Appropriate acid suppression for optimal healing of duodenal ulcer and gastro-oesophageal reflux disease

Efficacy and safety of vonoprazan versus proton pump inhibitors in the treatment of peptic ulcer disease: a systematic review and network meta-analysis for randomized controlled trails

Background and aims

Vonoprazan, a novel acid suppressant, has been employed in the treatment of peptic ulcer disease in recent years. However, the efficacy and safety of vonoprazan versus proton-pump inhibitors remains controversial. To address this gap, a systematic review and network meta-analysis were conducted to evaluate the efficacy and safety of vonoprazan in comparison with various proton-pump inhibitors.

Methods

Randomized controlled trials that met selection criteria in PubMed (Medline), EMBASE and the Cochrane Library were searched up to July 15, 2024. The primary outcome was ulcer healing rate. Secondary outcomes were treatment-emergent adverse events and drug-related adverse events. Effect size on outcomes is presented as odds ratios with 95% confidence intervals.

Results

Thirty-five randomized controlled trials containing 9,544 participants were included. In terms of the healing rate at 2 weeks, lansoprazole 30 mg ranked first, followed by vonoprazan 20 mg and ilaprazole 10 mg. In terms of the healing rate at 4 weeks, pantoprazole 40 mg ranked first, with rabeprazole 10 mg and lansoprazole 30 mg ranking second and third, respectively. Regarding the healing rate at 8 weeks, lansoprazole 30 mg is demonstrated to be the most efficacious regimen. Moreover, subgroup analysis indicated that lansoprazole 30 mg is the optimal regimen in the treatment of artificial gastric ulcer at 4 and 8 weeks. Importantly, lansoprazole 30 mg has fewer adverse reactions and higher safety.

Conclusion

The optimal regimen for the treatment of peptic ulcer disease may be lansoprazole 30 mg at 2 and 8 weeks, while pantoprazole 40 mg has demonstrated superior performance at the 4-week when compared to vonoprazan 20 mg. Furthermore, lansoprazole 30 mg has shown to be superior in terms of safety outcomes. These findings, derived from a network meta-analysis, necessitate further research for validation.

Comparative Efficacy and Safety of Potassium-Competitive Acid Blockers vs. Proton Pump Inhibitors for Peptic Ulcer with or without Helicobacter pylori Infection: A Systematic Review and Network Meta-Analysis

Novel potassium-competitive acid blockers (P-CABs) have emerged as effective acid-suppressive drugs in recent years, replacing proton pump inhibitors (PPIs). We aim to compare the efficacy and safety of P-CABs versus PPIs in the treatment of peptic ulcers with or without Helicobacter pylori (H. pylori) infection. We searched in PubMed, Embase, WOS, Cochrane Library, ClinicalTrials.gov, CNKI, and Wanfang databases (all years up to January 2024). Efficacy and safety outcomes were evaluated using odds ratio (OR) and 95% confidence intervals (CI). The Surface Under the Cumulative Ranking (SUCRA) probabilities were used to rank each intervention. Among 14,056 studies screened, 56 studies involving 9792 participants were analyzed. Vonoprazan demonstrated the best efficacy in ulcer healing rate and H. pylori eradication rate (SUCRA = 86.4% and 90.7%, respectively). Keverprazan ranked second in ulcer healing rates (SUCRA = 76.0%) and was more effective in pain remission rates (SUCRA = 91.7%). The risk of adverse events was low for keverprazan (SUCRA = 11.8%) and tegoprazan (SUCRA = 12.9%), and moderate risk for vonoprazan (SUCRA = 44.3%) was demonstrated. Compared to lansoprazole, vonoprazan exhibited a higher risk of drug-related adverse events (OR: 2.15; 95% CI: 1.60-2.89) and serious adverse events (OR: 2.22; 95% CI: 1.11-4.42). Subgroup analysis on patients with H. pylori-positive peptic ulcers showed that vonoprazan was at the top of the SUCRA rankings, followed by keverprazan. Vonoprazan showed superior performance in peptic ulcers, especially for patients with H. pylori-positive peptic ulcers. However, the risk of adverse events associated with vonoprazan should be noted. Keverprazan has also shown good therapeutic outcomes and has performed better in terms of safety.

