Dose-Finding Study of Omeprazole on Gastric pH in Neonates with Gastro-Esophageal Acid Reflux Using a Bayesian Sequential Approach

A Review of Histamine-2 Receptor Antagonist and Proton Pump Inhibitor Therapy for Gastroesophageal Reflux Disease in Neonates and Infants

Proton pump inhibitors (PPI) and histamine-2 receptor antagonists (H2RA) are commonly used medications in neonates and infants for the treatment of gastroesophageal reflux disease (GERD), especially in neonatal intensive care units (NICUs). A literature review was conducted to evaluate the efficacy and safety of histamine-2 receptor antagonists (H2RAs) and proton pump inhibitors (PPIs) in preterm neonates, term neonates, and infants. A total of 27 studies were included in this review. Antacid medications in studies have consistently shown positive pharmacodynamic effects, including increasing gastric pH, reducing the reflux index, and reducing the number of acidic reflux events. The benefit found in placebo-controlled trials are limited exclusively to these surrogate outcomes. The actual clinically salient outcomes which H2RAs and PPIs are used for, such as reduction in GERD symptoms, especially irritability and improved feed tolerance and weight gain, have consistently shown no clinical benefit. H2RAs and PPIs appear to be extremely well tolerated by the neonatal and infant populations, which would mimic our experience with these medications in our unit. The available data from large, retrospective cohort and case-control studies paint a much more concerning picture regarding the potential for an increased risk in the development of allergies, anaphylactic reactions, necrotizing enterocolitis (NEC), other nosocomial infections, and lower respiratory tract infections. Given the risks associated with and lack of clinical effectiveness of both H2RAs and PPIs, use of these medications should be limited to specific clinical situations. Further studies are required to determine whether antacid pharmacologic therapy might benefit certain neonates and infants, such as those with complex medical issues.

Pharmacological treatment of gastro-oesophageal reflux in children

BACKGROUND

Gastro-oesophageal reflux (GOR) is characterised by the regurgitation of gastric contents into the oesophagus. GOR is a common presentation in infancy, both in primary and secondary care, affecting approximately 50% of infants under three months old. The natural history of GOR in infancy is generally of a self-limiting condition that improves with age, but older children and children with co-existing medical conditions can have more protracted symptoms. The distinction between gastro-oesophageal reflux disease (GORD) and GOR is debated. Current National Institute of Health and Care Excellence (NICE) guidelines define GORD as GOR causing symptoms severe enough to merit treatment. This is an update of a review first published in 2014.

OBJECTIVES

To assess the effects of pharmacological treatments for GOR in infants and children.

SEARCH METHODS

For this update, we searched CENTRAL, MEDLINE, Embase, and Web of Science up to 17 September 2022. We also searched for ongoing trials in clinical trials registries, contacted experts in the field, and searched the reference lists of trials and reviews for any additional trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any currently-available pharmacological treatment for GOR in children with placebo or another medication. We excluded studies assessing dietary management of GORD and studies of thickened feeds. We included studies in infants and children up to 16 years old.

DATA COLLECTION AND ANALYSIS

We used standard methodology expected by Cochrane.

MAIN RESULTS

We included 36 RCTs involving 2251 children and infants. We were able to extract summary data from 14 RCTs; the remaining trials had insufficient data for extraction. We were unable to pool results in a meta-analysis due to methodological differences in the included studies (including heterogeneous outcomes, study populations, and study design). We present the results in two groups by age: infants up to 12 months old, and children aged 12 months to 16 years old. Infants Omeprazole versus placebo: there is no clear effect on symptoms from omeprazole. One study (30 infants; very low-certainty evidence) showed cry/fuss time in infants aged three to 12 months had altered from 246 ± 105 minutes/day at baseline (mean +/- standard deviation (SD)) to 191 ± 120 minutes/day in the omeprazole group and from 287 ± 132 minutes/day to 201 ± 100 minutes/day in the placebo group (mean difference (MD) 10 minutes/day lower (95% confidence interval (CI) -89.1 to 69.1)). The reflux index changed in the omeprazole group from 9.9 ± 5.8% in 24 hours to 1.0 ± 1.3% and in the placebo group from 7.2 ± 6.0% to 5.3 ± 4.9% in 24 hours (MD 7% lower, 95% CI -4.7 to -9.3). Omeprazole versus ranitidine: one study (76 infants; very low-certainty evidence) showed omeprazole may or may not provide symptomatic benefit equivalent to ranitidine. Symptom scores in the omeprazole group changed from 51.9 ± 5.4 to 2.4 ± 1.2, and in the ranitidine group from 47 ± 5.6 to 2.5 ± 0.6 after two weeks: MD -4.97 (95% CI -7.33 to -2.61). Esomeprazole versus placebo: esomeprazole appeared to show no additional reduction in the number of GORD symptoms compared to placebo (1 study, 52 neonates; very low-certainty evidence): both the esomeprazole group (184.7 ± 78.5 to 156.7 ± 75.1) and placebo group (183.1 ± 77.5 to 158.3 ± 75.9) improved: MD -3.2 (95% CI -4.6 to -1.8). Children Proton pump inhibitors (PPIs) at different doses may provide little to no symptomatic and endoscopic benefit. Rabeprazole given at different doses (0.5 mg/kg and 1 mg/kg) may provide similar symptom improvement (127 children in total; very low-certainty evidence). In the lower-dose group (0.5 mg/kg), symptom scores improved in both a low-weight group of children (< 15 kg) (mean -10.6 ± SD 11.13) and a high-weight group of children (> 15 kg) (mean -13.6 ± 13.1). In the higher-dose groups (1 mg/kg), scores improved in the low-weight (-9 ± 11.2) and higher-weight groups (-8.3 ± 9.2). For the higher-weight group, symptom score mean difference between the two different dosing regimens was 2.3 (95% CI -2 to 6.6), and for the lower-weight group, symptom score MD was 4.6 (95% CI -2.9 to 12). Pantoprazole: pantoprazole may or may not improve symptom scores at 0.3 mg/kg, 0.6 mg/kg, and 1.2 mg/kg pantoprazole in children aged one to five years by week eight, with no difference between 0.3 mg/kg and 1.2 mg/kg dosing (0.3 mg/kg mean -2.4 ± 1.7; 1.2 mg/kg -1.7 ± 1.2: MD 0.7 (95% CI -0.4 to 1.8)) (one study, 60 children; very low-certainty evidence). There were insufficient summary data to assess other medications.

