Diagnosis and treatment of gastro-oesophageal reflux disease in infants and children

Enteral formula compared to Nissen-Fundoplication: Data from a retrospective analysis on tolerance, utility, applicability, and safeness in children with neurological diseases

Objectives and study

Approximately 46–90% of children with neurological disorders (NDs) suffer from gastrointestinal diseases, such as gastro-esophageal reflux disease (GERD), constipation, or malnutrition. Therefore, enteral feeding is often necessary to achieve nutritional requirements. The treatment of GERD could be based on pharmacological therapy, nutritional treatment (changing the type of formula), or surgical treatment (Nissen Fundoplication, NF). The aim of this study was to describe and compare resource consumption between NE based on different formulas and NF in patients with ND.

Methods

We performed a retrospective analysis on all children with neurological damage (age: 29 days−17 years) treated from January 2009 to January 2019 due to nutritional problems and food and/or gastrointestinal intolerances. For all patients, demographic and anthropometric characteristics, symptoms, type of nutrition (formula and enteral access), and number and type of outpatient or emergency room visits were collected. Patients with <24 months of age at the closing of the database and with <24 months of follow-up were excluded.

Results

Out of 376 children, 309 children (M: 158; median age: 4 IQR 1–10) were enrolled, among which, 65 patients (NF group M: 33; median age: 5.3 IQR 1.8–10.7) underwent NF. Vomit, GERD, and dysphagia were more represented in the NF group (p < 0.05). Our analysis shows that the NF group seems to present a lower number of hospitalization and a lower number of visits for non-GI disorders, but a higher number of visits for GI disorders compared to non-NF. In the NF group, a higher prevalence of the use of amino-acid-based formula and free diet is observed, with a trend for the lower prevalence of casein-based or whey+casein-based formula (Fisher test p = 0.072). The median cost of a patient enrolled in the database is € 19,515 ± 540 ($ 20,742.32 ± 573.96) per year, with no significant difference between the two groups. Regarding formula, at baseline, 76 children consumed a free diet, 24 a casein-based formula, 139 a whey+casein-based formula, 46 a whey-based formula, and 24 an amino-acid-based formula.

Conclusions

In conclusion, compared to EN, NF may not improve the clinical aspect and related costs in children with NDs. Considering the psychological and QoL burden for patients, in a “step-up” strategy, EN could be proposed as an efficient alternative to NF.

To Wrap or Not? Utility of Anti-reflux Procedure in Infants Needing Gastrostomy Tubes

PURPOSE

Gastrostomy tube (GT) insertion is commonly performed in children with failure to thrive. Pediatric patients' frequently have gastroesophageal reflux (GER) and discerning pathological GER can be challenging. Moreover, there is some evidence that GT insertion may lead to worsening GER and to avoid a subsequent anti-reflux procedure (ARP), though controversial some surgeons advocate considering an ARP concomitantly. The purpose of this report is to assess outcomes in infants who underwent a GT vs. GT with ARP.

METHODS

Retrospective review of all infants who had a GT placed at a single institution from 2009-2014. The patients were then divided into two cohorts based on the index operation i.e., GT vs GT with ARP and outcomes compared.

RESULTS

226 operations (104 GT, 122 GT with ARP) were performed. The cohorts were similar in gender, gestational age, race, weight, median age, LOS, and proportion of neurologically impaired patients. Preoperative GER was significantly higher in the GT with ARP cohort (91 vs. 18%). No difference in the rate of immediate complications was noted between the two groups. Postoperative increase in anti-reflux medications was significantly higher in the GT cohort (p = 0.01). Post-op GER needing a secondary procedure (ARP or GJ tube) was noted in 21/104 (20%) patients. Those needing an additional procedure vs. those with GT alone were similar in the proportion of patients with pre-op GER, neurologic impairment, type of feeds, and age.

CONCLUSION

Identifying patients who would benefit from a concomitant ARP remains challenging. A fifth of GT patients needed a subsequent procedure despite most high-risk patients having already undergone an ARP. Since the overall rate of complications remained similar, initial GT approach can be considered reasonable.