Comparative efficiency and safety of potassium competitive acid blockers versus Lansoprazole in peptic ulcer: a systematic review and meta-analysis

Background: Lansoprazole, a proton-pump inhibitor (PPI), is the primary therapy for peptic ulcers (PU). Potassium competitive acid blockers (P-CAB) offer an alternative for acid suppression. However, the efficacy and safety of P-CABs versus lansoprazole in the management of PU has not been evaluated. Methods: Five databases were searched for randomized clinical trials in English until 31 August 2023. Data extraction provided outcome counts for ulcer healing, recurrent NSAID-related ulcer, and adverse events. The pooled effect, presented as rate difference (RD), was stratified by ulcer location, follow-up time, and the types of P-CAB, along with their corresponding 95% confidence intervals (95% CI). Results: The pooled healing rates of peptic ulcers were 95.3% (1,100/1,154) and 95.0% (945/995) for P-CABs and lansoprazole, respectively (RD: 0.4%, 95% CI: -1.4%-2.3%). The lower bounds of the 95% CI fell within the predefined non-inferiority margin of -6%. In subgroup analyses base on ulcer location, and follow-up time also demonstrated non-inferiority. The drug-related treatment-emergent adverse events (TEAEs) did not differ significantly among groups (RR: 0.997, 95% CI: 0.949-1.046, p = 0.893). However, P-CAB treatment was associated with an increased risk of the serious adverse events compared to lansoprazole (RR: 1.325, 95% CI: 1.005-1.747, p = 0.046). Conclusion: P-CABs demonstrated non-inferiority to lansoprazole in the management of peptic ulcer. The safety and tolerability profile are comparable, with similar TEAEs rates. However, P-CABs appear to have a higher risk of serious adverse events. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=458361 Identifier: PROSPERO (No. CRD42023458361).

Proton Pump Inhibitors, Kidney Damage, and Mortality: An Updated Narrative Review

Since their approval by the Food and Drug Administration (FDA) in 1989, proton pump inhibitors (PPIs) have become one of the most highly utilized drugs in the United States, assuming a position as one of the top 10 most prescribed medications in the country. The purpose of PPIs is to limit the amount of gastric acid secreted by the parietal cells via irreversible inhibition of the H+/K+-ATPase pump, therefore maintaining an elevated gastric acid pH of greater than 4 for 15-21 h. Even though PPIs have many clinical uses, they are not without their adverse effects, mimicking achlorhydria. Besides electrolyte abnormalities and vitamin deficiencies, long-term use of PPIs has been linked to acute interstitial nephritis, bone fractures, poor COVID-19 infection outcomes, pneumonia, and possibly an increase in all-cause mortality. The causality between PPI use and increased mortality and disease risk can be questioned since most studies are observational. Confounding variables can greatly affect an observational study and explain the wide-ranging associations with the use of PPIs. Patients on PPIs are generally older, obese, sicker with a higher number of baseline morbidities, and on more medications than the compared PPI non-users. These findings suggest that PPI users are at a higher risk of mortality and complications based on pre-existing conditions. This narrative review aims to update readers on the concerning effects that proton pump inhibitor use can have on patients and give providers a resource to create informed decisions on appropriate PPI use.

Efficacy of keverprazan for duodenal ulcer: A phase II randomized, double-blind, parallel-controlled trial

BACKGROUND AND AIM

Considering the limitation of varying acid suppression of proton pump inhibitors, this study was aimed to assess the efficacy, safety, and dose-effect relationship of keverprazan, a novel potassium-competitive acid blocker, in the treatment of duodenal ulcer (DU) compared with lansoprazole.

METHODS

A randomized, double-blind, double-dummy, multicenter, low-dose, high-dose, and positive-drug parallel-controlled study was conducted to verify the non-inferiority of keverprazan (20 or 30 mg) to lansoprazole of 30 mg once daily for 4 to 6 weeks and dose-effect relationship of keverprazan in the treatment of patients with active DU confirmed by endoscopy.

RESULTS

Of the 180 subjects randomized, including 55 cases in the keverprazan_20 mg group, 61 cases in the keverprazan_30 mg group, and 64 cases in the lansoprazole_30 mg group, 168 subjects (93.33%) completed the study. The proportions of healed DU subjects in the keverprazan_20 mg, keverprazan_30 mg, and lansoprazole_30 mg groups were respectively 87.27%, 90.16%, and 79.69% at week 4 (P = 0.4595) and were respectively 96.36%, 98.36%, and 92.19% at week 6 (P = 0.2577). The incidence of adverse events in the keverprazan_20 mg group was lower than that in the lansoprazole_30 mg (P = 0.0285) and keverprazan_30 mg groups (P = 0.0398).

CONCLUSIONS

Keverprazan was effective and non-inferior to lansoprazole in healing DU. Based on the comparable efficacy and safety data, keverprazan of 20 mg once daily is recommended for the follow-up study of acid-related disorders. (Trial registration number: ChiCTR2100043455.).

