Relationship between intragastric acid control and healing status in the treatment of moderate to severe erosive oesophagitis

Randomized, Double-Blind, Active-Controlled Phase 3 Study to Evaluate Efficacy and Safety of Zastaprazan Compared With Esomeprazole in Erosive Esophagitis

INTRODUCTION

Zastaprazan is a potent potassium-competitive acid blocker developed to treat gastroesophageal reflux disease. The aim of this study was to evaluate the efficacy and safety of zastaprazan compared with esomeprazole in patient with erosive esophagitis (EE).

METHODS

A phase III, multicenter, randomized, double-blind, noninferiority clinical study was conducted with 300 subjects with confirmed EE. Subjects were randomized to receive zastaprazan 20 mg or esomeprazole 40 mg once daily up to 8 weeks. The primary end point was the cumulative proportion of subject with healed EE confirmed by endoscopy at week 8. The secondary end points included the healing rate at week 4, symptom response, and quality of life assessment. Safety profiles and serum gastrin levels were also assessed.

RESULTS

In the full analysis set, the cumulative healing rate at week 8 were 97.92% (141/144) for zastaprazan and 94.93% (131/138) ( P = 0.178) for esomeprazole. The healing rate at week 4 in the zastaprazan group was higher than the esomeprazole group (95.14% [137/144] vs 87.68% [121/138]; P = 0.026). There was no significant difference between groups in healing rates (the per-protocol set) at week 8 and week 4, symptom responses, quality of life assessments, and safety profiles. In addition, serum gastrin levels increased during treatment in both groups, with a significant difference between the 2 groups ( P = 0.047), but both decreased after treatment.

DISCUSSION

An 8-week therapy of zastaprazan 20 mg is noninferior to esomeprazole 40 mg in subjects with predominantly low-grade EE. The healing rate at week 4 appears to be higher for zastaprazan than esomeprazole.

Vonoprazan is superior to lansoprazole for healing of severe but not mild erosive esophagitis: A systematic review with meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Healing rates of severe erosive esophagitis (EE; Los Angeles [LA] Grade C/D) in patients treated with a proton pump inhibitor (PPI) is suboptimal (~60-70%). Vonoprazan, a potassium-competitive acid blocker, is suggested to have better healing rates in patients with severe EE. This meta-analysis compares the efficacy and safety of vonoprazan 20 mg versus lansoprazole 30 mg daily in healing EE, specifically in those with LA Grade C/D.

METHODS

We searched MEDLINE, Embase, and CENTRAL on May 24, 2023. Studies that randomized EE patients to vonoprazan 20 mg daily or lansoprazole 30 mg daily and compared healing rates were included. The risk of bias was assessed using Cochrane's Risk of Bias 2 tool. The fixed-effect model was used to obtain the pooled efficacy and safety outcomes. Subgroup analysis was done to compare healing rates in mild (LA Grade A/B) versus severe EE and based on study location.

RESULTS

Four randomized controlled trials (RCTs) with low risks of bias comprising 2208 participants were included. Vonoprazan 20 mg was superior to lansoprazole 30 mg daily in healing severe EE at all weeks (Week 2 RR 1.294 [95% CI 1.169-1.433], Week 4 1.160 [1.059-1.270], and Week 8 1.175 [95% CI 1.107-1.247]), but was similar for mild EE at all weeks (P-interaction < 0.01). Vonoprazan 20 mg was more efficacious than lansoprazole 30 mg at Week 8 in Western versus Asian studies (P-interaction < 0.01). Any, serious, and drug-related treatment-emergent adverse events were comparable between groups.

CONCLUSION

Vonoprazan 20 mg is superior to lansoprazole 30 mg for healing severe EE but not mild EE. Vonoprazan 20 mg daily has a similar safety profile to lansoprazole 30 mg daily.

Comparative Efficacy of P-CAB vs Proton Pump Inhibitors for Grade C/D Esophagitis: A Systematic Review and Network Meta-analysis

INTRODUCTION

Los Angeles grade C/D esophagitis is a severe manifestation of gastroesophageal reflux disease that require active treatment and close follow-up. Potassium competitive acid blockers (P-CAB) are promising alternatives to proton pump inhibitors (PPI). We aimed to compare the efficacy and safety of P-CAB and PPI in healing grade C/D esophagitis to aid clinical decision-making.

METHODS

A systematic literature search was performed using PubMed, MEDLINE, and Cochrane Central Register of Controlled Trials. Randomized controlled trials were eligible for inclusion if efficacy of P-CAB and PPI in healing grade C/D esophagitis was reported. Pooled risk ratios and risk difference with 95% credible intervals were used to summarize estimated effect of each comparison. The benefit of treatments was ranked using the surface under the cumulative probability ranking score.

RESULTS

Of 5,876 articles identified in the database, 24 studies were eligible. Studies included incorporated 3 P-CAB (vonoprazan, tegoprazan, and keverprazan) and 6 PPI (lansoprazole, esomeprazole, omeprazole, rabeprazole extended-release (ER), pantoprazole, and dexlansoprazole). Based on the failure to achieve mucosal healing, 20 mg of vonoprazan q.d. ranked the first among PPI in initial and maintained healing of grade C/D esophagitis (surface under the cumulative probability ranking score = 0.89 and 0.87, respectively). Vonoprazan had similar risk of incurring adverse events, severe adverse events, and withdrawal to drug when compared with PPI. For those who attempted lower maintenance treatment dose, 10 mg of vonoprazan q.d. was a reasonable choice, considering its moderate efficacy and safety.

DISCUSSION

Vonoprazan has considerable efficacy in initial and maintained healing of grade C/D esophagitis compared with PPI, with moderate short-term and long-term safety.

The efficacy and safety of fexuprazan in treating erosive esophagitis: a phase III, randomized, double-blind, multicenter study

BACKGROUND AND AIM

Fexuprazan is a novel potassium-competitive acid blocker (P-CAB). This study aimed to explore the noninferior efficacy and safety of fexuprazan to esomeprazole in treating erosive esophagitis (EE).

METHODS

This was a phase III, randomized, double-blind multicenter study. Patients with endoscopically confirmed EE were randomized to receive fexuprazan 40 mg or esomeprazole 40 mg once a daily for 4-8 weeks. The healing rates of EE, symptom response, GERD-health-related quality life (GERD-HRQL), and treatment-emergent adverse events (TEAEs) were compared between fexuprazan group and esomeprazole group.

RESULTS

A total of 332 subjects were included in full analysis set (FAS) and 311 in per-protocol set (PPS). The healing rates of fexuprazan and esomeprazole groups at 8 weeks were 88.5% (146/165) and 89.0% (145/163), respectively, in FAS and 97.3% (145/149) and 97.9% (143/146), respectively, in PPS. Noninferiority of fexuprazan compared with esomeprazole according to EE healing rates at 8 weeks was demonstrated in both FAS and PPS analysis. No significant difference was found between groups in EE healing rates at 4 weeks, symptom responses, and changes of GERD-HRQL. The incidence of drug-related AEs was 19.4% (32/165) in fexuprazan arm and 19.6% (32/163) in esomeprazole arm.

CONCLUSION

This study demonstrated noninferior efficacy of fexuprazan to esomeprazole in treating EE. The incidence of TEAEs was similar between fexuprazan and esomeprazole. Trial registration number NCT05813561.

Vonoprazan Versus Lansoprazole for Healing and Maintenance of Healing of Erosive Esophagitis: A Randomized Trial

BACKGROUND & AIMS

For decades, proton pump inhibitors (PPIs) have been the mainstay of treatment for erosive esophagitis. The potassium-competitive acid blocker vonoprazan provides more potent acid inhibition than PPIs, but data on its efficacy for erosive esophagitis are limited.

METHODS

Adults with erosive esophagitis were randomized to once-daily vonoprazan, 20 mg, or lansoprazole, 30 mg, for up to 8 weeks. Patients with healing were rerandomized to once-daily vonoprazan, 10 mg, vonoprazan, 20 mg, or lansoprazole, 15 mg, for 24 weeks. Primary end points, percentage with healing by week 8 endoscopy, and maintenance of healing at week 24 endoscopy, were assessed in noninferiority comparisons (noninferiority margins, 10%), with superiority analyses prespecified if noninferiority was demonstrated. Analyses of primary and secondary end points were performed using fixed-sequence testing procedures.

RESULTS

Among 1024 patients in the healing phase, vonoprazan was noninferior to lansoprazole in the primary analysis and superior on the exploratory analysis of healing (92.9 vs 84.6%; difference, 8.3%; 95% confidence interval [CI], 4.5%-12.2%). Secondary analyses showed vonoprazan was noninferior in heartburn-free days (difference, 2.7%; 95% CI, -1.6% to 7.0%), and superior in healing Los Angeles Classification Grade C/D esophagitis at week 2 (difference, 17.6%; 95% CI, 7.4%-27.4%). Among 878 patients in the maintenance phase, vonoprazan was noninferior to lansoprazole in the primary analysis and superior on the secondary analysis of maintenance of healing (20 mg vs lansoprazole: difference, 8.7%; 95% CI, 1.8%-15.5%; 10 mg vs lansoprazole: difference, 7.2%; 95% CI, 0.2%-14.1%) and secondary analysis of maintenance of healing Grade C/D esophagitis (20 mg vs lansoprazole: difference, 15.7%; 95% CI, 2.5%-28.4%; 10 mg vs lansoprazole: difference, 13.3%; 95% CI, 0.02%-26.1%).