Esophageal Bolus Transit in Newborns with Gastroesophageal Reflux Disease Symptoms: A Multichannel Intraluminal Impedance Study

PURPOSE

The aim of this study was to evaluate bolus transit during esophageal swallow (ES) and gastroesophageal reflux (GER) events and to investigate the relationship between the characteristics of ES and GER events in a population of term and preterm newborns with symptoms of gastroesophageal reflux disease (GERD).

METHODS

The study population consisted of term and preterm newborns referred to combined multichannel intraluminal impedance (MII) and pH monitoring for GERD symptoms. The frequency and characteristics of ES and GER events were assessed by two independent investigators. Statistical significance was set at p<0.05.

RESULTS

Fifty-four newborns (23 preterm) were included in the analyses. Median bolus head advancing time corrected for esophageal length (BHATc) was shorter during mealtime than during the postprandial period (median, interquartile range): 0.20 (0.15-0.29) s/cm vs. 0.47 (0.39-0.64) s/cm, p<0.001. Median bolus presence time (BPT) was prolonged during mealtime: 4.71(3.49-6.27) s vs. 2.66 (1.82-3.73) s, p<0.001. Higher BHATc (p=0.03) and prolonged BPT (p<0.001) were observed in preterm newborns during the postprandial period. A significant positive correlation between BHATc and bolus clearance time was also observed (ρ=0.33, p=0.016).

CONCLUSION

The analysis of ES and GER events at the same time by MII provides useful information to better understand the physiopathology of GERD. In particular, the analysis of BHATc during the postprandial period could help clinicians identify newborns with prolonged esophageal clearance time due to impaired esophageal motility, which could allow for more accurate recommendations regarding further tests and treatment.

Prokinetics prescribing in paediatrics: evidence on cisapride, domperidone, and metoclopramide

OBJECTIVES

Domperidone and metoclopramide are prokinetics commonly prescribed off-label to infants and younger children in an attempt to treat gastro-oesophageal reflux symptoms. Another prokinetic drug, cisapride, was used but withdrawn in 2000 in the United Kingdom because of serious arrhythmic adverse events. Medicines and Healthcare Products Regulatory Agency issued safety warnings for domperidone in May 2012 and restricted its indications. We report here national primary care prescribing trends and safety signals of these drugs in children.

METHODS

We used data from the General Practice Research Database between 1990 and 2006 for children <18 years. Descriptive statistics and Poisson regressions were performed to characterise prescribing trends. We examined safety signals in nested case-control studies.

RESULTS

The proportion of children <2 years old being prescribed one of the medications doubled during the study period. Prescriptions of domperidone increased 10-fold, mainly following the withdrawal of cisapride in 2000. Prescriptions of metoclopramide did not change significantly. Despite the increase in prescriptions of domperidone, no new safety signals were identified.

CONCLUSIONS

These data showed dramatic changes in prescribing of cisapride and domperidone despite the lack of good-quality supporting evidence. It is possible that these prescribing trends were influenced by published guidelines. Even if produced without robust efficacy and safety evidence, published guidelines can influence clinicians and consequently affect prescribing. Therefore, improving the evidence base on prokinetics to inform future guidelines is vital. The lack of new safety signals during this period would support the development of suitable powered clinical studies.

In silico identification of plant miRNAs in mammalian breast milk exosomes--a small step forward?