AUTHORS' CONCLUSIONS

There is very low-certainty evidence about symptom improvements and changes in pH indices for infants. There are no summary data for endoscopic changes. Medications may or may not provide a benefit (based on very low-certainty evidence) for infants whose symptoms remain bothersome, despite nonmedical interventions or parental reassurance. If a medication is required, there is no clear evidence based on summary data for omeprazole, esomeprazole (in neonates), H₂antagonists, and alginates for symptom improvements (very low-certainty evidence). Further studies with longer follow-up are needed. In older children with GORD, in studies with summary data extracted, there is very low-certainty evidence that PPIs (rabeprazole and pantoprazole) may or may not improve GORD outcomes. No robust data exist for other medications. Further RCT evidence is required in all areas, including subgroups (preterm babies and children with neurodisabilities).

Rectal Omeprazole in Infants With Gastroesophageal Reflux Disease: A Randomized Pilot Trial

BACKGROUND AND OBJECTIVE

Omeprazole is a proton pump inhibitor that is used in acid suppression therapy in infants. Infants cannot swallow the oral tablets or capsules. Since, infants require a non-standard dose of omeprazole, the granules or tablets are often crushed or suspended in water or sodium bicarbonate, which may destroy the enteric coating. In this study we explore the efficacy and pharmacokinetics of rectally administered omeprazole in infants with gastroesophageal reflux disease (GERD) due to esophageal atresia (EA) or congenital diaphragmatic hernia (CDH) and compare these with orally administered omeprazole.

METHODS

Infants (6-12 weeks postnatal and bodyweight > 3 kg) with EA or CDH and GERD were randomized to receive a single dose of 1 mg/kg omeprazole rectally or orally. The primary outcome was the percentage of infants for whom omeprazole was effective according to predefined criteria for 24-h intraesophageal pH. Secondary outcomes were the percentages of time that gastric pH was < 3 or < 4, as well as the pharmacokinetic parameters.

RESULTS

Seventeen infants, 4 with EA and 13 with CDH, were included. The proportion of infants for whom omeprazole was effective was 56% (5 of 9 infants) after rectal administration and 50% (4 of 8 infants) after oral administration. The total reflux time in minutes and percentages and the number of reflux episodes of pH < 4 decreased statistically significantly after both rectal and oral omeprazole administration. Rectal and oral administration of omeprazole resulted in similar serum exposure.

CONCLUSIONS

A single rectal omeprazole dose (1 mg/kg) results in consistent increases in intraesophageal and gastric pH in infants with EA- or CDH-related GERD, similar to an oral dose. Considering the challenges with existing oral formulations, rectal omeprazole presents as an innovative, promising alternative for infants with pathological GERD.

CLINICAL TRIAL REGISTER

ClinicalTrials.gov Identifier: NCT00226044.

Role of feeding strategy bundle with acid-suppressive therapy in infants with esophageal acid reflux exposure: a randomized controlled trial

OBJECTIVE

To test the hypothesis that a feeding bundle concurrent with acid suppression is superior to acid suppression alone in improving gastroesophageal reflux disease (GERD) attributed-symptom scores and feeding outcomes in neonatal ICU infants.

