The pharmacodynamic effect of omeprazole 10 mg and 20 mg once daily in patients with nonerosive reflux disease in Japan

The early therapeutic response at 2 weeks is a crucial predictor of proton pump inhibitor-refractory gastroesophageal reflux disease

BACKGROUND

In recent years, the prevalence of proton pump inhibitor (PPI)-refractory gastroesophageal reflux disease (GERD) has been increasing, posing a clinical obstacle to improving the management of GERD patients. The ability of known predictive factors to explain therapeutic response to PPI remains insufficient. Therefore, we examined whether the addition of early therapeutic response to PPI as an explanatory variable may increase the predictive power for PPI-refractory GERD.

METHODS

The severity and therapeutic response of GERD symptoms to PPI were evaluated using the GastroEsophageal Reflux and Dyspepsia Therapeutic Efficacy and Satisfaction Test (GERD-TEST) questionnaire at baseline and at 2 and 4 weeks after treatment. The relevance of the therapeutic effect of PPI at 2 weeks compared to that at 4 weeks was examined in 301 patients with GERD. Independent predictive factors for refractory GERD at 4 weeks of PPI therapy were examined in 182 patients. The effect of various clinical factors, including the early response to PPI, was assessed using multiple regression analysis.

RESULTS

The number of PPI-therapy responders increased significantly with the duration of treatment (p < 0.0001). The response to PPI therapy at 2 weeks was significantly correlated with that at 4 weeks (p < 0.0001). Multiple regression analysis revealed that the therapeutic response to PPI at 2 weeks was by far the strongest predictor of the therapeutic effect at 4 weeks among all clinical factors.

CONCLUSIONS

Medication change for PPI-refractory GERD at 2 weeks may be an efficacious therapeutic strategy to improve patients' quality of life.

Oral esomeprazole in Japanese pediatric patients with gastric acid-related disease: Safety, efficacy, and pharmacokinetics

BACKGROUND

Proton pump inhibitors (PPI) are widely used for the treatment of gastric acid-related disease, but they are not approved for use in children in Japan. To assess the safety, pharmacokinetics, pharmacodynamics, and efficacy (gastrointestinal symptom improvement) of PPI in Japanese pediatric patients with gastric acid-related disease, we conducted an 8 week, open-label, parallel-group, multicenter, phase I/III study of once-daily oral esomeprazole use.

METHODS

Japanese children, aged 1-14 years with gastric acid-related disease, were stratified by weight and age into five groups (10 patients/group) to receive esomeprazole as granules for suspension (10 mg) or capsules (10 mg or 20 mg) once daily.

RESULTS

Esomeprazole was absorbed and eliminated rapidly in all groups, with a median time to reach maximum plasma concentration of 1.47-1.75 h, an arithmetic mean terminal elimination half-life of 0.80-1.37 h, and a weight-correlated apparent total body clearance of 0.216-0.343 L/h/kg. Area under the plasma concentration-time curve during a dosage interval and maximum plasma drug concentration were generally higher in groups given a higher dose (20 mg) or with a lower age/weight, but also in patients identified as poor metabolizers on cytochrome P450 2C19 genotype. Most patients who had any upper gastrointestinal symptoms at baseline were asymptomatic at the end of the study. Thirty-three patients (66%) reported ≥1 adverse events, including three patients who reported serious adverse events not judged to be causally related to esomeprazole.

CONCLUSIONS

Oral esomeprazole, at 10 mg or 20 mg once daily, had a similar safety, efficacy, and pharmacokinetic profile in Japanese pediatric patients to that previously seen in adults and Caucasian children.

The efficacy and safety of proton-pump inhibitors in treating patients with non-erosive reflux disease: a network meta-analysis

Proton-pump inhibitors (PPIs) have been proved as safe and effective ways to treat patients with non-erosive reflux disease (NERD). However, less is known about the comparisons among different PPIs and their best dosage. We aimed to synthesize the available evidence through network meta-analysis to investigate the efficacy and safety of different PPIs in treating patients with NERD. Fifteen studies with 6309 patients were included in the meta-analyses. For the rate of symptomatic relief, compared with control groups, all interventions except rabeprazole 5 mg significantly increased rate of symptomatic relief. Among the comparisons of different interventions, omeprazole 20 mg group was associated with a higher rate of symptomatic relief in contrast to omeprazole 10 mg group (odds ratio, OR: 1.89, 95% confidence interval, CI: 1.34, 2.67; p-value: 0.0005) or rabeprazole 5 mg group (OR: 2.51, 95%CI: 1.16, 5.42; p-value: 0.019); dexlansoprazole 30 mg therapy significantly improved the rate of symptomatic relief compared with rabeprazole 5 mg group (OR: 2.64, 95%CI: 1.08, 6.43; p-value: 0.03). For the rate of adverse events, there was no significant difference among all interventions.

