Search

Omeprazole triple therapy has been shown to produce Helicobacter pylori eradication rates of up to 96% in patients with current or recent peptic ulceration. Such therapy is also now being used without endoscopy in H. pylori-positive patients who may have an inactive ulcer or dyspepsia, and in whom their effectiveness has been less well documented. Compliance is an important variable affecting H. pylori eradication; with 1-week omeprazole triple therapy, however, compliance is uniformly high, and this allows more detailed analysis of other causes of treatment failure. The strains of H. pylori in patients with functional dyspepsia may be associated with a lower degree of inflammation. Two new, large studies (DU-MACH and GU-MACH) have therefore looked at the impact of inflammation on H. pylori eradication. Polymorph infiltration in the antrum of patients with inflammation of grades 2/3 was associated with a significantly higher eradication rate when compared with inflammation of grades 0/1. Inflammation may be important for a number of reasons, including degradation of the mucus and epithelial layers (which may allow better penetration of charged antibiotics from the gastric lumen) and altered vascular and epithelial permeability (which may allow better systemic delivery of drugs). Alternatively, inflammation may be a marker for more aggressive H. pylori subtypes, which are also more vulnerable to antibiotic therapy.

Aims: To study the efficacy of omeprazole triple therapy in the eradication of Helicobacter pylori in patients with active gastric ulcer, and to assess healing and relapse of gastric ulcer., Methods: A double-blind, randomized study was carried out in 18 centres in Germany, Hungary and Poland. Patients (n = 160) with gastric ulcer and a positive H. pylori screening test were randomized to a 7-day twice daily treatment with omeprazole 20 mg, clarithromycin 500 mg and amoxycillin 1000 mg (OAC) or omeprazole 20 mg, clarithromycin 250 mg and metronidazole 400 mg (OMC), or with omeprazole 20 mg once daily (O). After completion of this 1-week treatment, patients were treated with omeprazole until healing (maximum 12 weeks), and followed for 6 months. H. pylori was assessed by urea breath test (UBT) and histology., Results: Eradication rates ITT were OAC 79% (95% CI: 65-90%), OMC 86% (95% CI: 73-94%) and O 4% (95% CI: 0-14%). Eradication rates PP were OAC 83% (95% CI: 68-93%), OMC 93% (95% CI: 80-98%) and O 3% (95% CI: 0-13%). Gastric ulcer relapses occurred in 5, 0 and 11 patients in the groups, respectively., Conclusions: The results from the study demonstrate that OMC and OAC 1-week regimens are safe and effective for eradication of H. pylori in gastric ulcer patients, and that ulcer relapse is infrequent after successful eradication.

Aim: To investigate the efficacy of two omeprazole triple therapies for the eradication of Helicobacter pylori, ulcer healing and ulcer relapse during a 6-month treatment-free period in patients with active duodenal ulcer., Methods: This was a double-blind, randomized study in 15 centres across Canada. Patients (n = 149) were randomized to omeprazole 20 mg once daily (O) or one of two 1-week b. d. eradication regimens: omeprazole 20 mg, metronidazole 400 mg and clarithromycin 250 mg (OMC) or omeprazole 20 mg, amoxycillin 1000 mg and clarithromycin 500 mg (OAC). All patients were treated for three additional weeks with omeprazole 20 mg once daily. Ulcer healing was assessed by endoscopy after 4 weeks of study therapy. H. pylori eradication was determined by a 13C-urea breath test and histology, performed at pre-entry, at 4 weeks after the end of all therapy and at 6 months., Results: The intention-to-treat (intention-to-treat) analysis contained 146 patients and the per protocol (per protocol) analysis, 114 patients. The eradication rates were (intention-to-treat/per protocol): OMC-85% and 92%, OAC-78% and 87% and O-0% (O). Ulcer healing (intention-to-treat) was greater than 90% in all groups. The differences in the eradication and relapse rates between O vs. OMC and O vs. OAC were statistically significant (all, P < 0.001). Treatment was well tolerated and compliance was high., Conclusion: The OMC and OAC 1-week treatment regimens are safe and effective for eradication, healing and the prevention of relapse in duodenal ulcer patients.

