Rabeprazole: a pharmacologic and clinical review for acid-related disorders

13-Week Repeated Oral Toxicity and Toxicokinetic Studies of Rabeprazole Sodium and Sodium Bicarbonate Combination in Dogs

The subchronic toxicity and toxicokinetics of a combination of rabeprazole sodium and sodium bicarbonate were investigated in dogs by daily oral administration for 13 consecutive weeks with a 4-week recovery period. The dose groups consisted of control (vehicles), (5 + 200), (10 + 400), and (20 + 800) mg/kg of rabeprazole sodium + sodium bicarbonate, 20 mg/kg of rabeprazole sodium only, and 800 mg/kg of sodium bicarbonate only. Esophageal ulceration accompanied by inflammation was observed in only one animal in the male (20 + 800) mg/kg rabeprazole sodium + sodium bicarbonate group. However, the severity of the ulceration was moderate, and the site of occurrence was focally extensive; thus, it was assumed to be a treatment-related effect of rabeprazole sodium + sodium bicarbonate. In the toxicokinetics component of this study, systemic exposure to rabeprazole sodium (AUClast and Cmax at Day 91) was greater in males than females, suggesting sex differences. AUClast and Cmax at Day 91 were increased compared to those on Day 1 in a dose-dependent manner. A delayed Tmax and no drug accumulation were observed after repeated dosage. In conclusion, we suggest under the conditions of this study that the no-observed-adverse-effect level (NOAEL) of the combination of rabeprazole sodium + sodium bicarbonate in male and female dogs is (10 + 400) and (20 + 800) mg/kg, respectively.

Exploring Differences in Pharmacometrics of Rabeprazole between Genders via Population Pharmacokinetic-Pharmacodynamic Modeling

Rabeprazole is a proton pump inhibitor that inhibits gastric acid production and increases gastric pH; it is widely used clinically as a treatment option for gastritis and gastric ulcers. However, information on the inter-individual variability of rabeprazole pharmacometrics, which is a key element in establishing its scientific clinical use, is still lacking. Particularly, the differences in pharmacokinetics between genders and the degree of variation in pharmacodynamics have not been clearly identified. Thus, the main purpose of this study was to explore any differences in rabeprazole pharmacokinetics between genders and to quantitatively predict and compare the effects of any differences in pharmacokinetics between genders on known pharmacodynamics using population pharmacokinetic-pharmacodynamic modeling. To compare pharmacokinetics and modeling data between genders, bioequivalence results were used simultaneously on healthy Korean men and women using the physiological and biochemical parameters derived from each individual. Pharmacodynamic modeling was performed based on the data of previously reported gastric pH changes in response to rabeprazole plasma concentrations, which was co-linked to the central compartmental bioavailable concentration in the population pharmacokinetic model. There was no significant difference in the level of rabeprazole exposure and elimination of plasma between genders following oral administration of 10 mg enteric-coated rabeprazole tablets; however, there was a clear delay in absorption in women compared to men. Additionally, a comparison of pharmacokinetic parameters normalized to body weight between genders showed that the maximum plasma concentrations were significantly higher in women than in men, again suggesting gender differences in rabeprazole absorption. The population pharmacokinetic profiles for rabeprazole were described using a three-sequential multi-absorption with lag time (Tlag) two-compartment model, whereas body surface area and gender were explored as effective covariates for absorption rate constant and Tlag, respectively. The effect of increased gastric pH due to plasma exposure to rabeprazole was explained using the Sigmoid Emax model, with the baseline as a direct response. The significantly longer rabeprazole Tlag in females delayed the onset of an effect by an average of 1.58 times (2.02-3.20 h), yet the overall and maximum effects did not cause a significant difference within 15%. In the relative comparison of the overall efficacy of rabeprazole enteric-coated tablet administration between genders, it was predicted based on the model that males would have higher efficacy. This study will be very useful in broadening the perspective of interpreting drug diversity between individuals and narrowing the gap in knowledge related to scientific precision medicine by presenting new information on gender differences in rabeprazole pharmacometrics that had not been previously identified.

