A placebo-controlled study to assess the effects of 7-day dosing with 10, 20 and 40 mg rabeprazole on 24-h intragastric acidity and plasma gastrin in healthy male subjects

Mucosal Healing Effectiveness and Safety of Anaprazole, a Novel PPI, vs. Rabeprazole in Patients With Duodenal Ulcers: A Randomized Double-Blinded Multicenter Phase II Clinical Trial

Background: Proton pump inhibitors (PPIs) are validated gastric acid suppressors and have been widely used to treat patients with active duodenal ulcers. Although existing PPIs have shown great efficacy, many scientists are still devoted to developing more effective PPIs with better safety profile. Herein, we aimed to compare the safety and efficacy of anaprazole in duodenal mucosal healing, a novel PPI, to that of rabeprazole.

Methods: In this multicenter, randomized, positive-controlled, double-blinded, parallel-group phase II clinical trial, a total of 150 qualified patients with endoscopically confirmed active duodenal ulcers were randomized (1:1:1) to receive rabeprazole 10 mg, anaprazole 20 mg or anaprazole 40 mg for 4 weeks. The ulcer healing rates after 4 weeks of treatment were compared between groups by independent central review and investigator review. In addition, symptoms and safety were evaluated.

Results: Based on the independent central review, the ulcer healing rates of the 10 mg rabeprazole, 20 mg anaprazole and 40 mg anaprazole groups were 88.0, 85.1, and 87.5%, respectively, in the FAS population and 88.9, 86.0, and 90.9%, respectively, in the PPS population. The ulcer healing rate difference between anaprazole 20 mg and Rabeprazole 10 mg is −2.9% (95% CI, −16.5–10.7%), and −0.5% (95% CI, −13.5–12.5%) between anaprazole 40 mg and Rabeprazole 10 mg, in the FAS population. Based on the investigator review, the ulcer healing rates of the 10 mg rabeprazole, 20 mg anaprazole, and 40 mg anaprazole groups were 72.0, 70.2, and 77.1%, respectively, in the FAS population and 75.6, 72.1, and 79.5%, respectively, in the PPS population. The ulcer healing rate difference between anaprazole 20 mg and Rabeprazole 10 mg is −1.8% (95% CI, −19.8–16.3%), and 5.1% (95% CI, −12.2–22.3%) between anaprazole 40 mg and Rabeprazole 10 mg, in the FAS population. Most patients (>90%) eventually achieved complete symptom relief. The incidence rates of adverse events were of no significant differences among the treatment groups. Potential possible better liver tolerance was observed in two anaprazole dose groups than rabeprazole 10 mg group.

Conclusion: Both at a dosage of 20 and 40 mg daily, anaprazole, is effective with good safety profile in the treatment of active duodenal ulcers in this Phase 2 study, which allows anaprazole to be advanced to a phase III clinical trial.

Clinical Trial Registration:https://www.clinicaltrials.gov/ct2/results?cond=&term=NCT04503629&cntry=&state=&city=&dist=, Identifier: CTR20181464, NCT04503629.

Evaluation of the effects of formulation, food, or a proton-pump inhibitor on the pharmacokinetics of glasdegib (PF-04449913) in healthy volunteers: a randomized phase I study

PURPOSE

To demonstrate the bioequivalence of the planned maleate salt-based commercial glasdegib tablet formulation [International Council for Harmonization (ICH) glasdegib] to the clinical di-hydrochloride (di-HCl) salt-based glasdegib formulation (di-HCl glasdegib). Additionally, to estimate the effects of a high-fat, high-calorie meal and proton-pump inhibitor (PPI) on the pharmacokinetics of ICH glasdegib.

METHODS

This Phase I open-label study (ClinicalTrials.gov: NCT03130556) enrolled 24 healthy subjects to receive two different tablet formulations of single-dose 100-mg glasdegib under fasted conditions. A subset of healthy volunteers (n = 12) received single-dose 100-mg ICH glasdegib following a high-fat, high-calorie meal or concurrently with a PPI (rabeprazole).