CONCLUSIONS

Vonoprazan was noninferior and superior to the PPI lansoprazole in healing and maintenance of healing of erosive esophagitis. This benefit was seen predominantly in more severe erosive esophagitis. (ClinicalTrials.gov: NCT04124926).

ESNM/ANMS consensus paper: Diagnosis and management of refractory gastro-esophageal reflux disease

Up to 40% of patients with symptoms suspicious of gastroesophageal reflux disease (GERD) do not respond completely to proton pump inhibitor (PPI) therapy. The term "refractory GERD" has been used loosely in the literature. A distinction should be made between refractory symptoms (ie, symptoms may or may not be GERD-related), refractory GERD symptoms (ie, persisting symptoms in patients with proven GERD, regardless of relationship to ongoing reflux), and refractory GERD (ie, objective evidence of GERD despite adequate medical management). The present ESNM/ANMS consensus paper proposes use the term "refractory GERD symptoms" only in patients with persisting symptoms and previously proven GERD by either endoscopy or esophageal pH monitoring. Even in this context, symptoms may or may not be reflux related. Objective evaluation, including endoscopy and esophageal physiologic testing, is requisite to provide insights into mechanisms of symptom generation and evidence of true refractory GERD. Some patients may have true ongoing refractory acid or weakly acidic reflux despite PPIs, while others have no evidence of ongoing reflux, and yet others have functional esophageal disorders (overlapping with proven GERD confirmed off therapy). In this context, attention should also be paid to supragastric belching and rumination syndrome, which may be important contributors to refractory symptoms.

Randomised trial of acid inhibition by vonoprazan 10/20 mg once daily vs rabeprazole 10/20 mg twice daily in healthy Japanese volunteers (SAMURAI pH study)

BACKGROUND

Vonoprazan (V), a potassium-competitive acid blocker, has a more durable acid-inhibitory effect as compared with standard-dose proton pump inhibitors (PPIs) but has not been compared with 2-4 times higher daily PPI doses administered in two divided doses.

AIMS

To evaluate the acid-inhibitory effect of V 10/20 mg once-daily (OD; V10/V20) vs rabeprazole (R) 10/20 mg twice-daily (BID; R20/R40) in healthy Japanese volunteers.

METHODS

This multicentre, randomised, open-label, two-period, crossover study compared V10 or V20 vs R20, or V20 vs R40 using three cohorts of 10 healthy Japanese adults. Within each cohort, subjects were randomised to receive V or R for 7 days and, following a washout period ≥7 days, the other treatment for 7 days. On day 6 of each period, 24-hours multichannel gastric impedance-pH monitoring was performed. Percent times pH ≥ 3, ≥4 and ≥5 (pH 3, 4 and 5 holding time ratios [HTRs]) in 24 hours were evaluated as primary pharmacodynamic endpoints.

RESULTS

Acid-inhibitory effect (24-hours pH 3 HTR) of V20 was greater than those of R20 (91.0% vs 65.3%; P = .0049) and R40 (98.5% vs 85.9%; P = .0073). Similar results were obtained for 24-hours pH 4 and 5 HTRs. V20 also achieved greater nocturnal pH 4 (91.5% vs 73.2%; P = .0319) and 5 HTRs (78.8% vs 62.2%; P = .0325) as compared with R40. One subject (20%) developed diarrhoea while receiving R40 which was considered treatment-related.

CONCLUSIONS

Compared with 2-4 times the standard daily dose of R, V20 exerts a more potent and durable acid-inhibitory effect. Trial identifier: UMIN000022198 (www.umin.ac.jp/ctr/index.htm).

Pilot, Randomized, Blinded, Placebo-Controlled Trial Investigating the Correlation Between Acid Control and Heartburn Relief with 14 Days of Esomeprazole Treatment

INTRODUCTION

Reflux symptoms are frequently associated with esophageal acid exposure. However, other potential causes unrelated to acid secretion are possible, and the relationship between acid control and symptomatic improvement remains unclear. This study investigated the correlation between individual intragastric pH control and heartburn relief among subjects with frequent heartburn who are likely to self-treat with over-the-counter (OTC) medications. We hypothesized that improved acid control would provide greater symptomatic improvement among individuals representative of an OTC population.

METHODS

This phase 4, single-center, randomized, double-blind, placebo-controlled study was conducted in subjects without diagnosed gastroesophageal reflux disease or other gastrointestinal conditions who were experiencing frequent heartburn (≥ 3 episodes/week; ≥ 2 nighttime episodes/week over past 30 days) that was responsive to treatment. Subjects entered a 7-day run-in phase, received placebo BID (before breakfast and dinner), and completed symptom diaries. During the treatment phase, subjects received esomeprazole 20 mg BID, esomeprazole 20 mg then placebo, or placebo BID. Subjects underwent 24-h intragastric pH monitoring at baseline and day 14 and completed daily symptom diaries.

RESULTS

In the per-protocol population (n = 39), mean (SD) change from baseline in percentage of time with intragastric pH > 4 was 58.7% (± 26.4%) versus 41.0% (± 30.4%) for those who did and did not achieve 24-h heartburn relief. Significant correlations were observed between change in percentage of time with intragastric pH > 4 and 24-h heartburn relief (OR 1.028; 95% CI 1.001, 1.055; P = 0.0442) and complete resolution (OR 1.034; 95% CI 1.003, 1.065; P = 0.0301).

CONCLUSIONS

Individuals with greater improvements in duration of intragastric acid suppression had an increased likelihood of achieving heartburn relief and resolution. These results indicate that individuals not adequately controlling their intragastric pH may require an escalation in dose of their acid-suppressive therapy, assessment with 24-h pH monitoring, or a change in treatment regimen to address non-reflux-related etiologies of their heartburn.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02708355.

FUNDING

Pfizer Consumer Healthcare, Madison, NJ, USA. Plain language summary available for this article.

A randomized, double-blind study to evaluate the acid-inhibitory effect of vonoprazan (20 mg and 40 mg) in patients with proton-pump inhibitor-resistant erosive esophagitis

BACKGROUND

Standard treatment for patients with erosive esophagitis (EE) is proton-pump inhibitors (PPIs), but some patients are resistant to PPIs. We aimed to evaluate the acid-inhibitory effects and efficacy of a novel potassium-competitive acid blocker (vonoprazan) in patients with PPI-resistant EE.

METHODS

This randomized, double-blind, multicenter study of vonoprazan evaluated gastric and esophageal pH over a 24-hour period as the primary endpoint and EE healing rate as the secondary endpoint. Following a 7 to 14-day run-in period (lansoprazole 30 mg treatment), patients with endoscopically confirmed PPI-resistant EE received vonoprazan 20 mg or 40 mg for 8 weeks.

RESULTS

Patients were randomized to receive vonoprazan 20 mg (n = 9) or 40 mg (n = 10). Over a 24-hour period; both groups showed a significant increase from baseline in the percentage of time gastric pH ≥ 4, referred to as pH 4 holding time ratio (HTR): an increase from 73.21% to 96.46% in the 20 mg group, and from 69.97% to 100.00% in the 40 mg group. Increases from baseline in esophageal pH 4 HTRs were not significant. The 40 mg group showed greater increases in gastric and esophageal pH 4 HTRs compared with the 20 mg group, but differences between groups were not significant. After 8 weeks' treatment, the healing rate in subjects with baseline EE grades A-D was 60.0% (3/5 patients) in the 20 mg group and 71.4% (5/7 patients) in the 40 mg group. Vonoprazan was generally well tolerated. One patient (40 mg group) experienced four treatment-emergent adverse events (TEAEs) (unrelated to study drug), leading to study discontinuation.

CONCLUSIONS

Vonoprazan 20 mg and 40 mg effectively inhibited gastric acid secretion over a 24-hour period with significantly increased gastric pH 4 HTR, and resulted in an EE healing rate > 60.0% in this study. Vonoprazan treatment may be valuable for patients with PPI-resistant EE.

Pharmacokinetics and Acid Suppressant Efficacy of Esomeprazole after Intravenous, Oral, and Subcutaneous Administration to Healthy Beagle Dogs

Background

Esomeprazole is an S‐enantiomer of omeprazole that has favorable pharmacokinetics and efficacious acid suppressant properties in humans. However, the pharmacokinetics and effects on intragastric pH of esomeprazole in dogs have not been reported.

Objective

To determine the pharmacokinetics of esomeprazole administered via various routes (PK study) and to investigate the effect of esomeprazole on intragastric pH with a Bravo pH monitoring system (PD study).

Animals

Seven adult male Beagle dogs and 5 adult male Beagle dogs were used for PK and PD study, respectively.