Interchangeable Use of Proton Pump Inhibitors Based on Relative Potency

Although proton pump inhibitors (PPIs) are widely used, their relative potency and ideal dosing regimens remain unclear. We analyzed data from randomized clinical trials that performed pH testing in patients receiving solid-dose PPI formulations (omeprazole, esomeprazole, lansoprazole, pantoprazole, rabeprazole) for a minimum of 5 days. We used omeprazole equivalency and the surrogate biomarker, percentage time pH > 4 over a 24-hour period (pH4time), to compare PPI effectiveness for different PPIs given once, twice, or 3 times daily. We found that increasing strength of once-daily PPIs (9-64 mg omeprazole equivalents) increased pH4time linearly from approximately 10.0 to 15.6 hours; higher doses produced no further increase in pH4time. Increasing the frequency to twice-daily PPI increased pH4time linearly, from approximately 15.8 to 21.0 hours. Three-times daily PPIs performed similarly to twice-daily PPIs. The costs of PPIs varied greatly, but the cost variation was not directly related to potency. We conclude that PPIs can be used interchangeably based on potency. Using twice-daily PPIs is more effective in increasing efficacy increasing once-daily PPI dosage. Omeprazole and lansoprazole (30 mg) and 20 mg of esomeprazole rabeprazole are functionally equivalent.

Tyrosine Kinase Inhibitors and Proton Pump Inhibitors: An Evaluation of Treatment Options

Tyrosine kinase inhibitors (TKIs) have rapidly become an established factor in oncology, and have been shown to be effective in a wide variety of solid and hematologic malignancies. Use of the oral administration route of TKIs offers flexibility and is convenient for the patient; however, despite these advantages, the oral route of administration also causes a highly relevant new problem. Acid-inhibitory drugs, such as proton pump inhibitors (PPIs), increase the intragastric pH, which may subsequently decrease TKI solubility, bioavailability, and treatment efficacy. Clear and practical advice on how to manage PPI use during TKI therapy is currently not available in the literature. Since PPIs are extensively used during TKI therapy, prescribers are presented with a big dilemma as to whether or not to continue the combined treatment, resulting in patients possibly being deprived of optimal therapy. When all pharmacological characteristics and data of either TKIs and PPIs are considered, practical and safe advice on how to manage this drug combination can be given.

Vonoprazan is superior to proton pump inhibitors in healing artificial ulcers of the stomach post-endoscopic submucosal dissection: A propensity score-matching analysis

BACKGROUND AND AIM

Proton pump inhibitors (PPI) are effective at healing artificial ulcers after endoscopic submucosal dissection (ESD) for gastric neoplasms; however, the efficacy of vonoprazan is not completely understood. The aim of the present study was to determine the healing effect of vonoprazan on artificial ulcers post-gastric ESD relative to PPI.

METHODS

Thirty-five patients who underwent gastric ESD between April and November 2015 were treated with vonoprazan 20 mg/day for 4 weeks and subsequently underwent endoscopy for evaluation of ulcer size (V group). Ulcer contraction rate was determined by the following formula: ([ESD specimen size] - [ulcer size at 4 weeks after ESD])/(ESD specimen size) × 100%. We compared the results with those of a historical control group treated with esomeprazole 20 mg/day for 4 weeks after gastric ESD and subsequently measured their ulcer size (33 patients, E group) by propensity score-matching methods.

RESULTS

Sixty-two subjects were enrolled after propensity score-matching. Ulcer contraction rate at 4 weeks after ESD in the V group was significantly higher than that of the E group (97.7 ± 3.2% vs 94.5 ± 6.7%, respectively, P = 0.025). Number of subjects with a scar-stage ulcer (100% contraction rate) tended to be higher in the V group relative to the E group (32% [10 of 31] vs 13% [4 of 31], respectively, P = 0.070, McNemar's chi-squared test).

CONCLUSION

Vonoprazan has a faster post-gastric ESD artificial ulcer contraction rate than esomeprazole. Vonoprazan may supersede PPI in treating post-ESD artificial ulcers of the stomach.

