Ten mg dexrabeprazole daily is as effective as 20 mg dexrabeprazole daily

Ten mg dexrabeprazole daily has been shown to be more effective than 20 mg rabeprazole daily against gastroesophageal reflux disease (GERD). This report shows that the efficacy of 10 mg dexrabeprazole daily is equivalent to that of 20 mg dexrabeprazole daily against GERD. This implies that a dose of 10 mg dexra- beprazole is sufficient to block the maximum amount of proton pumps without any need to double the dose as suggested with rabeprazole.

Randomized, double-blind, comparative study of dexrabeprazole 10 mg versus rabeprazole 20 mg in the treatment of gastroesophageal reflux disease

AIM：TO compare the efficacy and safety of dexrabe-prazole 10 mg versus rabeprazole 20 mg in the treatment of gastroesophageal reflux disease （GERD）.METHODS： This was a randomized, double-blind clinical study. Fifty patients with GERD were randomly assigned to receive dexrabeprazole 10 mg or rabeprazole 20 mg once daily. Efficacy was assessed by evaluating improvement in visual analog scale （VAS） scores of heart-burn and regurgitation and safety was assessed by recording incidence of any adverse drug reactions. Laboratory investigations and upper gastro-intestinal endoscopy was conducted at baseline and after 28 d of therapy.RESULTS： A total of 50 patients （n = 25 in dexrabeprazole group and rabeprazole group each） completed the study. There were no significant differences in the baseline characteristics between the two groups. The VAS score （mean 4. SD） of heartburn and regurgitation in dexrabeprazole （64.8±5.1 and 64 ± 8.1, respectively） and rabeprazole （64.4 ± 8.7 and 57.6 ± 9.7, respectively） groups significantly reduced （P 〈 0.0001） to 30 ± 11.5, 24 ± 10 and 32 ± 9.5, 29.2±11.9, respectively on d 28. A significantly higher （P = 0.002） proportion of patients showed ≥ 50% improvement in regurgitation with dexrabeprazole 10 mg （96%） compared to rabeprazole 20 mg （60%）. Onset of symptom improvement was significantly earlier with dexrabeprazole than with rabeprazole （1.8 ± 0.8 d vs 2.6 ± 1.4 d; P 〈0.05）. The incidences of esophagitis in the dexrabeprazole group and rabeprazole group before therapy were 84% and 92%, respectively （P = 0.38）. The incidence of improvement/healing of esophagitis after therapy was more （P = 0,036） in the dexrabeprazole group （95.2%） compared to the rabeprazole group （65.2%）. No adverse drug reaction was seen in either group.CONCLUSION： In the treatment of GERD, efficacy of dexrabeprazole 10 mg is better than rabeprazole 20 mg, with regards to improvement/healing of endoscopic lesions and relief from symptoms of regurgitation.

Irsogladine maleate and rabeprazole in non-erosive reflux disease: A double-blind, placebo-controlled study

AIM:To evaluate the efficacy of adding irsogladine maleate(IM) to proton-pump inhibitor(PPI) therapy in non-erosive reflux disease(NERD) treatment.METHODS:One hundred patients with NERD were recruited and randomized to receive rabeprazole plus IM(group I) or rabeprazole plus placebo(group P).The efficacy of the treatment was assessed using the Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease(FSSG) and the short form(SF)-36 quality of life questionnaires after four weeks of treatment.We also assessed whether patients with NERD with minimal changes(grade M) had different responses to the therapies compared with patients who did not have minimal changes(grade N).RESULTS:Group I and group P showed significant improvements in their FSSG scores after the treatment(from 17.9 ± 7.9 to 9.0 ± 7.6, and from 17.7 ± 7.3 to 11.2 ± 7.9, respectively, P = 0.0001), but there was no statistically significant difference between the FSSG scores in group I and those in group P.Subgroup analysis showed that significant improvements in the FSSG scores occurred in the patients in group I who had NERD grade N(modified Los Angeles classification)(7.8 ± 7.4 vs 12.5 ± 9.8, P = 0.041).The SF-36 scores for patients with NERD grade N who had received IM and rabeprazole were significantly improved in relation to their vitality and mental health scores.CONCLUSION:The addition of IM to rabeprazole significantly improves gastroesophageal reflux diseasesymptoms and the quality of the lives of patients with NERD grade N.