Epidemiological evidence has suggested that the declining prevalence of duodenal ulcer disease may be attributable to rising consumption of polyunsaturated fatty acids, a hypothesis supported by in vitro evidence of toxicity of such substances to Helicobacter pylori. The objective of the present study was to establish whether this association is causal. Forty patients with proven infection with H. pylori and endoscopic evidence of past or present duodenal ulcer disease were randomized to receive either polyunsaturated fatty acids (PUFA group), in the form of capsules and margarine, or a placebo (control). Both groups received concurrent H2 antagonist therapy. Efficacy of therapy was determined endoscopically by assessment of ulcer healing while H. pylori status was determined by antral biopsy, urease (EC 3.5.1.5) culture and histological assessment of the severity of H. pylori infection. Antral levels of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) were quantified. Compliance was monitored. Before treatment, both groups were comparable for severity of H. pylori infection, smoking status and levels of LTB4 and PGE2. Despite a significant difference in consumption of linoleic acid (19.9 (SE 1.6) g for PUFA group v. 6.7 (SE 0.8) g for controls (P < 0.01) and linolenic acid (2.6 (SE 0.2) g v. 0.6 (SE 0.03) g (P < 0.01) there was no significant change in either the severity of H. pylori infection or prostaglandin levels in either group at 6 weeks. Consumption of a considerable amount of PUFA does not inhibit the colonization of the stomach by H. pylori nor does this alter the inflammatory changes characteristic of H. pylori gastritis. We conclude that the association between duodenal ulceration and a low level of dietary PUFA is likely to be spurious, probably reflecting the effect of confounding factors such as affluence, social class or smoking.

Although omeprazole is an important component in anti-Helicobacter pylori therapeutic regimes using clarithromycin, amoxycillin and metronidazole, the mechanism by which it enhances antimicrobial action is unknown. One potential explanation for this effect is increased antibiotic chemical stability resulting from gastric pH changes induced by co-administration of omeprazole. The chemical stability of clarithromycin, amoxycillin and metronidazole was investigated in aqueous solutions and in human gastric juice collected before and after a 7-day course of omeprazole. Amoxycillin, clarithromycin and metronidazole were prepared in buffered aqueous solutions of pH 1.0 to 8.0 and in gastric juice of pH 2.0 and 7.0. The gastric juice samples were obtained from fasted H. pylori-negative volunteers before and after they had received a 7-day course of omeprazole. All the samples were incubated at 37 degrees C and analysed at intervals by HPLC. Amoxycillin, clarithromycin and metronidazole were stable in aqueous solutions of pH 4.0-7.0, pH 5.0-8.0 and pH 2.0-7.0, respectively. At pH 2.0, the degradation half-lives were 19.0 +/- 0.2 h, 1.3 +/- 0.05 h and 2200 +/- 1100 h, respectively. In gastric juice samples of pH 2.0, the degradation half-lives were 15.2 +/- 0.3 h, 1.0 +/- 0.04 h and > or = 800 h, respectively. The half-lives of the drugs in the gastric juice samples of pH 7.0 were all > 68 h. The co-administration of omeprazole with amoxycillin or clarithromycin is likely to increase the chemical stability of amoxycillin and clarithromycin in gastric juice. Clarithromycin degrades rapidly at normal gastric pH (1.0-2.0) but amoxycillin and metronidazole are sufficiently stable at this pH to maintain an antibacterial concentration in the stomach.

Background: Both classical 2-week bismuth based triple therapy and the newer 1-week low-dose omeprazole based triple therapies achieve high Helicobacter pylori eradication rates in controlled clinical trials and are in widespread use in routine clinical practice. However, their efficacy and acceptability in this setting is unproved., Methods: Over a 1-year period, the notes for patients attending a dedicated H. pylori treatment clinic were audited. Assessments were made of patient demographics, diagnosis, smoking habits, use of H2-antagonists, regimen used, efficacy of treatment, compliance and side-effects experienced., Results: 223 sets of notes were audited. 89 patients received bismuth, tetracycline and metronidazole for two weeks and 111 patients received omeprazole, clarithromycin and either metronidazole (63 patients) or tinidazole (48 patients) for 1 week. Successful eradication was achieved in 75/89 (84.3%), 56/63 (89%) and 42/48 (88%), respectively, (P = N.S.). Severe side-effects occurred in 11 (12%) of patients receiving bismuth based treatment compared to 1 (0.9%) patient receiving omeprazole based regimens (P < 0.02). Treatment failure in patients receiving omeprazole based treatment was associated with smoking (P < 0.05)., Conclusions: Outside the context of clinical trials, both regimens achieved acceptable eradication rates. However, 1-week low-dose therapy is preferable due to the lower incidence of severe side-effects.

