Short report: omeprazole plus antibiotic combinations for the eradication of metronidazole-resistant Helicobacter pylori

Mucoadhesive microspheres containing amoxicillin for clearance of Helicobacter pylori

In an effort to augment the anti-Helicobacter pylori effect of amoxicillin, mucoadhesive microspheres, which have the ability to reside in the gastrointestinal tract for an extended period, were prepared. The microspheres contained the antimicrobial agent and an adhesive polymer (carboxyvinyl polymer) powder dispersed in waxy hydrogenated castor oil. The percentage of amoxicillin remaining in the stomach both 2 and 4 h after oral administration of the mucoadhesive microspheres to Mongolian gerbils under fed conditions was about three times higher than that after administration in the form of a 0.5% methylcellulose suspension. The in vivo clearance of H. pylori following oral administration of the mucoadhesive microspheres and the 0.5% methylcellulose suspension to infected Mongolian gerbils was examined under fed conditions. The mucoadhesive microspheres and the 0.5% methylcellulose suspension both showed anti-H. pylori effects in this experimental model of infection, but the required dose of amoxicillin was effectively reduced by a factor of 10 when the mucoadhesive microspheres were used. In conclusion, the mucoadhesive microspheres more effectively cleared H. pylori from the gastrointestinal tract than the 0.5% methylcellulose suspension due to the prolonged gastrointestinal residence time resulting from mucoadhesion. A dosage form consisting of mucoadhesive microspheres containing an appropriate antimicrobial agent should be useful for the eradication of H. pylori.

What other regimens are under investigation to treat Helicobacter pylori infection?

The most common infection in the world, Helicobacter pylori infection, is very specific, and present experience in treating infectious diseases is not applicable in general for this infection. Animal models (e.g., mouse and ferret) are thus far inadequate as reliable screening models. Old-fashioned trial-and-error treatment of infected humans is still the screening model and the gold standard in the evaluation of regimens aimed at eradication of H. pylori. A variety of studies on treatment of H. pylori infection have been performed with varying results. This pooled analysis of the following therapeutic combinations: proton pump inhibitor (PPI) plus two antibiotics or antimicrobials, quadruple therapies, and nonantibiotic regimens is an attempt to make a fair comparison of tested therapeutic strategies aimed at eradicating H. pylori. Data from treatment groups including specified drug combinations are pooled, regardless of dose or duration. Search methods are: MEDLINE 1984-1996, Digestive Disease Week 1988-1996, United European Gastroenterology Week 1992-1996, European Helicobacter pylori Study Group 1988-1996, Asia Pacific Congress 1996, H. pylori International Workshop Hong Kong 1996, and miscellaneous. Eradication rates (efficacy) are presented as intention-to-treat data (i.e., worst-case analysis). Separate subanalyses with regard to study quality, dose, and duration are performed for some groups. A general cost-efficacy analysis is performed based on pooled efficacy data. Convenience data are presented as total number of tablets, total number of intake occasions, and duration of therapy. Drugs evaluated in the analysis are bismuthdicitrate, tetracycline, amoxicillin, nitroimidazoles, macrolides, H2-receptor antagonists, PPIs, sucralfate, and sofalcone. The most effective and convenient drug combinations are the PPI-based triple therapies. No significant difference was observed between the three PPIs. The cure rate did not improve after addition of bismuth. Cost-effectiveness is closely associated with efficacy.

Lansoprazole and amoxycillin: observations on the treatment of Helicobacter pylori infection

Symptomatic patients (n = 101) with Helicobacter pylori infection were enrolled into a double-blind, double-dummy study to assess the efficacy of lansoprazole plus amoxycillin in the treatment of H. pylori infection. Patients were randomized to either lansoprazole 30 mg once daily (days 0-28) together with placebo (matched to amoxycillin) three times a day (days 0-14) followed by either placebo or amoxycillin 500 mg three times daily (days 15-28). Biopsy specimens for culture and histology were collected on days 0 and 56 or upon symptomatic relapse. Blood for serology was collected at days 0, 56 and 168. A [14C]-urea breath test was performed on day 168. Eighty-one (80.2%) patients completed the 56 day assessment. Of patients treated with lansoprazole plus amoxycillin, 35.1% (13/37) were cured of infection as assessed at day 56 (26.5% on an intention-to-treat basis), compared with 4.8% (2/42) of the placebo group (4% on an intention-to-treat basis). Recrudescence/re-infection occurred in one patient upon re-evaluation at day 168. Analysis of prognostic factors indicated that smoking and alcohol intake had little impact on the treatment outcome. Inflammation (both acute and chronic) improved in patients treated with lansoprazole plus amoxycillin. The relatively low efficacy of the treatment may relate to a single daily dose of lansoprazole (30 mg) being prescribed, treatment with amoxycillin being commenced 2 weeks after the initiation of lansoprazole or accurate assessment of treatment efficacy (both antral and body biopsy specimens taken).