Efficacy and safety of rabeprazole in non-steroidal anti-inflammatory drug-induced ulcer in Japan

AIM: To investigate the effi cacy and safety of rabepra-zole under continuous non-steroidal anti-inflammatory drug (NSAID) administration for NSAID-induced ulcer in Japan. METHODS: Subjects comprised patients undergoing NSAID treatment in whom upper gastrointestinal en-doscopy revealed an ulcerous lesion (open ulcer) with diameter ≥ 3 mm, who required continuous NSAID treatment. Endoscopies were performed at the start of treatment, during the treatment period, and at the conclusion (or discontinuation) of treatment. Findings were evaluated as size (maximum diameter) and stage based on the Sakita-Miwa classifi cation. An ulcer was regarded as cured when the "white coating" was seen to have disappeared under endoscopy. As criteria for evaluating safety, all medically untoward symptoms and signs (adverse events, laboratory abnormalities, accidental symptoms, etc.) occurring after the start of rabeprazole treatment were handled as adverse events.RESULTS: Endoscopic cure rate in 38 patients in the efficacy analysis (endoscopic evaluation) was 71.1% (27/38). Among those 38 patients, 35 had gastric ulcer with a cure rate of 71.4% (25/35), and 3 had duodenal ulcer with a cure rate of 66.7% (2/3). Three adverse drug reactions were reported from 64 patients in the safety analysis (interstitial pneumonia, low white blood cell count and pruritus); thus, the incidence rate for adverse drug reactions was 4.7% (3/64).CONCLUSION: The treatment efficacy of rabeprazole for NSAID-induced ulcer under continuous NSAID ad-ministration was confi rmed.

Rabeprazole is effective for bile reflux oesophagitis after total gastrectomy in a rat model

AIM:To elucidate the effect of a proton pump inhibitor(PPI,rabeparazole)on oesophageal bile reflux in oesophagitis after total gastrectomy.METHODS:Twenty-one 8-week-old male Wistar rats were studied.They were performed oesophagoduodenostomy of total gastrectomy to induce oesophageal reflux of biliary and pancreatic juice.Five rats were performed the sham operation(Sham).On post-operative day 7,they were treated with saline(Control)(n=8)or PPI(rabeprazole,30 mg/kg per day,ip)(n=8)for 2 wk.On post-operative 21,all rats were sacrificed and each oesophagus was evaluated histologically.Oesophageal injury was evaluated by macroscopic and microscopic findings as well as the expression of cyclooxygenase-2(COX2).We measured bile acid in the oesophageal lumen and the common bile duct.RESULTS:At 3 wk after surgery,a histological study analysis revealed an increase in the thickness of the epithelium,elongation of the lamina propria and basal cell hyperplasia in the oesophageal mucosa.The macroscopic ulcer score and microscopic ulcer length of the control group were significantly higher compared to those of the rabeprazole-treated group.The expression of COX2 was significantly increased according to the immunostaining in the control group compared to rabeprazole-treated group.Although there was no difference between the control and PPI groups in the total bile acid in the common bile duct,the bileacid activity in the oesophageal lumen was significantly decreased in the rabeprazole-treated group due to augmentation of the duodenal motor complex.CONCLUSION:With this model,rabeprazole is good effect for reflux esophagitis after total gastrectomy from bile reflux.Bile acid is an important factor in the mucosal lesion induced by duodenal reflux.

A prospective randomized trial of lafutidine vs rabeprazole on post-ESD gastric ulcers

AIM:To compare the effects of rabeprazole and lafutidine on post-endoscopic submucosal dissection(ESD) gastric ulcers.METHODS:Patients with gastric tumors indicated for ESD were prospectively studied.After ESD,all patients were treated with intravenous omeprazole for the first 3 d.Patients were then randomly assigned to oral lafutidine or rabeprazole.Ulcer size,ulcer size reduction rate,and ulcer stage were evaluated 4 wk later.Occurrence of complication was monitored throughout the 4-wk period.RESULTS:Sixty five patients were enrolled in the study,and 60 patients were subjected to the final analysis.In the lafutidine group(30 lesions in 29 patients),initial and 4-wk post-ESD ulcer sizes were 33.3 ± 9.2 and 10.5 ± 4.8 mm,respectively.In the rabeprazole group(34 lesions in 31 patients),the values were 34.7 ± 11.3 and 11.8 ± 6.7 mm,respectively.Ulcer size reduction rates in lafutidine and rabeprazole groups were 32.3% and 33.5%,respectively(P=0.974).Ulcer stage 4 wk post-ESD did not differ significantly between the two groups(P=0.868).Two cases in the rabeprazole group and no cases in the lafutidine group developed ulcer bleeding during the oral dose period,although the difference of bleeding rate between the two groups was not statistically significant(P=0.157).CONCLUSION:Lafutidine and rabeprazole have equivalent therapeutic effects on post-ESD gastric ulcers.