MicroRNAs (miRNAs) are a class of small RNA molecules that regulate gene expression by inhibiting the protein translation or targeting the mRNA cleavage. They play many important roles in living organism cells; however, the knowledge on miRNAs functions has become more extensive upon their identification in biological fluids and recent reports on plant-origin miRNAs abundance in human plasma and serum. Considering these findings, we performed a rigorous bioinformatics analysis of publicly available, raw data from high-throughput sequencing studies on miRNAs composition in human and porcine breast milk exosomes to identify the fraction of food-derived miRNAs. Several processing and filtering steps were applied to increase the accuracy, and to avoid false positives. Through aforementioned analysis, 35 and 17 miRNA species, belonging to 25 and 11 MIR families, were identified, respectively. In the human samples the highest abundance levels yielded the ath-miR166a, pab-miR951, ptc-miR472a and bdi-miR168, while in the porcine breast milk exosomes, the zma-miR168a, zma-miR156a and ath-miR166a have been identified in the largest amounts. The consensus prediction and annotation of potential human targets for select plant miRNAs suggest that the aforementioned molecules may interact with mRNAs coding several transcription factors, protein receptors, transporters and immune-related proteins, thus potentially influencing human organism. Taken together, the presented analysis shows proof of abundant plant miRNAs in mammal breast milk exosomes, pointing at the same time to the new possibilities arising from this discovery.

Prophylactic ranitidine treatment in critically ill children--a population pharmacokinetic study

AIMS

To characterize the population pharmacokinetics of ranitidine in critically ill children and to determine the influence of various clinical and demographic factors on its disposition.

METHODS

Data were collected prospectively from 78 paediatric patients (n = 248 plasma samples) who received oral or intravenous ranitidine for prophylaxis against stress ulcers, gastrointestinal bleeding or the treatment of gastro-oesophageal reflux. Plasma samples were analysed using high-performance liquid chromatography, and the data were subjected to population pharmacokinetic analysis using nonlinear mixed-effects modelling.

RESULTS

A one-compartment model best described the plasma concentration profile, with an exponential structure for interindividual errors and a proportional structure for intra-individual error. After backward stepwise elimination, the final model showed a significant decrease in objective function value (-12.618; P < 0.001) compared with the weight-corrected base model. Final parameter estimates for the population were 32.1 l h(-1) for total clearance and 285 l for volume of distribution, both allometrically modelled for a 70 kg adult. Final estimates for absorption rate constant and bioavailability were 1.31 h(-1) and 27.5%, respectively. No significant relationship was found between age and weight-corrected ranitidine pharmacokinetic parameters in the final model, with the covariate for cardiac failure or surgery being shown to reduce clearance significantly by a factor of 0.46.

CONCLUSIONS

Currently, ranitidine dose recommendations are based on children's weights. However, our findings suggest that a dosing scheme that takes into consideration both weight and cardiac failure/surgery would be more appropriate in order to avoid administration of higher or more frequent doses than necessary.

Fundoplication versus postoperative medication for gastro-oesophageal reflux in children with neurological impairment undergoing gastrostomy

BACKGROUND

Children with neurological impairments frequently experience feeding difficulties, which can lead to malnutrition and growth failure. Gastrostomy feeding is now the preferred method of providing nutritional support to children with neurological impairments who are unable to feed adequately by mouth. Complications may arise as a result of gastrostomy placement, and the development or worsening of gastro-oesophageal reflux (GOR) has been widely reported. This has led to the frequent use of surgical antireflux treatment in the form of a fundoplication, or other antireflux procedures. Fundoplication is associated with a high recurrence rate, surgical failure, and significant morbidity and mortality.Since proton pump inhibitors (PPIs) were introduced in the 1990s, they have come to play a larger part in the medical management of GOR in children with neurological impairments. Uncontrolled studies suggest that PPIs may be a safe, appropriate treatment for GOR. Other agents currently used include milk thickeners, acid suppression drugs, acid buffering agents, gut motility stimulants and sodium alginate preparations.There are risks and benefits associated with both surgical and medical interventions and further comparison is necessary to determine the optimal treatment choice.

OBJECTIVES

To compare the effectiveness of antireflux surgery and antireflux medications for children with neurological impairments and GOR who are undergoing placement of a gastrostomy feeding tube.

SEARCH METHODS

We searched the following databases on 23 March 2012: the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, EMBASE, CINAHL, LILACS and ISI Web of Science. Previously, we searched the Child Health Library in June 2009. We also performed online searches of trial registries, medical journals, conference proceedings, dissertations and theses. We contacted specialists in the medical and industry setting for knowledge of completed or ongoing trials.