RESULTS

The adjusted geometric mean ratio (ICH glasdegib:di-HCl glasdegib) and 90% confidence intervals (CI) of area under the plasma concentration-time curve from time zero to infinity (AUC_inf) and maximum plasma concentration (C_max) were 104.0% (99.7‒108.5%) and 101.6% (96.1‒107.4%), respectively, within the acceptance range for bioequivalence (80‒125%). The adjusted geometric mean ratio (90% CIs) for AUC_inf and C_max under fed conditions were 84.3% (78.6‒90.6%) and 69.0% (61.8‒77.0%), respectively, relative to fasted conditions. When ICH glasdegib was administered concurrently with the PPI, the adjusted geometric mean ratio (90% CI) of AUC_inf and C_max were 100.6% (93.2‒108.6%) and 80.5% (70.7‒91.6%), respectively, relative to fasted conditions. Glasdegib was generally well tolerated under all conditions studied.

CONCLUSIONS

The ICH glasdegib tablet formulation was bioequivalent to the clinical di-HCl formulation under fasted conditions. A high-fat, high-calorie meal or concurrent PPI treatment had a minimal effect on glasdegib exposure, and was not considered clinically meaningful.

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.

Impact of Acid-Reducing Agents on the Pharmacokinetics of Palbociclib, a Weak Base With pH-Dependent Solubility, With Different Food Intake Conditions

Palbociclib free base capsule is a weak base drug with highly pH-dependent solubility. In vitro and in vivo studies evaluated the impact of acid-reducing agents on exposure of palbociclib and determined whether the impact, if any, can be mitigated by food. A drug-drug interaction study (study 1) was conducted first under fasted conditions and showed that coadministration of multiple doses of the proton-pump inhibitor rabeprazole substantially reduced palbociclib mean area under the concentration-time curve from time 0 to infinity and maximum observed plasma concentration by 62% and 80%, respectively. In vitro assessment suggested that the presence of bile salt mixed micelles to mimic the fed state can significantly enhance the solubility of palbociclib. Subsequently, study 2 was conducted under fed conditions and demonstrated that coadministration of rabeprazole decreased palbociclib maximum observed plasma concentration by 41% but had limited impact on area under the concentration-time curve from 0 to infinity (13% decrease). This study also showed that the histamine-2 receptor antagonist famotidine and local antacid with staggered dosing had no impact on palbociclib exposure under fed conditions. Food intake effectively mitigated the impact of acid-reducing agents on palbociclib exposure. Palbociclib free base capsule should be taken with food, and acid-reducing agent use does not need to be avoided.

Systematic review: the use of proton pump inhibitors and increased susceptibility to enteric infection

The use of proton pump inhibitors (PPIs) is increasing worldwide. Suppression of gastric acid alters the susceptibility to enteric bacterial pathogens. AIM  This systematic review was undertaken to examine the relationship between PPI use and susceptibility to enteric infections by a specific pathogen based on published literature and to discuss the potential mechanisms of PPI enhanced pathogenesis of enteric infections. METHODS  PubMed, OVID Medline Databases were searched. Search terms included proton pump inhibitors and mechanisms of, actions of, gastric acid, enteric infections, diarrhoea, Clostridium difficile, Salmonella, Shigella and Campylobacter. RESULTS The use of PPIs increases gastric pH, encourages growth of the gut microflora, increases bacterial translocation and alters various immunomodulatory and anti-inflammatory effects. Enteric pathogens show variable gastric acid pH susceptibility and acid tolerance levels. By multiple mechanisms, PPIs appear to increase susceptibility to the following bacterial enteropathogens: Salmonella, Campylobacter jejuni, invasive strains of Escherichia coli, vegetative cells of Clostridium difficile, Vibrio cholerae and Listeria. We describe the available evidence for enhanced susceptibility to enteric infection caused by Salmonella, Campylobacter and C. difficile by PPI use, with adjusted relative risk ranges of 4.2-8.3 (two studies); 3.5-11.7 (four studies); and 1.2-5.0 (17 of 27 studies) for the three respective organisms. CONCLUSIONS Severe hypochlorhydria generated by PPI use leads to bacterial colonisation and increased susceptibility to enteric bacterial infection. The clinical implication of chronic PPI use among hospitalized patients placed on antibiotics and travellers departing for areas with high incidence of diarrhoea should be considered by their physicians.