Effect of omeprazole on movement of intravenously administered metronidazole into gastric juice and its significance in treatment of Helicobacter pylori

Four healthy, Helicobacter-negative volunteers were studied to determine the effect of omeprazole on the movement of metronidazole across the gastric mucosa into the gastric lumen. Each received a 500-mg intravenous infusion of metronidazole and repeated serum, and gastric juice samples were obtained concomitantly over an 8-hr study via indwelling intravenous catheter and nasogastric tube. The same protocol was repeated following one week of oral omeprazole 20 mg twice daily. Metronidazole concentrations were measured by high-performance liquid chromatography. The results demonstrated that: metronidazole moves rapidly from serum into gastric juice; omeprazole causes a marked reduction in total metronidazole concentrations in gastric juice, completely accounted for by pH-related shifts in the proportion of ionized metronidazole, but does not alter concentrations of nonionized metronidazole, which remain above the MIC level against H. pylori; and even under conditions where no pH-related drug trapping occurs (pH > 4), concentrations of metronidazole were higher in gastric juice than in serum during most of the study, indicating that a special transport mechanism may be operational. The practical implication of this effect of omeprazole in combination therapy with metronidazole remains to be established.

A risk-benefit assessment of drugs used in the eradication of Helicobacter pylori infection

Helicobacter pylori is the cause of chronic active gastritis and predisposes to peptic ulcer disease (PUD). Furthermore, H. pylori is linked to the pathogenesis of gastric lymphoma and gastric cancer. However, treatment of this infection has proven difficult. In the last decade, many antimicrobial compounds have been studied extensively as monotherapy as well as in combination with bismuth or acid-suppressive drugs. The individual drugs and the most important eradication regimens are discussed with special regard to their risks. In the past, highly complex multidrug regimens, fear of adverse effects and frequent eradication failures have hampered the broad acceptance of H. pylori-eradication therapies. Recently, new 1-week, low-dose combination regimens of 2 antibacterials with a proton pump inhibitor have consistently achieved eradication rates of 90% and more with an acceptably low rate of adverse effects. One week's standard triple therapy [tripotassium dicitrato bismuthate (or bismuth salicylate plus metronidazole plus tetracycline or amoxicillin) has been shown to be highly effective and tolerated better in combination with a proton pump inhibitor. This regimen is, however, more complex and has more adverse effects. Therefore, it is not recommended as first-line therapy. Equipped with these therapies physicians can now be strongly encouraged to use H. pylori eradication as the therapy of choice for patients with PUD and even extend this treatment to other H. pylori-associated disease conditions.

Treatment of Helicobacter pylori infection: a review of the world literature

BACKGROUND

None of the currently used anti-Helicobacter pylori drug regimens cures the infection 100%, and cure results still vary considerably. The present article reviews the effectiveness of currently used antimicrobial regimens, aimed to cure H. pylori infection.

METHODS

Data collection started from the beginning of the anti-H. pylori-therapy era until May 1995. No attempt at formal metanalysis has been made, because many studies have been published only in abstract form. Attempts were made to exclude duplicates of studies by comparison to previously reported ones; the authors of suspected duplicates were contacted. After amalgamation of the number of included patients and the number of successfully treated patients, the mean values of eradication rates and the 95% confidence intervals were calculated.

RESULTS

A total of 237 treatment arms were analyzed. Bismuth triple therapy continues to reach high eradication rates worldwide (78-89%). Side effects leading to diminished patient compliance and the marked decline of eradication efficacy in cases of metronidazole resistance are considered to be the major drawbacks of this therapy. Proton pump inhibitor (PPI) dual therapy is better tolerated with fewer side effects than is bismuth triple therapy. The mean eradication rates vary from 55 to 75%, and the extremes lie between 24 and 93%. PPI triple therapies have been shown to be very effective against H. pylori (eradication rates, 80-89%). Quadruple therapy leads to a mean eradication rate of 96%.

