using sequential methods in comparative clinical trials with binary responses requires a precise knowledge of the response rate under standard treatment to avoid losses in power or inappropriate increases in sample size.

Prokinetic drug therapy in children: a review of current options

OBJECTIVE

To review the pharmacology, safety, and efficacy of the prokinetic agents metoclopramide and erythromycin in children.

DATA SOURCES

English-language literature was accessed using MEDLINE (1970-June 2004) with metoclopramide, erythromycin, macrolides, gastroesophageal reflux, and gastrointestinal motility as the search terms.

STUDY SELECTION AND DATA EXTRACTION

Abstracts and original research articles were included. Preference was given to published controlled trials. Articles providing descriptions of pharmacology, safety, and effectiveness of metoclopramide and erythromycin for the treatment of gastroesophageal reflux (GER) were also used in this review.

DATA SYNTHESIS

Some authors advocate using a prokinetic agent along with acid suppression for treatment of GER in children. The 2 prokinetic agents most commonly used are erythromycin and metoclopramide. Erythromycin has numerous observational reports and controlled trials demonstrating its efficacy in improving feeding tolerance in children. Adverse drug reactions associated with its use were uncommon in prospective controlled trials. Few data support the use of metoclopramide for management of GER, and the potential adverse effects associated with its use need to be considered before prescribing.

CONCLUSIONS

The literature supports the use of erythromycin as a prokinetic agent. Many children with GER are adequately controlled with acid suppression alone; however, if use of a prokinetic agent is warranted, erythromycin in combination with acid suppression should be considered. Given the lack of prospective controlled studies demonstrating metoclopramide's efficacy and safety in the treatment of GER in children, metoclopramide should not be considered a treatment option.

Metoclopramide, thickened feedings, and positioning for gastro-oesophageal reflux in children under two years

BACKGROUND

Gastro-esophageal reflux (GER) is the refluxing of gastric contents into the esophagus. Fifty per cent of all infants 0 to 3 months regurgitate at least once a day. This drops to 5% once infants are 10 to 12 months old. Three per cent of parents of 10 to 12 month old infants view this as a problem.

OBJECTIVES

To investigate the effectiveness of thickened feeds, positioning, and metoclopramide as compared to placebo in improving the outcome of GER in developmentally normal infants aged one month to two years.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2003), MEDLINE (January 1966 to 23 January 2003), EMBASE (January 1985 to 27 January 2003), and reference lists of articles.

SELECTION CRITERIA

Randomised studies (parallel or cross over) which evaluated thickened feeds, positional alternations or metoclopramide for the treatment of GER in children between the age of one month and two years who were developmentally normal.

DATA COLLECTION AND ANALYSIS

All three reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

MAIN RESULTS

Twenty trials involving 771 children met the inclusion criteria: eight dealt with thickened feeds, five with positioning, and seven with metoclopramide. Few comparisons could be made, and so summary measures were often made with two or three studies. Thickened feeds reduce the regurgitation severity score (standardized mean difference (SMD) -0.94;95% confidence interval -1.35 to -0.52), as well as the frequency of emesis (SMD -0.91; confidence interval -1.22 to -0.61). The reflux index was not reduced (weighted mean difference (WMD) 0.48%; 95% confidence interval-3.27 to 4.23). All five positioning studies utilized esophageal pH monitoring as their outcome measure. Elevating the head of the crib for treating reflux in the supine position is not justifiable. The seven metoclopramide studies used a variety of outcomes. Compared to placebo, metoclopramide appears to reduce daily symptoms ( SMD -0.73; 95% confidence interval -1.16 to -0.30), and reduce the reflux index (WMD -2.80%; 95% confidence interval -5.58 to -0.01). It does increase side effects.

REVIEWERS' CONCLUSIONS

Thickened feeds are helpful in reducing the symptoms of GER. Elevating the head of the crib in the supine position does not have any effect. Metoclopramide may have some benefit in comparison to placebo in the symptomatic treatment for GER, but that must be weighed against possible side effects. .