CYP2C19 genotypes in the pharmacokinetics/pharmacodynamics of proton pump inhibitor-based therapy of Helicobacter pylori infection

IMPORTANCE OF THE FIELD

Proton pump inhibitors (PPIs) are potent gastric acid inhibitors. Therapies with a PPI and antibiotics are used to cure Helicobacter pylori (H. pylori) infection, which is closely related to many gastrointestinal diseases. Most PPIs are mainly metabolized by cytochrome 2C19 (CYP2C19). The genetic polymorphisms of CYP2C19 may lead to the differences in pharmacokinetics (PK), pharmacodynamics (PD) and clinical efficacy of PPIs.

AREAS COVERED IN THIS REVIEW

The roles of PPIs on the eradication of H. pylori are summarized. The impact f CYP2C19 polymorphism on the PK and PD of PPIs is addressed and related to the present status of therapy for H. pylori infection. The opinions on the strategy of PPIs-based therapies of H. pylori infection are provided.

WHAT THE READER WILL GAIN

Update the factors that may influence the PPIs-based therapies of H. pylori infection.

TAKE HOME MESSAGE

The eradication rates of H. pylori infection are significantly different between patients who are CYP2C19 extensive metabolizers and poor metabolizers, partly because of the differences in the PK and PD of PPIs. Nonetheless, the differences can be improved by adjusting the regimens of PPIs and using antibiotics that have less H. pylori-resistance.

Effects of dexlansoprazole MR, a novel dual delayed release formulation of a proton pump inhibitor, on plasma gastrin levels in healthy subjects

Dexlansoprazole MR is a modified release formulation of a proton pump inhibitor being developed for the treatment of acid-related disorders. The purpose of this study is to characterize the plasma gastrin (PG) profile associated with administration of dexlansoprazole MR. Forty-two healthy subjects receive dexlansoprazole MR 90 mg, dexlansoprazole MR 120 mg, and lansoprazole 30 mg once daily for 5 days in a randomized, open-label, 3-period crossover study with at least 14-day washout intervals. Twenty-four-hour PG profiles are obtained at baseline (day -1 of period 1) and on days 1 and 5 in each period. Fasting PG levels are determined on days 8 and 12 in periods 1 and 2. On day 1, 24-hour PG levels increase from baseline to a similar extent with all regimens. On day 5, 24-hour PG levels with both dexlansoprazole MR regimens increase further and to a similar extent and are slightly higher than PG levels with lansoprazole. For all regimens, fasting PG levels on days 5 and 6 are higher than baseline levels (P<.05) and start to decrease by day 8, returning to near baseline at day 12. In this study, dexlansoprazole MR administration results in moderate increases in PG, similar to lansoprazole, which return to baseline levels within 7 days post dosing.

Pharmacokinetic- pharmacodynamic analysis of the role of CYP2C19 genotypes in short-term rabeprazole-based triple therapy against Helicobacter pylori

AIMS

The aim was to explore the role of CYP2C19 polymorphism in short-term rabeprazole-based triple therapy against Helicobacter pylori infection.

METHODS

Patients with H. pylori infection were tested for CYP2C19 genotype as poor metabolizers (PMs) or extensive metabolizers (EMs, homozygous EM or heterozygous EM) and given rabeprazole for 7 days. Antibiotics (clarithromycin and amoxicillin) were given on days 1-4, days 4-7, or days 1-7. A direct link model with an effect compartment was used in the population pharmacokinetic-pharmacodynamic analysis. The status of H. pylori infection was evaluated.

RESULTS

Rabeprazole clearance was lower in CYP2C19 PMs than in EMs (with average values of 10.7 vs. 16.8 l h(-1) in PMs and EMs, respectively), resulting in higher plasma levels in the former group. The values of EC(50) and k(eo) of gastrin response increased with multiple doses of rabeprazole. The k(eo) values were lower in CYP2C19 PMs than in EMs on day 1 (0.012 vs. 0.017 x 10(-4) l min(-1)), and higher than in EMs on day 4 (0.804 vs. 0.169 x 10(-4) l min(-1)) of rabeprazole treatment. The predicted gastrin-time profile showed a higher response in CYP2C19 PMs than in EMs on days 4 and 7. Helicobacter pylori was eradicated in all CYP2C19 PMs except in one patient infected by a resistant strain. In contrast, in CYP2C19 EMs the eradication rates ranged from 58 to 85%.

