The effect of antibiotic resistance on the outcome of three 1-week triple therapies against Helicobacter pylori

Clarithromycin Versus Metronidazole in First-Line Helicobacter Pylori Triple Eradication Therapy Based on Resistance to Antimicrobial Agents: Meta-Analysis

BACKGROUND

International treatment guidelines for Helicobacter pylori infection recommend a proton pump inhibitor (PPI)/amoxicillin/clarithromycin (CAM) regimen (PAC) or PPI/amoxicillin/metronidazole (MNZ) regimen (PAM) as first-line therapy based on culture and sensitivity testing. As incidence rates of antimicrobial agent-resistant strains are changing year by year, it is important to reevaluate the efficacy of eradication regimens. We performed a meta-analysis to evaluate the efficacy and safety of PAC and PAM based on different locations categorized by the reported incidence of CAM- and MNZ-resistant strains.

METHODS

Randomized control trials (RCTs) comparing eradication rates between PAC and PAM first-line treatment up to December 2018 were included. We divided RCTs into four groups based on resistance to CAM (< 15% or ≥ 15%) and MNZ (< 15% or ≥ 15%).

RESULTS

A total of 27 studies (4825 patients) were included. Overall eradication rates between PAC and PAM were similar (74.8% and 72.5%, relative risk (RR): 1.13, 95% confidence interval (CI): 0.91-1.39, P = 0.27) in the intention-to-treat analysis. In areas with low MNZ- and high CAM-resistance rates, PAM had a significantly higher eradication rate than PAC (92.5% vs. 70.8%, RR: 0.29, 95% CI: 0.13-0.68). In areas with high MNZ- and low CAM-resistance rates, the eradication rate with PAC was only 72.9%.

CONCLUSIONS

Overall eradication rates with PAC and PAM were equivalent worldwide. In low MNZ-resistance areas, PAM may be recommended as first-line therapy. However, the efficacy of PAC may be insufficient, irrespective of susceptibility to CAM.

Application of next-generation sequencing to characterize novel mutations in clarithromycin-susceptible Helicobacter pylori strains with A2143G of 23S rRNA gene

Background

Clarithromycin (CLR) resistance has become a predominant factor for treatment failure of Helicobacter pylori eradication. Although the molecular mechanism of CLR resistance has been clearly understood in H. pylori, it is lack of evidence of other genes involved in drug resistance. Furthermore, the molecular mechanism of phenotype susceptible to CLR while genotype of 23S rRNA is mutant with A2143G is unclear. Here, we characterized the mutations of CLR-resistant and -susceptible H. pylori strains to explore bacterial resistance.

Methods

In the present study, the whole genomes of twelve clinical isolated H. pylori strains were sequenced, including two CLR-susceptible strains with mutation of A2143G. Single nucleotide variants (SNVs) were extracted and analyzed from multidrug efflux transporter genes.

Results

We did not find mutations associated with known CLR-resistant sites except for controversial T2182C outside of A2143G in the 23S rRNA gene. Although total SNVs of multidrug efflux transporter gene and the SNVs of HP0605 were significant differences (P ≤ 0.05) between phenotype resistant and susceptible strains. There is no significant difference in SNVs of RND or MFS (HP1181) family. However, the number of mutations in the RND family was significantly higher in the mutant strain (A2143G) than in the wild type. In addition, three special variations from two membrane proteins of mtrC and hefD were identified in both CLR-susceptible strains with A2143G.

Conclusions

Next-generation sequencing is a practical strategy for analyzing genomic variation associated with antibiotic resistance in H. pylori. The variations of membrane proteins of the RND family may be able to participate in the regulation of clinical isolated H. pylori susceptibility profiles.

Systematic review and meta-analysis: triple therapy combining a proton-pump inhibitor, amoxicillin and metronidazole for Helicobacter pylori first-line treatment

BACKGROUND

Due to clarithromycin resistance, the current efficacy of Helicobacter pylori first-line triple therapies including clarithromycin is low. It seems reasonable to explore alternative clarithromycin-free therapies.

OBJECTIVES

The objective of this study was to evaluate the efficacy of triple therapy including a proton-pump inhibitor (PPI), amoxicillin and metronidazole (PAM) as first-line H. pylori therapy by systematic review and meta-analysis.

METHODS

Studies evaluating PAM in adult patients were included. Meta-analyses comparing PAM with other treatments were performed. The primary endpoint was the ITT eradication rate for H. pylori first-line treatment. In addition, sensitivity analyses ascertained the effects of treatment schedule, dosage and duration on cure rates.