Pharmacoeconomic Analysis of Fixed-Dose Combinations of Proton Pump Inhibitors Available in India

Introduction The global proton pump inhibitors (PPIs) market was valued at US$ 2.9 billion in 2020 and is expected to exhibit a compound aggregated growth rate of 4.30% during the forecast period (2020-2027), as they are regularly prescribed for many gastrointestinal disorders, and the treatment usually lasts for a longer period. PPIs are usually combined with antiemetics and prokinetic drugs. The price of PPIs for the same combination varies a lot, which can lead to a lot of financial burden on the patients. Objective To evaluate the cost ratio and percentage cost variation of commonly used PPIs in various combinations. Methodology The cost of different brands of commonly used PPIs in combination with other drugs was analyzed in our study. A total of 21 different combinations (10 capsules/tablets for oral use) were tabulated by referring to the "Monthly Index of Medical Specialities" October-December 2021, and 1mg online pharmacy. The cost ratio and percentage cost variation for various brands of a particular strength and dosage form were calculated and compared. Cost ratio > 2 and cost variation > 100% were considered significant. Results The results show a huge variation (1788.88%) in costs of different brands with the highest being rabeprazole 20 mg and domperidone 10 mg (cost ratio: 18.88, percentage cost variation: 1788.88%) in oral formulation, followed by pantoprazole 40 mg and itopride 150 mg. The minimum cost ratio (1.35) and percentage cost variation (1.35%) is for pantoprazole 40 mg and levosulpiride 75 mg. Logistic regression analysis between the number of brands and percentage cost variation gives an R² value of 0.0923. Conclusion There is a wide variation in the prices of PPIs available in the market, which can inadvertently increase the financial burden of therapy on patients. Physicians need to be made aware of these price differences so that they can choose the best available alternative for patients, which can help in increasing compliance with the prescribed drugs.

High-dose dual therapy is effective as first-line treatment for Helicobacter pylori infection

BACKGROUND/AIMS

Although many regimens, including quadruple, sequential, and concomitant treatment, are used and recommended as first-line or rescue therapies for Helicobacter pylori infection, eradication rates are still below 90% in intention-to-treat analyses. Treatment protocols with substantially high eradication rates and low antibiotic resistance are needed. In this study, we investigated the efficacy of high-dose dual therapy as first-line treatment in a Turkish population.

MATERIALS AND METHODS

All patients underwent upper gastrointestinal endoscopy for the initial H. pylori status because of dyspeptic symptoms. All patients received a 14-day, high-dose dual therapy comprising rabeprazole (20 mg t.i.d.) and amoxicillin (1 g t.i.d.) for H. pylori eradication. H. pylori stool antigen tests of eradication were administered to all participants at least 4 weeks after the completion of the treatment.

RESULTS

The high-dose dual therapy demonstrated a 91.3% rate of successful eradication of H. pylori infection. Per-protocol success was 94.4% among female patients (n=51) and 89.6% among male patients (n=86); in terms of gender, the differences were not significant (p=0.310). No side effects were observed during the study in any patient. Six other patients did not take adequate doses of the treatment protocol.

CONCLUSION

High-dose dual therapy with rabeprazole and amoxicillin was highly effective and well tolerated as a first-line therapy for H. pylori eradication.

Quality by Design Applied Development of Immediate-Release Rabeprazole Sodium Dry-Coated Tablet

The aim of this study was to develop immediate-release oral rabeprazole sodium tablets with rapid efficacy and gastric stability for the treatment of gastroesophageal reflux disease. Rabeprazole sodium is a commonly prescribed proton pump inhibitor; however, it is extremely unstable and degrades in acidic environments. Hence, it has been manufactured and supplied only in enteric-coated tablet form, while immediate-release (IR) formulations for this drug are very limited. In this study, we applied the quality by design (QbD) approach to formulate and optimize an IR dry-coated tablet containing rabeprazole sodium as an inner core with an outer sodium bicarbonate layer to stabilize the active pharmaceutical ingredient at gastric pH. We also investigated the stability of the pharmaceutical dosage form and its pharmacokinetic profile. The results show that the developed tablets are stable for approximately 12 months and have a high dissolution rate, greater than or equal to 90% at 30 min. Further, in vivo beagle pharmacokinetics confirmed that the newly developed IR tablet had an AUC_t which is bioequivalent to the existing delayed-release rabeprazole tablet; however, its T_max was 0.5 h, which is up to seven times faster than that of the existing tablet. Moreover, the IR tablet was found to immediately absorb in the stomach. Hence, the development of IR tablets can be used as a platform to overcome the technical and commercial limitations currently associated with various proton pump inhibitors used to treat patients with gastroesophageal reflux disease that require immediate therapeutic relief.