CONCLUSION

Based on efficacy, PPI triple or bismuth triple therapy are recommended as first-line treatment for H. pylori infection. Quadruple therapy could serve as second-line treatment for eradication of initial failures and in case of metronidazole resistance.

Helicobacter pylori reinfection after apparent eradication--the Ipswich experience

The reported rate of Helicobacter pylori reinfection following eradication therapy is highly variable. In Ipswich, the 14C-urea breath test (UBT) has been used since 1986 as a tool to study H. pylori eradication and reinfection. Updated results from 1182 patients in whom the organism had apparently been successfully eradicated, following a number of different eradication regimens between October 1986 and 31 March 1995, are presented. During this period, 57 "reinfections' were observed, of which 45 had occurred within 6 months of treatment. After the first year, the 'reinfection' rate was less than 0.6% per year. The criterion for eradication of the infection was a UBT (2-hour area under curve) of less than 40 at least 1 month after treatment. The treatment regimens were arbitrarily divided into five groups with eradication rates of: less than 20%, 20-39%, 40-59%, 60-79% and over 80%. In these groups, the 6-month 'reinfection' rates were 28.0%, 15.8%, 16.4%, 4.6% and 1.7%, respectively (p < 0.001). These and other data presented in the paper strongly suggest that, in Westernized countries, most so-called reinfections in adults are in fact the late recrudescence of a suppressed infection rather than a true reinfection. Our data also suggest that the true reinfection rate is particularly low if the eradication therapy chosen has an efficacy of more than 85%. Several effective and well-tolerated 1-week triple H. pylori eradication regimens are now available, and we would advocate their use in preference to the less effective dual regimens where initial eradication rates are lower and there is consequently a higher risk of 'reinfection'. We would predict that even in developing countries with a high prevalence of metronidazole-resistant H. pylori, the 'reinfection' rate would be low if a combination of omeprazole, amoxycillin and clarithromycin were to be used.

Pooled analysis of anti-Helicobacter pylori treatment regimens

BACKGROUND

The human pathogen Helicobacter pylori and its association with peptic ulcer has dramatically changed the therapeutic approach to patients with this disease. Successful treatment of the infection has consistently been shown to prevent ulcer recurrence. Published data on therapeutic options are sometimes confusing since only few studies have similar design, drug combinations, dosage, dosing, formulation, patient material, and size. A formal meta-analysis is therefore of limited value.

METHOD

Data on anti-H. pylori therapies from a large number of publications are pooled into a few groups based on the combination of drugs, regardless of dosage, duration, etc., of the therapy. A mean success rate is calculated for all studies with subanalysis with regard to study design, size, doses and duration.

RESULTS

Triple combinations are needed to achieve a success rate of more than 80%. Bismuth/tetracycline based triple therapy gives 82% success rate (range 43-100%) compared to 85% and 87% success rate (range 72-100% and 43-100%) achieved with omeprazole/clarithromycin based triples respectively.

CONCLUSION

Omeprazole/clarithromycin based triple regimens are the most effective anti-H. pylori therapeutic strategies, slightly superior to bismuth triple regimens.

Current guidelines for the eradication of Helicobacter pylori in peptic ulcer disease

Pharmacological suppression of gastric acid secretion has traditionally been the most rational approach to healing ulcers successfully. However, ulcers initially healed using antisecretory therapy have a tendency to relapse after treatment is withdrawn. This tendency is altered definitively by eradication of Helicobacter pylori. Antimicrobial therapy should be given to all patients with documented duodenal and gastric ulcer associated with H. pylori infection. The optimal therapeutic regimen to eradicate H. pylori is still not completely clear. The requirement for treatment to be effective in more than 90% of patients makes monotherapy and dual therapy inappropriate. Bismuth-based triple therapy (bismuth, tetracycline and metronidazole) is highly efficacious if the H. pylori strain is sensitive to metronidazole and the patient is compliant, but adverse effects often occur. Triple therapy consisting of omeprazole and 2 antimicrobials (clarithromycin and/or amoxicillin and/or metronidazole) and quadruple therapy (bismuth-based triple therapy plus omeprazole) are both very effective and patient compliance may be better because of the shortened (1 week) course. Preliminary data indicate that the efficacy of the regimen is not influenced by imidazole resistance. Eradication of H. pylori prevents complications and relapse of peptic ulcer disease and is a cost-effective option compared with maintenance acid-suppressive therapy.