CONCLUSIONS

CYP2C19 genotypes play a role in H. pylori eradication therapy. Rabeprazole-based short-term triple therapy may be applicable in CYP2C19 PMs for H. pylori eradication.

Relative potency of proton-pump inhibitors-comparison of effects on intragastric pH

AIM

Comparative potency of proton-pump inhibitors (PPIs) is an important clinical issue. Most available trials have compared the different PPIs at one or a few selected specific dosages, making it difficult to derive quantitative equivalence dosages. Here we derived PPI dose equivalents based on a comprehensive assessment of dose-dependent effects on intragastric pH.

METHODS

All available clinical studies reporting the effects of PPIs on mean 24-h intragastric pH were sought from electronic databases including Medline. Studies included were restricted to those targeting the Caucasian population, and healthy volunteers or gastroesophageal reflux disease (GERD) patients. The dose-effect relationships for mean 24-h intragastric pH and for percentage of time with pH > 4 in 24 h were analyzed for each PPI using pharmacodynamic modeling with NONMEM and a model integrating all available data.

RESULTS

Fifty-seven studies fulfilled the inclusion criteria. Based on the mean 24-h gastric pH, the relative potencies of the five PPIs compared to omeprazole were 0.23, 0.90, 1.00, 1.60, and 1.82 for pantoprazole, lansoprazole, omeprazole, esomeprazole, and rabeprazole, respectively. Compared with healthy volunteers, patients with GERD needed a 1.9-fold higher dose and Helicobacter pylori-positive individuals needed only about 20% of the dose to achieve a given increase in mean 24-h intragastric pH.

CONCLUSION

The present meta-analysis provides quantitative estimates on clinical potency of individual PPIs that may be helpful when switching between PPIs and for assessing the cost-effectiveness of specific PPIs. However, our estimates must be viewed with caution because only a limited dose range has been tested and not exactly the same study conditions were applied for the different substances.

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.

Acid-suppressive effects of rabeprazole: comparing 10mg and 20mg twice daily in Japanese Helicobacter pylori-negative and -positive CYP2C19 extensive metabolisers

BACKGROUND

Rabeprazole 10mg b.i.d. is often administered as therapy for eradication of Helicobacter pylori (H. pylori) and is also proposed as therapy for refractory gastro-oesophageal reflux disease. However, there has not been a comprehensive assessment of its acid-suppressive effects.

AIMS

To compare the acid-suppressive effects of rabeprazole 10mg b.i.d. with 20mg b.i.d. considering H. pylori status.

SUBJECTS

Thirteen H. pylori-negative and eleven H. pylori-positive Japanese CYP2C19 extensive metabolisers (<35 years).

METHODS

Intragastric pH was measured for 24h three times in a randomised manner; on day 7 of the repeated administration of rabeprazole 10mg b.i.d. or 20mg b.i.d., or a placebo.

RESULTS

In median intragastric pH value and percent time of pH>3.0, >4.0, >5.0, >6.0, and >7.0 for 24h, no significant differences were observed between the two doses in either H. pylori-negative or H. pylori-positive subjects. At either dose, these parameters were significantly higher in H. pylori-positive subjects than in H. pylori-negative subjects. Nocturnal acid breakthrough occurred in seven and two of the thirteen H. pylori-negative subjects and one and two of the eleven H. pylori-positive subjects at each dose, respectively.

CONCLUSIONS

The effects of rabeprazole 10mg b.i.d. were equal to those of 20mg b.i.d. in H. pylori-positive subjects; whereas in H. pylori-negative subjects, 20mg b.i.d. was superior for prevention of nocturnal acid breakthrough.

Comparison of the efficacy of rabeprazole 10 mg and omeprazole 20 mg for the healing rapidity of peptic ulcer diseases

AIM

Rabeprazole has been known to inhibit H(+)/K(+)-ATPase more rapidly than omeprazole, the prototype proton pump inhibitor (PPI). The aim of this study was to demonstrate equivalence between low-dose rabeprazole 10 mg and omeprazole 20 mg for the healing rapidity of active peptic ulcer and for improvement of symptoms. Also, the effect of CYP2C19 genotypes on ulcer healing rapidity was investigated.