Rabeprazole test for the diagnosis of gastro-oesophageal reflux disease: Results of a study in a primary care setting

AIM： To determine the diagnostic value of the rabeprazole test in patients seen by general practitioners. METHODS： Eighty-three patients with symptoms suggestive of GERD were enrolled by general practitioners in this multi-centre, randomized and doubleblind study. All patients received either rabeprazole （20 mg bid） or a placebo for one week. The diagnosis of GERD was established on the presence of mucosal breaks at endoscopy and/or an abnormal esophageal 24-h pH test. The test was considered to be positive if patients reported at least a ＂clear improvement＂ of symptoms on a 7-point Likert scale. RESULTS： The sensitivities of the test for rabeprazole and the placebo were 83% and 40%, respectively. The corresponding specificity, positive and negative predictive values were 45% and 67%, 71% and 71%, and 62% and 35%, respectively. A receiver operating characteristics （ROC） analysis confirmed that the best discriminatory cut-off corresponded to description of ＂clear improvement＂ CONCLUSION： The poor specificity of the proton-pump inhibitor （PPI） test does not support such an approach to establish a diagnosis of GERD in a primary care setting.

Rabeprazole, clarithromycin, and amoxicillin Helicobacter pylori eradication therapy: Report of an efficacy study

AIM: To investigate the efficacy of a standard triple therapy (comprising rabeprazole, clarithromycin, and amoxicillin) for Helicobacter pylori (H. pylori) eradication, noting factors that influence the outcome and documenting any adverse events.

CYP2C19 polymorphism has no influence on rabeprazole-based hybrid therapy for Helicobacter pylori eradication

AIM To evaluate the impact of cytochrome P450 2C19(CYP2C19) and interleukin-1β(IL-1β) polymorphisms on the efficacy of Helicobacter pylori(H. pylori) eradication by using rabeprazole-based hybrid therapy.METHODS A total of 88 H. pylori-infected patients were recruited to receive 14-d of hybrid therapy from March 2013 to May 2014. Three patients were excluded from analysis because of incomplete compliance. Either a follow-up endoscopy or 13 C-urea test was performed to determine the results of H. pylori eradication therapy. The genotypes of CYP2C19 and IL-1β were analyzed to investigate the impact on treatment effect. RESULTS The total eradication rate of H. pylori was 92.94%(79/85). According to the CYP2C19 genotypes, the rates of H. pylori eradication were 89.19% in extensive metabolizers(EM) and 95.83% in non-EM. The H.pylori eradication rates regarding the IL-1β genotypes were 92.59% in the normal acid secretion group and 93.10% in the low acid secretion group. After multivariable logistic regression analysis, both the genotypes of CYP2C19 and IL-1β had no significant influences on the eradication rates of H. pylori.CONCLUSION The CYP2C19 and IL-1β polymorphisms are not significantly independent factors of H.pylori eradication using rabeprazole-based hybrid therapy.

Development and validation of a high throughput UPLC–MS/MS method for simultaneous quantification of esomeprazole,rabeprazole and levosulpiride in human plasma

A high throughput ultra pressure liquid chromatography-mass spectrometry （UPLC-MS/MS） method with good sensitivity and selectivity has been developed and validated for simultaneous quantification of esomeprazole, rabeprazole and levosulpiride in human plasma using lansoprazole as internal standard （IS）. The extraction method based on liquid-liquid extraction technique was used to extract the analytes and IS from of 50 μL of human plasma using methyl tert-butyl ether：ethyl acetate （80：20, v/v）, which offers a high recovery. Chromatographic separation of analytes and IS was achieved on a Hypersil gold C18 column using gradient mobile phase consisting of 2 mM ammonium formate/acetonitrile. The flow rate was set at 0.5 mL/min to elute all the analytes and IS within 1.00 min runtime. Detection of target compounds was performed on a triple quadruple mass spectrometer by multiple reaction monitoring （MRM） mode via positive electrospray ionization （ESI）. Method validation results demonstrated that the developed method has good precision and accuracy over the concentration ranges of 0.1-2000 ng/mL for each analyte. Stability of compounds was established in a battery of stability studies, i.e., bench top, autosampler, dry extract and long-term storage stability as well as freeze-thaw cycles. The validated method has been successfully applied to analyze human plasma samples for application in pharmaco- kinetic studies.