RESULTS

Ninety-four studies (8061 patients) were included. Meta-analyses comparing PAM versus clarithromycin-including triple therapies showed a significant difference in favour of PPI, amoxicillin and clarithromycin (PAC) (70% versus 77.1%; OR = 0.70, 95% CI = 0.56-0.88) and PPI, metronidazole and clarithromycin (PMC) therapy (66.4% versus 77.7%; OR = 0.55, 95% CI = 0.39-0.76). Sensitivity analyses showed a similar efficacy of PAM versus PAC when drugs were administered for 14 days (80% versus 84%; OR = 0.70, 95% CI = 0.44-1.12). There were not enough studies to perform further comparisons. Number of antibiotic doses (P = 0.012), length of treatment (P < 0.001) and use of high metronidazole doses (P = 0.021) were related to higher cure rates in the sensitivity analysis including observational studies.

CONCLUSIONS

PAM was less efficacious than clarithromycin-including triple therapies. However, its efficacy was similar to that of PAC when drugs were administered for 14 days, although ITT cure rates did not reach 90%. Use of 14 day, thrice daily and high-metronidazole-dose PAM treatments markedly increased the cure rate.

Pretreatment antimicrobial susceptibility-guided vs. clarithromycin-based triple therapy for Helicobacter pylori eradication in a region with high rates of multiple drug resistance

OBJECTIVES

Helicobacter pylori eradication rates with clarithromycin-based triple therapy are declining, and an alternative strategy is needed urgently. We sought to compare the efficacy of pretreatment antimicrobial susceptibility-guided vs. clarithromycin-based triple therapy for H. pylori eradication in a region with high rates of multiple drug resistance.

METHODS

Consecutive H. pylori-infected patients with gastric epithelial neoplasms were randomized to receive antimicrobial susceptibility-guided therapy or clarithromycin-based triple therapy for 7 days. In patients in whom the infection was not eradicated, antibiotics were given according to an initial antimicrobial susceptibility test as a second-line therapy in both groups. Eradication rates, antibiotics resistance rates, and drug compliance owing to adverse effects were compared between the groups.

RESULTS

In total, 114 patients were enrolled, and 112 completed the protocols. Drug compliance and side effects were similar between the groups. The intention-to-treat eradication rates were 94.7% (95% confidence interval (CI)=88.8-100%, 54/57) in the antimicrobial susceptibility-guided group and 71.9% (95% CI=60.2-83.5%, 41/57) in the clarithromycin-based triple therapy group after the initial treatment (P=0.002), whereas the per-protocol (PP) eradication rates were 96.4% (95% CI=91.5-100%, 54/56) in the antimicrobial susceptibility-guided group and 73.2% (95% CI=61.5-84.8%, 41/56) in the clarithromycin-based triple therapy group (P=0.001). In H. pylori with clarithromycin resistance, the eradication failure rate with first-line treatment was lower in the susceptibility-guided therapy group (0%, 0/12) compared with the clarithromycin-based triple therapy group (80.0%, 95% CI=59.7-100%, 12/15) by PP analysis (P<0.001).

CONCLUSIONS

Pretreatment antimicrobial susceptibility-guided therapy is more effective than clarithromycin-based triple therapy for H. pylori eradication in a region with high rates of multiple drug resistance.

Influence of pretreatment with H2 receptor antagonists on the cure rates of Helicobacter pylori eradication

Background

Pretreatment with a proton pump inhibitor (PPI) reportedly decreases the efficacy of Helicobacter pylori (H. pylori) eradication, however, the effect of pretreatment with an H2 receptor antagonist (H2RA) on H. pylori eradication has not yet been studied. We compared the efficacy of eradication regimen (lansoprazole/amoxicillin/clarithromycin) in patients with H. pylori infection with or without H2RA pretreatment.

Material/Methods

In this retrospective study conducted at three centers, 310 patients with H. pylori infection were treated. The diagnosis of H. pylori infection was made using the rapid urease test, bacterial cultures and histological examination of endoscopic biopsy specimens. The patients were assigned to receive an eradication regimen first or following pretreatment with H2RA. Eradication was assessed using the ¹³C-urea breath test more than 4 weeks after the completion of therapy.