Potassium-competitive acid blockers: Advanced therapeutic option for acid-related diseases

Acid-related diseases (ARDs), such as peptic ulcers and gastroesophageal reflux disease, represent a major health-care concern. Some major milestones in our understanding of gastric acid secretion and ARD treatment reached during the last 50years include 1) discovery of histamine H₂-receptors and development of H₂-receptor antagonists, 2) identification of H⁺,K⁺-ATPase as the parietal cell proton pump and development of proton pump inhibitors (PPIs), and 3) identification of Helicobacter pylori (H. pylori) as the major cause of peptic ulcers and development of effective eradication regimens. Although PPI treatments have been effective and successful, there are limitations to their efficacy and usage, i.e. short half-life, insufficient acid suppression, slow onset of action, and large variation in efficacy among patients due to CYP2C19 metabolism. Potassium-competitive acid blockers (P-CABs) inhibit H⁺,K⁺-ATPase in a reversible and K⁺-competitive manner, and exhibit almost complete inhibition of gastric acid secretion from the first dose. Many pharmaceutical companies have tried to develop P-CABs, but most of their clinical development has been discontinued due to safety concerns or a similar efficacy to PPIs. Revaprazan was developed in Korea and was the first P-CAB approved for sale. Vonoprazan, approved in 2014 in Japan, has a completely different chemical structure and higher pKa value compared to other P-CABs, and exhibits rapid onset of action and prolonged control of intragastric acidity. Vonoprazan is an effective treatment for ARDs that is especially effective in healing reflux esophagitis and for H. pylori eradication. P-CABs, such as vonoprazan, promise to further improve the management of ARDs.

Acid peptic diseases: pharmacological approach to treatment

Acid peptic disorders are the result of distinctive, but overlapping pathogenic mechanisms leading to either excessive acid secretion or diminished mucosal defense. They are common entities present in daily clinical practice that, owing to their chronicity, represent a significant cost to healthcare. Key elements in the success of controlling these entities have been the development of potent and safe drugs based on physiological targets. The histamine-2 receptor antagonists revolutionized the treatment of acid peptic disorders owing to their safety and efficacy profile. The proton-pump inhibitors (PPIs) represent a further therapeutic advance due to more potent inhibition of acid secretion. Ample data from clinical trials and observational experience have confirmed the utility of these agents in the treatment of acid peptic diseases, with differential efficacy and safety characteristics between and within drug classes. Paradigms in their speed and duration of action have underscored the need for new chemical entities that, from a single dose, would provide reliable duration of acid control, particularly at night. Moreover, PPIs reduce, but do not eliminate, the risk of ulcers in patients taking NSAIDs, reflecting untargeted physiopathologic pathways and a breach in the ability to sustain an intragastric pH of more than 4. This review provides an assessment of the current understanding of the physiology of acid production, a discussion of medications targeting gastric acid production and a review of efficacy in specific acid peptic diseases, as well as current challenges and future directions in the treatment of acid-mediated diseases.

A comparison of the acid-inhibitory effects of esomeprazole and pantoprazole in relation to pharmacokinetics and CYP2C19 polymorphism

BACKGROUND

Esomeprazole and pantoprazole are metabolized in the liver and the polymorphic CYP2C19 enzyme is involved in that process. This genetic polymorphism determines fast (70% of Caucasians), intermediate (25-30% of Caucasians) and slow (2-5% of Caucasians) metabolism of PPIs.

AIM

To compare the acid-inhibitory effects of esomeprazole 40 mg and pantoprazole 40 mg at 4, 24 and 120 h after oral administration in relation to CYP2C19 genotype and pharmacokinetics.

METHODS

CYP2C19*2, *3, *4, *5 and *17 genotypes were determined in healthy Helicobacter pylori-negative Caucasian subjects. 7 wt/wt, 7 wt/*2, 2 wt/*17, 2 *2/*17 and 1 *2/*2 were included in a randomized investigator-blinded cross-over study with esomeprazole 40 mg and pantoprazole 40 mg. Intragastric 24-h pH-monitoring was performed on days 0, 1 and 5 of oral dosing.

RESULTS

A total of 19 subjects (mean age 24 years, 7 male) completed the study. At day 1 and 5, acid-inhibition with esomeprazole was significantly greater and faster than with pantoprazole. Differences in acid-inhibition and pharmacokinetics between wt/wt and wt/*2 genotype were significant for pantoprazole at day 1 and 5.

CONCLUSIONS

Esomeprazole provides acid-inhibition faster than and superior to pantoprazole after single and repeated administration. The acid-inhibitory effect and the kinetics of pantoprazole are influenced by CYP2C19 genotype.

Evolving issues in the management of reflux disease?

PURPOSE OF REVIEW

Gastroesophageal reflux disease (GERD) is a common chronic disorder often successfully treated, although there are several evolving issues in management. We reviewed the issues related to unmet needs over the past 12 months.