Causes of, and therapeutic approaches for, proton pump inhibitor-resistant gastroesophageal reflux disease in Asia

Proton pump inhibitors (PPIs) are the most widely used drugs for treatment of gastroesophageal reflux disease. However, approximately 20% of patients with reflux esophagitis and 40% of those with nonerosive reflux diseases complain of troublesome symptoms, even during treatment with PPIs. In patients with reflux esophagitis, dose escalation and co-administration with a histamine H(2)-receptor antagonist are potential approaches, since the major cause of PPI resistance is incomplete suppression of gastric acid secretion. On the other hand, for patients with nonerosive reflux disease, switching from PPIs to pain modulators is often necessary for improvement of symptoms, since 25% of patients with nonerosive reflux disease have symptoms not caused by gastroesophageal acid reflux. Therapeutic approaches for PPI-resistant patients with reflux esophagitis and nonerosive reflux diseases are considered according to pathogenesis.

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.

Characteristics of non-erosive gastroesophageal reflux disease refractory to proton pump inhibitor therapy

AIM

To investigate whether potent acid inhibition is effective in non-erosive reflux disease (NERD) refractory to standard rabeprazole (RPZ) treatment.

METHODS

We treated 10 Japanese patients with NERD resistant to standard dosages of RPZ: 10 mg or 20 mg od, 20 mg bid, or 10 mg qid for 14 d. All patients completed a frequency scale for symptoms of gastroesophageal reflux disease questionnaire frequency scale for the symptoms of GERD (FSSG); and underwent 24 h pH monitoring on day 14.

RESULTS

With increased dosages and frequency of administration of RPZ, median intragastric pH significantly increased, and FSSG scores significantly decreased. With RPZ 10 mg qid, potent acid inhibition was attained throughout 24 h. However, five subjects were refractory to RPZ 10 mg qid, although the median intragastric pH in these subjects (6.6, range: 6.2-7.1) was similar to that in the remaining five responsive subjects (6.5, range: 5.3-7.3). With baseline RPZ 10 mg od, FSSG scores in responsive patients improved by > 30%, whereas there was no significant decrease in the resistant group.

CONCLUSION

NERD patients whose FSSG score fails to decrease by > 30% after treatment with RPZ 10 mg od for 14 d are refractory to higher dosage.

Randomised clinical trial: efficacy of the addition of a prokinetic, mosapride citrate, to omeprazole in the treatment of patients with non-erosive reflux disease - a double-blind, placebo-controlled study

BACKGROUND

Proton pump inhibitors (PPIs) are less effective in non-erosive reflux disease (NERD) patients than in reflux oesophagitis patients. Whether the addition of prokinetics to PPIs improves NERD patients' symptoms remains unknown.

AIM

To evaluate the efficacy of mosapride in NERD patients when used with PPI.

METHODS

A total of 200 NERD patients were randomised to one of two arms: omeprazole (10 mg once daily) plus mosapride citrate (5 mg three times a day) (treatment arm) and omeprazole plus placebo (placebo arm). The primary endpoint was the rate of responders [visual analogue scale (VAS) was zero or <1 cm] after 4 weeks of treatment. The secondary endpoints were changes in the VAS score and the safety profile.

RESULTS

There was no significant difference between the rates of responders in both arms in intent-to-treat (ITT) and per-protocol (PP) analysis. The change in the VAS score in treatment arm was significantly better than placebo arm in PP analysis (-4.0 ± 0.2 and -3.3 ± 0.2, mean ± S.E.M.) (N.S. in ITT analysis). The rate of adverse events was similar in both groups.

CONCLUSION

The addition of mosapride to omeprazole was not more effective than omeprazole alone.

Acid and non-acid reflux in Japanese patients with non-erosive reflux disease with persistent reflux symptoms, despite taking a double-dose of proton pump inhibitor: a study using combined pH-impedance monitoring

BACKGROUND

Combined multi-channel intra-luminal impedance and pH (Mll-pH) monitoring can detect gastro-esophageal reflux and identify acid and non-acid reflux (NAR) events. It can be used for patients with persistent symptoms who are having proton pump inhibitor (PPI) therapy. The aim of this study is to determine the frequency of acid reflux and NAR and to establish their relationship with persistent reflux symptoms in Japanese patients with non-erosive reflux disease (NERD) who are on a double-dose of PPI therapy.

METHODS

Thirteen patients with NERD, with persistent reflux symptoms, despite taking PPI at least twice daily, were included in this study. Twenty-four-hour combined Mll-pH monitoring was carried out on all patients and reflux episodes were detected by impedance channels, located at 3, 5, 7, 9, 15 and 17 cm above the lower esophageal sphincter (LES) and classified into acid reflux and NAR, based on pH data from 5 cm above the LES. A positive symptom index (SI) was declared, if at least half of the symptoms were preceded by reflux episodes within 5 min.