Combination Therapy of High-Dose Rabeprazole Plus Metronomic Capecitabine in Advanced Gastro-Intestinal Cancer: A Randomized Phase II Trial

Simple Summary

This is the first phase II study of high dose rabeprazole repurposing (1.5 mg/kg bid, three days a week) combined with metronomic capecitabine (mCAP), 1500 mg/daily, in gastrointestinal cancer, aimed at evaluating the activity and safety of high-dose proton pump inhibitor in combination with mCAP as salvage treatment in pretreated patients. A 3-months PFS rate of 66% and 57% was reported in the mCAP-rabeprazole and mCAP group, respectively. Although, the adjunct of high dose rabeprazole to mCAP did not improve mCAP activity, the combination of proton pump inhibitor with chemotherapy would deserve to be further investigated.

Abstract

Background: In recent years, proton pump inhibitors (PPIs) have been investigated at high-dose to modulate tumor microenvironment acidification thus restoring chemotherapeutic sensitivity. This is the first trial to study activity and safety of repurposing high dose rabeprazole combined with metronomic capecitabine (mCAP). Methods: A phase II study in which patients with gastrointestinal cancer, refractory to standard treatments, who had a life expectancy >3 months, were blind randomized 1:1 to mCAP, 1500 mg/daily, continuously with or without rabeprazole 1.5 mg/kg bid, three days a week. The primary endpoint was 3-months progression-free survival (PFS). The secondary endpoints were clinical benefit (CB) and overall survival (OS). Safety and plasma concentrations of capecitabine and its metabolites (5′-DFUR and 5-FU) were also evaluated. Results: Sixty-seven (median age 69 years; 63% male; 84% colorectal cancer, 76% ECOG-PS ≤ 1; 84% pretreated with two or more lines of chemotherapy) out of 90 patients screened for eligibility, were randomized to receive mCAP+rabeprazole (n = 32) vs. mCAP (n = 35). All patients were evaluable for response. No significant difference between mCAP+rabeprazole vs. mCAP, in terms of 3-months PFS rate (HR = 1.43, 95%CI 0.53–3.85; p = 0.477), median PFS (HR = 1.22, 95%CI 0.75–2.00, p = 0.420), CB (RR = 0.85, 95%CI 0.29–2.44; p = 0.786) and median OS (HR = 0.89, 95%CI 0.54–1.48; p = 0.664) was observed. However, a 3-year OS rate of 10% and 12% was reported in the mCAP-rabeprazole and mCAP groups, respectively. Overall, no grade 3 or 4 toxicity occurred but grade 1 or 2 adverse event of any type were more frequently in the mCAP+rabeprazole group than in the mCAP (OR 2.83, 95%CI 1.03–7.79; p = 0.043). Finally, there was not statistically significant difference in the plasma concentration of capecitabine and its metabolites between the two groups. Conclusions: Although the adjunct of high dose rabeprazole to mCAP was not shown to affect mCAP activity, as PPI are being investigated worldwide as drugs to be repositioned in cancer treatment and also considering the limited sample size as well as the favorable safety profile of the combination in the present study, further clinical investigations are desirable.

Synthesis and biological activities of novel trifluoromethylpyridine amide derivatives containing sulfur moieties

A series of trifluoromethylpyridine amide derivatives containing sulfur moieties (thioether, sulfone and sulfoxide) was designed and synthesized. Their antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo), Ralstonia solanacearum (R. solanacearum) and insecticidal activities against P. xylostella were evaluated. Notably, the half-maximal effective concentration (EC50) value of sulfone-containing compound F10 is 83 mg L-1 against Xoo, which is better than that of commercial thiodiazole copper (97 mg L-1) and bismerthiazol (112 mg L-1). Thioether-containing compounds E1, E3, E5, E6, E10, E11 and E13 showed much higher activities against R. solanacearum with the EC50 value from 40 to 78 mg L-1, which are much lower than that of thiodiazole copper (87 mg L-1) and bismerthiazol (124 mg L-1). Generally, most of the sulfone-containing compounds and sulfoxide-containing compounds showed higher activities against Xoo than that of the corresponding thioether-containing compound, but most of the thioether-containing compounds contributed higher antibacterial activities against R. solanacearum. Furthermore, title compounds E3, E11, E24 and G2 showed good insecticidal activities of 75%, 70%, 70% and 75%, respectively.

Efficacy of a high-dose proton pump inhibitor in patients with gastroesophageal reflux disease: a single center, randomized, open-label trial

Background

The extraesophageal manifestations of gastroesophageal reflux disease (GERD) are more difficult to manage than the typical symptoms. The efficacy of high-dose and standard-dose proton pump inhibitors against these atypical symptoms is not yet established.