METHODS

A total of 112 patients with active peptic ulcer were randomized to receive either rabeprazole 10 mg q.d. or omeprazole 20 mg q.d. for 6 weeks. The remaining ratios (%) and complete healing of the ulcer were determined by endoscopy at 1 week and 6 weeks of treatment. The severity of ulcer pain was also investigated during treatment. CYP2C19 genotype was determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

The remaining ratio of peptic ulcers after 1 week and the complete healing rate after 6 weeks in the rabeprazole versus omeprazole group were 45.5% versus 50.3% (P = 0.475) and 80.6% versus 87.0% (P = 0.423), respectively. CYP2C19 genotypes had no effect on the remaining ratio of peptic ulcers after 1 week and the healing rate of peptic ulcers after 6 weeks in both groups. The proportions of patients with symptom improvement or resolution were comparable between the two groups.

CONCLUSION

Low-dose rabeprazole 10 mg has a similar efficacy for the healing rapidity of active peptic ulcer disease and symptom improvement compared with standard-dose omeprazole 20 mg.

Acid-suppressive efficacy of a reduced dosage of rabeprazole: comparison of 10 mg twice daily rabeprazole with 20 mg twice daily rabeprazole, 30 mg twice daily lansoprazole, and 20 mg twice daily omeprazole by 24-hr intragastric pH-metry

Rabeprazole achieves more potent acid suppression than other proton pump inhibitors. Therefore it is administered at reduced as well as high dosages in eradication therapy for Helicobacter pylori; however, there is incomplete assessment of the efficacy of a reduced dosage of rabeprazole as might be employed in therapy. In this study, we evaluated acid-suppressive efficacy of a reduced dosage of rabeprazole on day 7 by 24-hr pH-metry in 10 healthy male cytochrome P-450 2C19 extensive metabolizers without Helicobacterpylori infection and compared the results with those of high dosages of rabeprazole, lansoprazole, and omeprazole. Median intragastric pH value, pH >3 holding time ratio (pH>3HT), pH>4HT, pH>5HT, pH>6HT, and pH>7HT for 24 hr with rabeprazole, 10 mg twice daily, were not significantly different from those of rabeprazole, 20 mg twice daily, lansoprazole, 30 mg twice daily, and omeprazole, 20 mg twice daily. In conclusion, for acid-suppressive efficacy, a reduced dosage of rabeprazole is comparable to high dosages of rabeprazole, lansoprazole, and omeprazole.

Review of rabeprazole in the treatment of gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GERD) is an increasing health problem in developed countries and is associated with enormous costs in terms of reduced quality of life, loss of productivity, health expenses and mortality. The gastrointestinal disease with the highest annual direct costs in the US (in the year 2000) was GERD (9.3 billion US dollars). GERD is primarily a motility disorder of the oesophagus, however, there are no available promotility drugs on the market. The main symptoms are heartburn and acid regurgitation arising from the reflux of gastric acid, which is the only factor at present suited for pharmacological intervention. The proton pump inhibitors (PPIs) give optimal benefit in the treatment of GERD. The sales of PPIs in the year 2002 amounted to 12 billion US dollars in North America and 4 billion US dollars in Europe and the sales have been increasing by > 10% annually. This paper reviews the use of PPIs in the treatment of GERD with particular focus on one of the newer agents, rabeprazole.

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.

Effect of low-dose rabeprazole and omeprazole on gastric acidity: results of a double blind, randomized, placebo-controlled, three-way crossover study in healthy subjects

BACKGROUND

The treatment of acid-related symptoms requires rapid and consistent acid suppression, especially with on-demand regimens.

AIM

To compare the antisecretory activity of low-dose rabeprazole and omeprazole in healthy, Helicobacter pylori-negative subjects.

METHODS

In this randomized, double-blind, placebo-controlled, three-way crossover study, 27 volunteers were given rabeprazole 10 mg, omeprazole 10 mg, or placebo once daily for 7 days with a 10-14-day washout between treatments. Intragastric pH was monitored for 24-h on days 1 and 7 of each treatment.

RESULTS

Median gastric pH was significantly higher with rabeprazole than with omeprazole or placebo: day 1: 2.3, 1.4 and 1.3, respectively (P = 0.0056, rabeprazole vs. omeprazole; P < 0.0001, rabeprazole vs. placebo); day 7: 3.7, 2.2 and 1.3, respectively (P = 0.0016 rabeprazole vs. omeprazole; P < 0.0001, rabeprazole vs. placebo). Time with gastric pH above 4 was significantly higher with rabeprazole than with omeprazole: day 1, 5.8 h vs. 3.7 h, respectively (P < 0.02); day 7, 10.5 h vs. 4.6 h, respectively (P = 0.0008).