SELECTION CRITERIA

We sought to include randomised controlled trials that recruited children up to the age of 18 years with neurological impairments and GOR who were undergoing gastrostomy tube insertion.

DATA COLLECTION AND ANALYSIS

The review authors worked independently to select trials; none were identified.

MAIN RESULTS

We identified no trials that satisfied the criteria for this review.

AUTHORS' CONCLUSIONS

There remains considerable uncertainty regarding the optimal treatment when faced with the decision of fundoplication surgery versus antireflux medications for children with GOR and neurological impairment who are undergoing gastrostomy insertion. There is a need for robust scientific evidence in order to provide data on the comparable risks or benefits of the two interventions.

Whey- vs casein-based enteral formula and gastrointestinal function in children with cerebral palsy

OBJECTIVES

Children with severe cerebral palsy (CP) commonly have gastrointestinal (GI) dysfunction. Whey-based enteral formulas have been postulated to reduce gastroesophageal reflux (GOR) and accelerate gastric emptying (GE). The authors investigated whether whey-based (vs casein-based) enteral formulas reduce GOR and accelerate GE in children who have severe CP with a gastrostomy and fundoplication.

METHODS

Thirteen children received a casein-based formula for 1 week and either a 50% whey whole protein (50% WWP) or a 100% whey partially hydrolyzed protein (100% WPHP) formula for 1 week. Reflux episodes, gastric half-emptying time (GE t(1/2)), and reported pain and GI symptoms were measured.

RESULTS

Whey formulas emptied significantly faster than casein (median [interquartile range (IQR)] GE t(1/2), 33.9 [25.3-166.2] min vs 56.6 [46-191] min; P = .033). Reflux parameters were unchanged. GI symptoms were lower in children who received 50% WWP (visual analog symptom score, median [IQR], 0 [0-11.8]) vs 100% WPHP (13.0 [2.5-24.8]) (P = .035).

CONCLUSION

This pilot study shows that in children who have severe CP with a gastrostomy and fundoplication, GE of the whey-based enteral formula is significantly faster than casein. The acceleration in GE does not alter GOR frequency, and there appears to be no effect of whey vs casein in reducing acid, nonacid, and total reflux episodes. The results indicate that enteral formula selection may be particularly important for children with severe CP and delayed GE.

Relationship between sleep and acid gastro-oesophageal reflux in neonates

The aim of the present study was to investigate the impact of gastro-oesophageal acid reflux on sleep in neonates and, reciprocally, the influence of wakefulness (W) and sleep stages on the characteristics of the reflux (including the retrograde bolus migration of oesophageal acid contents). The pH and multichannel intraluminal impedance were measured during nocturnal polysomnography in 25 infants hospitalised for suspicion of gastro-oesophageal reflux. Two groups were constituted according to whether or not the infants displayed gastro-oesophageal reflux (i.e. a reflux group and a control group). There were no differences between the reflux and control groups in terms of sleep duration, sleep structure and sleep state change frequency. Vigilance states significantly influenced the gastro-oesophageal reflux pattern: the occurrence of gastro-oesophageal reflux episodes was greater during W (59 ± 32%) and active sleep (AS; 35 ± 30%) than during quiet sleep (QS; 6 ± 11%), whereas the mean duration of gastro-oesophageal reflux episodes was higher in QS than in W and AS. The percentage of retrograde bolus migrations of distal oesophageal acid content was significantly higher in AS (62 ± 26%) than in W (42 ± 26%) and QS (4.5 ± 9%). In neonates, gastro-oesophageal reflux occurred more frequently during W, whereas the physiological changes associated with sleep state increase the physiopathological impact of the gastro-oesophageal reflux. The duration of oesophagus-acid contact was greater during sleep; AS facilitated the retrograde migration of oesophageal acid content, and QS was characterised by the risk of prolonged acid mucosal contact.

