Comparison of lansoprazole-based triple and dual therapy for treatment of Helicobacter pylori-related duodenal ulcer: an Asian multicentre double-blind randomized placebo controlled study. (41/641)

BACKGROUND: [corrected] In Asian countries with limited resources, clarithromycin-based triple therapy may not be readily available. There are also few direct comparisons of different regimens in Asia. AIM: To compare two lansoprazole-based non-clarithromycin triple therapies and one dual therapy in a prospective double-blind placebo-controlled study of Helicobacter pylori eradication and duodenal ulcer healing. METHODS: Fourteen centres in Asia participated in this study. Patients with acute duodenal ulcer who were H. pylori-positive were recruited. They were randomized to receive: (a) lansoprazole 30 mg b.d., amoxycillin 1 g b.d. and metronidazole 500 mg b.d. for 2 weeks (LAM-2 W), or (b) LAM for 1 week and placebo (LAM-1 W), or (c) lansoprazole 30 mg b.d., amoxycillin 1 g b.d. and placebo for 2 weeks (LA-2 W). Upper endoscopy was repeated at week 6 to check for duodenal ulcer healing. Symptoms and side-effects were recorded. RESULTS: A total of 228 patients were recruited, and two patients took less than 50% of the drugs. H. pylori eradication rates (intention-to-treat) were 68 out of 82 (83%) with LAM-2 W, 55 out of 71 (78%) with LAM-1 W and 43 out of 75 (57%) with LA-2 W. There were significant differences (P=0. 001) in eradication rates when comparing either LAM-2 W or LAM-1 W with LA-2 W. The eradication rate in patients with metronidazole resistant H. pylori strains were significantly lower than those with metronidazole sensitive strains (P=0.0001). The duodenal ulcer healing rates at week 6 were 85%, 85% and 72% in LAM-2 W, LAM-1 W and LA-2 W, respectively (P=0.065). Side-effects occurred in 13%, 11% and 9% in LAM-2 W, LAM-1 W and LA-2 W, respectively. H. pylori eradication and initial ulcer size were factors affecting duodenal ulcer healing. CONCLUSIONS: This Asian multicentre study showed that 1-week lansoprazole-based triple therapy without clarithromycin has similar efficacy in H. pylori eradication and ulcer healing compared with a 2-week regimen. Both triple therapies were significantly better than dual therapy in H. pylori eradication. Therefore, 1-week lansoprazole-based triple therapy is as safe and effective as 2-week therapy in eradication of H. pylori infection and healing of duodenal ulcer in these Asian centres.  (+info)

Formation of omeprazole sulphone but not 5-hydroxyomeprazole is inhibited by grapefruit juice. (42/641)

AIMS: To determine the effect of grapefruit juice on omeprazole metabolism in vivo. METHODS: This was a randomized crossover study with a 2 week washout period. Omeprazole (20 mg) was taken orally by 13 healthy volunteers after an overnight fast with either grapefruit juice or water. Serial blood samples were obtained over 12 h and standardized meals were served 3 and 10 h after the administration of omeprazole. Plasma concentrations of omeprazole and its major metabolites, 5-hydroxyomeprazole and omeprazole sulphone, were determined by high performance liquid chromatography (h.p.l.c.). RESULTS: Mean area under the plasma concentration vs time curve (AUC) between 0 and 12 h for omeprazole sulphone was approximately 20% lower (P<0.01) in the group receiving grapefruit juice. There was no significant difference in the mean AUC of 5-hydroxyomeprazole or omeprazole. The AUC ratio of omeprazole sulphone to omeprazole, an index of CYP3A4 activity, was decreased by 33% (P<0.001) after administration of grapefruit juice whereas the AUC ratio of 5-hydroxyomeprazole to omeprazole, an index of CYP2C19 activity, did not differ between the two phases of the study. Although the time to peak concentration (tmax ) and terminal half-life (t1/2,z) of omeprazole and its two main metabolites were not altered, the peak concentration (Cmax ) of omeprazole sulphone was significantly reduced after administration of grapefruit juice. CONCLUSION: Administration of grapefruit juice decreased the formation of omeprazole sulphone but not 5-hydroxyomeprazole. These results indicate that activities of CYP3A4, but not of CYP2C19, are inhibited by the simultaneous administration of grapefruit juice.  (+info)

Importance of Helicobacter pylori cagA and vacA status for the efficacy of antibiotic treatment. (43/641)