METHODS

Infants (N = 76) between 34 and 60 weeks' postmenstrual age with acid reflux index > 3% were randomly allocated to study (acid-suppressive therapy + feeding bundle) or conventional (acid-suppressive therapy only) arms for 4 weeks. Feeding bundle included: total fluid volume < 140 mL/kg/day, fed over 30 min in right lateral position, and supine postprandial position. Primary outcome was independent oral feeding and/or ≥6-point decrease in symptom score (I-GERQ-R). Secondary outcomes included growth (weight, length, head circumference), length of hospital stay (LOHS, days), airway (oxygen at discharge), and developmental (Bayley scores) milestones.

RESULTS

Of 688 screened: 76 infants were randomized and used for the primary outcome as intent-to-treat, and secondary outcomes analyzed for 72 infants (N = 35 conventional, N = 37 study). For study vs. conventional groups, respectively: (a) 33% (95% CI, 19-49%) vs. 44% (95% CI, 28-62%), P = 0.28 achieved primary outcome success, and (b) secondary outcomes did not significantly differ (P > 0.05).

CONCLUSIONS

Feeding strategy modifications concurrent with acid suppression are not superior to PPI alone in improving GERD symptoms or discharge feeding, short-term and long-term outcomes.

IMPACT

Conservative feeding therapies are thought to modify GERD symptoms and its consequences. However, in this randomized controlled trial in convalescing neonatal ICU infants with GERD symptoms, when controlling for preterm or full-term birth and severity of esophageal acid reflux index, the effectiveness of acid suppression plus a feeding modification bundle (volume restriction, intra- and postprandial body positions, and prolonged feeding periods) vs. acid suppression alone, administered over a 4-week period was not superior in improving symptom scores or feeding outcomes. Restrictive feeding strategies are of no impact in modifying GERD symptoms or clinically meaningful outcomes. Further studies are needed to define true GERD and to identify effective therapies in modifying pathophysiology and outcomes. The improvement in symptoms and feeding outcomes over time irrespective of feeding modifications may suggest a maturational effect. This study justifies the use of placebo-controlled randomized clinical trial among NICU infants with objectively defined GERD.

Optimizing the Use of Medications and Other Therapies in Infant Gastroesophageal Reflux

Gastroesophageal reflux (GER) is the retrograde movement of gastric (and sometimes duodenal) contents into the esophagus. While the majority of GER is physiologic, for patients, it can be associated with symptoms. While some symptoms are merely bothersome (crying), others can be life threatening (cough, gagging, choking). The main driver of GER in infants is the frequent feedings that produce increased intra-abdominal pressure, which is known to trigger transient relaxations of the lower esophageal sphincter. The recent 2018 clinical practice guidelines reported by the North American and European Societies for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN/ESPGHAN) have recommended non-pharmacologic management initially with subsequent consideration of brief trials with acid suppressants. The main target for these acid suppressants is the gastric parietal cells. Our review of the literature has revealed a paucity of data regarding the use of histamine-2 receptor antagonists and proton pump inhibitors in infants. Despite the absence of well-controlled clinical studies, the prescription rate of these medications has increased internationally. Risks to patients of all ages have become increasingly recognized, with new associations being reported all too often. Here we report our review of all pharmacologic modalities as well as some non-surgical options.

Sequential analysis in neonatal research-systematic review

As more new drugs are discovered, traditional designs come at their limits. Ten years after the adoption of the European Paediatric Regulation, we performed a systematic review on the US National Library of Medicine and Excerpta Medica database of sequential trials involving newborns. Out of 326 identified scientific reports, 21 trials were included. They enrolled 2832 patients, of whom 2099 were analyzed: the median number of neonates included per trial was 48 (IQR 22-87), median gestational age was 28.7 (IQR 27.9-30.9) weeks. Eighteen trials used sequential techniques to determine sample size, while 3 used continual reassessment methods for dose-finding. In 16 studies reporting sufficient data, the sequential design allowed to non-significantly reduce the number of enrolled neonates by a median of 24 (31%) patients (IQR - 4.75 to 136.5, p = 0.0674) with respect to a traditional trial. When the number of neonates finally included in the analysis was considered, the difference became significant: 35 (57%) patients (IQR 10 to 136.5, p = 0.0033).

CONCLUSION

Sequential trial designs have not been frequently used in Neonatology. They might potentially be able to reduce the number of patients in drug trials, although this is not always the case. What is known: • In evaluating rare diseases in fragile populations, traditional designs come at their limits. About 20% of pediatric trials are discontinued, mainly because of recruitment problems. What is new: • Sequential trials involving newborns were infrequently used and only a few (n = 21) are available for analysis. • The sequential design allowed to non-significantly reduce the number of enrolled neonates by a median of 24 (31%) patients (IQR - 4.75 to 136.5, p = 0.0674).