CONCLUSIONS

Rabeprazole 10 mg provides more rapid acid inhibition compared with omeprazole 10 mg. After 7 days, the time with pH above 4 is more than doubled with rabeprazole 10 mg vs. omeprazole 10 mg.

Rabeprazole 10 mg twice daily is superior to 20 mg once daily for night-time gastric acid suppression

BACKGROUND

Insufficient acid suppression is one of the main causes of proton pump inhibitor-refractory gastro-oesophageal reflux disease.

AIM

To achieve more potent and long-lasting acid suppression, different dosage regimens of rabeprazole were compared in relation to the CYP2C19 genotype status.

METHODS

In a cross-over study, 18 healthy Helicobacter pylori-negative males (six homozygous extensive metabolizers, six heterozygous extensive metabolizers and six poor metabolizers) were given rabeprazole 10 mg once daily, 20 mg once daily or 10 mg twice daily, or water only (baseline data), for 7 days each. On day 7 of each regimen, 24-h intragastric pH-metry was performed.

RESULTS

No significant differences were observed in median pH values and pH>4 holding time ratios between rabeprazole 10 mg once daily and 20 mg once daily. However, with rabeprazole 10 mg twice daily, these parameters were significantly higher than those with 20 mg once daily. The potency of acid suppression by rabeprazole was influenced by the CYP2C19 genotype status. The differences were somewhat significant but not large. The incidence of nocturnal acid breakthrough was lowest with rabeprazole 10 mg twice daily.

CONCLUSIONS

Rabeprazole 10 mg twice daily, not 20 mg once daily, should be administered to achieve more potent and long-lasting acid suppression.

Meta-analysis: comparative efficacy of different proton-pump inhibitors in triple therapy for Helicobacter pylori eradication

BACKGROUND

It is not known whether certain proton-pump inhibitors are more efficacious than others when used in triple therapy for Helicobacter pylori eradication.

AIM

To compare the efficacy of different proton-pump inhibitors in triple therapy by performing a meta-analysis.

METHODS

A MEDLINE search was performed. Abstracts of the European Helicobacter pylori Study Group and the American Gastroenterological Association congresses from 1996 to 2002 were also examined. Randomized studies with at least two branches of triple therapy that differed only in terms of type of proton-pump inhibitor were included in a meta-analysis using Review Manager 4.1.

RESULTS

Fourteen studies were included. Intention-to-treat cure rates were similar for omeprazole and lansoprazole: 74.7% vs. 76%, odds ratio (OR) 0.91 [95% confidence interval (CI) 0.69-1.21] in a total of 1085 patients; for omeprazole and rabeprazole: 77.9% vs. 81.2%, OR 0.81 (95% CI 0.58-1.15) in a total of 825 patients; for omeprazole and esomeprazole: 87.7% vs. 89%, OR 0.89 (95% CI 0.58-1.35) in 833 patients; and for lansoprazole and rabeprazole: 81% vs. 85.7%, OR 0.77 (95% CI 0.48-1.22) in 550 patients.

CONCLUSION

The efficacy of various proton-pump inhibitors seems to be similar when used for H. pylori eradication in standard triple therapy.

Rabeprazole in a one-week eradication therapy of Helicobacter pylori: comparison of different dosages

AIM

Many data regarding omeprazole-, lanzoprazole- and pantoprazole-based triple therapy for Helicobacter pylori (H. pylori) eradication have been reported, but there is few data present regarding rabeprazole (R). We report the efficacy and tolerability of rabeprazole in different dosages in association with clarithromycin (C)and tinidazole (T) in H. pylori eradication.

DESIGN AND METHODS

Ninety-four H. pylori-positive patients with dyspeptic symptoms were enrolled and randomly allocated to eradication therapy in two different one-week regimens. In regimen A, 47 patients received R 20 mg b.i.d, C 500 mg b.i.d and T 500 mg b.i.d, while in regimen B, 47 patients received R 10 mg b.i.d, C 500 mg b.i.d and T 500 mg b.i.d. Eradication of H. pylori was evaluated by a 13C urea breath test (UBT) two months after the end of the therapy.