BACKGROUND: Virulence factors of Helicobacter pylori are associated with peptic ulcer disease and may be also associated with the efficacy of treatment. AIMS: To determine the relation between the vacA and the cagA status of H pylori, clinical disease, and treatment outcome. PATIENTS: 121 patients with H pylori infection and peptic ulcer disease or functional dyspepsia were treated by quadruple antibiotic therapy in two groups for one and two days, respectively. METHODS: DNA was isolated from gastric antral biopsy specimens, taken before and after treatment, and the vacA and cagA status was determined by polymerase chain reaction and reverse hybridisation. RESULTS: Peptic ulcer disease was significantly associated with the vacA s1 type, and cagA positivity, but not with the vacA m type. Treatment efficacy was significantly higher in patients with peptic ulcer disease, or infected with cagA+/vacA s1 strains. CONCLUSIONS: The strong association between the cagA and vacA status and peptic ulcer disease was confirmed. Cure rates seem to be higher for patients with cagA+/vacA s1 H pylori strains, which is consistent with the higher cure rate observed among ulcer patients compared with functional dyspepsia patients. Therefore, treatment studies may require stratification for presence of ulcers as well as H pylori genotypes.  (+info)

The gastric H,K-ATPase blocker lansoprazole is an inhibitor of chloride channels. (44/641)

1. It was postulated that swelling dependent chloride channels are involved in the proton secretion of parietal cells. Since omeprazole, lansoprazole and its acid activated sulphenamide form AG2000 are structurally related to phenol derivatives known to block swelling dependent chloride channels, we set out to test, whether these substances--which are known to block the H,K-ATPase--could also lead to an inhibition of swelling-dependent chloride channels. Swelling-dependent chloride channels--characterized in many different cell types--show highly conserved biophysical and pharmacological features, therefore we investigated the effect of omeprazole, lansoprazole and its acid activated sulphenamide form AG2000 on swelling-dependent chloride channels elicited in fibroblasts, after the reduction of the extracellular osmolarity. 2. Omeprazole, lansoprazole and its acid activated sulphenamide form AG2000 are able to block swelling-dependent chloride channels (IClswell). 3. Lansoprazole and its protonated metabolite AG2000 act on at least two different sites of the IClswell protein: on an extracellular site which seems to be in a functional proximity to the nucleotide binding site, and on an intracellular site which allows the formation of disulfide-bridges. 4. The inhibition of the proton pump and the simultaneous blocking of chloride channels by omeprazole, lansoprazole and its acid activated sulphenamide form AG2000, as described here could be an effective mode to restrict proton secretion in parietal cells.  (+info)

Effect of ornidazole and clarithromycin resistance on eradication of Helicobacter pylori in peptic ulcer disease. (45/641)

BACKGROUND: Clarithromycin and nitroimidazoles such as metronidazole and ornidazole are among the most frequently used antibiotics for curing Helicobacter pylori infection. However, controversial data exist on whether their in vitro resistance has a negative impact on treatment outcome. METHODS: Patients with H. pylori positive active peptic ulcer disease were randomly assigned to receive lansoprazole 30 mg o.d., amoxycillin 1 g b.d. and ornidazole 500 mg b.d. (LAO) or lansoprazole 30 mg o.d., amoxycillin 1 g b.d. and clarithromycin 500 mg b.d. (LAC) for 2 weeks. Pre-treatment resistance to ornidazole and clarithromycin was assessed by Epsilometer (E-) test. Four weeks after completion of treatment, patients underwent a 13C urea breath test to assess H. pylori status. RESULTS: Data from 80 patients with active peptic ulcer disease and positive H. pylori status were analysed. The prevalence of primary drug resistance was 25% for metronidazole and 7.5% for clarithromycin. In patients treated with LAO, effective treatment was achieved in 87% of metronidazole-susceptible, but only 30% of metronidazole-resistant strains (P < 0.01). In the LAC group, therapy was successful in 81% of clarithromycin-susceptible strains, whereas treatment failed in all patients with primary clarithromycin resistance (n = 3). CONCLUSION: Resistance against nitroimidazoles significantly affects treatment outcome in H. pylori eradication therapy.  (+info)

Lack of a pharmacokinetic interaction between lansoprazole or pantoprazole and theophylline. (46/641)