Results

Overall, H. pylori was eradicated in 79.7% of the cases: the eradication rate was 81.6% in the pretreatment group, and 77.6% in the eradication first group (p=0.3799, chi-square test). No significant difference in the eradication rate was observed between the two groups.

Conclusions

Pretreatment with H2RA had no significant influence on the efficacy of H. pylori eradication therapy.

Test-and-treat strategy for Helicobacter pylori (HP) infection in older patients

Despite Helicobacter pylori (HP) infection is highly prevalent in older populations, low rates of HP diagnosis and eradication are reported in older persons, even in geriatric wards. We aim to evaluate the results of a HP-eradicating program in a sample of older patients in relation to dyspeptic symptoms and to endoscopic findings. A pool of 140 subjects (female/ale=86/54, mean age 68.6±5.4 years) with positive C(13)-urea breath test were recruited, clinically evaluated to investigate the presence and characteristics of dyspepsia and abdominal pain, and underwent gastric endoscopic examination. HP-eradication was obtained in 87.9% of subjects with first-line triple therapy, regardless of endoscopic findings. Sixty-eight (48.6%) patients were symptomatic and 72 (51.4%) were asymptomatic. HP-related organic disease in endoscopic examination was frequent (present in 53.6% of the patients) but the distribution of different pathologies were similar in patients with and without symptoms (p=0.86).

CONCLUSIONS

even if diagnosis and treatment of HP infection in older patients is underestimated, this population should be a priority for HP-eradication since the infection is more frequent, peptic disease and gastric cancer are frequent, and eradication is effective.

Standard triple, bismuth pectin quadruple and sequential therapies for Helicobacter pylori eradication

AIM: To compare the effectiveness of standard triple, bismuth pectin quadruple and sequential therapies for Helicobacter pylori (H. pylori) eradication in a randomized, double-blinded, comparative clinical trial in China.

METHODS: A total of 215 H. pylori-positive patients were enrolled in the study and randomly allocated into three groups: group A (n = 72) received a 10-d bismuth pectin quadruple therapy (20 mg rabeprazole bid, 1000 mg amoxicillin bid, 100 mg bismuth pectin qid, and 500 mg levofloxacin qd); group B (n = 72) received the sequential therapy (20 mg omeprazole bid, 1000 mg amoxicillin bid, in 5 d, followed by 20 mg omeprazole bid, 500 mg tinidazole bid, 500 mg clarithromycin bid, for another 5 d); group C (n = 71) received a standard 1-wk triple therapy (20 mg omeprazole bid, 1000 mg amoxicillin bid, 500 mg clarithromycin bid). After all these treatments, 20 mg omeprazole bid was administrated for 3 wk. H. pylori status was assessed by histology, 13C-urea breath test and rapid urease test at baseline and 4-6 wk after completion of treatment. Ulcer cicatrization was assessed by gastroscopy. χ² test (P < 0.05) was used to compare the eradication rates and ulcer cicatrisation rates among the three groups.

RESULTS: The eradication rate was 83.33% (60/72) in group A, 88.89% (64/72) in group B, and 80.56% (58/71) in group C. The ulcer cicatrisation rate was 86.44% (51/59) in group A, 90.16% (55/61) in group B, and 84.91% (45/53) in group C. The sequential therapy yielded a higher eradication rate and ulcer cicatrisation rate than the standard triple and bismuth pectin quadruple therapies. Statistically, the eradication rate of group B was significantly different from groups A and C (P < 0.05), but the difference of ulcer cicatrisation rate and side effects was not statistically significant among the three groups (P > 0.05). The three protocols were generally well tolerated.

CONCLUSION: The sequential therapy has achieved a significantly higher eradication rate, and is a more suitable first-line alternative protocol for anti-H. pylori infection compared with the standard triple and bismuth pectin quadruple therapies.

Is antimicrobial susceptibility testing necessary before first-line treatment for Helicobacter pylori infection? Meta-analysis of randomized controlled trials

BACKGROUND

With the wide use of antibiotics, antibiotic-resistant Helicobacter pylori strains are becoming increasingly prevalent. It has been hypothesized that culture-guided therapy might help to increase treatment success. But the effects and the costs still remain controversial.

AIMS

To systematically review the efficacy and the cost of culture-guided triple therapy, compared to standard triple regimen for first-line treatment of Helicobacter pylori infection.

