Eradication therapies for Helicobacter pylori.

Eradication therapies for Helicobacter pylori evolved from monotherapy, through dual therapies and finally to bismuth-based triple therapies by the mid-1980s. The advent of proton pump inhibitors (PPI) and clarithromycin added a new impetus in the development of newer and often more effective regimens. Following large numbers of therapeutic trials, two broad groups of therapies stand out which consistently achieve over 90% eradication. Both are PPI-based. PPI/amoxycillin/clarithromycin twice daily therapy is the simplest but perhaps the most expensive. The 7-day quadruple (quad) therapy, consisting of a PPI and bismuth/tetracycline/metronidazole, is rapidly emerging as the "all rounder" therapy able not only to overcome metronidazole and clarithromycin resistance but to also have a consistently high eradication rate of well over 90%. Extensive clinical use of older and cut-down versions of combination therapies is resulting in a rising population of treated patients who continue to be infected with H. pylori, often resistant to further eradication attempts. Failure to recognise the need to use regimens which achieve high first-time eradication success will lead inexorably to an enlarging pool of patients with resistant strains and "difficult-to-eradicate" H. pylori.

Evaluation of whole blood antibody kit to detect active Helicobacter pylori infection.

OBJECTIVES: To evaluate the sensitivity and specificity of a whole blood antibody test (Helisal Rapid Blood test) for the detection of Helicobacter pylori using endoscopic diagnostic criteria of histology and urease tests as the "gold standard." METHODS: A prospective trial of Helisal Rapid Blood (HRB) test was carried out in patients undergoing investigations for dyspepsia that included endoscopic biopsy for rapid urease test, microbiological culture, and histology. Blood samples were obtained at the time of endoscopy and were tested for the presence of antibody to H. pylori using the HRB test. In a separate patient group, results of antibody tests in whole venous and capillary blood were compared (n = 25). RESULTS: The rapid blood test was carried out immediately after the endoscopic examination with a result available in under 10 min in all cases. In 203 patients examined, the HRB test detected 70 of 203 to be H. pylori positive as compared with 71 of 203 using urease/histology. Against combined urease/histology tests, the HRB test achieved 82% sensitivity and 91% specificity. Five patients were judged to be "false negative" on endoscopic tests for H. pylori (extensive intestinal metaplasia n = 3; recent use of antimicrobials) yet the HRB test diagnosed the presence of infection, which could be shown to resolve on treatment. The HRB achieved 89% sensitivity and 91% specificity upon correctly including these five patients in the calculations. In all 25 patients tested, venous and capillary blood results concurred giving HRB test positivity in each case. CONCLUSIONS: Whether using whole venous or capillary blood, the HRB test is a quick, convenient, and accurate test for the diagnosis of active H. pylori infection in patients previously not treated. In a subgroup of patients with low level infection due to recent antimicrobials or intestinal metaplasia negative to all endoscopic tests, the blood test can still correctly diagnose H. pylori infection. Because blood samples require no centrifugation before testing, the greatest usefulness of this test will be that of a primary office diagnostic device.

Omeprazole enhances efficacy of triple therapy in eradicating Helicobacter pylori.

Triple therapy has been recommended as the most effective treatment for Helicobacter pylori eradication. Despite achieving a comparatively high eradication result, however, around 10% of patients still fail to be cured. Omeprazole can enhance efficacy of single and double antibiotic protocols and is particularly effective when combined with clarithromycin and a nitroimidazole. This study examined the effect of combining triple therapy with omeprazole. A prospective, randomised, unblinded, single centre trial was carried out on consecutive patients with symptoms of dyspepsia and H pylori infection confirmed by rapid urease test, microbiological culture, and histological assessment. Patients were given a five times/day, 12 day course of colloidal bismuth subcitrate chewable tablets (108 mg), tetracycline HCl (250 mg), and metronidazole (200 mg) with either 20 mg omeprazole twice daily (triple therapy+omeprazole) or 40 mg famotidine (triple therapy+famotidine) at night. Compliance and side effects were determined using a standard questionnaire form. One hundred and twenty five of 165 triple therapy+omeprazole patients and 124 of 171 triple therapy+famotidine patients returned for rebiopsy four weeks after completion of treatment. Significantly more triple therapy+omeprazole patients achieved eradication 122 of 125 (97.6%) as assessed by negative urease test, culture, and histological assessment, when compared with 110 of 124 (89%) triple therapy+famotidine patients (p = 0.006; chi 2). There were 30 triple therapy+omeprazole (24%) and 26 triple therapy+famotidine (21%) patients with de novo metronidazole resistant H pylori included in the study. Side effects were mild and infrequent and were comparable in both groups, although pain in duodenal ulcer, gastric ulcer, and oesophagitis patients seemed to subside earlier in those taking omeprazole. Compliance (>95% of drugs taken) was achieved by 98% of patients of both groups. A 12 days regimen of triple therapy with omeprazole is more effective in achieving H pylori eradication than is triple therapy plus famotidine. Use of 20 mg omeprazole twice daily rather than 40 mg famotidine with a 12 day, low dose triple therapy enhances eradication to over 97% whether the H pylori is metronidazole sensitive or resistant.

Helicobacter pylori reinfection rate, in patients with cured duodenal ulcer.

OBJECTIVE: To determine the reinfection rate of the gastric mucosa in patients previously cured of duodenal ulcers, following the eradication of Helicobacter pylori. Only those remaining H. pylori-negative beyond 12 months of follow-up were studied, to minimize the potential inclusion of patients with H. pylori recrudescence. METHODS: Patients with endoscopically proven duodenal ulcers who had been treated with triple therapy, resulting in documented eradication of H. pylori and cure of the ulcer for at least 4 years, were recalled and had their H. pylori status determined by the 14C-urea breath test. Those found positive for H. pylori underwent endoscopic confirmation of the infection. RESULTS: Of the 94 patients restudied, with a follow-up period range of 48-96 months or a total of 549.8 yr, only two (2.2%) were again H. pylori positive. This gives an effective reinfection rate of 0.36% per patient year. In the two H. pylori-positive patients, one had normal mucosa endoscopically, whereas duodenitis without active ulceration was present in the other. The former was asymptomatic, whereas the latter patient was using ranitidine daily for symptom control. CONCLUSION: In the Australian setting, following cure of duodenal ulcer disease by eradication of H. pylori, subsequent reinfection is an unusual phenomenon. We conclude that efforts aimed at eradication of H. pylori in duodenal ulcer are justified and are worthwhile.