AIM: To study the potential pharmacokinetic interaction between lansoprazole or pantoprazole and theophylline at steady state. METHODS: Theophylline 200 mg extended-release formulation was administered twice daily on days 1-11 to 30 healthy, non-smoking males. On days 5-11, 15 subjects received concomitant lansoprazole 30 mg once daily (o.d.) and 15 subjects received concomitant pantoprazole 40 mg o.d. RESULTS: No significant changes in the steady-state theophylline maximum plasma concentration (Cmax), time to Cmax (Tmax), minimum plasma concentration (Cmin), area under the plasma concentration-time curve over the 12-h dosing interval (AUC0-12), or apparent total oral clearance (CL/F) were observed within the two treatment groups when theophylline was administered alone or in combination with lansoprazole or pantoprazole. In addition, no significant differences in the changes of steady-state theophylline pharmacokinetics from day 4 to day 11 were noted between the two treatment groups. Treatment with theophylline in combination with either lansoprazole or pantoprazole was well tolerated. All adverse events were transient and rated mild to moderate in severity. CONCLUSION: Co-administration of either lansoprazole or pantoprazole in healthy subjects does not significantly affect the steady-state pharmacokinetics of theophylline at the therapeutic doses tested.  (+info)

Clinical and fiscal impact of lansoprazole intolerance in veterans with gastro-oesophageal reflux disease. (47/641)

BACKGROUND: Omeprazole was replaced by lansoprazole as the only proton pump inhibitor on the Veterans Affairs (VA) formulary in February 1997. We aimed to assess the clinical and fiscal impact of this conversion at two VA hospitals. METHODS: We identified lansoprazole intolerant patients using pharmacy databases. We reviewed medical records to obtain data regarding reasons for lansoprazole intolerance. The costs of the formulary change and the savings to the VA were calculated. RESULTS: A total of 3833 patients required long-term proton pump inhibitor therapy; 2224 (58%) were started on lansoprazole and 1479 (39%) were converted from omeprazole to lansoprazole. The remaining 130 (3.4%) patients were never converted from omeprazole to lansoprazole. Of the 3833 patients, 325 (8.5%) currently receive omeprazole therapy; of these, 195 out of 3703 (5.3%) patients are true lansoprazole failures; 172 of these 195 patients completed the study. Most (87%) of the lansoprazole intolerant patients received prior omeprazole. Discontinuation of lansoprazole was due to poor symptom control in 69% and/or side-effects (22%) including diarrhoea (10%), abdominal pain (5%), or hives (1%). The 1-year cost of managing lansoprazole failure in 195 patients was $61 690. However, the savings to the VA during the same time period, which totalled $321 360, more than offset the costs associated with the conversion. CONCLUSIONS: Lansoprazole intolerance requiring omeprazole conversion occurred in 5% of veterans on proton pump inhibitor therapy for chronic gastro-oesophageal reflux disease (GERD) symptoms and in 10% of patients with prior omeprazole success. The VA realized substantial cost savings in association with the formulary change.  (+info)

Pharmacokinetic interaction between proton pump inhibitors and roxithromycin in volunteers. (48/641)

BACKGROUND: Triple therapy including two antibiotics and a proton pump inhibitor is a rational approach to the treatment of Helicobacter pylori induced peptic ulcer disease. The interaction of antimicrobial therapy and acid suppression is not yet well elucidated. AIMS: To investigate the effects of proton pump inhibitors on roxithromycin levels in plasma and gastric tissue under steady-state conditions in volunteers. METHODS: In two crossover studies omeprazole 20 mg b.d., lansoprazole 30 mg b.d., roxithromycin 300 mg b.d., and the combination of roxithromycin with either omeprazole or lansoprazole were administered to 12 healthy volunteers over 6 days. Blood plasma levels of the drugs were measured. In addition, roxithromycin concentrations were also determined in gastric juice and gastric tissue obtained during endoscopy. RESULTS: The proton pump inhibitors and roxithromycin did not alter the blood plasma pharmacokinetics of each other. When compared to roxithromycin administered alone, its combination with a proton pump inhibitor significantly increased the roxithromycin concentrations in gastric juice (3.0-5.0 microg/mL vs. 0.3-0.4 microg/mL) and gastric tissue (antrum: 3.8-4.0 vs. 2.8 microg/g, fundus: 5.9-7.4 vs. 4.2-4.4 microg/g). CONCLUSIONS: Proton pump inhibitors and roxithromycin do not alter the systemic bioavailability of each other. However, proton pump inhibitors increase the local concentration of roxithromycin in the stomach which may contribute to the clinically proven synergic beneficial action in eradication therapy of H. pylori.  (+info)