Stability-indicating HPLC-DAD methods for determination of two binary mixtures:Rabeprazole sodium-mosapride citrate and rabeprazole sodium-itopride hydrochloride

Two selective stability-indicating HPLC methods are described for determination of rabeprazole sodium （RZ）-mosapride citrate （MR） and RZ-itopride hydrochloride （IO） mixturcs in the presence of their ICH-stress formed degradation products. Separations were achieved on X-Bridge CI 8 column using two mobile phases： the first for RZ-MR mixture consisted of acetonitrile： 0.（125 M KH,PO4 solution： TEA （30：69：1 v/v; pH 7.0）; the second for RZ-IO mixture was at ratio of 25：74：1 Iv/v： pH 9.25J. The detection wavelength was 283 nm. The two methods were validated and wdidation acceptance criteria were met in all cases. Peak purity testing using contrast angle theory, relative absorbance and log A versus the wavelengths plots were presented. The % recoveries of the intact drugs were between 99.1% and 102.2% with RSD% values less than 1.6%. Application of the proposed HPLC methods indicated that the methods could be adopted to follow the stability of their formulations.

Effect and safety of anaprazole in the treatment of duodenal ulcers:a randomized,rabeprazole-controlled,phase Ⅲ non-inferiority study

Background:The pharmacokinetic and clinical behaviors of many proton pump inhibitors(PPIs)in peptic ulcer treatment are altered by CYP2C19 genetic polymorphisms.This non-inferiority study evaluated the efficacy and safety of the novel PPI anaprazole compared with rabeprazole.We also explored the influence of Helicobacter pylori(H.pylori)infection status and CYP2C19 polymorphism on anaprazole.Methods:In this multicenter,randomized,double-blind,double-dummy,positive-drug parallel-controlled,phase Ⅲ study,Chinese patients with duodenal ulcers were randomized 1:1 to receive rabeprazole 10 mg+anaprazole placebo or rabeprazole placebo+anaprazole 20 mg once daily for 4 weeks.The primary efficacy endpoint was the 4-week ulcer healing rate assessed by blinded independent review.Secondary endpoints were the proportion of patients with improved overall and individual duodenal ulcer symptoms at 4 weeks.Furthermore,exploratory subgroup analysis of the primary endpoint by H.pylori status and CYP2C19 polymorphism was conducted.Adverse events were monitored for safety.Non-inferiority analysis was conducted for the primary endpoint.Results:The study enrolled 448 patients(anaprazole,n=225;rabeprazole,n=223).The 4-week healing rates were 90.9%and 93.7%for anaprazole and rabeprazole,respectively(difference,-2.8%[95%confidence interval,-7.7%,2.2%]),demonstrating non-inferiority of anaprazole to rabeprazole.Overall duodenal ulcer symptoms improved in 90.9%and 92.5%of patients,respectively.Improvement rates of individual symptoms were similar between the groups.Healing rates did not significantly differ by H.pylori status or CYP2C19 genotype for either treatment group.The incidence of treatment-emergent adverse events was similar for anaprazole(72/220,32.7%)and rabeprazole(84/219,38.4%).Conclusions:The efficacy of anaprazole is non-inferior to that of rabeprazole in Chinese patients with duodenal ulcers.Registration:ClinicalTrials.gov,NCT04215653.

Rabeprazole 10 mg versus 20 mg in preventing relapse of gastroesophageal reflux disease： a meta-analysis

Background Several randomized controlled trials （RCTs） have compared endoscopic and symptomatic relapses in patients with erosive gastroesophageal reflux disease （GERD）.We have summarized current evidence for rabeprazole 10 or 20 mg once daily for GERD maintenance treatment over 1 or 5 years.Methods MEDLINE,EMBASE,and the Cochrane Central Register of Controlled Trials were searched,through August 2012,for eligible RCTs of adults with erosive GERD.The efficacies of rabeprazole 10 and 20 mg/d were compared.Results The search identified 288 citations,and five RCTs containing 1480 patients were considered eligible.Heartburn relapse rates did not differ significantly between patients treated with rabeprazole 10 and 20 mg/d for 1 year （relative risk （RR）=1.29; 95％ confidence interval （CI）：0.97-1.72）,but differed in patients treated for 5 years （RR=1.274; 95％ CI：1.005-1.615）.Endoscopic relapse rates differed significantly between rabeprazole 10 and 20 mg/d for 1 year （RR=1.92;95％ CI：1.21-3.06）,for 5 years （RR=1.667; 95％ CI：1.073-2.589）,and in combined 1-and 5-year maintenance trials （RR=1.785; 95％ CI：1.298-2.456）.Conclusion Rabeprazole 20 mg/d was superior to rabeprazole 10 mg/d in preventing endoscopic relapse of erosive GERD,but that the two dosages were equivalent in symptomatic relief over 1 year.