Eradication of Helicobacter pylori

Although there are numerous publications reporting eradication results, the general picture is confused by the bewildering multiplicity of treatment schedules employed by the various workers. The over-riding need now is for large scale trials, and more especially for direct comparisons of different treatment regimens in the same populations of patients. Such data are entirely absent from the literature at present. Standardization of definitions and of methodology pertaining to diagnosis of eradication, recording of side effects, measurement of compliance and determination of recurrence or of reinfection, is badly needed. As the definition of eradication remains arbitrary, it is important to include genome fingerprinting techniques in the long-term follow-up for recurrence, so that the question of reinfection versus recrudescence can be examined (Bell et al, 1993b; Xia et al, 1994). Because of the wide differences in the agents used in H. pylori eradication therapies, proper double-blinding of treatment trials remains a difficult problem. This can be dealt with to some extent by ensuring that the interpretation of tests for H. pylori eradication is performed by personnel unaware of the clinical details. Review of the existing data on eradication of H. pylori indicates that clinically useful results can be achieved in some 70 to 95% of patients, on an intention to treat basis. Compliance, side effects and resistance to metronidazole remain the limiting factors. Efficacy, freedom from side effects, simplicity and low cost will determine the success of any regimen in the future. At present, it is not possible to make firm recommendations in favour of one regimen over another, but it seems reasonable to forecast that dual therapies consisting of a PPI and an antibiotic will receive much attention. Preparations consisting of an H2RA associated with a bismuth compound, which are used together with an antibiotic are an interesting approach. Compliance should be as good as with a normal dual therapy and the eradication results look promising (Wyeth et al, 1994; Webb et al, 1994). The advantages of dual therapies that include a PPI lie in their simplicity, in not relying on imidazole for their anti-H. pylori effect but on the profound inhibition of acid output produced by the PPI. Thus PPI based dual therapy can probably evoke better compliance than the more complicated regimens. The use of PPIs has other advantages in addition to decreasing the MIC90 of the antibiotic combined with it. This is because administration of a powerful inhibitor of gastric acid secretion, such as a PPI, will aid the rapid healing of an ulcer crater and will rapidly relieve the symptoms of peptic ulceration. Gastrin releasing peptide-stimulated acid secretion is raised in duodenal ulcer patients to approximately sixfold over control levels according to El-Omar et al (1993b), and although it returns to normal following the eradication of H. pylori, this process takes time to become effective (El-Omar et al, 1993a). Suppression of acid output provides an immediate therapeutic shield, while the decrease in inflammation and acid output secondary to H. pylori eradication can be established. The most widespread resistance to antibiotics exhibited by H. pylori is with respect to imidazoles. The prevalence of metronidazole resistance is widespread in the emergent countries (Glupczynski et al, 1990), but it is also appreciable in the West, especially in women, who may have been given metronidazole in the treatment of pelvic infections (Rautelin et al, 1992; Banatvala et al, 1994). Moreover, H. pylori becomes resistant to metronidazole very easily and often as a result of treatment which includes an imidazole compound (Malfertheiner, 1993; Banatavala et al, 1994). On the other hand, H. pylori resistance to macrolides is not widespread and does not develop easily during their administration. It is difficult to forecast which antibiotic will be the most widely used agent

Eradication of Helicobacter pylori and prevention of recurrence of duodenal ulcer: a randomized, double-blind, multi-centre trial of omeprazole with or without clarithromycin

BACKGROUND

Antimicrobial treatment for Helicobacter pylori eradication is currently recommended for all patients with duodenal ulcer disease, but consensus on the best treatment is lacking.

METHODS

Patients with active duodenal ulcer and H. pylori were enrolled in a double-blind, randomized, placebo-controlled multi-centre study. Patients received omeprazole 40 mg daily for 28 days and either clarithromycin 500 mg t.d.s. or placebo t.d.s. for the first 14 days. Patients underwent endoscopy before starting treatment, at 2 weeks, immediately after stopping treatment if unhealed at 2 weeks, and at 1, 6 and 12 months after the end of treatment, or at the recurrence of symptoms. Eradication of H. pylori, duodenal ulcer healing and ulcer recurrence were measured.