Methods

Both studies used an open, randomized, and crossover design. In the PK study, 7 dogs received intravenous (IV), subcutaneous (SC), and oral doses (PO) of esomeprazole (1 mg/kg). Each treatment period was separated by a washout period of at least 10 days. Esomeprazole plasma concentrations were measured by HPLC/MS/MS. In the efficacy study, intragastric pH was recorded without medication (baseline pH) and following IV, SC, and PO esomeprazole dosing regimens (1 mg/kg) in 5 dogs.

Results

The bioavailability of esomeprazole administered as PO enteric‐coated granules and as SC injections was 71.4 and 106%, respectively. The half‐life was approximately 1 hour. Mean ± SD percent time intragastric pH was ≥3 and ≥4 was 58.9 ± 21.1% and 40.9 ± 17.3% for IV group, 75.8 ± 16.4% and 62.7 ± 17.7% for SC group, 88.2 ± 8.9% and 82.5 ± 7.7% for PO group, and 12.5 ± 3.6% and 3.7 ± 1.8% for baseline. The mean percent time with intragastric pH was ≥3 or ≥4 was significantly increased regardless of the dosing route (P < .05).

Conclusion

The PK parameters for PO and SC esomeprazole administration were favorable, and esomeprazole significantly increased intragastric pH after IV, PO, and SC administration. IV and SC administration of esomeprazole might be useful when PO administration is not possible. No significant adverse effects were observed.

Effects of rikkunshito on quality of life in patients with gastroesophageal reflux disease refractory to proton pump inhibitor therapy

We investigated the effects of rikkunshito, in combination with a proton pump inhibitor, on symptoms and quality of life in patients with proton pump inhibitor-refractory gastroesophageal reflux disease. The subjects were 47 patients with gastroesophageal reflux disease with residual symptoms such as heartburn following 8 weeks of proton pump inhibitor therapy. We administered these subjects rikkunshito in combination with a proton pump inhibitor for 6-8 weeks. We scored their symptoms of heartburn, fullness, abdominal discomfort, and abdominal pain, and surveyed their quality of life using the Reflux Esophagitis Symptom Questionnaire, comprising questions concerning daily activities, meals (changes in amount and favorite foods), and sleep (getting to sleep and early morning waking). Improvement was seen in all symptoms, and quality of life scores for meals and sleep also improved. These results indicate that combination therapy with rikkunshito and a proton pump inhibitor improves quality of life related to eating and sleep in patients with patients with proton pump inhibitor-refractory gastroesophageal reflux disease.

Effects of rikkunshito on quality of life in patients with gastroesophageal reflux disease refractory to proton pump inhibitor therapy

We investigated the effects of rikkunshito, in combination with a proton pump inhibitor, on symptoms and quality of life in patients with proton pump inhibitor-refractory gastroesophageal reflux disease. The subjects were 47 patients with gastroesophageal reflux disease with residual symptoms such as heartburn following 8 weeks of proton pump inhibitor therapy. We administered these subjects rikkunshito in combination with a proton pump inhibitor for 6–8 weeks. We scored their symptoms of heartburn, fullness, abdominal discomfort, and abdominal pain, and surveyed their quality of life using the Reflux Esophagitis Symptom Questionnaire, comprising questions concerning daily activities, meals (changes in amount and favorite foods), and sleep (getting to sleep and early morning waking). Improvement was seen in all symptoms, and quality of life scores for meals and sleep also improved. These results indicate that combination therapy with rikkunshito and a proton pump inhibitor improves quality of life related to eating and sleep in patients with patients with proton pump inhibitor-refractory gastroesophageal reflux disease.

Gastroesophageal Acid Reflux Control 5 Years After Antireflux Surgery, Compared With Long-term Esomeprazole Therapy

BACKGROUND & AIMS

We compared the ability of laparoscopic antireflux surgery (LARS) and esomeprazole to control esophageal acid exposure, over a 5-year period, in patients with chronic gastroesophageal reflux disease (GERD). We also studied whether intraesophageal and intragastric pH parameters off and on therapy were associated with long-term outcomes.

METHODS

We analyzed data from a prospective, randomized, open-label trial comparing the efficacy and safety of LARS vs esomeprazole (20 or 40 mg/d) over 5 years in patients with chronic GERD. Ambulatory intraesophageal and intragastric 24-hour pH monitoring data were compared between groups before LARS or the start of esomeprazole treatment, and 6 months and 5 years afterward. A secondary aim was to evaluate the association between baseline and 6-month pH parameters and esomeprazole dose escalation, reappearance of GERD symptoms, and treatment failure over 5 years in patients receiving LARS or esomeprazole.

RESULTS

In the LARS group (n = 116), the median 24-hour esophageal acid exposure was 8.6% at baseline and 0.7% after 6 months and 5 years (P < .001 vs baseline). In the esomeprazole group (n = 151), the median 24-hour esophageal acid exposure was 8.8% at baseline, 2.1% after 6 months, and 1.9% after 5 years (P < .001, therapy vs baseline, and LARS vs esomeprazole). Gastric acidity was stable in both groups. Patients who required a dose increase to 40 mg/d had more severe supine reflux at baseline, and decreased esophageal acid exposure (P < .02) and gastric acidity after dose escalation. Esophageal and intragastric pH parameters, off and on therapy, did not predict long-term symptom breakthrough.

CONCLUSIONS

In a prospective study of patients with chronic GERD, esophageal acid reflux was reduced greatly by LARS or esomeprazole therapy. However, patients receiving LARS had significantly greater reductions in 24-hour esophageal acid exposure after 6 months and 5 years. Esophageal and gastric pH, off and on therapy, did not predict long-term outcomes of patients. Abnormal supine acid exposure predicted esomeprazole dose escalation. ClinicalTrials.Gov identifier: NCT00251927 (available: http://clinicaltrials.gov/ct2/show/NCT00251927).

Management of reflux esophagitis: does the choice of proton pump inhibitor matter?

BACKGROUND

Proton pump inhibitors (PPIs) are the treatment of choice for reflux esophagitis (RE). The effectiveness of PPIs throughout RE management, from healing to maintenance, has not been fully studied.

AIM

To compare esomeprazole with lansoprazole or pantoprazole for RE management using a management model.

METHODS

Data from six studies comparing esomeprazole with lansoprazole or pantoprazole for healing (4-8 weeks) or maintenance of healing (6 months) of RE were incorporated into hypothetical management models to determine the proportion of patients in endoscopic remission after sequential healing and maintenance therapy, assuming that patients received the same PPI throughout. The number needed to treat (NNT) to achieve one more patient in remission with esomeprazole vs. other PPIs was estimated. The hypothetical model was validated using results from the EXPO study, which compared esomeprazole with pantoprazole for RE healing and maintenance.

RESULTS

Overall, esomeprazole 40 mg produced higher rates of healing (life-table estimates) than lansoprazole 30 mg (82.4-92.6% vs. 77.5-88.8%; p < 0.01) or pantoprazole 40 mg (95.5% vs. 92.0%; p < 0.001) and higher rates of endoscopic and symptomatic remission at 6 months than lansoprazole (83.0-84.8% vs. 74.0-75.9%; p < 0.001; life-table estimates) or pantoprazole (70.9% vs. 59.6%; p < 0.0001; observed rates). In the hypothetical management model, the NNT for esomeprazole was 9 vs. lansoprazole and 8 vs. pantoprazole. The actual NNT for esomeprazole vs. pantoprazole in the EXPO study was 9 (95% confidence interval: 6; 16).

CONCLUSIONS

In this management model, esomeprazole was more effective than either lansoprazole or pantoprazole for maintaining remission after sequential healing and 6 months' maintenance therapy for RE.

Predictors of either rapid healing or refractory reflux oesophagitis during treatment with potent acid suppression

BACKGROUND

Little is known regarding patient characteristics that influence the speed of reflux oesophagitis (RO) healing.

AIM

To investigate patient characteristics that may influence RO healing rates.

METHODS

A post hoc analysis of clinical trial data for potent acid suppression treatment of RO (esomeprazole or AZD0865) was conducted. Group A underwent endoscopy at baseline, week 2 and 4, and group B at baseline, week 4 and 8. Group A patients were sub-grouped as 'rapid' (healed at 2 weeks) or unhealed at 2 weeks. Group B patients were sub-grouped as 'slow' (healed at 8 weeks, not at 4 weeks) or 'refractory' (not healed at 8 weeks). Logistic regression analysis was performed only for comparisons within group A.

RESULTS

At 2, 4 and 8 weeks, RO had healed in 68%, 65% and 61% of patients unhealed at previous endoscopy, respectively. Low-grade [vs. high-grade (C or D)] RO was the only independent predictor of rapid healing in group A after logistic regression analysis. Significantly more rapid healers had low grade RO (A or B) at baseline than patients with refractory RO (84% vs. 49%; P < 0.001), and significantly more refractory patients had frequent regurgitation at baseline than slow healers (80% vs. 63%; P = 0.039).

CONCLUSIONS

Low- (vs. high-) grade RO determines the most rapid benefit from acid suppression. Roughly two-thirds of patients healed with each time increment of potent acid suppression therapy. This suggests that some unhealed patients may still heal with continued therapy and that truly refractory RO is rare. (ClinicalTrials.gov: NCT00206245).

