BACKGROUND/AIMS: Reflux esophagitis is a recurring condition for which many patients require maintenance therapy. This comparative, randomized multicenter study was designed to evaluate the effect of long-term maintenance treatment comparing proton pump inhibitor, rabeprazole and H2 receptor antagonist, ranitidine. METHODS: Eighty four patients with healed reflux esophagitis confirmed by endoscopy were randomly allocated to receive maintenance treatment with either rabeprazole 10 mg once daily or ranitidine 300 mg once daily for 32 weeks. Patients were seen every 8 weeks or at symptomatic relapse. RESULTS: Of 84 initially treated patients, 73 entered the maintenance study. The percentage of asymptomatic patients after 90-day and 210-day treatment were 97% and 81.5%, for rabeprazole and 74.3% and 62.3%, for ranitidine, respectively. After 32 weeks, the relapse rates of esophagitis were 21.3% in the rabeprazole group and 62.9% in the ranitidine group (RR: 0.405, 95% CI: 0.215-0.766). CONCLUSIONS: Maintenance treatment with rabeprazole (10 mg once daily) is superior to ranitidine (300 mg once daily) in keeping the patients with reflux esophagitis in remission over a 32 week period.
2-Pyridinylmethylsulfinylbenzimidazoles ; Adult ; Anti-Ulcer Agents/*therapeutic use ; Benzimidazoles/*therapeutic use ; Esophagitis, Peptic/*drug therapy ; Female ; Humans ; Male ; Middle Aged ; Omeprazole/*analogs & derivatives/therapeutic use ; Ranitidine/*therapeutic use

OBJECTIVETo investigate the impact of omeprazole on platelet response to clopidogrel and the effect of polymorphisms of CYP2C19 on the antiplatelet effect of clopidogrel.

METHODSPlatelet aggregation (PA) was assessed before 300 mg aspirin plus 300 mg loading dose of clopidogrel and after 300 mg aspirin plus 75 mg maintenance dose of clopidogrel 7 days later in 414 patients with acute coronary syndrome who have undergone percutaneous coronary intervention (PCI). Thereafter, gastric mucosal protective drugs were given (omeprazolem 20 mg, n=224 or cimetidine 800 mg, n=190). Fourteen days later, PA was measured again. Genotypes of CYP2C19*2 were analyzed with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTSAfter taken aspirin and clopidogrel, PA has decreased significantly in both groups. Compared with cimetidine, omeprazole had no significant impact on PA on 7 and 21 days post PCI. Compared with homozygotes or heterozygotes for the wild-type CYP2C19*2, patients with CYP2C19*2 AA genotype had significantly higher PA on 7 and 21 days post PCI (P<0.05).

CONCLUSIONNo attenuating effect on platelet response to clopidogrel has been observed for Omeprazole. The variant of CYP2C19*2 AA genotype is significantly associated with attenuated response to clopidogrel.

Adult ; Aged ; Aryl Hydrocarbon Hydroxylases ; genetics ; metabolism ; Cytochrome P-450 CYP2C19 ; Drug Interactions ; Female ; Humans ; Male ; Middle Aged ; Omeprazole ; pharmacology ; Platelet Aggregation Inhibitors ; pharmacology ; Proton Pump Inhibitors ; pharmacology ; Ticlopidine ; analogs & derivatives ; pharmacology

BACKGROUNDOmeprazole, usually used in the antiplatelet therapy during percutaneous coronary intervention (PCI) in acute coronary syndrome (ACS), has been reported to increase ischemic events in retrospective studies. However, other clinical trials gave paradoxical results. The aim of this study was to assess the effects of omeprazole on clopidogrel efficacy and clinical events.

METHODSAll patients (n = 172) received aspirin (loading dose 300 mg and maintenance dose 100 mg/d) and clopidogrel (loading dose 600 mg and maintenance dose 75 mg/d) during the therapy. They were randomized to receive omeprazole (20 mg/d) or placebo for 30 days. Residual platelet activities in the adenosine 5'-diphosphate (ADP) pathway were detected on the fifth day after PCI with thrombelastography (TEG)-mapping. The clinical events were recorded after one month.