RECENT FINDINGS

A substantial number of patients fail to respond adequately to once or even twice daily proton pump inhibitor (PPI). There is no standard definition of PPI failure in GERD; a universally accepted definition for treatment success is also not available. Differentiation between erosive esophagitis and nonerosive reflux disease can be made but requires endoscopy; but studies still confuse functional heartburn and nonerosive reflux disease, which impacts management. Acid reflux plays an important role in GERD pathogenesis and the precise role of acid requires more studies of differences between erosive esophagitis and nonerosive reflux disease symptom generation and the implication of nocturnal acidification. Several possible mechanisms may explain GERD refractory to PPIs.

SUMMARY

Management of PPI nonresponders remains a challenge. Objective and precise evaluation of symptoms and treatment response requires study in high-quality trials. New therapeutic approaches are under investigation to answer unmet needs and improve erosive esophagitis healing rates and symptom control.

Systematic reviews: the good, the bad, and the ugly

Systematic reviews systematically evaluate and summarize current knowledge and have many advantages over narrative reviews. Meta-analyses provide a more reliable and enhanced precision of effect estimate than do individual studies. Systematic reviews are invaluable for defining the methods used in subsequent studies, but, as retrospective research projects, they are subject to bias. Rigorous research methods are essential, and the quality depends on the extent to which scientific review methods are used. Systematic reviews can be misleading, unhelpful, or even harmful when data are inappropriately handled; meta-analyses can be misused when the difference between a patient seen in the clinic and those included in the meta-analysis is not considered. Furthermore, systematic reviews cannot answer all clinically relevant questions, and their conclusions may be difficult to incorporate into practice. They should be reviewed on an ongoing basis. As clinicians, we need proper methodological training to perform good systematic reviews and must ask the appropriate questions before we can properly interpret such a review and apply its conclusions to our patients. This paper aims to assist in the reading of a systematic review.

Comparing resource utilization and gastrointestinal outcomes in patients treated with either standard-dose or high-dose proton pump inhibitors: a matched cohort study

The use of double-dose proton pump inhibitors (PPIs) for initial management of upper gastrointestinal (UGI) symptoms is common, though little evidence supports this practice. The aim of this study was to determine whether initial prescription of double-dose PPIs in outpatients with UGI complaints is superior to standard-dose PPIs prescription in reducing resource utilization. Patients in the Manitoba Health database prescribed double-dose PPIs were matched to individuals prescribed PPIs at standard doses. UGI-related inpatient and outpatient resource utilization and prescription drug usage were compared for both groups over the following year. Cases and controls had a similar duration of PPI use, and no difference in either UGI-related outpatient visits or UGI-related hospital admissions. Twelve-month UGI related costs were higher for double-dose PPI users. Initial therapy with double-dose PPIs does not reduce GI-related resource utilization. Prescription of double-dose PPIs as initial therapy for upper gastrointestinal symptoms should be discouraged.

Effect of esomeprazole and rabeprazole on intragastric pH in healthy Chinese: an open, randomized crossover trial

BACKGROUND AND AIM

Esomeprazole is the S-isomer of omeprazole, with a stronger acid suppressive effect than omeprazole. This open, randomized crossover study was designed to evaluate the effect of esomeprazole and another proton-pump inhibitor, rabeprazole, on intragastric pH in healthy Chinese.

METHODS

Thirty-six healthy volunteers (26 men and 10 women, aged between 20 and 31 years) were enrolled. Subjects were given either esomeprazole 40 mg (n = 18) or rabeprazole 10 mg (n = 18) orally once daily for 5 days during the first dosing period, then the other medicine at the set dosage for the second dosing period. The two periods were separated by a 14-day washout phase. The doses were chosen according to the State Food and Drug Administration of China for the treatment of acid-related diseases. Intragastric pH was continuously monitored for 24 h on days 1 and 5 of each dosing period. CYP2C19 genotypes were analyzed to identify the extensive metabolizers (EM) and poor metabolizers (PM).

RESULTS

The percentage of time with intragastric pH >4 was significantly higher (P < 0.001) in subjects receiving esomeprazole than in those receiving rabeprazole in the first 4 h after administration of the first dose (70.65% vs 44.87%), at 24 h on day 1 (73.7% vs 54.8%) and at 24 h on day 5 (84.2% vs 76.2%). The median intragastric pH was also higher in subjects receiving esomeprazole than in those receiving rabeprazole in the first 6 h, day 1 and day 5 (P <or= 0.001). The percentage of subjects with intragastric pH >4 for at least 16 h on day 1 (63.9% vs 33.3%) and on day 5 (88.9% vs 61.1%) was higher after administration of esomeprazole than after rabeprazole (both P < 0.05). On genotype analysis, 28 of the subjects were EM and eight were PM. Those who were PM tended to have a higher, albeit not statistically significant, percentage of time with intragastric pH >4 and the median 24-h intragastric pH than those who were EM. Both drugs were well tolerated.