Impairment of chemical clearance is relevant to the pathogenesis of refractory reflux oesophagitis

BACKGROUND

The pathophysiological mechanisms underlying proton pump inhibitor-refractory reflux oesophagitis has been scarcely studied.

AIMS

To assess impedance-pH parameters relevant to the pathogenesis of refractory reflux oesophagitis.

METHODS

Cases referred for heartburn/regurgitation refractory to high-dosage proton pump inhibitors between January 2008 and December 2012 were reviewed and subdivided into refractory oesophagitis (29 patients, 72% males, median age 50 years), healed oesophagitis (18 patients, 67% males, median age 54 years), and non-erosive reflux disease (49 patients, 53% males, median age 42 years). On-therapy impedance-pH tracings were blindly re-analysed by one observer to assess gastric and oesophageal acid exposure time and chemical clearance as expressed by the post-reflux swallow-induced peristaltic wave index.

RESULTS

The median gastric and oesophageal acid exposure time did not differ among the three groups (35%, 34%, 41% and 1.2%, 0.7%, 0.8%, respectively; P>0.05 for all comparisons). A normal oesophageal acid exposure time was found in two thirds of patients with refractory oesophagitis. The post-reflux swallow-induced peristaltic wave index was significantly lower in refractory oesophagitis (16%) than in healed oesophagitis (30%) and non-erosive reflux disease (29%) (P=0.003).

CONCLUSIONS

Refractory reflux oesophagitis is characterized by impairment of chemical clearance. Adequate acid suppression is found in the majority of patients who would likely not benefit from further proton pump inhibitor dose escalation.

Should peri-gastrectomy gastric acidity be our focus among gastric cancer patients?

AIM: To investigate the necessity and correctness of acid suppression pre- and post-gastrectomy among gastric carcinoma (GC) patients.

METHODS: From June 2011 to April 2013, 99 patients who were diagnosed with GC or adenocarcinoma of the gastroesophageal junction (type II or III) and needed surgical management were enrolled. They all underwent gastrectomy by the same operators [35 undergoing total gastrectomy (TG) plus Roux-en-Y reconstruction, 34 distal gastrectomy (DG) plus Billroth I reconstruction, and 30 proximal gastrectomy (PG) plus gastroesophagostomy]. We collected and analyzed their gastrointestinal juice and tissues from the pre-operational day to the 5^th day post-operation, and 6 mo post-surgery. Gastric pH was detected with a precise acidity meter. Gastric juice contents including potassium, sodium and bicarbonate ions, urea nitrogen, direct and indirect bilirubin, and bile acid were detected using Automatic Biochemical Analyzer. Data regarding tumor size, histological type, tumor penetration and tumor-node-metastasis (TNM) stage were obtained from the pathological records. Reflux symptoms pre- and 6 mo post-gastrectomy were evaluated by reflux disease questionnaire (RDQ) and gastroesophageal reflux disease questionnaire (GERD-Q). SPSS 16.0 was applied to analyze the data.

RESULTS: Before surgery, gastric pH was higher than the threshold of hypoacidity (4.25 ± 1.45 vs 3.5, P = 0.000), and significantly affected by age, tumor size and differentiation grade, and potassium and bicarbonate ions; advanced malignancies were accompanied with higher pH compared with early ones (4.49 ± 1.31 vs 3.66 ± 1.61, P = 0.008). After operation, gastric pH in all groups was of weak-acidity and significantly higher than that pre-gastrectomy; on days 3-5, comparisons of gastric pH were similar between the 3 groups. Six months later, gastric pH was comparable to that on days 3-5; older patients were accompanied with higher total bilirubin level, indicating more serious reflux (r = 0.238, P = 0.018); the TG and PG groups had higher RDQ (TG vs DG: 15.80 ± 5.06 vs 12.26 ± 2.14, P = 0.000; PG vs DG: 15.37 ± 3.49 vs 12.26 ± 2.14, P = 0.000) and GERD-Q scores (TG vs DG: 10.54 ± 3.16 vs 9.15 ± 2.27, P = 0.039; PG vs DG: 11.00 ± 2.07 vs 9.15 ± 2.27, P = 0.001) compared with the DG group; all gastric juice contents except potassium ion significantly rose; reflux symptom was significantly associated with patient’s body mass index, direct and indirect bilirubin, and total bile acid, while pH played no role.

CONCLUSION: Acidity is not an important factor causing unfitness among GC patients. There is no need to further alkalify gastrointestinal juice both pre- and post-gastrectomy.

Histamine2-receptor antagonists: Rapid development of tachyphylaxis with repeat dosing

Histamine2-receptor antagonists (H2RAs) are available over-the-counter (OTC) for the treatment and prevention of heartburn, but more than occasional, single-dose use can lead to rapid development of tachyphylaxis. The aim of this review is to assess the published evidence regarding the development of tachyphylaxis with repeat usage of H2RAs. PubMed and SCOPUS were searched across all years to identify clinical studies that examined the development of tachyphylaxis with repeated dosing of H2RAs. Although a single (first) dose of an H2RA can be effective for controlling gastric acid and preventing or relieving food-related heartburn, numerous studies confirm that tachyphylaxis, also known as tolerance, is consistently detected at the first time point assessed after the first dose, including the second day and/or second dose. Even if symptom relief is achieved with an H2RA, it may be due to desensitization of the esophagus to acid exposure, potentially providing symptom relief without significantly decreasing esophageal acid exposure. When recommending OTC drugs for treatment of frequent heartburn, clinicians should be aware of the potential for rapid development of tachyphylaxis in patients who use H2RAs for 2 or more consecutive days. Even if symptom relief is achieved, it may be due to desensitization of the esophagus to acid by the H2RA, potentially providing symptom relief without significantly decreasing esophageal acid exposure. Other strategies, such as an OTC proton pump inhibitor, may be needed to optimize management of frequent heartburn.

Mortality associated with proton pump inhibitors in cirrhotic patients with spontaneous bacterial peritonitis

BACKGROUND AND AIM

The aims of this study were to investigate whether acid suppressive therapy increases the risk of spontaneous bacterial peritonitis (SBP) and to define factors associated with mortality in cirrhotic patients with SBP.

METHODS

Cirrhotic patients who had undergone paracentesis after hospitalization were included. Those patients were divided into two groups according to the presence or absence of SBP. Factors associated with the development of SBP were analyzed. Mortality rates during hospitalization or within 30 days after SBP and the factors associated with mortality were also analyzed.

RESULTS

A total of 1140 patients (median age, 62; men, 75%; model for end-stage liver disease [MELD] score, 17) were included. Five hundred thirty-three patients were identified as having SBP. In the logistic regression, the use of histamine-2 receptor antagonists, the use of proton pump inhibitors (PPIs), a high admission MELD score, and old age were associated with the development of SBP. The use of PPIs within 30 days (adjusted odds ratio [aOR] 1.960; 95% confidence interval [CI] 1.190-3.227; P = 0.008), a higher admission MELD score (aOR 1.054; 95% CI 1.032-1.076; P < 0.001), and hepatocellular carcinoma (aOR 1.852; 95% CI 1.256-2.730; P = 0.002) were associated with mortality after SBP.

CONCLUSIONS

Acid suppressive therapy is associated with the development of SBP in cirrhotic patients with ascites. The use of PPIs is associated with mortality after SBP independent of the severity of the underlying liver disease in our retrospective cohort study.

Management of reflux-related symptoms

Gastro-oesophageal reflux disease develops when the reflux of gastric contents into the oesophagus results in troublesome symptoms and/or complications [1]. Refluxate contains predominantly acid which causes tissue injury at oesophageal and extra-oesophageal sites. It is one of the commonest gastrointestinal diagnosis worlds over. It is associated with chronic symptoms, reduced QOL, significant cost and serious complications. Goals of therapy are to provide symptom relief, heal oesophagitis and prevent long-term complications. Therapeutic measures are directed at reducing the noxiousness of the refluxate; reducing the gastro-oesophageal reflux; enhancing clearance; protecting the mucosa; reducing the mucosal sensitivity and improving healing. Acid suppression with proton pump inhibitors remains the cornerstone of therapy. Recent studies have resulted in better understanding of disease and relative efficacies of various strategies. This has paved way for a better evidence based approach. The therapy however needs to be individualized depending upon the clinical profile, disease severity, the dominant pathophysiological mechanism, cost, availability and individual preferences.

Proton pump inhibitors: the good, the bad, and the unwanted

Proton pump inhibitors (PPIs) are one of the most commonly prescribed classes of medications in the United States. By inhibiting gastric H/K adenosine triphosphatase via covalent binding to the cysteine residues of the proton pump, they provide the most potent acid suppression available. Long-term PPI use accounts for the majority of total PPI use. Absolute indications include peptic ulcer disease, chronic nonsteroidal anti-inflammatory drugs use, treatment of Helicobacter pylori, and erosive esophagitis. Although PPIs are generally considered safe, numerous adverse effects, particularly associated with long-term use have been reported. Many patients receiving chronic PPI therapy do not have clear indications for their use, prompting consideration for reduction or discontinuation of their use. This article reviews the indications for PPI use, the adverse effects/risks involved with their use, and conditions in which their use is controversial.