RESULTSAccording to the five levels of platelet activities, the frequency distributions of the inhibition rates were significantly different (P = 0.0062). However, no significant change was seen in the distribution among the highest or the lowest inhibiting levels (> 95% and < 30% inhibition rate). And there were no significant differences (P > 0.05) in events incidence, while gastro-intestinal bleeding decreased in co-administration of omeprazole.

CONCLUSIONSOmeprazole significantly blunts clopidogrel efficacy while not exacerbates ischemic events in ACS undergoing PCI. Omeprazole even can decrease gastro-intestinal bleeding in those patients.

Acute Coronary Syndrome ; blood ; drug therapy ; pathology ; therapy ; Aged ; Angioplasty, Balloon, Coronary ; methods ; Aspirin ; therapeutic use ; Female ; Humans ; Male ; Middle Aged ; Omeprazole ; therapeutic use ; Platelet Aggregation Inhibitors ; therapeutic use ; Ticlopidine ; analogs & derivatives ; therapeutic use

This study is to investigate the effect of high altitude hypoxia on the activity and protein expression of CYP2C9 and CYP2C19. Rats from plain (P) and rats with acute middle altitude hypoxia (AMH), chronic middle altitude hypoxia (CMH), acute high altitude hypoxia (AHH) and chronic high altitude hypoxia (CHH) were administered orally phenytoin sodium (PHT) and omeprazole (OMZ) to evaluate the activity of CYP2C9 and CYP2C19, separately. The serum concentrations of PHT and metabolite 4'-hydroxyphenytoin (HPPH) at 12 h after treatment and the serum concentrations of OMZ and metabolite 5-hydroxy omeprazole (5-OHOMZ) at 3 h after treatment were determined by RP-HPLC. The activity of CYP2C9 and CYP2C19 was evaluated by the ratio of HPPH to PHT and the ratio of 5-OHOMZ to OMZ, respectively. The protein expressions of CYP2C9 and CYP2C19 were determined by ELISA method. The activities of CYP2C9 (HPPH/PHT) in P, AMH, CMH, AHH and CHH were 0.67 +/- 0.31, 0.75 +/- 0.29, 0.76 +/- 0.23, 0.79 +/- 0.31 and 0.75 +/- 0.18, respectively, and the activities of CYP2C19 (5-OHOMZ/OMZ) in P, AMH, CMH, AHH and CHH were 0.17 +/- 0.06, 0.20 +/- 0.10, 0.11 +/- 0.05, 0.37 +/- 0.13 and 0.19 +/- 0.05, respectively. The protein expressions of CYP2C9 in P, AMH, CMH, AHH and CHH were 4.20 +/- 1.27, 3.95 +/- 0.81, 3.93 +/- 1.11, 4.32 +/- 1.03 and 4.12 +/- 0.86 ng x g(-1), respectively, and the protein expressions of CYP2C19 in P, AMH, CMH, AHH and CHH were 3.91 +/- 1.82, 3.63 +/- 2.07, 2.55 +/- 0.85, 4.78 +/- 2.37 and 3.51 +/- 1.03 ng x g(-1), respectively. The activities and protein expressions of CYP2C9 in AMH, CMH, AHH and CHH were not significantly different with those of P. The protein expressions of CYP2C19 in AMH, CMH, AHH and CHH were not significantly different with those of P, but the activity of CYP2C19 in AHH was significantly higher than that of P. This study found significant changes in the activity of CYP2C19 under the special environment of acute high altitude hypoxia.
2-Pyridinylmethylsulfinylbenzimidazoles ; blood ; Administration, Oral ; Altitude ; Animals ; Cytochrome P-450 Enzyme System ; metabolism ; Enzyme Activation ; Female ; Hypoxia ; metabolism ; Male ; Omeprazole ; administration & dosage ; blood ; pharmacokinetics ; Phenytoin ; administration & dosage ; analogs & derivatives ; blood ; pharmacokinetics ; Rats ; Rats, Sprague-Dawley

AIMTo study the chiral inversion of dextropantoprazole in human.