RESULTS

Four patients (two in each regimen) did not complete treatment. The H. pylori eradication rate was 91.4% in group A compared to 89.3% in group B (P-value not significant). Minor side-effects were reported in 4.2% of group A and 6.4% of group B patients.

CONCLUSION

Rabeprazole showed good efficacy and tolerability in one-week H. pylori therapy at 20 mg b.i.d and 10 mg b.i.d, suggesting the use of the lower dosage.

Time-dependent amplified pharmacokinetic and pharmacodynamic responses of rabeprazole in cytochrome P450 2C19 poor metabolizers

STUDY OBJECTIVES

To determine the pharmacokinetic and pharmacodynamic rationale for the optimum regimen of rabeprazole in the treatment of Helicobacter pylori infection in patients who are cytochrome P450 (CYP) 2C19 poor metabolizers or extensive metabolizers.

DESIGN

Prospective, multiple-dose pharmacokinetic and pharmacodynamic study.

SETTING

University-affiliated medical center in Taiwan.

SUBJECTS

Twelve healthy volunteers (aged 20-30 yrs) who were identified as CYP2C19 poor metabolizers (six subjects) or extensive metabolizers (six).

INTERVENTION

Each subject received rabeprazole 20 mg twice/day for 3 consecutive days and once/day on the fourth day.

MEASUREMENTS AND MAIN RESULTS

Pharmacokinetic and pharmacodynamic parameters were compared between CYP2C19 poor and extensive metabolizers on day 1 and day 4 of dosing. The mean +/- SD values of area under the concentration-time curve of rabeprazole and rabeprazole thioether were significantly higher in poor metabolizers than in extensive metabolizers on day 1 (5357 +/- 883 vs 1131 +/- 512 ng x hr/ml and 1703 +/- 432 vs 561 +/- 358 ng x hr/ml, respectively; p<0.001) and on day 4 (5601 +/- 669 vs 1619 +/- 778 ng x hr/ml and 1914 +/- 378 vs 511 +/- 360 ng x hr/ml, respectively; p<0.001). However, no significant difference was noted between day 1 and day 4 of dosing within the same genotype groups. Only CYP2C19 poor metabolizers had significantly higher plasma gastrin levels on day 4 compared with those levels on day 1 (p<0.05). The pharmacokinetic-pharmacodynamic relationship of rabeprazole appears to be time dependent.

CONCLUSION

The pharmacokinetic and pharmacodynamic data suggest that CYP2C19 poor metabolizers might be subject to advantageous conditions, especially after day 4, for treating H. pylori infection with rabeprazole.

Rabeprazole is superior to omeprazole for the inhibition of peptone meal-stimulated gastric acid secretion in Helicobacter pylori-negative subjects

BACKGROUND

Peptone meal-stimulated gastric acid output is considered to be a reliable means to evaluate drug-mediated inhibition of stimulated gastric acid output, an important measure of the efficacy of the agents--such as proton pump inhibitors--used to treat acid-related disorders.

AIM

To compare the initial and overall inhibitory effects on peptone meal-stimulated gastric acid secretion of rabeprazole and omeprazole, 20 mg, in Helicobacter pylori-negative subjects on the first and eighth days of treatment.

METHODS

Healthy volunteers (n = 27) were randomized in a single-centre, double-blind, double-dummy, 2 x 2 cross-over study. Subjects received an oral dose of rabeprazole or omeprazole, 20 mg once daily, for 8 days. After a 2-4-week washout period, subjects were crossed over to receive the other medication for 8 days. Peptone meal-stimulated gastric acid secretion was measured at hours 11 and 23 at baseline and on days 1 and 8 of treatment.

RESULTS

On days 1 and 8, rabeprazole demonstrated a significantly greater inhibition of peptone meal-stimulated gastric acid secretion compared with omeprazole at all time points (P < 0.03). Median values of steady-state inhibition on day 1 were statistically significant at hour 23 (rabeprazole 100% vs. omeprazole 74%, P < 0.02).