Discerning differences: gastroesophageal reflux and gastroesophageal reflux disease in infants

Gastroesophageal reflux (GER) is a frequently encountered problem in infancy; it commonly resolves spontaneously by 12 months of age. Caregivers are challenged to discriminate between physiologic GER and the much less common and more serious condition of pathologic gastroesophageal reflux disease (GERD). Pathologic GERD may require more extensive clinical evaluation and necessitate treatment. GERD may be primary or secondary; secondary GERD is associated with a number of genetic syndromes, chromosomal abnormalities, birth defects, or a host of neurologic conditions frequently seen in the newborn intensive care unit. This article reviews the unique anatomic, physiologic, developmental, and nutritional vulnerabilities of infants that make them susceptible to GER and GERD. The North American Society of Pediatric Gastroenterology and Nutrition have recently developed a comprehensive evidence-based clinical practice guideline that structures the diagnostic approach and treatment option in infants with suspected and confirmed GERD. These guidelines provide clear definitions of GER and GERD to aid the clinician in distinguishing between the 2 conditions. They emphasize the use of history and physical examination and discuss the indications for the use of other diagnostic procedures, such as upper gastrointestinal studies, nuclear medicine scintiscan, esophagogastroduodenoscopy with biopsy, and esophageal pH probe monitoring. Management of GERD begins with a nonpharmacologic approach; the emphasis is on positioning, a trial of a hypoallergenic formula, and thickening of feedings. When these measures fail to control symptoms, a trial of either histamine(2) antagonists or a proton pump inhibitor may be indicated. Finally, surgical treatment may be needed if all other management measures fail. New sleep recommendations for infants with GERD are now consistent with the American Academy of Pediatrics' standard recommendations. Prone sleep positioning is only considered in unusual cases, where the risk of death and complications from GERD outweighs the potential increased risk of sudden infant death syndrome (SIDS). The nursing care of infants with GER and GERD, as well as relevant issues for parent education and support, are reviewed and are essential elements in managing this common condition.

Sequential methods and group sequential designs for comparative clinical trials

Comparative clinical trials are performed to assess whether a new treatment has superior efficacy than a placebo or a standard treatment (one-sided formulation) or whether two active treatments have different efficacies (two-sided formulation) in a given population. The reference approach is the single-stage design and the statistical test is performed after inclusion and evaluation of a predetermined sample size. In practice, the single-stage design is sometimes difficult to implement because of ethical concerns and/or economic reasons. Thus, specific early termination procedures have been developed to allow repeated statistical analyses to be performed on accumulating data and stop the trial as soon as the information is sufficient to conclude. Two main different approaches can be used. The first one is derived from strictly sequential methods and includes the sequential probability ratio test and the triangular test. The second one is derived from group sequential designs and includes Peto, Pocock, and O'Brien and Fleming methods, alpha and beta spending functions, and one-parameter boundaries. We review all these methods and describe the bases on which they rely as well as their statistical properties. We also compare these methods and comment on their advantages and drawbacks. We present software packages which are available for the planning, monitoring and analysis of comparative clinical trials with these methods and discuss the practical problems encountered when using them. The latest versions of all these methods can offer substantial sample size reductions when compared with the single-stage design not only in the case of clear efficacy but also in the case of complete lack of efficacy of the new treatment. The software packages make their use quite simple. However, it has to be stressed that using these methods requires efficient logistics with real-time data monitoring and, apart from survival studies or long-term clinical trials with censored endpoints, is most appropriate when the endpoint is obtained quickly when compared with the recruitment rate.