Methods

In this single center, randomized, open-label study, patients with GERD received rabeprazole for 8 weeks, either 20 mg once daily (standard-dose group) or 20 mg twice daily (high-dose group). Patients were assessed before treatment and at weeks 4 and 8 with a 5-graded scale questionnaire consisting of 2 typical symptoms (heartburn and acid regurgitation) and 8 atypical symptoms (chest pain, cough, globus, wheezing, laryngopharyngitis, hoarseness, belching, and dysphagia). Sufficient improvement of reflux symptoms was defined as ≥50% reduction from the initial questionnaire score.

Results

Final analyses included 35 patients in the standard-dose group and 38 patients in the high-dose group. The rate of sufficient improvement for typical symptoms was significantly higher in the high-dose group than in the standard-dose group (100.0% vs. 84.0%, P = 0.040). For atypical symptoms, the rate of sufficient improvement tended to be higher in the high-dose group than in the standard-dose group (82.4% vs. 63.0%, P = 0.087). Scores of typical and some atypical symptoms (cough and globus) improved after treatment, with significant inter-group differences in time-course changes.

Conclusions

High-dose rabeprazole is more effective for relieving typical GERD symptoms and some atypical symptoms such as cough and globus than a standard-dose regimen.

Trial registration

This research was enrolled in a registry of clinical trials run by United States National Library of Medicine at the National Institutes of Health (ClinicalTrials.gov Protocol Registration and Results system ID: NCT04001400). This study was registered on June 26, 2019 - Retrospectively registered.

Effects of the Proton Pump Inhibitors Omeprazole and Pantoprazole on the Cytochrome P450-Mediated Metabolism of Venlafaxine

BACKGROUND AND OBJECTIVE: An increasing trend in prescribing proton pump inhibitors (PPIs) inevitably increases the risk of unwanted drug-drug interactions (DDIs). The aim of this study was to uncover pharmacokinetic interactions between two PPIs-omeprazole and pantoprazole-and venlafaxine.

METHODS

A therapeutic drug monitoring database contained plasma concentrations of venlafaxine and its active metabolite O-desmethylvenlafaxine. We considered three groups: a group of patients who received venlafaxine without confounding medications (non-PPI group, n = 906); a group of patients who were comedicated with omeprazole (n = 40); and a group of patients comedicated with pantoprazole (n = 40). Plasma concentrations of venlafaxine, O-desmethylvenlafaxine and active moiety (venlafaxine + O-desmethylvenlafaxine), as well as dose-adjusted plasma concentrations, were compared using non-parametrical tests.

RESULTS

Daily doses of venlafaxine did not differ between groups (p = 0.949). The Mann-Whitney U test showed significantly higher plasma concentrations of active moiety, as well as venlafaxine and O-desmethylvenlafaxine, in both PPI groups [p = 0.023, p = 0.011, p = 0.026, +29% active moiety, +27% venlafaxine, +36% O-desmethylvenlafaxine (pantoprazole); p = 0.003, p = 0.039 and p < 0.001, +36% active moiety, +27% venlafaxine, +55% O-desmethylvenlafaxine (omeprazole)]. Significantly higher concentration-by-dose (C/D) values for venlafaxine and active moiety were detected in the pantoprazole group (p = 0.013, p = 0.006, respectively), while in the omeprazole group, C/D ratios for all three parameters-venlafaxine, O-desmethylvenlafaxine and active moiety-were significantly higher (p = 0.021, p < 0.001 and p < 0.001, respectively).

CONCLUSIONS

Significantly higher plasma concentrations for all parameters (venlafaxine, O-desmethylvenlafaxine, active moiety) suggest clinically relevant inhibitory effects of both PPIs, most likely on the cytochrome P450 (CYP) 2C19-mediated metabolism of venlafaxine. The findings might be the result of different degrees of CYP2C19 involvement, therefore the inhibition of CYP2C19 by both PPIs may lead to an increased metabolism via CYP2D6 to O-desmethylvenlafaxine.