Regurgitation in healthy and non healthy infants

Uncomplicate regurgitation in otherwise healthy infants is not a disease. It consists of milk flow from mouth during or after feeding. Common causes include overfeeding, air swallowed during feeding, crying or coughing; physical exam is normal and weight gain is adequate. History and physical exam are diagnostic, and conservative therapy is recommended. Pathologic gastroesophageal reflux or gastroesophageal reflux disease refers to infants with regurgitation and vomiting associated with poor weight gain, respiratory symptoms, esophagitis. Reflux episodes occur most often during transient relaxations of the lower esophageal sphincter unaccompanied by swallowing, which permit gastric content to flow into the esophagus. A minor proportion of reflux episodes occurs when the lower esophageal sphincter fails to increase pressure during a sudden increase in intraabdominal pressure or when lower esophageal sphincter resting pressure is chronically reduced. Alterations in several protective mechanisms allow physiologic reflux to become gastroesophageal reflux disease; diagnostic approach is both clinical and instrumental: radiological series are useful to exclude anatomic abnormalities; pH-testing evaluates the quantity, frequency and duration of the acid reflux episodes; endoscopy and biopsy are performed in the case of esophagitis. Therapy with H2 receptor antagonists and proton pump inhibitors are suggested.

Fundoplication versus post-operative medication for gastro-oesophageal reflux in children with neurological impairment undergoing gastrostomy

BACKGROUND

Children with neurological impairments (NI) frequently experience feeding difficulties which can lead to malnutrition and growth failure. Gastrostomy feeding is now the preferred method of providing nutritional support to children with NI who are unable to feed adequately by mouth. Complications may arise as a result of gastrostomy placement and the development or worsening of gastro-oesophageal reflux (GOR) has been widely reported. This has led to the frequent use of surgical anti-reflux treatment in the form of a fundoplication, or other Anti-Reflux Procedures. Fundoplication is associated with a high recurrence rate, surgical failure and significant morbidity and mortality. Since Proton Pump Inhibitors (PPIs) were introduced in the 1990s they have come to play a larger part in the medical management of GOR in children with NI. Uncontrolled studies suggest that PPIs may be a safe, appropriate treatment for GOR. Other agents currently used include milk thickeners, acid suppression drugs, acid buffering agents, gut motility stimulants and sodium alginate preparations. There are risks and benefits associated with both surgical and medical interventions and further comparison is necessary to determine the optimal treatment choice.

OBJECTIVES

To compare the effectiveness of anti-reflux surgery and anti-reflux medications for children with NI and GOR who are undergoing placement of a gastrostomy feeding tube.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) up to Issue 2, 2006, MEDLINE (1966 to June 2006), EMBASE (1980 to week 33, 2006), CINAHL (1982 -to May, week 4, 2006), LILACS (1982 to June 2006), ISI Web of Science (1970 to June 2006) and the Child Health Library (searched June 2006). We also performed online searches of trial registries, medical journals, conference proceedings, dissertations and theses. Specialists in the medical and industry setting were contacted for knowledge of completed or ongoing trials.

SELECTION CRITERIA

We sought to include only randomised controlled trials that recruited children up to the age of 18 years with NI and GOR who were undergoing gastrostomy tube insertion.

DATA COLLECTION AND ANALYSIS

Two reviewers worked independently on selected trials and performed data extraction and assessment of trial quality.

MAIN RESULTS

No trials were identified that satisfied the criteria for this review.

AUTHORS' CONCLUSIONS

There remains considerable uncertainty regarding the optimal treatment when faced with the decision of fundoplication surgery versus anti-reflux medications for gastro-oesophageal-reflux in the child with neurological impairment who is undergoing gastrostomy insertion. There is a need for robust scientific evidence in order to provide data on the comparable risks or benefits of the two interventions.