RESULTS

One-hundred and fifty-four patients were recruited and randomized to omeprazole plus clarithromycin (n = 74) or to omeprazole plus placebo (n = 80). One month after treatment, H. pylori was eradicated in 57 of 69 (83%; 95% CI: 72-91%) patients receiving omeprazole plus clarithromycin, compared with 1 of 75 (1%; 95% CI: 0-7%) receiving omeprazole alone (P < 0.001). In patients receiving omeprazole plus clarithromycin the ulcer healed at 2 weeks in 83% (95% CI: 71-91%) and at 4 weeks in 100% (95% CI: 95-100%), compared with 77% (95% CI: 66-86%) and 97% (95% CI: 91-100%) in those given omeprazole plus placebo (N.S.). Ulcers recurred at 12 months in 6% (95% CI: 1-16%) of patients given omeprazole plus clarithromycin, compared with 76% (95% CI: 63-86%) of patients given omeprazole plus placebo (P < 0.001). The incidence of side-effects was similar in both treatment groups (38% with clarithromycin dual therapy and 29% with omeprazole plus placebo; P = 0.304). Ninety per cent of patients took at least 90% of their prescribed medication.

CONCLUSIONS

Omeprazole plus clarithromycin dual therapy eradicated H. pylori in 83% of patients with duodenal ulcer and significantly decreased 12-month recurrence from 76% to 6%.

Double-blind trial of omeprazole and amoxicillin to cure Helicobacter pylori infection in patients with duodenal ulcers

BACKGROUND/AIMS

Anti-Helicobacter pylori treatment with combinations of omeprazole and amoxicillin is a promising treatment option. The aim of this study was to investigate whether a daily omeprazole dose of 120 mg combined with amoxicillin would cure H. pylori infection at a rate comparable with that achieved with "triple therapy."

METHODS

In a double-blind, randomized, controlled, and multicenter trial in Germany, 270 patients with an H. pylori-associated duodenal ulcer were treated with 40 mg omeprazole three times a day and 750 mg amoxicillin three times a day for the first 14 days (n = 139) followed by 20 mg omeprazole once daily until day 42 or with omeprazole plus 750 mg amoxicillin placebo three times a day for the same time period (n = 131).

RESULTS

Cure rates of H. pylori infection were 91% in the omeprazole plus amoxicillin group, 0% in the omeprazole plus placebo group, and 89% and 0%, respectively, performing an intention-to-treat analysis. Cure of H. pylori infection in patients pretreated with omeprazole was only 58% compared with 95% in patients who were not. The cumulative 12-month relapse rates were 11.3% and 44% in the treatment groups and 1.6% in H. pylori-negative and 49% in H. pylori-positive patients.

CONCLUSIONS

The combination of 120 mg omeprazole daily and 2.25 g amoxicillin daily with its H. pylori cure rate of around 90% is one of the best tolerated and most effective treatment regimens.

Treatment of Helicobacter pylori infection

Helicobacter pylori infects the human stomach and is associated with chronic gastritis, peptic ulcer disease and gastric cancer. Most patients with peptic ulcers are infected with H pylori. These patients suffer a high relapse rate following initial healing of the ulcer with anti-secretory agents. The rate of relapse can be greatly diminished following successful eradication of the organism. Although experience is still being accumulated, it is reasonable to use eradication therapy in any patient with H pylori positive active peptic ulcer disease. Combination triple and dual therapy regimens are effective but the search continues for better therapies. This review outlines the current evidence regarding which, when, how and with what H pylori infected patients should be treated.

Amoxycillin capsules with omeprazole for the eradication of Helicobacter pylori. Assessment of the importance of antibiotic dose timing in relation to meals

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.