CONCLUSIONS

Esomeprazole 40 mg orally once daily is more effective and faster in increasing intragastric pH than rabeprazole 10 mg orally once daily, and thus offers a potential for improved efficacy in acid-related diseases.

Potassium-competitive acid blockade: a new therapeutic strategy in acid-related diseases

Current therapies to treat gastroesophageal reflux disease (GERD), peptic ulcer disease (PUD), and other acid-related diseases either prevent stimulation of the parietal cell (H2 receptor antagonists, H2RAs) or inhibit gastric H+,K+-ATPase (e.g., proton pump inhibitors, PPIs). Of the 2 approaches, the inhibition of the final step in acid production by PPIs provides more effective relief of symptoms and healing. Despite the documented efficacy of the PPIs, therapeutic doses have a gradual onset of effect and do not provide complete symptom relief in all patients. There is scope for further improvements in acid suppressive therapy to maximize healing and offer more complete symptom relief. It is unlikely that cholecystokinin2 (CCK2, gastrin) receptor antagonists, a class in clinical trials, will be superior to H2RAs or PPIs. However, a new class of acid suppressant, the potassium-competitive acid blockers (P-CABs), is undergoing clinical trials in GERD and other acid-related diseases. These drugs block gastric H+,K+-ATPase by reversible and K+-competitive ionic binding. After oral doses, P-CABs rapidly achieve high plasma concentrations and have linear, dose-dependent pharmacokinetics. The pharmacodynamic properties reflect the pharmacokinetics of this group (i.e., the effect on acid secretion is correlated with plasma concentrations). These agents dose dependently inhibit gastric acid secretion with a fast onset of action and have similar effects after single and repeated doses (i.e., full effect from the first dose). Animal studies comparing P-CABs with PPIs suggest some important pharmacodynamic differences (e.g., faster and better control of 24-hr intragastric acidity). Studies in humans comparing PPIs with P-CABs will help to define the place of this new class in the management of acid-related diseases.

Diagnostic interpretation of extended pH monitoring: is there a single best method?

Our aims were to compare the specificity and sensitivity of the reflux index (RI), Euler and Byrne score (EBS), and area under the curve (AUC) at pH < 4.0 in infants 1 year old for identifying pathologic gastroesophageal reflux (GER) and to identify new cutoffs on formula feedings. We undertook a prospective investigation of extended pH monitoring (EPM) in 117 infants with symptoms of GER. Infants were categorized as having pathologic reflux by three measures: RI > or = 5%, EBS > or = 50, or AUC pH < 4.0 or < or = 21.3, as determined by receiver operating characteristic (ROC) curve analysis. Using the RI as a criterion, 27 infants (23%) had pathologic reflux. When EBS and AUC were used, 65 (56%), and 67 (57%) respectively, were classified as having pathologic reflux. The specificities of RI, EBS, and AUC were 97.8, 100.0, and 100.0%, respectively, and the sensitivities were 93.0, 91.5, and 94.4, respectively. A new cutoff value for RI of 2.1% was determined using ROC curve analysis to improve the specificity and sensitivity of RI to the above values. The number of infants with pathologic GER is likely to be significantly less using the traditional RI alone on formula feedings, however, the revised RI cutoff value and AUC analysis by computerized pH tracings can enhance the accuracy on formula feedings.

Cost-minimization analysis of treatment of gastroesophageal reflux disease. Implications of varying holding time on conclusions

Gastroesophageal reflux disease (GERD), is a common disorder. The most effective medical treatment for GERD is a proton pump inhibitor (PPI). The aim of this study was to specify the most inexpensive PPI therapy for GERD, and to examine the implications of varying outcome measure, holding time, on the conclusions about the cost-effectiveness of the treatments. Proton pump inhibitors that have holding time of intragastric pH>4 for at least 11h in 24h period (esomeprazole, lansoprazole, omeprazole and rabeprazole), were included. In this cost-minimization analysis (CMA), data on holding times were gathered from scientific publications listed in MEDLINE, prices of proton pump inhibitors from the Finnish database of drug prices and the treatment dosages were taken from the official guide of drug therapies in Finland. A decision tree was applied and the probabilities utilized were acquired from three expert physicians. The cost-minimization analysis was performed in three settings. At first, drugs that had a holding time (pH>4) of 11h or more were included. Secondly, drugs that had a holding time of 12h or more were included, and thirdly, a holding time of 13h or more was required. In the first analysis, the least expensive PPI treatment was lansoprazole (average cost of 138.89 per patient). In the second analysis, least expensive treatment was rabeprazole (193.81 per patient), and in the third, rabeprazole again (193.81 per patient). Esomeprazole and omeprazole were not among two of the least expensive alternatives in any of the settings. Which proton pump therapy turns out to be the least expensive for GERD, depends on the length of the holding time desired. Varying the holding time of the drug had a profound effect on the conclusions about the cost-effectiveness of the alternative treatments.