Inhibidores de la bomba de protones en pediatría

In last years the use in the pediatric area of proton pump inhibitors (omeprazole, lansoprazole, pantoprazole, rabeprazole and esomeprazole) is more often, nevertheless the clinical trials carried out are poor. The aim of this work is to analyse the bibliography published about this kind of drugs in children and to make a revision of its use in the last seven years. More studies with omeprazole and lansoprazole have been developed, to be exact omeprazole and lansoprazole is present in 122 bibliographic appointments and 34 for lansoprazole, which include studies that demonstrate a good tolerance and efficacy. The remaining proton pump inhibitors count with very few studies. The main therapeutic indications were the eradication of Helicobacter pylori, gastroesophageal reflux disease and esophagitis. The number of patients included in the reviewed studies is quite heterogeneous, from 8 to 122 and the age range between 8 days and 17 years. On the other hand, it could be highlighted the non-existence of formulations adapted to the pediatric population and the difficulty of administration specially in the youngest patients. As in many other drugs, it would be necessary to carry out clinical trials in order to determinate the pharmacologic parameters at difference ages, which will allow a safe and effective administration, and its authorization by all Health Authorities.

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.

Developmental pharmacokinetics and pharmacodynamics of nizatidine

OBJECTIVES

To characterize the impact of development on the pharmacokinetics and pharmacodynamics of nizatidine.

METHODS

Children (age range, 5 days-18 years) and adults (age range, 18-50 years) were enrolled in four open-label trials. Nizatidine formulation and dose were determined by age: infants received 2 or 4 mg/kg i.v., children 2.5 or 5 mg/kg in one of three oral liquid formulations, and adolescents and adults received a fixed 150-mg capsule. Nizatidine and N-desmethylnizatidine concentrations were measured in serial post-dose plasma samples by a high-performance liquid chromatographic assay with mass spectrometric detection. Intragastric pH was recorded during a 24-hour post-dose interval.

RESULTS

Data on 93 subjects were combined with previous values from 36 individuals to cover an age group not adequately captured and to control for formulation effects. Dose-normalized exposure estimates revealed no apparent age dependence; however, maximum plasma concentration (298.5 +/- 100.7 v 552.8 +/- 152.4 ng/mL per mg/kg dose) and AUC0-infinity (954.4 +/- 379.8 v 1,573.0 +/- 347.4 ng*hour/mL per mg/kg dose) were reduced in extemporaneous formulations in apple juice. The apparent modest age dependence observed for total body clearance (Cl/F) (r = 0.365) and Vss/F (r = 0.221) reflected a formulation-dependent decrease in bioavailability rather than a true age effect. The age-associated changes in lambda z observed for nizatidine and its metabolite were predictable and consistent with developmental acquisition of renal function. Mean and median pH, as well as fraction of time that the dosing interval remained above target pH values, were significantly greater with administration of the drug than without.

CONCLUSIONS

The biodisposition of nizatidine in children and adults is similar; however, response after a comparable weight-based dose is equal and potentially greater in children.

Gastro-oesophageal reflux disease and motility disorders

Gastro-oesophageal reflux (GOR) is a common phenomenon occurring at any age with a benign prognosis in the majority of cases, but requiring prompt evaluation and treatment when presenting with alarm symptoms or when persisting. Complications of GOR disease (GORD) may be severe. This chapter will discuss the epidemiology, natural course, pathophysiology, clinical presentation, diagnostic and therapeutic approach towards GORD and motility disorders according to different ages. Similarities and differences between infants, children and adults will be highlighted. The superior efficacy and safety of proton pump inhibitors have recently changed the diagnostic and therapeutic recommendations in adults, and possible indications in children are discussed. Only in patients unresponsive to optimal medical treatment are further investigations to exclude other aetiologies for GORD needed (e.g. eosinophilic oesophagitis in infants, scleroderma in adults). Special patient groups such as those with congenital malformations (e.g. oesophageal atresia) are not considered, whereas neurological, respiratory and allergy-affected patients as well as Helicobacter pylori infection are briefly discussed.