Background: Strategies to improve antibiotic treatment of Helicobacter pylori infection are hampered by lack of knowledge about the route of antibiotic delivery. Post-prandial dosing with antibiotics prolongs their gastric residence time and improves their intragastric distribution, leading to improved local delivery compared with pre-prandial dosing. We aimed to assess whether pre- or post-prandial dosing. with amoxycillin suspension was more effective for H. pylori eradication in an amoxycillin/omeprazole regimen., Methods: Seventy-nine patients with H. pylori infection were treated with omeprazole 40 mg o.m. for 28 days and amoxycillin suspension 500 mg q.d.s. for days 15-28, the amoxycillin being randomized to either 1 h before or immediately after food., Results: The H. pylori eradication rate, for those completing the trial, was 67% (22/33) when amoxycillin suspension was given pre-prandially, compared with 39% (15/38) when it was given post-prandially (P < 0.05). Good compliance was achieved, with H. pylori eradication in 59% (28/46) of good compliers compared with 36% (9/25) of others completing the protocol (P < 0.05)., Conclusion: When given with omeprazole, pre-prandial dosing with amoxycillin suspension is more effective for H. pylori eradication than post-prandial dosing. This is consistent with the hypothesis that systemic rather than local delivery of amoxycillin is important for H. pylori eradication.

Treatment of Helicobacter pylori infection with amoxycillin is known to reduce the bacterial load to undetectable levels, while not eradicating the infection. It seems, therefore, that bacteria escape treatment at a 'sanctuary site'. This study examined whether such a site existed in the gastric antrum, body, or fundus. Twenty two patients with H pylori infection and duodenal ulcer disease were treated for one week with amoxycillin (500 mg three times a day) and cimetidine (800 mg at night). Before treatment, H pylori was detected throughout all stomachs, and 13C-urea breath testing at least 28 days after treatment confirmed that eradication of H pylori had occurred in no patients. While under treatment, H pylori was sought by conventional methods and by polymerase chain reaction assay and was found in the gastric fundus in 13 of 22 subjects, in the body in 10 of 22, and the antrum in three of 22: the difference between fundus and antrum was significant (p < 0.01). The continued antral infection in three subjects may have resulted from generalised treatment failure as two of three had H pylori detected throughout the stomach, and these two had compiled relatively poorly with treatment. This study suggests that amoxycillin and cimetidine are relatively effective at clearing H pylori from the gastric antrum, but that escape from treatment may occur in the gastric body, and especially the fundus.

Test meals are invariably used in the 13C-urea breath test (UBT) but their effect on the intragastric distribution and gastric residence time of urea given in the test is unknown. The site of Helicobacter pylori urease measured in the test is unknown and whether the test measures total or regional gastric urease is uncertain. This study reports the results of paired UBTs with simultaneous gastric distribution studies, one with and one without a fatty test meal, two weeks apart on seven H pylori infected subjects. The test meal did not affect UBT results at 10 minutes, but increased values at 30 minutes and thereafter. The amount of scintigraphic label in the antrum at 10 minutes was also unaffected by the meal but increased at 30 minutes and thereafter, whereas the amount in the body/fundus was greatly increased both at 10 minutes and throughout the test. There was considerable variation in intragastric distribution of urea between subjects, both with and without the test meal. This study shows that a test meal profoundly affects intragastric distribution of urea solution in the UBT, and increases UBT values at 30 minutes and later. Variability between subjects, however, means that accurate measurement of total or regional gastric urease is probably unrealistic.

Background: Giving antibiotics after meals prolongs their gastric residence time and improves their intragastric distribution. We aimed to see whether this would result in improved eradication of Helicobacter pylori., Methods: Eighty patients with H. pylori infection were treated with 40 mg omeprazole in the morning for 28 days and amoxycillin 500 mg q.d.s. for days 15-28. Amoxycillin dosing was randomised to either 1 h before or 10 min after food. Good compliance was pre-defined as missing less than four doses of amoxycillin or two of omeprazole., Results: Amoxycillin dosing after meals was shown not to affect H. pylori eradication rate either when results were analysed on an intention-to-treat basis [amoxycillin before meals successful in 63% (25/40), after in 65% 26/40)] or for good compliers only [before meals 81% (17/21), after 71% (20/28)]. This excludes, with 95% confidence, a benefit of greater than 18% from dosing before, or 23% from dosing after meals. Good compliance, however, was shown to be important, with H. pylori eradication in 76% (37/49) of good compliers compared with 48% (11/23) of others completing the protocol (P < 0.05)., Conclusions: The timing of antibiotic administration in relation to meals is not important in the treatment of H. pylori infection with this regimen of amoxycillin capsules and omeprazole. Good compliance, is however, an important determinant of treatment success.