Review article: relief of symptoms in gastric acid-related diseases--correlation with acid suppression in rabeprazole treatment

Symptom relief is one of the key goals in the management of gastric acid-related disorders such as gastro-oesophageal reflux disease (GERD), including nonerosive reflux disease (NERD), and duodenal and gastric ulcer. Whereas heartburn and regurgitation are classic symptoms of GERD, duodenal and gastric ulcers are associated with epigastric pain. The relationship between gastric acid and the presence of symptoms correlates well in GERD and duodenal ulcer, but not in gastric ulcer and NERD. Nevertheless, in all these disorders, gastric acid is considered a key pathogenic element, and acid suppression remains central to therapy. With their profound, prolonged effect on acid inhibition, proton pump inhibitors are considered the first-choice therapy for these disorders. Rabeprazole is a newer generation proton pump inhibitor that suppresses the gastric proton pump and acid secretion more rapidly than does omeprazole, lansoprazole or pantoprazole. In clinical trial settings, rabeprazole provided fast and sustained symptom relief, which can help ensure patient acceptance of therapy and aid in patient compliance.

Lansoprazole in the treatment of functional dyspepsia: two double-blind, randomized, placebo-controlled trials

PURPOSE

The efficacy of proton pump inhibitor therapy for symptom resolution in patients with functional dyspepsia remains controversial. This study was designed to compare the efficacy of lansoprazole with placebo in relieving upper abdominal discomfort in patients with functional dyspepsia.

METHODS

We enrolled 921 patients with functional dyspepsia (defined as persistent or recurrent upper abdominal discomfort during the prior 3 months) and moderate upper abdominal discomfort on at least 30% of screening days; none of the patients had predominant symptoms suggestive of gastroesophageal reflux or endoscopic evidence of erosive or ulcerative esophagitis, or gastric or duodenal ulcer or erosion. Patients were assigned randomly to receive lansoprazole 15 mg (n = 305), lansoprazole 30 mg (n = 308), or placebo (n = 308) daily for 8 weeks. Patients recorded the frequency and severity of symptoms in daily diaries.

RESULTS

At week 8, significantly (P <0.001) greater mean reductions in the percentage of days with upper abdominal discomfort were reported in patients treated with lansoprazole 15 mg (35%) or 30 mg (34%) compared with those treated with placebo (19%). Similarly, more patients treated with lansoprazole 15 mg (44%) or 30 mg (44%) reported complete symptom resolution (defined as no episodes of upper abdominal discomfort in the 3 days before the study visit) at 8 weeks than did placebo-treated patients (29%, P <0.001). Improvement of upper abdominal discomfort, however, was seen only in patients who had at least some symptoms of heartburn at enrollment.

CONCLUSION

Lansoprazole, at a daily dose of 15 mg or 30 mg, is significantly better than placebo in reducing symptoms of persistent or recurrent upper abdominal discomfort accompanied by at least some symptoms of heartburn.

Treatment of acid-related diseases in the elderly with emphasis on the use of proton pump inhibitors

Proton pump inhibitors (PPIs) have revolutionised the treatment of acid-related disorders, and they have also made it possible to define the spectrum of acid inhibition required for optimal treatment in each disorder. Five PPIs are now available: the older drugs, omeprazole, lansoprazole and pantoprazole, and the two newest, rabeprazole and esomeprazole. These agents have predominantly been developed in the younger adult population, and data for the elderly population are limited. Subtle differences have emerged between the old and the new PPIs in their pharmacokinetic, pharmacodynamic and efficacy profiles. The degree of clinical relevance of these differences in the adult population is in question. However, according to this review, based on the available data for the elderly and by inference from the adult population, the differences are highly relevant in the elderly population. Studies of the pharmacokinetics of older PPIs demonstrated considerable variation in drug clearance that was reflected in a wide range of efficacy related to acid suppression with standard dosages. The newer PPIs offer several advantages over older agents, particularly in terms of rapid, profound and consistent acid inhibition. Consistent acid inhibition is particularly important in the elderly since clinical response is often difficult to judge in this patient group. An individual's cytochrome P450 (CYP) 2C19 genotype predicts the degree of acid suppression and consequently the clinical efficacy of the PPIs. The older PPIs are predominantly metabolised by CYP2C19, with this being of more importance for omeprazole and lansoprazole than pantoprazole. The hepatic metabolism of rabeprazole is predominantly by nonenzymatic reactions and minimally by CYP-mediated reactions, which therefore confers an advantage over older PPIs in that genetic polymorphisms for CYP2C19 do not significantly influence rabeprazole clearance, clinical efficacy or potential for drug interactions. The metabolism of esomeprazole involves CYP2C19 but to a lesser extent than its predecessor omeprazole. Furthermore, esomeprazole has a more rapid onset of action and less variation in clearance rates than omeprazole. Drug clearance decreases with age independently of CYP2C19 status, exaggerating some of the differences between the PPIs and increasing the risk of drug interactions.