Gastro-esophageal reflux disease in healthy older children and adolescents

Gastro-esophageal reflux disease (GERD) in otherwise healthy older children and adolescents is commonly encountered in pediatric clinics and poses a complex treatment problem involving changes of diets and lifestyle. After an initial history taking and a physical examination, typical symptoms of GERD in older children and adolescenct are initially treated with the trials of acid suppressants. With an increase of severe cases, more and more GERD children have been evaluated with endoscopy, which helps to delineate an erosive esophagitis from a non-erosive reflux disease as they are presumed to have different pathogenesis. For the pediatric patients without a significant underlying disease, a reflux esophagitis can be treated adequately with acid suppressants. Recently, the rapid increase of children who are taking anti-reflux medication has brought up a serious alarm among pediatricians. Some at risk pediatric patients with recurrent and/or chronic GERD have been linked to adulthood GERD. In this paper, pediatric GERD with and without erosive esophagitis was reviewed along with treatment options and issues specifically for the otherwise healthy older children and adolescents in the primary clinics or the secondary hospitals.

Evolving pharmacological approaches in gastroesophageal reflux disease

INTRODUCTION

Proton pump inhibitors (PPIs) have considerably improved quality of life in patients with gastroesophageal reflux disease (GERD). However, many patients remain symptomatic despite standard PPI therapy.

AREAS COVERED

This review focuses on evolving therapeutic strategies related to the pathophysiological processes of GERD and insufficient response to PPIs. Several clinical trials evaluated new PPI formulations and newer types of acid-suppressive drugs. These studies have evaluated traditional end points in GERD, but have not shown clinical superiority to current PPIs. Novel therapeutic strategies targeting underlying mechanisms of GERD, such as transient lower esophageal sphincter relaxations (TLESRs) and esophageal hypersensitivity, are being developed for add-on therapy to PPIs. Prokinetic drugs may also have some potential in the add-on treatment of GERD with insufficient response to PPIs. Add-on studies are hampered by insufficient information on optimal patient selection and lack of established end points.

EXPERT OPINION

Newer drugs for symptomatic control in GERD have largely focused on improved acid suppression, without evidence of clinical superiority. Drugs targeting esophageal motility and sensitivity to be used as add-onc therapy in PPI insufficient responders have not reached Phase III trials to date, due to difficulties with patient selection, tolerability and end points.

High-dose esomeprazole is required for intraesophageal acid control in gastroesophageal reflux disease patients with hiatus hernia

BACKGROUND AND AIM

The aim of this study was to assess whether the efficacy of proton pump inhibitors (PPI) therapy at a standard dose in esophageal acid control is affected by the presence of hiatus hernia in Chinese gastroesophageal reflux disease patients, and whether a higher dose of PPI is required for acid control.

METHODS

Consecutive gastroesophageal reflux disease patients who had typical reflux symptoms and abnormal baseline 24-h esophageal pH and underwent upper endoscopy were enrolled to receive esomeprazole at 40 mg once daily for 4 weeks. Patients underwent the dual-channel 24-h pH test at the end of 4-week therapy. If the 24-h esophageal pH was still abnormal at the end of 4-week therapy, then esomeprazole at 40 mg twice daily was given for another 4 weeks after a washout interval of 1 week, and a 24-h pH test was repeated at the end of the therapy.

RESULTS

Overall, 76 patients were included, 13 with hiatus hernia. Of the 76 patients treated with a 40 mg of esomeprazole daily, esophageal acid exposure was normalized in 64 (84.2%). Normalization of acid exposure was achieved by standard PPI therapy in 53.2% (7/13) of patients with hiatus hernia and 90.5% (57/63) of those without (P = 0.004). A double dose of esomeprazole was successful in normalizing the esophageal pH in all 12 non-responders to the standard dose of esomeprazole, including the six patients with hiatus hernia and six patients without.

CONCLUSIONS

The standard-dose of esomeprazole fails to normalize the esophageal pH in almost 50% of patients with hiatus hernia, in whom the "double-dose" esomeprazole therapy is required.

Comparator pH study to evaluate the single-dose pharmacodynamics of dual delayed-release dexlansoprazole 60 mg and delayed-release esomeprazole 40 mg

Background:

This paper describes a Phase 1, single-center, randomized, open-label, two-period crossover study which compared the pharmacodynamic effects of single doses of dexlansoprazole modified-release 60 mg and esomeprazole 40 mg on 24-hour intragastric pH in healthy adult subjects.

Methods:

Forty-four subjects aged 20–54 years were randomized in a 1:1 ratio to two sequence groups defining the order in which they received dexlansoprazole and esomeprazole in periods 1 and 2. Primary pharmacodynamic end points over 24 hours postdose were percentage of time with intragastric pH > 4 and mean pH, and secondary pharmacodynamic end points were percentage of time intragastric pH > 4, and mean pH at 0–12 hours, and at >12–24 hours postdose. Each drug was given after an overnight fast and one hour before breakfast. Continuous pH recording began immediately before dosing through to 24 hours postdose.

Results:

At 0–24 hours postdose, the mean percentage of time with pH > 4 for dexlansoprazole and esomeprazole was 58% and 48%, respectively; the difference was statistically significant (P = 0.003). The average of mean pH values at 0–24 hours postdose for dexlansoprazole and esomeprazole were 4.3 and 3.7, respectively; the difference was statistically significant (P < 0.001). At >12–24 hours postdose, mean percentage of time with pH > 4 and average of mean pH were greater for dexlansoprazole (60% and 4.5, respectively) compared with esomeprazole (42% and 3.5, respectively); the difference was statistically significant (P < 0.001 for both intervals). At 0–12 hours postdose, the difference in dexlansoprazole and esomeprazole values for the pharmacodynamic end points was not statistically significant.

Conclusion:

For the entire 24-hour postdose period, predominantly resulting from the >12–24-hour postdose interval, the average intragastric pH following a single dose of dexlansoprazole 60 mg was higher compared with that observed following a single dose of esomeprazole 40 mg, and the difference was statistically significant.

Review of proton pump inhibitors for the initial treatment of heartburn: is there a dose ceiling effect?

Proton pump inhibitors (PPIs) are widely used in clinical practice. However, concerns have been expressed about their long-term use, particularly with regard to bone health, Clostridium difficile infections, and drug interactions with platelet aggregation inhibitors. There has been limited guidance for clinicians concerning appropriate dose selection of PPIs for the initial treatment of heartburn. This review explored whether published clinical trials provide evidence of a ceiling above which higher PPI doses do not provide additional clinical benefit over the lowest approved dose. All articles of randomized, controlled clinical trials in nonerosive gastroesophageal reflux disease (GERD) in which the effects of two or more doses of the same PPI on symptomatic relief of heartburn were quantified as a study endpoint were identified and analyzed through PubMed searches up to the end of September 2010. The majority of trials evaluated provided no evidence that higher PPI doses were superior to the lowest approved dose for the initial treatment of heartburn. There were no clinically relevant findings with respect to dose dependence and safety outcomes in these studies. Efficacy outcomes from the trials suggest there may be a dose ceiling effect and highlight the need for further research on the use of the lowest effective PPI doses as an appropriate strategy in the initial treatment of uncomplicated heartburn. Observational studies and some meta-analyses have suggested that long-term PPI pharmacotherapy might be associated with safety concerns, which necessitate the periodic evaluation of therapeutic benefit in terms of symptom resolution and regimen tolerability. However, evidence to date suggests that use of the lowest effective dose for the indication is not associated with significant adverse events, particularly in the short term. Clinical practice suggests that patients requiring long-term treatment should be maintained on the lowest dose necessary to control symptoms, and monitored for potentially confounding factors that may lead to safety concerns.

An open-label, parallel, multiple-dose study comparing the pharmacokinetics and gastric acid suppression of rabeprazole extended-release with esomeprazole 40 mg and rabeprazole delayed-release 20 mg in healthy volunteers

BACKGROUND

Novel rabeprazole extended-release (ER) formulations were developed to provide prolonged gastric acid suppression and potentially improved clinical outcomes in GERD patients.

AIM

To evaluate the pharmacodynamics and pharmacokinetics of six rabeprazole-ER formulations vs. esomeprazole 40 mg and rabeprazole delayed-release (DR) 20 mg.

METHODS

Helicobacter pylori-negative healthy subjects were randomised to receive one of eight treatments once daily for 5 days. Twenty-four-hour intragastric pH was monitored on days -1, 1 and 5. Rabeprazole plasma concentrations were measured on day 5.

RESULTS

A total of 248 subjects (N=31/group) were enrolled in the study. On day 5, rabeprazole-ER groups provided mean durations of 18.5-20.2 h (77.0-84.1% of 24-h) with intragastric pH >4.0 vs. esomeprazole 40 mg (15.9 h/66.1% of 24-h) and rabeprazole-DR 20 mg (15.2 h/63.2% of 24-h). A similar increase was observed on day 1. While percentage of daytime (8 am-10 pm) with intragastric pH >4.0 on day 5 was overall similar across the groups, percentage of night-time (10 pm-8 am) with intragastric pH >4.0 was higher with the rabeprazole-ER groups (57.0-72.4%) vs. esomeprazole 40 mg (32.8%) and rabeprazole-DR 20 mg (34.0%).