METHODSThree healthy Chinese male volunteers after an oral dose of 40 mg dextropantoprazole. An HPLC method was developed and used to determine the total plasma concentrations of each enantiomer. The ratios of the enantiomers in plasma samples were measured on a Chiral-AGP column. The plasma concentration of each enantiomer was then calculated using the ratios of enantiomers and total concentrations of the two enantiomers previously measured.

RESULTSThe AUC0-t of levopantoprazole was only 1.5% of the total AUC0-t of enantiomers.

CONCLUSIONThe chiral inversion from dextropantoprazole to levopantoprazole does not occur in the three healthy Chinese male volunteers after an oral dose of 40 mg dextropantoprazol.

2-Pyridinylmethylsulfinylbenzimidazoles ; Administration, Oral ; Adult ; Anti-Ulcer Agents ; blood ; chemistry ; pharmacokinetics ; Area Under Curve ; Benzimidazoles ; blood ; chemistry ; pharmacokinetics ; Chromatography, High Pressure Liquid ; Humans ; Male ; Omeprazole ; analogs & derivatives ; blood ; chemistry ; pharmacokinetics ; Stereoisomerism ; Sulfoxides ; blood ; chemistry ; pharmacokinetics

BACKGROUND/AIMS: This study was done to evaluate the efficacy of rabeprazole (proton-pump-inhibitor) and ranitidine (H2-receptor antagonist) in the symptom relief and treatment of erosive esophagitis diagnosed by endoscopy. METHODS: A total of 110 patients with typical gastroesophageal reflux disease (GERD) symptoms were enrolled in this multicenter study. They were randomized into rabeprazole group (53 patients) and ranitidine group (57 patients) respectively. The patients in rabeprazole group were given 10 mg of rabeprazole and ranitidine group received 300 mg of ranitidine before breakfast and dinner for 8 weeks. After the end of treatment, we evaluated the endoscopic healing rate of reflux esophagitis and symptomatic improvement. RESULTS: After 8 weeks of treatment, rabeprazole group showed significantly higher complete endoscopic cure rate than ranitidine group (86.8% [46/53] vs. 57.9% [33/57], p=0.001) and higher symptomatic improvement of heartburn (91.2% [31/34] vs. 76.2% [32/42], p=0.085), especially in the first 7 days (76.7% vs. 45.3%, p=0.008). Also, rabeprazole group showed significantly higher improvement of regurgitation symptom than ranitidine group (100% [35/35] vs. 83% [39/47], p=0.009). Both group showed no differences in the improvement of chest pain and globus sensation. All the adverse events (rabeprazole group 4 events vs. ranitidine group 3 events) were mild and there was no abnormality in laboratory test. CONCLUSIONS: In patients with GERD, rabeprazole 10 mg b.i.d. is superior to ranitidine 300 mg b.i.d. in healing of reflux esophagitis and resolving typical GERD symptoms. Rabeprazole is an effective and well-tolerated drug for GERD treatment.
2-Pyridinylmethylsulfinylbenzimidazoles ; Adult ; Anti-Ulcer Agents/*therapeutic use ; Benzimidazoles/*therapeutic use ; Esophagitis, Peptic/*drug therapy ; Female ; Histamine H2 Antagonists/*therapeutic use ; Humans ; Male ; Middle Aged ; Omeprazole/*analogs & derivatives/therapeutic use ; Proton Pumps/*antagonists & inhibitors ; Proton-Translocating ATPases/therapeutic use ; Ranitidine/*therapeutic use