The bioequivalence of nizatidine (Axid) in two extemporaneously and one commercially prepared oral liquid formulations compared with capsule

Nizatidine (Axid) is an H2-receptor antagonist used for the treatment of acid-related gastrointestinal disorders. Given the frequency of these conditions in children and the potential for pediatric use of nizatidine, an oral liquid dosage formulation would provide an alternative treatment option for patients unable to swallow solid oral dosage forms. This study was designed as an open-label, single-dose, four-way crossover trial to investigate the bioequivalence of 150 mg nizatidine administered in three oral liquid formulations (a commercially prepared oral syrup, an extemporaneous solution in apple juice, and an extemporaneous suspension in infant formula) relative to the marketed capsule formulation. Twenty-four adult subjects (ages 31.2 +/- 7.5 years; weight 71.1 +/- 11.8 kg) were enrolled, and blood samples for determination of plasma nizatidine concentrations were collected prior to drug administration and at 19 discrete intervals over a 24-hour postdose interval. Nizatidine was quantitated from plasma using a validated HPLC-MS assay, and a noncompartmental approach was used to describe nizatidine biodisposition in all subjects. Significant treatment effects were observed for log-normalized Cmax, AUC0-n, and AUC0-infinity (p < 0.001). Further evaluation revealed that nizatidine prepared in apple juice was markedly less bioavailable than the reference capsule, with 90% confidence intervals (CIs) of 0.518-0.626, 0.682-0.751, and 0.696-0.763 for Cmax, AUC0-n, and AUC0-infinity, respectively. The remaining two oral formulations demonstrated 90% CI within the guidelines established by the Food and Drug Administration (e.g., 0.80-1.25). Thus, nizatidine in infant formula and the commercially prepared oral syrup can be considered bioequivalent to the reference capsule.

Gastroesophageal reflux and cow milk allergy: is there a link?

Gastroesophageal reflux (GER) and cow milk allergy (CMA) occur frequently in infants younger than 1 year. In recent years, the relation between these 2 entities has been investigated and some important conclusions have been reached: in up to half of the cases of GER in infants younger than 1 year, there may be an association with CMA. In a high proportion of cases, GER is not only CMA associated but also CMA induced. The frequency of this association should induce pediatricians to screen for possible concomitant CMA in all infants who have GER and are younger than 1 year. With the exception of some patients with mild typical CMA manifestations (diarrhea, dermatitis, or rhinitis), the symptoms of GER associated with CMA are the same as those observed in primary GER. Immunologic tests and esophageal pH monitoring (with a typical pH pattern characterized by a progressive, slow decrease in esophageal pH between feedings) may be helpful if an association between GER and CMA is suspected, although the clinical response to an elimination diet and challenge is the only clue to the diagnosis. This article reviews the main features of GER and CMA, focusing on the aspects in common and the discrepancies between both conditions.

Mechanisms of gastroesophageal reflux and gastroesophageal reflux disease

Gastroesophageal reflux is a physiological phenomenon, occurring with different severity and duration in different individuals. Reflux occurs when this normal event results in the occurrence of symptoms/signs or complications. The pathophysiology of gastroesophageal reflux is complex and diverse, since it is influenced by factors that are genetic, environmental (e.g., diet smoking), anatomic, hormonal, and neurogenic. However, many mechanisms remain incompletely understood. Future research should focus on a better understanding of the physiology of the upper and lower esophageal sphincters, and of gastric motility. The afferent and efferent neural pathways and neuropharmacologic mediators of transient lower esophageal sphincter relaxations and gastric dysmotility require further study. The role of anatomic malformations such as hiatal hernia in children has been underestimated. While therapeutic possibilities are greater in number and largely improved, the outcomes of some treatments are far from satisfactory in many cases. In addition to development of new forms of treatment, research should address better use of currently available medical and surgical treatments.

Comparison between pediatricians and family practitioners in the use of the prokinetic cisapride for gastroesophageal reflux disease in children

OBJECTIVE

The North American Society for Pediatric Gastroenterology, Hepatology and Nutrition and the European Society of Pediatric Gastroenterology, Hepatology and Nutrition have recently issued treatment guidelines for the use of cisapride in children. Our hypothesis was that cisapride is misused in the community and is not prescribed according to suggested recommendations. Therefore, the aim of this study was to evaluate the knowledge of pediatricians and family practitioners regarding the prescribing practice and adverse effects of cisapride.