CONCLUSION

Rabeprazole-ER once daily for 5 days demonstrated a significantly longer duration of gastric acid suppression in 24 h vs. esomeprazole 40 mg and rabeprazole-DR 20 mg. The increase in acid suppression was predominantly due to prolonged acid suppression during the night-time; this was supported by the extended-release pharmacokinetic characteristics.

Weakly acidic refluxes have a major role in the pathogenesis of proton pump inhibitor-resistant reflux oesophagitis

BACKGROUND

In patients with heartburn that persists despite proton pump inhibitor (PPI) therapy, reflux oesophagitis is found rarely, and its pathogenesis has been scarcely studied.

AIM

To assess reflux parameters by impedance-pH monitoring in PPI-resistant reflux oesophagitis.

METHODS

Impedance-pH monitoring was performed on PPI therapy in patients with symptomatic reflux oesophagitis detected despite standard or high-dose PPI therapy of at least 8-week duration.

RESULTS

Twenty patients, ten on once daily and ten on twice daily PPI regimens, were studied. The gastric acid exposure time (per cent time pH <4) ranged from 10% to 81% and was >30% in 70% of cases, but the oesophageal acid exposure time (per cent time pH <4) was abnormal in 20% of patients only. The number of acid, weakly acidic and weakly alkaline refluxes was abnormal in 25%, 100% and 15% of patients, respectively.

CONCLUSIONS

Weakly acidic refluxes were above the normal range in all cases, whereas acid reflux parameters and weakly alkaline refluxes were normal in the vast majority of cases. Gastric acid secretion, with consequent intra-gastric pepsins activation, persists despite ongoing PPI therapy and activated pepsins may well be present in weakly acidic refluxes. As activated pepsins maintain their proteolytic activity in a weakly acidic environment, they may be responsible for mucosal damage. We conclude that weakly acidic refluxes have a major role in the pathogenesis of PPI-resistant reflux oesophagitis. Therapeutic interventions in patients with PPI-resistant reflux oesophagitis should be tailored on the basis of impedance-pH-monitoring results.

Randomised clinical trial: a novel rabeprazole extended release 50 mg formulation vs. esomeprazole 40 mg in healing of moderate-to-severe erosive oesophagitis - the results of two double-blind studies

BACKGROUND

Current PPIs may not achieve desired outcomes in some GERD patients due to limited duration of acid inhibition.

AIM

To evaluate a novel rabeprazole extended release (ER), which provides longer duration of drug exposure and acid suppression, in healing and symptomatic resolution of moderate-severe erosive oesophagitis.

METHODS

Patients with LA grade C or D oesophagitis were randomised to rabeprazole-ER 50 mg or esomeprazole 40 mg once daily in two identical 8-week double-blind trials (N = 2130). Two primary endpoints were tested sequentially: (1) healing by 8 weeks [hypothesis: rabeprazole-ER non-inferior to esomeprazole (non-inferiority margin = 8%)], (2) healing by 4 weeks [hypothesis: rabeprazole-ER superior to esomeprazole (P < 0.05)]. The secondary endpoint was sustained heartburn resolution at 4 weeks.

RESULTS

Rabeprazole-ER was non-inferior to esomeprazole in week-8 healing (80.0% vs. 75.0%; 77.5% vs. 78.4%). Week-4 healing (54.8% vs. 50.3%; 50.9% vs. 50.7%) and sustained heartburn resolution (48.3% vs. 48.2%; 53.2% vs. 52.5%) were not significantly different. Post hoc combined results for grade D revealed rabeprazole-ER vs. esomeprazole differences in week-8 healing = 10.4% (95% CI: -1.4%, 22.2%) and week-4 healing = 12.0% (P = 0.048).

CONCLUSIONS

Rabeprazole-ER is as effective as esomeprazole in healing moderate-severe oesophagitis and achieves similar rates of heartburn resolution. Subgroup analysis suggests the possibility of benefit in severe oesophagitis, but this requires further evaluation (ClinicalTrials.gov: NCT00658528 and NCT00658775).

Short and long-term PPI treatment for GERD. Do we need more-potent anti-secretory drugs?

Because the reflux of the acidic gastric content into the esophagus plays a major role in the pathogenesis of symptoms of GERD and lesions of erosive esophagitis, acid suppression with a proton pump inhibitor (PPI) is currently the mainstay of anti-reflux therapy. There is a strong correlation between the degree of acid suppression provided by a given drug and its efficacy. The superiority of PPIs over other drugs (antacids, prokinetics and H(2)-receptor antagonists) has now been established beyond doubt, both for short- and long-term treatment. However, there are still some unmet therapeutic needs in GERD; hence, patients with non-erosive reflux disease (NERD) are less responsive to PPIs than those with erosive esophagitis. Moreover, the efficacy of PPIs in patients with atypical symptoms is frequently limited to the relief of associated heartburn or regurgitation. With respect to safety, although most studies on short- and long-term PPI use have provided reassuring data, recent reports have drawn attention to potential side effects or drug-drug interference. Better healing rates in the most severe forms of esophagitis, or a faster onset of symptom relief, may require optimization of acid suppressive therapy with regard to the daily course of acid secretion, especially during the night. Different pharmacological approaches can be considered, with the ultimate goals of achieving faster, stronger and more-sustained acid inhibition. How a better pharmacological profile may translate into clinical benefit should now be tested in appropriate, controlled studies.

Relationship between esomeprazole dose and timing to heartburn resolution in selected patients with gastroesophageal reflux disease

OBJECTIVE

To increase response rates to therapy by increasing the dosage of proton pump inhibitor (PPI) therapy in patients with gastroesophageal reflux disease (GERD) whose symptoms are predominantly associated with acid reflux.

METHODS

In this double-blind, randomized, proof-of-concept study, 369 patients with GERD and moderate heartburn lasting ≥three days/week, a history of response to antacids/acid suppression therapy, and a positive esophageal acid perfusion test result were randomized to esomeprazole 20 or 40 mg once daily, or to 40 mg twice daily for four weeks. Heartburn symptom relief/resolution was subsequently evaluated.

RESULTS

In this study population, no relationship was apparent between esomeprazole dosage and efficacy variables for sustained heartburn resolution (seven days without symptoms) at week 4 (48.0%, 44.0%, and 41.4% for esomeprazole 20 mg once daily, 40 mg once daily, and 40 mg twice daily, respectively). Nocturnal heartburn resolution with esomeprazole 40 mg twice daily showed a numeric improvement trend versus esomeprazole 20 and 40 mg once daily, but this was not statistically significant.

CONCLUSIONS

Heartburn resolution rates at four weeks were similar for all esomeprazole dosages and comparable with rates reported previously, suggesting a plateau effect in terms of clinical response to acid suppression with PPI therapy in this population of selected GERD patients.

Evolving drugs in gastroesophageal reflux disease: pharmacologic treatment beyond proton pump inhibitors

IMPORTANCE OF THE FIELD

Despite the clinical success of proton pump inhibitors to treat gastroesophageal reflux disease (GERD), for the majority of patients in both gastroenterology and primary care clinics there is still a substantial group of patients (up to 40% in some studies) who do not completely respond symptomatically to a standard dose of proton pump inhibitors (PPIs). Specific explanations for these PPI noncomplete responders included transient lower esophageal sphincter relaxations (TLESRs), sensitivity to weakly acidic and/or alkaline reflux, large volume of reflux and esophageal hypersensitivity. There is a clear need for GERD therapies beyond the PPIs.

AREAS COVERED IN THIS REVIEW

These drug classes include the GABA(B) receptor agonists (including lesogaberan and arbaclofen placarbil), mGluR5 receptor antagonists, P-CABs, cholecystokinin(2) antagonists and add-on therapies to PPIs including mosapride and rikkunshito.

WHAT THE READER WILL GAIN

Both physicians and patients are eagerly awaiting the development and FDA approval of a new class of anti-GERD medications targeting distinct mechanisms. This article provides information on pharmacologic strategies, clinical trials and side-effect profiles on several of the most promising and heavily researched compounds being developed today for the treatment of GERD symptoms and inflammation. Hopefully, this important research will help a large group of PPI noncomplete responding patients receive symptomatic relief and reduce esophageal inflammation through a unique pharmacologic mechanism in the near future.

TAKE HOME MESSAGE

The treatment of GERD has greatly improved with the PPI class of therapy. Despite excellent success, there is a sizeable population of patients who do not have adequate response to therapies directed only at acid suppression. Emerging new pharmacologic treatment options show promise in further advancing the treatment success of GERD.

A model of healing of Los Angeles grades C and D reflux oesophagitis: is there an optimal time of acid suppression for maximal healing?

BACKGROUND

In patients with Los Angeles (LA) grade C or D oesophagitis, a positive relationship has been established between the duration of intragastric acid suppression and healing.