CYP2C19 polymorphism influences Helicobacter pylori eradication

The known factors that have contributed to the decline of Helicobacter pylori (H. pylori) eradication rate include antibiotic resistance, poor compliance, high gastric acidity, high bacterial load, and cytochrome P450 2C19 (CYP2C19) polymorphism. Proton pump inhibitor (PPI) is important in the eradication regimen. The principal enzyme implicated in the metabolism of PPIs is CYP2C19. The effects of PPI depend on metabolic enzyme, cytochrome P450 enzymes, and CYP2C19 with genetic differences in the activity of this enzyme (the homozygous EM, heterozygous EM (HetEM), and poor metabolizer). The frequency of the CYP2C19 polymorphism is highly varied among different ethnic populations. The CYP2C19 genotype is a cardinal factor of H. pylori eradication in patients taking omeprazole- based or lansoprazole-based triple therapies. In contrast, the CYP2C19 polymorphism has no significant effect on the rabeprazole-based or esomeprazole-based triple therapies. The efficacy of levofloxacin-based rescue triple therapy might be also affected by the CYP2C19 polymorphism, but CYP2C19 genotypes did not show obvious impact on other levofloxacin-based rescue therapies. Choice of different PPIs and/or increasing doses of PPIs should be individualized based on the pharmacogenetics background of each patient and pharmacological profile of each drug. Other possible factors influencing gastric acid secretion (e.g., IL-1β- 511 polymorphism) would be also under consideration.

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

AIM:To investigate whether potent acid inhibition is effective in non-erosive reflux disease (NERD) refractory to standard rabeprazole (RPZ) treatment. METHODS:We treated 10 Japanese patients with NERD resistant to standard dosages of RPZ:10 mg or 20 mg od,20 mg bid,or 10 mg qid for 14 d. All patients completed a frequency scale for symptoms of gastroesophageal reflux disease questionnaire frequency scale for the symptoms of GERD (FSSG); and underwent 24 h pH monitoring on day 14. RESULTS:With increased dosages and frequency of administration of RPZ,median intragastric pH significantly increased,and FSSG scores significantly decreased. With RPZ 10 mg qid,potent acid inhibition was attained throughout 24 h. However,five subjects were refractory to RPZ 10 mg qid,although the median intragastric pH in these subjects (6.6,range:6.2-7.1) was similar to that in the remaining five responsive subjects (6.5,range:5.3-7.3). With baseline RPZ 10 mg od,FSSG scores in responsive patients improved by > 30%,whereas there was no significant decrease in the resistant group. CONCLUSION:NERD patients whose FSSG score fails to decrease by > 30% after treatment with RPZ 10 mg od for 14 d are refractory to higher dosage.

Quadruple therapy for eradication of Helicobacter pylori

AIM:To investigate quadruple therapy with rabeprazole,amoxicillin,levofloxacin and furazolidone for the eradication of Helicobacter pylori (H.pylori) infection.METHODS:A total of 147 patients were divided into the experimental treatment group (n=78) and the standard triple treatment group (n=69).The experimental treatment group received rabeprazole 20 mg,amoxicillin 1.0 g,levofloxacin 0.2 g and furazolidone 0.1 g,twice daily.The standard triple treatment group received omeprazole 20 mg,amoxicillin 1.0 g and clarithromycin 0.5 g,twice daily.RESULTS:One month after treatment,the 13 C urea breath test was carried out to detect H.pylori.The eradication rate using per-protocol analysis was 94.3% in the experimental treatment group and 73% in the standard triple treatment group (P < 0.05),and using intention to test analysis,these figures were 86% and 67% in the two groups,respectively.Side effects were observed in 34 patients,and included mild dizziness,nausea,diarrhea and increased bowel movement.Eleven of the 34 patients needed no treatment for their side effects.CONCLUSION:Rabeprazole,amoxicillin,levofloxacinand furazolidone quadruple therapy is a safe method for the eradication of H.pylori with high efficacy and good tolerability.