RESULTS

A total of 916 liquid reflux episodes were detected, and a total of 171 symptoms were recorded. Eight (4.7%) of 171 symptoms were related to acid reflux, and 68 (39.8%) were related to NAR. Seven (53.8%) patients had a positive SI and in these seven patients, a total of 79 symptoms were recorded. 5 (6.3%) of the 79 symptoms were related to acid reflux and 44 (55.7%) were related to NAR.

CONCLUSIONS

Persistent reflux symptoms, in SI-positive patients with NERD on double-dose PPI therapy, are more likely to be associated with primarily non-acid reflux.

Meta-analysis used to identify factors associated with the effectiveness of proton pump inhibitors against non-erosive reflux disease

BACKGROUND

A lack of published data remains on factors associated with the treatment response to proton pump inhibitors (PPI) in patients with non-erosive reflux disease (NERD).

METHODS

Studies on effectiveness of PPI in patients with NERD were identified using the MEDLINE database and manual searches of the available literature. Twenty publications that comprised a total of 22 study arms were eligible, and meta-analyses of these 22 study arms were carried out.

RESULTS

Overall improvement rate in patients with PPI was 68%. Univariate meta-regression analysis was used to explore the source of heterogeneity, P-value for males was 0.192, and in the presence of Helicobacter pylori (H. pylori) infection was 0.186, indicating that these factors are associated with treatment effectiveness. Thus, as the frequency of male and H. pylori-infected patients increased, the effectiveness of PPI against NERD improved. By multivariate meta-regression analysis, the P-value for male and H. pylori infection decreased further (P = 0.002 and P = 0.003, respectively), indicating little interaction between male sex and H. pylori infection.

CONCLUSION

These results suggest that H. pylori infection and patient sex may be associated with the effectiveness of PPI against patients with NERD. The reasons are still unclear, and further examinations are needed to clarify them.

Efficacy and safety of omeprazole in Japanese patients with nonerosive reflux disease

BACKGROUND

There is increasing awareness of nonerosive reflux disease (NERD) as a disease requiring treatment in Japan. This randomized, double-blind, placebo-controlled, parallel-group study was conducted to investigate the efficacy and safety of omeprazole 10 mg and 20 mg once daily in Japanese patients with NERD.

METHODS

Patients with heartburn for at least 2 days a week during the month before entry into the study and no endoscopic signs of a mucosal break (grade M or N according to Hoshihara's modification of the Los Angeles classification) were randomly assigned to one of three groups (omeprazole 10 mg or 20 mg, or placebo) once daily for 4 weeks.

RESULTS

Overall, 355 patients were enrolled, of whom 284 were randomly assigned to one of the three groups (omeprazole 10 mg, n = 96; omeprazole 20 mg, n = 93; placebo, n = 95). The rate of complete resolution of heartburn in week 4 was significantly higher in patients treated with omeprazole 10 mg [32.3%, 95% confidence interval (CI), 22.9%-41.6%] or 20 mg (25.8%, 95% CI, 16.9%-34.7%) than in the placebo group (12.0%, 95% CI, 5.3%-18.6%). No significant difference between the two omeprazole groups was observed. The rate of complete resolution of heartburn by omeprazole was similar between patients with grade M and those with grade N esophagus. Omeprazole also increased the rate of sufficient relief from heartburn. Omeprazole was well tolerated.

CONCLUSIONS

Omeprazole 10 mg or 20 mg once daily is effective and well tolerated in patients with NERD regardless of their endoscopic classification.

Strategy for treatment of nonerosive reflux disease in Asia

The paper is to review the clinical and pathophysiologic differences between of nonerosive reflux disease (NERD) and reflux esophagitis (RE), and to propose a treatment strategy for NERD, especially for patients in Asia. A Medline search was performed regarding the clinical and pathophysiologic differences between NERD and RE, and treatment of NERD and RE. The characteristics of NERD patients in Asia are as follows: (1) high proportion of female patients, (2) low frequency of hiatal hernia, (3) high frequency of H pylori infection, (4) severe glandular atrophy of the gastric mucosa, and (5) frequent resistance to proton pump inhibitor (PPI) therapy. In Asian NERD patients, exposure of the esophagus to acid is not increased, and esophageal motility is normal. These characteristics are similar to those of patients in Western countries. Our recommended first-choice treatment is administration of PPI in combination with a prokinetic agent. However, at present, because there is limited evidence regarding effective treatments for NERD, it is best to try several different treatment strategies to find the best treatment for each patient.