AIM

To determine whether there is an apparent optimal time of intragastric acid suppression for maximal healing of reflux oesophagitis.

METHODS

Post hoc analysis of data from a proof-of-concept, double-blind, randomized study of 134 adult patients treated with esomeprazole (10 or 40 mg od for 4 weeks) for LA grade C or D oesophagitis. A curve was fitted to pooled 24-h intragastric pH (day 5) and endoscopically assessed healing (4 weeks) data using piecewise quadratic logistic regression.

RESULTS

Maximal reflux oesophagitis healing rates were achieved when intragastric pH >4 was achieved for approximately 50-70% (12-17 h) of the 24-h period. Acid suppression above this threshold did not yield further increases in healing rates.

CONCLUSION

After 4 weeks' acid-suppressive therapy for LA grade C or D oesophagitis, successful healing appears to reach a threshold above which improvements are unlikely to be achieved despite an increase in number of hours with intragastric pH >4.

Prevention of relapse of healed reflux esophagitis is related to the duration of intragastric pH > 4

Proton pump inhibitors (PPIs) are the preferred treatment for maintenance of healed reflux esophagitis (RE). However, little is known regarding the relationship between prevention of RE relapse and degree of gastric acid suppression. The aim of this review was to examine this relationship in further detail. Data from four comparative studies on maintenance PPI therapy for prevention of relapse of RE were combined with data from two pharmacodynamic studies of duration of intragastric pH >4 during the 24-hour period on day 5 of PPI dosing in healthy subjects. A log-linear model was fitted to the data using the method of maximum likelihood. Variability in relapse rates and pH data was taken into account using a binomial and normal likelihood function, respectively. Pharmacodynamic studies resulted in a wide range of acid-suppressive effect, and based on corresponding maintenance of RE healing rates with different PPIs and doses, an inverse (non-linear) statistically significant relationship between percentage of time with pH >4 and maintenance of RE healing was identified (P<0.001). These findings indicate that long-term maintenance of healed RE is related to the extent of acid suppression in a 24-hour period.

Acute Vomiting in Cats

Practical relevance The control of nausea and vomiting in cats is important in order to prevent the development of food aversion, anorexia (with its associated complications of weight loss and dehydration), and hepatic lipidosis.

Clinical challenges There are several antiemetic drugs that are clinically effective in cats. Making a rational choice from the available options requires knowledge of the likely cause of the vomiting, and the mechanisms of action and side effects of each drug. For example, a drug such as prochlorperazine, which can cause sedation, may be a useful first-line choice in a hospitalized cat that requires mild sedation to be handled, but would be undesirable in a critically ill cat.

Audience For companion animal and feline practitioners, the vomiting cat is a common presentation.

Evidence base The guidance provided in this review draws on the findings of clinical trials in humans, experimental studies in cats, some clinical trials in cats, and clinical experience.

Esophageal impedance and esophagitis in children: any correlation?

AIM

: The aim of this study was to correlate the data obtained with multiple intraluminal esophageal impedance and pH (MII-pH) recordings in infants and children referred for suspected gastroesophageal reflux disease with esophageal histology.

MATERIALS AND METHODS

: In a prospective study, results of esophageal biopsies and MII-pH recording obtained in 45 children (mean age +/- SD: 69 +/- 55 months) were analyzed. Regarding the MII-pH data, an automatic (Autoscan Bioview Analysis Software, version 5.3.4, Sandhill Scientific Inc, Highlands Ranch, CO) and a manual reading were performed; an automatic pH analysis (meal included) was also performed.

RESULTS

: Acidic, weakly acidic, and alkaline reflux episodes accounted, respectively, for 48.7%, 49.5%, and 1.8% of the total number of reflux episodes detected by MII-pH. Esophagitis was present in 25 (56%) children. Concordance between classic pH-study analysis (alone) and esophageal histology was found in 19 of 45 (42%) children. According to the MII-pH analysis, the mean and median value of the pH were significantly higher in the group with esophagitis than in the group with normal esophageal histology. A longer clearance time was found in the group with esophagitis than in subjects with normal histology. Gas reflux episodes represented 21% of the total reflux episodes and were comparable in both groups.

CONCLUSIONS

: Multiple intraluminal esophageal impedance and pH analysis does not provide a distinct parameter to predict esophageal mucosal injury in children. In our population, MII-pH shows comparable acidic, weakly acidic, alkaline, and gas reflux in children with and without esophagitis. Further research is needed to analyze clearance parameters.

Clinical trial: the effect and timing of food on the pharmacokinetics and pharmacodynamics of dexlansoprazole MR, a novel Dual Delayed Release formulation of a proton pump inhibitor--evidence for dosing flexibility

BACKGROUND

Dexlansoprazole MR is a proton pump inhibitor with a Dual Delayed Release (DDR) formulation designed to prolong the dexlansoprazole plasma concentration-time profile. The presence of food or time of dosing relative to food may affect dexlansoprazole absorption.

AIMS

To evaluate the effect of food on the pharmacokinetics (PK) and pharmacodynamics (PD) of dexlansoprazole following oral administration of dexlansoprazole MR.

METHODS

In this open-label, single-dose, randomized, 4-way crossover study, 48 healthy subjects received placebo (day 1) and dexlansoprazole MR 90 mg (day 3) after fasting, 5 or 30 min before a high-fat breakfast, or 30 min after a high-fat breakfast. Intragastric pH (days 1 and 3) and PK (day 3) of dexlansoprazole were assessed over a 24-h interval after each dose.

RESULTS

Following administration of dexlansoprazole MR under fasted/fed conditions, mean dexlansoprazole plasma concentration-time profiles generally exhibited two distinct peaks, resulting from the DDR formulation. Increases in dexlansoprazole maximum plasma concentration (12-31%) and area under the plasma concentration-time curve (9-21%) were observed with the fed regimens; however, differences in intragastric pH were not considered clinically relevant.

CONCLUSION

Dexlansoprazole MR can be administered without regard to food or the timing of food in most patients.

Control of 24-hour intragastric acidity with morning dosing of immediate-release and delayed-release proton pump inhibitors in patients with GERD

GOALS

To compare the effects of immediate-release omeprazole and 2 different delayed-release proton pump inhibitors on 24-hour intragastric acidity in gastroesophageal reflux disease patients.

BACKGROUND

Because of its unique pharmacokinetic properties, immediate-release omeprazole does not need to be dosed before a meal to control intragastric acidity. Previous studies showed effectiveness of immediate-release omeprazole in controlling nocturnal intragastric acidity with bedtime dosing. This is the first study to compare the effects of prebreakfast dosing of immediate-release omeprazole and delayed-release lansoprazole and pantoprazole on 24-hour intragastric acidity.

AIM

To compare the effects of prebreakfast dosing of immediate-release omeprazole 40 mg capsules, lansoprazole 30 mg capsules, and pantoprazole 40 mg tablets on 24-hour intragastric acidity.

METHODS

Fifty-five patients with gastroesophageal reflux disease received 7 consecutive once-daily morning doses of each drug in this open-label, randomized, 3-period crossover study. On day 7, intragastric pH was recorded for 24 hours.

RESULTS

After 7 days, the percentage of time with intragastric pH >4 over 24 hours was 59.7% (14.3 hours) with immediate-release omeprazole, 48.8% (11.7 hours) with lansoprazole (P=0.005), and 41.8% (10.0 hours) with pantoprazole (P<0.001). Median intragastric pH was significantly higher with immediate-release omeprazole than with lansoprazole (P=0.003) or pantoprazole (P<0.001). All drugs were well tolerated.

CONCLUSIONS

When dosed in the morning, immediate-release omeprazole provided significantly better control of 24-hour intragastric acidity than lansoprazole and pantoprazole.

Pharmacokinetics and pharmacodynamics of a known active PPI with a novel Dual Delayed Release technology, dexlansoprazole MR: a combined analysis of randomized controlled clinical trials

BACKGROUND

Dexlansoprazole MR is a novel Dual Delayed Release formulation of dexlansoprazole, an enantiomer of lansoprazole, designed to prolong the plasma concentration-time profile of dexlansoprazole and extend duration of acid suppression with once-daily (QD) dosing.

OBJECTIVES

To assess the pharmacokinetics and pharmacodynamics of dexlansoprazole at different doses of dexlansoprazole MR and delineate the exposure-response relationship following oral administration of dexlansoprazole MR.

METHODS

Dexlansoprazole MR was evaluated in two prospective randomized studies in healthy subjects. In study 1 (n = 40), subjects received dexlansoprazole MR 60, 90, and 120 mg and lansoprazole 30 mg QD. In study 2 (n = 45), subjects received dexlansoprazole MR 30 and 60 mg and lansoprazole 15 mg QD. Data from these trials were pooled and analyzed to describe the relationship between intragastric pH and dexlansoprazole systemic exposure.