Review article: Helicobacter pylori eradication--understandable caution but no excuse for inertia

The long-term management of patients with peptic ulcer disease is unsatisfactory, as judged by the persistently high levels of haemorrhage, perforation and death from this condition in Western countries. Although ulcer recurrence and complications can be prevented, many patients with peptic ulcer disease fail to receive the benefits of modern therapeutic regimens. In recent years, eradication of Helicobactor pylori has been promoted as a 'cure' for peptic ulcer disease and, while such claims are premature, there can be little doubt that this treatment--when successful--dramatically improves the medium-term prognosis of ulcer patients. However, in general, clinicians have given this promising therapeutic advance a lukewarm welcome. The aim of this detailed review of the literature is to remove the uncertainty and confusion surrounding many aspects of eradication therapy. Estimates are provided of the eradication rates after either triple therapy or the combination of omeprazole plus amoxycillin, and the sources of variation in published studies are discussed. Problems associated with eradication therapy, including side effects, compliance and re-infection, are addressed in order to ascertain the extent and clinical significance of each factor. In addition, studies reporting the outcome of patients with peptic ulcer disease after eradication are assessed with reference to both ulcer recurrence and complications. The result of the review is to dissipate much of the scepticism concerning eradication therapy. However, whilst acknowledging the efficacy of eradication therapy, its limitations have also to be recognized. By itself, it does not provide the complete answer to peptic ulcer disease. For some ulcer patients, eradication therapy is the preferred option; for others, prophylactic therapy with H2-receptor antagonists is more suitable. Guidelines are proposed for the selection of patients for each alternative therapy. The crucial point is that patients with peptic ulcer--excluding the small proportion with a mild form of the disease--require positive, long-term management consisting of either continuous prophylaxis with H2-receptor antagonists or the eradication of Helicobacter pylori.

Review article: treatments that impact favourably upon the eradication of Helicobacter pylori and ulcer recurrence

Healing the gastroduodenal mucosa through Helicobacter pylori eradication leads to a dramatic reduction in gastroduodenal ulcer relapse. Eradication of H. pylori proves to be difficult. Although the organism is sensitive to many antibiotics in vitro, the in vivo eradicating efficacy is often disappointing. This overview summarizes the most commonly used currently-available eradication schemes and the consequences of successful eradication in peptic ulcer disease.

Omeprazole. An update of its pharmacology and therapeutic use in acid-related disorders

Omeprazole, a gastric acid pump inhibitor, dose-dependently controls gastric acid secretion: the drug has greater antisecretory activity than histamine H2-receptor antagonists. Omeprazole 20 to 40 mg/day is more effective than histamine H2-receptor antagonists in the short term treatment of duodenal ulcer, gastric ulcer and reflux oesophagitis. Available data suggest that omeprazole 10 to 40 mg/day is also more effective than ranitidine in the maintenance therapy of duodenal ulcer and reflux oesophagitis. The drug is also effective in patients with duodenal ulcer, gastric ulcer or reflux oesophagitis poorly responsive to histamine H2-receptor antagonists. The efficacy of omeprazole 20 mg/day appears to be similar to that of lansoprazole 30 mg/day in the short term treatment of duodenal ulcer, gastric ulcer and reflux oesophagitis. However, most available studies have been reported in abstract form only, and 2 of 3 studies in patients with duodenal ulcer have shown greater healing rates at 2 (but not 4) weeks with lansoprazole. Helicobacter pylori eradication decreases duodenal ulcer relapse rates and appears to be associated with improved duodenal ulcer healing rates. Evidence also suggests that H. pylori eradication is associated with reduced gastric ulcer relapse rates. Omeprazole monotherapy may suppress but does not eradicate H. pylori infection. Eradication rates with omeprazole 20 or 40 mg twice daily plus amoxicillin usually up to 2 g/day (3 g/day in a few studies) for 2 weeks appear to be similar to those of standard triple therapy (bismuth salt plus metronidazole, plus tetracycline or amoxicillin) or omeprazole plus clarithromycin, although eradication rates vary widely. Omeprazole plus amoxicillin appears to be better tolerated than triple therapy and represents a first-line treatment alternative in patients with H. pylori-associated peptic ulcer disease. Omeprazole plus amoxicillin plus metronidazole appears to be more effective than omeprazole plus amoxicillin in patients with metronidazole-sensitive H. pylori infection. Omeprazole remains a treatment of choice in patients with Zollinger-Ellison syndrome. The dosages should be adjusted according to individual response. However, relatively low dosages of 10 to 40 mg/day may be sufficient in some patients. The drug has also shown promise in the treatment of children with severe reflux oesophagitis, in patients with reflux oesophagitis and coexisting systemic sclerosis, and in the prevention of aspiration pneumonia. Evidence suggests that omeprazole is more effective than ranitidine in patients with nonsteroidal anti-inflammatory drug (NSAID)-induced gastric damage who continue to take NSAIDs, especially in patients with large gastric ulcers; however, completion of ongoing studies is required to verify this.(ABSTRACT TRUNCATED AT 400 WORDS)