Gastroesophageal reflux in children: pathogenesis, prevalence, diagnosis, and role of proton pump inhibitors in treatment

A substantial percentage of infants, children and adolescents experience gastroesophageal reflux disease (GERD) and its accompanying symptoms, as well as disease complications. The diagnosis of GERD in children is made based upon the child's history, and data derived primarily from pH monitoring tests and endoscopy. In those children with confirmed reflux disease, the options for management parallel those recommended in adult patients, with the first step consisting of lifestyle changes. Surgical procedures may also be performed; however, these are rarely recommended prior to an adequate course of pharmacologic therapy, and appropriate case selection is important. Among the current pharmacotherapeutic options available in the US, the prokinetic agents and the acid-inhibitory agents (histamine-2 receptor antagonists, proton pump inhibitors) are the most widely used. The clinical utility of the prokinetic agents has been limited by the recent withdrawal of cisapride from the US marketplace and the potential for irreversible central nervous system complications with metoclopramide. Numerous clinical studies performed in adults, and several studies involving children, have demonstrated that the proton pump inhibitors are more effective than the histamine-2 receptor antagonists in the relief of GERD symptoms and healing of erosive esophagitis. In children, omeprazole and lansoprazole may be administered as the intact oral capsule, or in those who are unable or unwilling to swallow, the granule contents of the capsule may be mixed with soft foods (e.g. apple sauce) or fruit drinks/liquid dietary supplements prior to oral administration with no detrimental effects on pharmacokinetics, bioavailability, or pharmacodynamics. Studies performed with omeprazole and lansoprazole in children have shown pharmacokinetic parameters that closely resemble those observed in adults. In over a decade of use in adults, the proton pump inhibitor class of agents has been found to have a good safety profile. Studies involving children have also shown these agents to be well tolerated. In numerous drug-drug interaction studies performed with these two proton pump inhibitors, relatively few clinically significant interactions have been observed.

Pharmacology for the gastrointestinal tract

A variety of drugs are used in the neonatal nursery for the management of feeding intolerance, gastroesophageal reflux, and acid-related disease. Although the pharmacokinetics of some of these drugs have been described in infants and older children, further data are needed, particularly for preterm infants. No data are available characterizing the disposition of the proton pump inhibitors, which will likely be used in infants with refractory, acid-related disease. Further data are also needed to characterize fully the pharmacodynamics, or efficacy, of many of the commonly used drugs.

Guidelines for evaluation and treatment of gastroesophageal reflux in infants and children: recommendations of the North American Society for Pediatric Gastroenterology and Nutrition

Gastroesophageal reflux (GER), defined as passage of gastric contents into the esophagus, and GER disease (GERD), defined as symptoms or complications of GER, are common pediatric problems encountered by both primary and specialty medical providers. Clinical manifestations of GERD in children include vomiting, poor weight gain, dysphagia, abdominal or substernal pain, esophagitis and respiratory disorders. The GER Guideline Committee of the North American Society for Pediatric Gastroenterology and Nutrition has formulated a clinical practice guideline for the management of pediatric GER. The GER Guideline Committee, consisting of a primary care pediatrician, two clinical epidemiologists (who also practice primary care pediatrics) and five pediatric gastroenterologists, based its recommendations on an integration of a comprehensive and systematic review of the medical literature combined with expert opinion. Consensus was achieved through Nominal Group Technique, a structured quantitative method. The Committee examined the value of diagnostic tests and treatment modalities commonly used for the management of GERD, and how those interventions can be applied to clinical situations in the infant and older child. The guideline provides recommendations for management by the primary care provider, including evaluation, initial treatment, follow-up management and indications for consultation by a specialist. The guideline also provides recommendations for management by the pediatric gastroenterologist. This document represents the official recommendations of the North American Society for Pediatric Gastroenterology and Nutrition on the evaluation and treatment of gastroesophageal reflux in infants and children. The American Academy of Pediatrics has also endorsed these recommendations. The recommendations are summarized in a synopsis within the article. This review and recommendations are a general guideline and are not intended as a substitute for clinical judgment or as a protocol for the management of all patients with this problem.