METHODS

A standardized questionnaire was sent to a randomly selected group of pediatricians and family practitioners in Northern Israel. The questionnaire was designed to evaluate the knowledge of the physician regarding the treatment of gastroesophageal reflux disease and the use of cisapride in children (indications, dosages, duration of treatment, limitations in certain age groups, the need for pretreatment laboratory tests, interactions with other drugs, and contraindications). Replies were scored from 0 to 100 according to the treatment guidelines of both the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition and the European Society of Pediatric Gastroenterology, Hepatology and Nutrition. In addition, 2 questions dealt with the subjective efficacy of the drug and its adverse events.

RESULTS

The knowledge scores were 62% and 51% in the pediatricians and family practitioners, respectively. Other major findings were as follows: 1) 40% of pediatricians and 65% of family practitioners do not prescribe the recommended dose of cisapride, 2) 6% of pediatricians and 42% of family practitioners prescribe cisapride for infantile colic, 3) only 50% of pediatricians and 22% of family practitioners were aware of possible interactions with macrolides, and 4) only 31% of pediatricians and 54% of family practitioners were aware that cisapride might cause prolongation of the QT interval. Only minor adverse events were reported.

CONCLUSIONS

The knowledge of both pediatricians and family practitioners in the use of cisapride in children is suboptimal. It is essential to improve the education of community physicians to reduce the potential for adverse events arising from the misuse of this prokinetic agent.

PH monitoring in the distal and proximal esophagus in symptomatic infants

BACKGROUND

Standard distal esophageal pH monitoring data are sometimes within normal ranges in children with clinically suspected gastroesophageal reflux disease. Therefore, the authors hypothesized that the amount of acid reflux reaching the proximal esophagus may be greater in some subgroups of patients than in healthy controls or in other subgroups of patients.

METHODS

The parameters of 24-hour pH monitoring in the proximal part of the esophagus were analyzed in 120 symptomatic infants in who the reflux parameters in the lower esophagus were clearly within normal ranges (reflux index < 5.0%). The infants were classified into four patient groups: excessive regurgitation (n = 41): inconsolable crying (n = 31), apparent life-threatening event (ALTE) (n = 18), and chronic respiratory disorders (n = 30). The control group consisted also of 120 infants. The following parameters were calculated: reflux index, the number of reflux episodes, the number of reflux episodes lasting longer than 5 minutes, the duration of the longest reflux episode, and the acid clearance time (ACT, duration of reflux episodes divided by number of reflux episodes).

RESULTS

The patients with chronic respiratory disorders were significantly older than the patients in the other groups and the controls. In the distal esophagus, there was no statistically significant difference between the reflux parameters. As could be expected, every parameter was statistically (paired t test, Wilcoxon signed-rank test) significantly smaller in the proximal than in the distal esophagus, except for the ACT in infants who presented with inconsolable crying. In the proximal esophagus, there was no statistically significant difference between the different patient subgroups or controls, except for the number of reflux episodes in the group with chronic respiratory disorders and the group with inconsolable crying, applying one-way analysis of variance. As determined by applying the Mann-Whitney test, the number of reflux episodes in the upper esophagus was significantly higher in the group with chronic respiratory disorders than in the other patient groups and controls. Therefore, the authors' data do not support the hypothesis that reflux reaching the proximal esophagus is a frequent cause of ALTE. However, the data may suggest that the number of reflux episodes reaching the proximal esophagus in children with chronic respiratory disorders and with distal pH monitoring data within normal ranges may be increased. Whether this finding reflects reality or a statistical coincidence, or is influenced by the older age of this patient group, needs further evaluation.

CONCLUSIONS

In theory, dual simultaneous esophageal pH monitoring in the distal and proximal esophagus may increase the diagnostic accuracy of pH monitoring in infants. Our results do not support a substantial advantage of a systematic application of this new technique, especially not in infants presenting with ALTE, excessive regurgitation, or inconsolable crying. In the subgroup of patients with chronic respiratory disorders, more data are needed before conclusions can be determined and recommendations can be made.