Comparison of PCR-based restriction length polymorphism analysis of urease genes with rRNA gene profiling for monitoring Helicobacter pylori infections in patients on triple therapy

Multiple isolates of Helicobacter pylori from antral biopsies of nine patients were examined by DNA fingerprinting. Analysis of rRNA gene patterns and HaeIII restriction fragment length polymorphism of PCR-amplified urease genes were compared and used to study colonization before and after failed triple therapy. H. pylori isolates from a single biopsy shared the same HaeIII DNA fingerprint regardless of the isolation method (plate or broth). DNA pattern types of paired strains of H. pylori were distinct between patients and were not grossly affected by treatment except for one patient with an altered strain type. H. pylori infections were generally associated with several subpopulations of strains, evident from the subtypic variation before and after treatment, detectable by both DNA fingerprinting methods. The urease gene patterns also provided evidence that some cultures of H. pylori probably contained a mixture of genomic subtypes. The study suggests that triple therapy has the effect either of inducing minor genomic variations or of changing the proportions of different subtypes of H. pylori. It was concluded that urease gene profiling provides a simple yet reliable method of establishing whether treatment failures are attributable to incomplete eradication of H. pylori.

Duodenal ulcer treatment: progress from pH to HP

The treatment of duodenal ulcer has evolved from ineffective medical treatments through an era of surgical management, back to increasingly effective medical treatment. The advent of H2-receptor antagonists changed the outlook for ulcer patients. More recently, Helicobacter pylori, an organism which inhabits gastric mucosa exclusively, has been implicated in the pathogenesis of peptic ulcer. This bacterium is found in the stomachs of around 95% of duodenal ulcer patients. Its eradication is shown dramatically to improve the rate at which ulcers relapse. The mechanisms whereby it may cause ulceration are not established--we review current hypotheses. No method of eradication is 100% effective, and many different dual or triple therapy regimens have been tried. Metronidazole resistance is reported but its importance is not yet known. Helicobacter eradication is likely to prove a cost-effective and acceptable treatment for duodenal ulcer, and once its value has gained acceptance widespread uptake of this option is anticipated.

Short report: omeprazole-tetracycline combinations are inadequate as therapy for Helicobacter pylori infection

BACKGROUND

Current triple antimicrobial therapies cure Helicobacter pylori infection in 60-90% of cases but are cumbersome. Addition of omeprazole to amoxycillin has been shown to enhance effectiveness when compared to amoxycillin alone.

METHOD

We studied omeprazole 20 mg t.d.s. plus tetracycline 500 mg q.d.s. for 14 days (OMP/TCN) and omeprazole 40 mg in the morning plus tetracycline 500 mg q.d.s. along with bismuth subsalicylate tablets 2 q.d.s. (OMP/TCN/BSS) for 14 days. Forty-four patients (19 OMP/TCN, 25 OMP/TCN/BSS) with H. pylori peptic ulcer disease were studied. H. pylori status was evaluated at least 4 weeks after ending antimicrobial therapy.

RESULTS

In the OMP/TCN group cure of H. pylori infection was achieved in 5/19 (26%). Adding bismuth to the regimen improved the results; 4 weeks after ending therapy cure of H. pylori infection was achieved in 12/25 (48%).

CONCLUSIONS

Neither regimen can be recommended for routine cure of H. pylori infection. Although one cannot predict which antimicrobial therapies will be enhanced by the addition of omeprazole, these data suggest that future studies should evaluate drugs whose effectiveness is compromised by low pH.

Eradication of Helicobacter pylori and its effect in peptic ulcer disease

Since Helicobacter pylori was first cultured 10 years ago, there have been remarkable changes in our approach to the therapy of peptic ulcer disease. We now know that 90% of duodenal ulcer patients and 70% of all gastric ulcer patients are infected with H. pylori. Evidence is presented that the relapse rate of both duodenal and gastric ulcers can be substantially reduced if the bacterium is eradicated from the patient's stomach. Some of the anti-H. pylori eradication regimens currently available are discussed, with particular emphasis on the relative merits of standard triple therapy and an omeprazole/amoxycillin combination.