Comparison of the two-sided single triangular test to the double triangular test

Comparative clinical trials are designed to determine whether a new treatment has either superior or different efficacy than a standard, that is, if theta represents a measure of treatment difference, to test the null hypothesis H(0): theta = 0 against the alternative hypothesis H(1) of either superior (theta > 0, one-sided) or different (theta not equal 0, two-sided with H(1)(+): theta > 0 and H(-)(1): theta < 0) efficacy. The triangular test (TT), a group sequential method, allows for early stopping of such trials. Its one-sided version (single TT) and two-sided version (double TT) were implemented in the first release of PEST software. The third release of PEST proposed a modification of the single TT, allowing rejection of H(0) in favor of H(-)(1) when very early data show strong inferiority of the new treatment as compared with the standard. Thus, our aim was to compare this modified single TT, referred to as a two-sided test in PEST 3, with the double TT and two-sided single-stage design (SSD). The statistical properties of the SSD and double TT were perfectly similar under all hypotheses. The modified single TT was underpowered as compared to the two others (the probability of falsely accepting H(0) strictly under H(-)(1) was 0.65 instead of 0.05), but the average sample number function was lower than the one of the double TT under all H(-)(1) hypotheses (-56% strictly under H(-)(1)). We conclude that the modified single TT offers a two-sided conclusion with many fewer patients than the double TT, but at the expense of a strong decrease in power under H(-)(1).

[What's new in pediatric pharmacology?]

Only a minority of the drugs administered to children and infants have a pediatric labeling and have been sufficiently tested for efficacy, safety and correct pediatric dosing, which cannot necessarily be extrapolated from adult data. This situation is scientifically and ethically unacceptable. To address this problem, the suggestion is being made in several countries that more formal legal requirements should be introduced. In the United States, in 1997, a new legislation encouraged pharmaceutical companies to study medicines in children (for example, by offering the financial incentive of a six-month extension to patent exclusivity). However, there are undeniable difficulties in pediatric and neonatal studies. To minimize the risks of clinical investigation in children, appropriate methodologies should be used. New in vitro and in vivo methods are now available, taking into account pediatric characteristics.

Testing secondary hypotheses following sequential clinical trials

Sequential monitoring in a clinical trial poses difficulty in hypotheses testing on secondary endpoints after the trial is terminated. The conventional likelihood-based testing procedure that ignores the sequential monitoring inflates Type I error and undermines power. In this article, we show that the power of the conventional testing procedure can be substantially improved while the Type I error is controlled. The method is illustrated with a real clinical trial.

Pharmacokinetics of metoclopramide in neonates

Despite its wide use as a prokinetic agent in neonates and infants with gastroesophageal reflux (GER), the pharmacokinetics of metoclopramide have not been characterized in this pediatric subpopulation. A single-dose pharmacokinetic study of oral metoclopramide (0.1 to 0.15 mg/kg) was performed in 10 fasted premature infants (weight 1.1 to 3.2 kg) ranging from 31 to 40 weeks postconceptional age. Metoclopramide was quantitated from repeated blood samples (n = 9 over 24 hours) by high-performance liquid chromatography. A one-compartment open model with first-order absorption best described the plasma concentration-time data. No correlations were observed between gestational, postnatal, or postconceptional age and any of the pharmacokinetic parameters studied. Comparison of the pharmacokinetic parameters from the study cohort and those reported previously from a similar study of older infants revealed no statistically significant differences. However, a prolonged apparent plasma clearance (Cl/F) of metoclopramide was observed in 30% of the infants studied, and the mean Cl/F and apparent steady-state volume of distribution (Vdss/F) were approximately 1.4- and 2.1-fold higher, respectively, than values reported in previous studies of metoclopramide disposition in adults. These data suggest that metoclopramide pharmacokinetics may exhibit a developmental dependency. Thus, a metoclopramide dose of 0.15 mg/kg given orally every 6 hours is recommended for the initiation of prokinetic therapy with this agent in infants who are < or = 31 weeks postconceptional age.