RESULTS

Data from 83 subjects were analyzed. The dexlansoprazole plasma concentration-time profile following administration of dexlansoprazole MR was characterized by two distinct peaks and a prolonged drug exposure during the 24-h dosing interval. Approximate dose proportionality was observed for mean peak plasma concentration and area under the plasma-concentration time curve after administration of dexlansoprazole MR. In each study, doses of dexlansoprazole MR generally produced greater gastric acid suppression than lansoprazole. Based on the exposure-response analysis using combined data from these two trials, the predicted mean 24-h intragastric pH values were 4.06 and 4.35 for the dexlansoprazole MR 30- and 90-mg doses, respectively. The percent of time pH > 4 over 24 h values were 59.2% and 66.7% for dexlansoprazole MR 30 and 90 mg, respectively. No appreciable additional gain in the pharmacodynamic response was predicted for dexlansoprazole MR 120 mg. Despite combining data from two studies to evaluate a broader dose range, this analysis provided a reasonable estimate of the pharmacodynamic parameters and a good characterization of the dexlansoprazole MR exposure-response relationship.

CONCLUSIONS

Dexlansoprazole MR, a proton pump inhibitor that uses Dual Delayed Release technology, produced a pharmacokinetic profile with a plasma concentration-time curve characterized by two distinct peaks and an extended duration of pharmacologically active dexlansoprazole concentration in plasma. Exposure-response analysis indicated a progressive increase in the pharmacodynamic response as dexlansoprazole MR doses increased from 30 to 90 mg.

Esomeprazole: a proton pump inhibitor

Proton pump inhibitors (PPIs) are the most potent inhibitors of gastric acid secretion available, and they are effective for treating all acid-related disorders. Esomeprazole is one of several most recent PPIs that became available to the market in 2001. Esomeprazole is indicated for the treatment of gastroesophageal reflux disease in adults and children, risk reduction of NSAIDs-associated gastric ulcer, Helicobacter pylori eradication and control of pathological hypersecretory conditions associated with Zollinger-Ellison syndrome. Esomeprazole is available in both oral and intravenous formulations. A number of studies have compared esomeprazole with other PPIs. While differences supporting esomeprazole have been reported, the magnitude of differences has been variable and of uncertain clinical importance. Cost plays a major role in prescribing patterns of PPIs.

Medical management of gastroesophageal reflux disease

Antisecretory therapies that raise intragastric pH provide the best healing of the esophageal mucosal damage that occurs in gastroesophageal reflux disease. Continuous maintenance therapy is also effective to reduce the likelihood of recurrence of esophagitis and control symptoms in the long term. Proton pump inhibitor (PPI) therapy is an effective approach for healing esophagitis and controlling symptoms. Endoscopic and surgical treatments may provide an option for patients who are refractory to PPIs in whom reflux has been clearly demonstrated. Long-term antireflux medication is often needed after surgical treatment because of persisting or recurrent pathologic reflux and symptoms. An alternative approach to controlling transient lower esophageal sphincter relaxations, such as the GABA-B agonists, deserves further study.

Effect of increasing esomeprazole and pantoprazole doses on acid control in patients with symptoms of gastro-oesophageal reflux disease: a randomized, dose-response study

BACKGROUND AND OBJECTIVE

In patients with gastro-oesophageal reflux disease (GORD), dose escalation or drug switching may be considered in those with symptoms that persist despite standard-dose proton pump inhibitor (PPI) therapy. This study set out to assess whether increasing the dosage of oral esomeprazole and pantoprazole improves acid control in GORD patients, and to compare the pharmacodynamic efficacy of esomeprazole and pantoprazole administered at different dosages.

METHODS

This was an open-label, randomized, six-way crossover study that included Helicobacter pylori-negative GORD patients (aged 20-60 years) with <30% of time with intragastric pH>4. Patients were treated with oral once-daily esomeprazole 20 mg, 40 mg and 80 mg, and pantoprazole 20 mg, 40 mg and 80 mg, for 5 days. The main outcome measures were time with intragastric pH>4 over 24 hours, median pH over 24 hours and area under the hydrogen ion versus time curve on day 5 for each treatment period.

RESULTS

Dose escalation with both PPIs improved acid control. The proportion of time with intragastric pH>4 (day 5) was 46.7% with esomeprazole 20 mg/day, 58.6% with esomeprazole 40 mg/day, and 65.8% with esomeprazole 80 mg/day; the corresponding percentages with pantoprazole were 28.6%, 36.9% and 44.9%, respectively. On a milligram-per-milligram basis, esomeprazole provided greater acid control than pantoprazole (p<0.001).

CONCLUSION

Dose escalation with oral esomeprazole and pantoprazole improves acid control in patients with GORD, although esomeprazole provides significantly greater acid control on a milligram-per-milligram basis.

Proton pump inhibitors: an update of their clinical use and pharmacokinetics

BACKGROUND

Proton pump inhibitors (PPIs) represent drugs of first choice for treating peptic ulcer, Helicobacter pylori infection, gastrooesophageal reflux disease, nonsteroidal anti-inflammatory drug (NSAID)-induced gastrointestinal lesions (complications), and Zollinger-Ellison syndrome.

RESULTS

The available agents (omeprazole/esomeprazole, lansoprazole, pantoprazole, and rabeprazole) differ somewhat in their pharmacokinetic properties (e.g., time-/dose-dependent bioavailability, metabolic pattern, interaction potential, genetic variability). For all PPIs, there is a clear relationship between drug exposure (area under the plasma concentration/time curve) and the pharmacodynamic response (inhibition of acid secretion). Furthermore, clinical outcome (e.g., healing and eradication rates) depends on maintaining intragastric pH values above certain threshold levels. Thus, any changes in drug disposition will subsequently be translated directly into clinical efficiency so that extensive metabolizers of CYP2C19 will demonstrate a higher rate of therapeutic nonresponse.

CONCLUSIONS

This update of pharmacokinetic, pharmacodynamic, and clinical data will provide the necessary guide by which to select between the various PPIs that differ-based on pharmacodynamic assessments-in their relative potencies (e.g., higher doses are needed for pantoprazole and lansoprazole compared with rabeprazole). Despite their well-documented clinical efficacy and safety, there is still a certain number of patients who are refractory to treatment with PPIs (nonresponder), which will leave sufficient space for future drug development and clinical research.

Esomeprazole in acute and maintenance treatment of reflux oesophagitis: a multicentre prospective study

INTRODUCTION

The aim of this study was to assess the efficacy and safety of esomeprazole 40 mg once daily (q.d.) in healing reflux oesophagitis at 4 and 8 weeks, and the efficacy of esomeprazole 20 mg q.d. for 12 weeks in the maintenance of remission.

METHODS

A total of 235 patients with endoscopically proven reflux oesophagitis were enrolled in this study, which consisted of two phases (healing and maintenance therapy). Patients who showed complete endoscopic and symptomatic healing at the end of 4 or 8 weeks were switched to maintenance treatment with esomeprazole 20 mg q.d. for 12 weeks. The primary efficacy endpoint was healing of reflux oesophagitis at week 8. Secondary assessments included the proportion of patients with symptomatic relapse in the maintenance phase.

RESULTS

At the end of week 8, 88% (95% life-table confidence intervals [CI]: 84%, 92%) of patients were healed endoscopically and 90.6% of the patients were asymptomatic. Patient age, gender and Helicobacter pylori status had no effect on the efficacy of treatment. During the 12-week maintenance treatment phase, symptomatic relapse ratios were 0.5%, 2.2%, and 0%, for the first, second, and third 4-week periods, respectively. The proportions of patients satisfied with treatment were 95% and 99.4% at the end of acute and maintenance treatment, respectively. The most common adverse effects were headache, upper respiratory tract infection and abdominal pain.

CONCLUSIONS

Esomeprazole is effective in the healing of reflux oesophagitis, the resolution of heartburn, and in maintaining symptomatic remission. The effectiveness of esomeprazole in patients with gastroesophageal reflux disease is not affected by the presence of H. pylori.

Intravenous esomeprazole 40 mg vs. intravenous lansoprazole 30 mg for controlling intragastric acidity in healthy adults

BACKGROUND

Intravenous (IV) formulations of proton pump inhibitors are effective for patients in whom oral therapy is not appropriate.

AIM

To compare IV esomeprazole and IV lansoprazole for the control of intragastric pH.

METHODS

In this open-label crossover study, healthy, Helicobacter pylori-negative adults were randomized to one of two treatment sequences, each consisting of two 5-day dosing periods of IV esomeprazole 40 mg or IV lansoprazole 30 mg. Twenty-four-hour intragastric pH monitoring was conducted on days 1 and 5 of each dosing period.

RESULTS

On days 1 and 5, intragastric pH was >4.0 significantly longer with esomeprazole than lansoprazole (least-squares means: day 1, 40.0% vs. 33.6%; day 5, 61.9% vs. 45.4%; both P < 0.0001). During the first 4 h of pH monitoring, intragastric pH was >4.0 significantly longer on days 1 and 5 with esomeprazole than lansoprazole (P < 0.0001). Kaplan-Meier estimates of median hours to stable pH >4.0 were 4.92 for esomeprazole and 5.75 for lansoprazole (P = 0.0014 for test on Gehan scores).

CONCLUSION

In healthy adults, IV esomeprazole 40 mg controlled intragastric acidity faster and more effectively than IV lansoprazole 30 mg.