BACKGROUND: Non-erosive reflux disorder, which represents more than 60% of gastro-esophageal reflux disorders, lacks objective parameters for diagnosis. The purpose of this study was to evaluate the correlation between non-erosive minimal lesions at the lower esophagus and gastro-esophageal reflux disorder. METHODS: Patients were asked to answer a symptom questionnaire. The endoscopic findings were either graded by LA classification or recorded as non-erosive minimal lesions. Patients with minimal lesions were treated with rabeprazole or a placebo and responses were evaluated at weeks 1 and 4. RESULTS: In 8 centers, 3454 patients were screened. In patients with heartburn or acid regurgitation as the most bothersome symptom, 23.7% had endoscopy negative reflux disorder, 40.1% showed minimal lesions, and 36.2% had mucosal break esophagitis. Thirty-four percent of patients with minimal lesions and 39.1% of patients with LA 'grade A' mild esophagitis reported typical reflux symptoms as their main symptom. In patients with minimal lesions, medication with rabeprazole reduced symptoms significantly at weeks 1 and 4, but not with the placebo. CONCLUSION: Patients with non-erosive minimal esophageal lesions had similar reflux symptoms comparable to those with mild erosive reflux esophagitis, and reflux symptoms were improved with a short-term proton pump inhibitor. Thus, non-erosive minimal esophageal lesion constitutes a great part of gastro-esophageal reflux disorder.
2-Pyridinylmethylsulfinylbenzimidazoles ; Adult ; Aged ; Aged, 80 and over ; Anti-Ulcer Agents/*therapeutic use ; Benzimidazoles/*therapeutic use ; Enzyme Inhibitors/*therapeutic use ; Esophageal Diseases/*pathology ; Female ; Follow-Up Studies ; Gastroesophageal Reflux/drug therapy/epidemiology/*pathology ; Humans ; Korea/epidemiology ; Male ; Middle Aged ; Omeprazole/*analogs & derivatives/therapeutic use ; Prospective Studies ; Proton-Translocating ATPases/*antagonists & inhibitors ; Treatment Outcome

OBJECTIVETo evaluate the impact of different proton pump inhibitors on the antiplatelet activity of clopidogrel.

METHODSA total of 60 hospitalized patients undergoing percutaneous coronary intervention were randomly assigned to receive omeprazole group 40 mg/d (20 patients), pantoprazole group 40 mg/d (20 patients) and control group (20 patients). All patients also received standard clopidogrel therapy, continuing 30 days treatments. The percentage clotting inhibition was measured by the use of thrombelastogram and the maximal platelet aggregation rate (MPAR) was measured by turbidity method at the first day before admission and 15 or 30 days after treatment. Major adverse cardiac and cerebral events (MACCE) and hemorrhagic events within 30 days were recorded.

RESULTSThe baseline clinical characteristics, angiography and PCI result were compared among the three groups. At the first day before admission and 15 or 30 days after treatment, no significant difference was shown in the percentage clotting inhibition measured by thrombelastogram and the maximal platelet aggregation rate (MPAR) measured by turbidity method among the three groups. Though the platelet agglutination inhibition rate measured at 15 and 30 days increased and MPAR measured at 15 and 30 days declined compared with the baseline data (P < 0.05), no significant difference was found between levels measured at 15 and 30 days (P > 0.05). The rates of MACCE had no significant difference among the three groups. Compared with control group, the rates of hemorrhagic event were significantly decreased in omeprazole or pantoprazole group (P < 0.05), but no significant difference was shown between the omeprazole and pantoprazole group.

CONCLUSIONNo significant impact of different proton pump inhibitors on the antiplatelet activity of clopidogrel has been found in patients undergoing coronary stent implantation and short-time combined administration is safe.

2-Pyridinylmethylsulfinylbenzimidazoles ; pharmacology ; therapeutic use ; Adult ; Aged ; Angioplasty, Balloon ; Aspirin ; pharmacology ; therapeutic use ; Coronary Disease ; therapy ; Drug Therapy, Combination ; Female ; Humans ; Male ; Middle Aged ; Omeprazole ; pharmacology ; therapeutic use ; Platelet Aggregation ; drug effects ; Postoperative Period ; Proton Pump Inhibitors ; pharmacology ; therapeutic use ; Stents ; Ticlopidine ; analogs & derivatives ; pharmacology ; therapeutic use