CONCLUSIONS

Rabeprazole, 20 mg, demonstrated superior control of peptone meal-stimulated gastric acid secretion compared with omeprazole, 20 mg, after the first dose and after the eighth daily dose. Rabeprazole achieved a more rapid onset of acid inhibition and a greater steady-state reduction in peptone meal-stimulated gastric acid secretion.

Rabeprazole: an update of its use in acid-related disorders

Rabeprazole is an inhibitor of the gastric proton pump. It causes dose-dependent inhibition of acid secretion. In 8-week studies, among patients with gastro-oesophageal reflux disease (GORD), rabeprazole 20 mg/day or 10mg twice daily was as effective as omeprazole and superior to ranitidine in the healing of GORD. Symptom relief with rabeprazole was superior to that provided by placebo and ranitidine and similar to omeprazole. In long-term trials rabeprazole 10 mg/day was similar to omeprazole 20 mg/day in a 2-year study and superior to placebo in 1-year studies, in both the maintenance of healing and prevention of symptoms in patients with healed GORD. In nonerosive GORD, 4-week studies have shown rabeprazole to be more effective than placebo in relieving heartburn and various other gastrointestinal symptoms. Data among patients with Barrett's oesophagus suggest rabeprazole 20 mg/day may be more effective than placebo in maintaining healing of associated oesophagitis after 1 year of treatment. One-week triple Helicobacter pylori eradication therapy with rabeprazole plus clarithromycin and amoxicillin achieved eradication rates of > or =85%. Rabeprazole is as effective as omeprazole and lansoprazole when included as part of a triple-therapy regimen for the eradication of H. pylori. Eradication rates of >90% were achieved when rabeprazole 20 to 40 mg/day was included as part of a quadruple eradication regimen. As monotherapy for peptic ulcer healing and symptom relief, 4- to 8-week studies have shown rabeprazole 10 to 40 mg/day to be superior to placebo and ranitidine and have similar efficacy to omeprazole. Preliminary 1-year data among 16 patients with Zollinger-Ellison syndrome suggest rabeprazole 60 to 120 mg/day can resolve and prevent the recurrence of symptoms and endoscopic lesions associated with this condition. In clinical trials of up to 2 years' duration the tolerability of rabeprazole is similar to that of placebo, ranitidine and omeprazole. Common adverse events assigned to rabeprazole have been diarrhoea, headache, rhinitis, nausea, pharyngitis and abdominal pain. Histological changes and increases in serum gastrin levels were unremarkable and typical of proton pump inhibitors. No dosage adjustment is necessary in renal and mild to moderate hepatic impairment.

CONCLUSION

Rabeprazole is a well tolerated proton pump inhibitor. It has proven efficacy in healing, symptom relief and prevention of relapse of peptic ulcers and GORD and can form part of effective H. pylori eradication regimens. It is an important alternative to H(2) antagonists and an additional treatment option to other proton pump inhibitors in the management of acid-related disorders.

Efficacy of triple therapy with rabeprazole for Helicobacter pylori infection and CYP2C19 genetic polymorphism

BACKGROUND

Rabeprazole is a new, potent, proton pump inhibitor. The metabolism of rabeprazole is less dependent on CYP2C19 genetic polymorphism.

METHODS

A total of 102 Helicobacter pylori-positive patients with gastric ulcer were randomly allocated to three groups: rabeprazole 10 mg (RAC10), rabeprazole 20 mg (RAC20) or rabeprazole 40 mg (RAC40) plus amoxicillin 750 mg and clarithromycin 200 mg twice daily for 7 days. CYP2C19 genotype was determined by the polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

All-patients-treated-based eradication rates in patients treated with RAC10, RAC20 and RAC40 were 83%, 77% and 90%, respectively, and per protocol-based eradication rates were 83%, 80% and 90%, respectively. The eradication rates in the three groups were not significantly different. There was also no significant difference between the all-patients-treated-based eradication rate in CYP2C19 extensive metabolizers and that in poor metabolizers (86% vs. 77%). Adverse events were 12% in extensive metabolizers and 23% in poor metabolizers, and the difference in these incidence rates was also not statistically significant.

CONCLUSIONS

Triple therapy with 10 mg of rabeprazole combined with amoxicillin/clarithromycin is effective for Japanese patients with H. pylori infection, and the H. pylori eradication rate is not affected by CYP2C19 genetic polymorphism.