Effects of antacid formulation on postprandial oesophageal acidity in patients with a history of episodic heartburn

BACKGROUND

Heartburn self-treatment with antacids is extremely common. If the oesophagus is the primary site of antacid action, chewable antacids might raise the oesophageal pH more effectively than swallowable tablets.

AIM

To establish a model to assess postprandial acid reflux and to compare the onset and duration of action on oesophageal pH of different antacid formulations.

METHODS

Twenty subjects with a history of episodic heartburn underwent eight pH monitoring sessions each for 5.5 h postprandially. One hour after consuming a meal consisting of chili, cheese, raw onions and cola, subjects received 750 mg, 1500 mg and 3000 mg of either chewable or swallowable CaCO3 tablets, an effervescent bicarbonate solution or placebo. Oesophageal and gastric pH data were collected.

RESULTS

Mean intra-oesophageal pH remained lower than baseline for more than 1 h (pH range 5-5.5) postprandially, indicating reflux of somewhat acidic intragastric contents into the oesophagus. The onset of action on oesophageal pH was similar for all antacids (30-35 min). The duration of action on pH varied: chewable tablets and effervescent bicarbonate had relatively long durations of action (oesophagus, 40-45 min; stomach, 100-180 min); swallowable tablets had little effect.

CONCLUSIONS

The meal model used in this study dependably produced acidic gastro-oesophageal reflux. Antacids increased oesophageal pH independent of gastric pH, demonstrating that chewing antacids controls oesophageal acidity more effectively than swallowing antacid tablets.

Review article: the control of gastric acid and Helicobacter pylori eradication

This review focuses on the gastric acid pump as a therapeutic target for the control of acid secretion in peptic ulcer and gastro-oesophageal reflux disease. The mechanism of the proton pump inhibitors is discussed as well as their clinical use. The biology of Helicobacter pylori as a gastric denizen is then discussed, with special regard to its mechanisms of acid resistance. Here the properties of the products of the urease gene clusters, ureA, B and ureI, E, F, G and H are explored in order to explain the unique location of this pathogen. The dominant requirement for acid resistance is the presence of a proton gated urea transporter, UreI, which increases access of gastric juice urea to the intrabacterial urease 300-fold. This enables rapid and continuous buffering of the bacterial periplasm to approximately pH 6.0, allowing acid resistance and growth at acidic pH in the presence of 1 mM urea. A hypothesis for the basis of combination therapy for eradication is also presented.

Pharmacodynamics and kinetics of omeprazole MUPS 20 mg and pantoprazole 40 mg during repeated oral administration in Helicobacter pylori-negative subjects

BACKGROUND

Omeprazole has become available in a tablet formulation, a Multiple Unit Pellet System (MUPS) containing a large number of small individually enteric-coated micropellets.

AIM

To compare the acid-inhibitory effect of omeprazole MUPS 20 mg with pantoprazole 40 mg and to describe the pharmacokinetics of both drugs following administration on day 1 and day 6.

METHODS

Randomized, two-way crossover study. Sixteen Helicobacter pylori-negative healthy subjects, whose gastric acidity fell below pH 4 for 70% of a 24-h baseline period were included. Intragastric pH was measured continuously.

RESULTS

On day 1 both drugs significantly raised median 24-h gastric pH compared to baseline. Median pH and percentages of time above pH 3 and 4 on day 1 and day 6 of administration were not significantly different, with the exception of median daytime pH on day 6, which was significantly higher with omeprazole (4.65 vs. 4.05). AUC and Cmax of omeprazole were significantly increased on day 6. AUC and Cmax of pantoprazole were not significantly increased.

CONCLUSIONS

No significant difference in acid-inhibitory effect on day 1. On day 6 median daytime pH was significantly higher with omeprazole MUPS, but the percentages of time spent above pH 3 and 4 were not significantly different. The significant increase in bioavailability of omeprazole may contribute to the increased effect on day 6.