BACKGROUND/AIMS: Genetic polymorphism of cytochrome P450 CYP2C19 influences the efficacy of proton pump inhibitor (PPI) in Helicobacter pylori (H. pylori) eradication therapy. We investigated the difference in the cure rates of H. pylori infection by triple (rabeprazole plus amoxacillin and clarithromycin) therapy in relation to CYP2C19 genotype status. METHODS: One hundred and sixteen H. pylori infected patients with gastric ulcer and duodenal ulcer completed the triple therapy with 10 mg of rabeprazole b.i.d., 1,000 mg amoxacillin b.i.d. and 500 mg of clarithromycin b.i.d. for one week. The genotype of CYP2C19 was determined by a PCR-restriction fragment length polymorphism method. RESULTS: According to the univariate analysis, heterozygous extensive metabolizers (hetero EMs) and poor metabolizers (PMs) showed the highest (87.0%) and the lowest (80.0%) eradication rates, respectively. The difference in the therapeutic efficacy of rabeprazole among the different CYP2C19 genotypes was insignificant. With regard to gender, age and smoking history in relation to eradication rate, a statistical significance was noted only with age with odds ratio of 1.063 and p-value of 0.0202. CONCLUSIONS: In the eradication therapy of H. pylori, no statistically significant difference in therapeutic efficacy of rabeprazole was found among different CYP2C19 genotypes.
2-Pyridinylmethylsulfinylbenzimidazoles ; Adult ; Aged ; Amoxicillin/administration & dosage ; Anti-Bacterial Agents/administration & dosage ; Anti-Ulcer Agents/*administration & dosage ; Aryl Hydrocarbon Hydroxylases/*genetics ; Benzimidazoles/*administration & dosage ; Clarithromycin/administration & dosage ; Drug Therapy, Combination ; Duodenal Ulcer/drug therapy/*genetics/microbiology ; Female ; Genotype ; Helicobacter Infections/*drug therapy ; *Helicobacter pylori ; Humans ; Male ; Middle Aged ; Mixed Function Oxygenases/*genetics ; Omeprazole/analogs & derivatives ; Proton Pumps/*antagonists & inhibitors ; Stomach Ulcer/drug therapy/*genetics/microbiology

BACKGROUND/AIMS: Conflicting results have been reported whether patients with non-ulcer dyspepsia (NUD) respond differently to Helicobacter pylori (H. pylori) eradication treatment compared with patients with peptic ulcer diseases (PUD). The aim of this study was to evaluate any difference in H. pylori eradication rates between patients with NUD and PUD according to each proton pump inhibitor (PPI). METHODS: From September, 2004 to April, 2007, we retrospectively reviewed 2,297 patients with NUD (1,050 patients) or PUD (1,247 patients) infected with H. pylori. All patients received a standard 1 week triple therapy comprising of one of the five PPIs (pantoprazole, esomeprazole, omeprazole, lansoprazole, rabeprazole), clarithromycin and amoxicillin. The follow-up H. pylori test was performed 4 weeks after the completion of therapy. RESULTS: There was no significant difference in the eradication rates between the two groups. In comparison of eradication rates according to PPI, omeprazole- based triple therapy group showed higher eradication rate than other groups in patients with NUD, but not in patients with PUD. CONCLUSIONS: This study failed to show any difference in H. pylori eradication rate between patients with NUD and PUD. There is no convincing evidence that the eradication rate may be affected by different PPI.
2-Pyridinylmethylsulfinylbenzimidazoles/therapeutic use ; Adult ; Amoxicillin/administration & dosage ; Anti-Bacterial Agents/administration & dosage ; Anti-Ulcer Agents/administration & dosage ; Clarithromycin/administration & dosage ; Data Interpretation, Statistical ; Drug Therapy, Combination ; Dyspepsia/*drug therapy/etiology/microbiology ; Enzyme Inhibitors/therapeutic use ; Female ; Helicobacter Infections/complications/*drug therapy/microbiology ; *Helicobacter pylori ; Humans ; Male ; Middle Aged ; Omeprazole/analogs & derivatives/therapeutic use ; Peptic Ulcer/*drug therapy/etiology/microbiology ; Proton Pump Inhibitors/therapeutic use