Association Between Proton Pump Inhibitors and Metronomic Capecitabine as Salvage Treatment for Patients With Advanced Gastrointestinal Tumors: A Randomized Phase II Trial

The acidification of extracellular compartment represents a conceivable mechanism of drug resistance in malignant cells. In addition, it has been reported to drive proliferation and promote invasion and metastasis. Experimental evidence has shown that proton pump inhibitors can counteract tumor acidification and restore sensitivity to anticancer drugs. Moreover, early clinical data have supported the role of proton pump inhibitors in anticancer treatments. Metronomic capecitabine has demonstrated beneficial effects as salvage chemotherapy for heavily pretreated or frail patients with gastrointestinal cancer. The present study (EudraCT Number: 2013-001096-20) was aimed at investigating the activity and safety of high-dose rabeprazole in combination with metronomic capecitabine in patients with advanced gastrointestinal cancer refractory to standard treatment. A total of 66 patients will be randomized 1:1 to receive capecitabine 1500 mg/daily, continuously with or without rabeprazole 1.5 mg/kg twice a day, 3 days a week until disease progression, undue toxicity, or withdrawal of informed consent. The primary endpoint is progression-free survival. The secondary endpoints are clinical benefit, which reflects the proportion of patients with complete response, partial response, and stable disease, and overall survival. Progression-free and overall survival will be evaluated using a log-rank test to determine the effect of rabeprazole independently at the 2-sided α-level of 0.05. Other assessments will include the frequency and severity of adverse events and changes in laboratory parameters to measure the safety, and the pharmacokinetics of capecitabine. The results are expected in 2016.

Information for physicians and pharmacists about drugs that might cause dry mouth: a study of monographs and published literature

BACKGROUND

Over three-quarters of the older population take medications that can potentially cause dry mouth. Physicians or pharmacists rarely inform patients about this adverse effect and its potentially severe damage to the teeth, mouth and general health.

OBJECTIVES

The objectives of this study were to (1) identify warnings in the literature about dry mouth associated with the most frequently prescribed pharmaceutical products in Canada; and (2) consider how this information might be obtained by physicians, pharmacists and patients.

METHODS

Monographs on the 72 most frequently prescribed medications during 2010 were retrieved from the Compendium of Pharmaceuticals and Specialties (CPS, a standard drug information reference for physicians and pharmacists), the National Library of Medicine's 'DailyMed' database, directly from the manufacturers, and from a systematic search of biomedical journals.

RESULTS

The CPS provided monographs for 43% of the medications, and requests to manufacturers produced the remaining monographs. Mentions of dry mouth were identified in 61% of the products (43% amongst CPS monographs; an additional 43% amongst manufacturers' monographs; 7% in the DailyMed database and 7% from biomedical journals); five medications had contradictory reports in different monographs.

CONCLUSION

Nearly two-thirds (61%) of the most commonly prescribed medications can cause dry mouth, yet warnings about this adverse effect and its potentially serious consequences are not readily available to physicians, pharmacists, dentists or patients.

Effects of CYP2C19 loss-of-function variants on the eradication of H. pylori infection in patients treated with proton pump inhibitor-based triple therapy regimens: a meta-analysis of randomized clinical trials

Background

There are inconsistent conclusions about whether CYP2C19 variants could affect H. pylori eradication rate in patients treated with the proton pump inhibitor (PPI)-based therapy. We therefore performed a meta-analysis of randomized clinical trials (RCTs) to re-evaluate the impact of CYP2C19 variants on PPI-based triple therapy for the above indication.

Methods

All relevant RCTs in the PubMed, Cochrane Library, EMBASE, Web of Science and two Chinese databases (up to February 2013) were systematically searched, and a pooled analysis was performed with the odds ratio (OR) and 95% confidence interval (CI) by the STATA software.

Results

Sixteen RCT datasets derived from 3680 patients were included. There was no significant heterogeneity across the data available in this meta-analysis. There were significant differences in that rate between homozygous (HomEMs) and heterozygous (HetEMs) extensive metabolizers (OR 0.724; 95% CI 0.594–0.881), between HomEMs and poor metabolizers (PM) (OR 0.507; 95%CI 0.379–0.679), or between HetEMs and PMs (OR 0.688; 95%CI 0.515–0.920), regardless of the PPI being taken. Furthermore, sub-analysis of individual PPIs was carried out to explore the difference across all the PPIs used. A significantly low rate was seen in HomEMs vs. HetEMs taking either omeprazole (OR 0.329; 95%CI 0.195–0.553) or lansoprazole (OR 0.692; 95%CI 0.485–0.988), and also in HomEMs vs. PMs for omeprazole (OR 0.232; 95%CI 0.105–0.515) or lansoprazole (OR 0.441; 95%CI 0.252–0.771). However, there was no significant difference between HetEMs and PMs taking either one. No significant differences were observed for rabeprazole or esomeprazole across the CYP2C19 genotypes of interest.

Conclusions

Carriage of CYP2C19 loss-of-function variants is associated with increased H. pylori eradication rate in patients taking PPI-based triple therapies when omeprazole or lansoprazole is chosen. However, there is no a class effect after use of rabeprazole or esomeprazole.