Clinical relevance of clopidogrel-proton pump inhibitors interaction

Clopidogrel is a widely used antiplatelet agent for the secondary prevention of cardiovascular events in patients with stable coronary heart disease, acute coronary syndromes and ischemic stroke. Even though clopidogrel is safer than aspirin in terms of risk for gastrointestinal(GI) bleeding, the elderly, and patients with a history of prior GI bleeding, with Helicobacter pylori infection or those who are also treated with aspirin, anticoagulants, corticosteroids or nonsteroidal antiinflammatory drugs are at high risk for GI complications when treated with clopidogrel. Accordingly, proton pump inhibitors are frequently administered in combination with clopidogrel to reduce the risk for GI bleeding. Nevertheless, pharmacodynamic studies suggest that omeprazole might attenuate the antiplatelet effect of clopidogrel. However, in observational studies, this interaction does not appear to translate into increased cardiovascular risk in patients treated with this combination. Moreover, in the only randomized, double-blind study that assessed the cardiovascular implications of combining clopidogrel and omeprazole, patients treated with clopidogrel/omeprazole combination had reduced risk for GI events and similar risk for cardiovascular events than patients treated with clopidogrel and placebo. However, the premature interruption of the study and the lack of power analysis in terms of the cardiovascular endpoint do not allow definite conclusions regarding the cardiovascular safety of clopidogrel/omeprazole combination. Other proton pump inhibitors do not appear to interact with clopidogrel. Nevertheless, given the limitations of existing observational and interventional studies, the decision to administer proton pump inhibitors to patients treated with clopidogrel should be individualized based on the patient's bleeding and cardiovascular risk.

Relationship between the acid-suppression efficacy of proton pump inhibitors and CYP2C19 genetic polymorphism in patients with peptic ulcer

Objective To investigate acid-suppression efficacy of proton pump inhibitors(PPIs) in relation to CYP2C19 genetic polymorphism on patients with peptic ulcer. Methods By an open, randomized and control trial, fifty nine patients with active peptic ulcer were randomly assigned to receive one of three PPIs on a single dose (20 mg of each drug): omeprazole group (n=19), rabeprazole group (n=20) and esomeprazole group (n=20). Intragastric pH was recorded 1 hour before and 24 hours after administration. CYP2C19 genotype was tested in all patients. Results The EMs/PMs ratio of each group was 16/3,17/3 and 17/3, respectively. The total time that intragastric pH>4, time percent pH>4 and median pH in PMs patients were significantly higher than those in EMs patients of omeprazole group (P<0.05). But all these differences were not found in rabeprazole group and esomeprazole group. The pH of nocturnal acid breakthrough(NAB) in both rabeprazole group and esomeprazole group was higher than that of omeprazole group, while there was no significant difference between rabeprazole group and esomeprazole group.Conclusion The acid-suppression efficacy of omeprazole is highly dependent on CYP2C19 genetic polymorphism, while CYP2C19 genetic polymorphism may have a little influence on the acid-suppression efficacy of rabeprazole and esomeprazole. The acid-suppression action of rabeprazole and esomeprazole is superior to omeprazole, especially on night acid secretion.

Influence of the Meal and Genotype of CYP2C19 on the Pharmacokinetics of Proton Pump Inhibitors in Healthy Japanese Subjects

Objectives: To evaluate the influence of meals on the pharmacokinetics of omeprazole and rabeprazole and to investigate these PPIs with reference to CYP2C19 genotypes in healthy Japanese men. Methods: This was a randomized, open label, four-way crossover study. Twelve healthy Japanese male volunteers received a single oral dose of either 20 mg omeprazole or 10 mg rabeprazole, in the fasted state and after a standardized breakfast. Results: Between the administration of omeprazole in the fasted state and after breakfast, there were no significant differences in Cmax, AUC, Tmax, and half-life. Between the administration of rabeprazole in the fasted state and after breakfast, there were no significant differences in Cmax, AUC and half-life, whereas the Tmax of rabeprazole after breakfast was significantly delayed (2.8 ± 1.0 vs 5.3 ± 1.8 h, respectively;p = 0.006). PMs demonstrated the highest Cmax and AUC after drug intake under the fasting state and after breakfast, and homo EMs showed a significantly delayed Tmax. Conclusion: When a single dose of either PPI was administered, the pharmacokinetics of omeprazole was not affected by the meal, whereas the Tmax of rabeprazole after the meal was significantly delayed.