METHODS

A search of the Cochrane Library, PubMed, EMBASE, Science Citation Index Expanded and CBM was performed. Randomized controlled trials comparing culture-guided triple therapy to standard triple therapy in the first-line treatment of Helicobacter pylori infection were selected for meta-analysis. Relative risk was used as a measure of the effect of two regimens mentioned above with a fixed-effects model using the methods of DerSimonian and Laird.

RESULTS

Five randomized controlled trials totaling 701 patients were included. The meta-analysis showed that culture-guided triple therapy was superior referring to a higher eradication rate from intention-to-treat analyses (RR, 0.84; 95% CI,0.77, 0.90; p<0.00001) and a lower overall cost.

CONCLUSION

Culture-guided triple therapy was more effective than standard triple therapy for first-line treatment of Helicobacter pylori infection. Based on the only paper focused on the overall cost, the culture-guided triple therapy was also more cost saving. Antimicrobial susceptibility testing is necessary before first-line treatment for Helicobacter pylori infection.

Helicobacter pylori eradication: role of individual therapy constituents and therapy duration

Treatment of Helicobacter pylori (H. pylori) infection has become a key factor in the management of dyspepsia and is the treatment of choice for peptic ulcer disease. First-line eradication regimens combining a proton pump inhibitor (PPI) with clarithromycin and amoxicillin or metronidazole are considered most effective when given for a minimum period of 1 week. Eradication regimens of shorter duration have shown promising results but clinical experience remains limited. Pharmacological properties such as bioavailability and plasma concentrations of individual PPIs differ between individuals but it remains unclear whether these differences impact on the efficacy of eradication therapy and are influenced by renal or hepatic impairment. Bioavailability of PPIs also differs and is impacted on by factors including intragastric pH, metabolic pathways, potency on an mg-for-mg basis and intrinsic antibacterial activity. Several significant pharmacokinetic differences between the PPIs do not seem to influence overall H. pylori eradication rates for first-line triple therapy. However, comparison of factors including pharmacokinetics and treatment duration may prove important in achieving successful eradication with second- and third-line treatments. Based on the factors which influence therapy outcome, we suggest an algorithm for the use of H. pylori eradication therapies.

Mechanisms of aspirin increasing the susceptibility of Helicobacter pylori to clarithromycin

AIM: To investigate the mechanisms of aspirin increasing the susceptibility of H. pylori to clarithromycin.

METHODS: Mutations in V function domain of 23SrRNA gene were identified by polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis. H. pylori strain 26695 treated with or without aspirin was incubated with [7-3H] tetracycline. Endocellular radioactivity at different time points was analyzed in a liquid scintillation counter. Outer membrane proteins (OMPs) of H. pylori 26695 were depurated and analyzed by SDS-PAGE. Total RNA of H. pylori 26695 was extracted and the cDNA of the 5 porins (hopA, hopB, hopC, hopD, hopE) and the putative RND efflux system (hefABC) were obtained by reverse transcription (RT). The expression of the above 8 cDNAs were analyzed using Taqman-based real-time PCR.

RESULTS: Position 2143A-G mutations in V function domain of 23SrRNA gene did not change in clarithromycin resistant strains treated with aspirin. The radioactivities of H. pylori cells increased when treated with aspirin, indicating that aspirin improved the permeability of the outer membrane of H. pylori to antimicrobials. The OMP profiles of H. pylori treated with aspirin were similar to that of controls. However, the expression of two OMPs between 55-72 kDa altered in the presence of aspirin. Irrespective of the presence of aspirin, the expression of hopA, hopB, hopC, hopD, hopE and hefA, hefB, hefC did not change at the mRNA level.

CONCLUSION: Aspirin may enhance the permeability of the outer membrane of H. pylori to antimicrobials, and thus increase the endocellular concentrations of antimicrobials probably by altering the OMP expression.

Meta-analysis: the effect of antibiotic resistance status on the efficacy of triple and quadruple first-line therapies for Helicobacter pylori

BACKGROUND

Information regarding the effects of drug resistance on therapies for Helicobacter pylori is limited.

AIMS

To determine the effect of drug resistance on the efficacy of first-line treatment regimens for H. pylori and identify the most efficacious treatments in the presence of drug resistance.

METHODS

We searched for studies using the keywords: 'Helicobacter pylori','resistance' and 'treatment' or 'therapy'. Multilevel meta-regression models were used to determine the effect of drug resistance on treatment efficacy.

RESULTS

We analysed data from 93 studies with 10,178 participants. For triple therapies, clarithromycin resistance had a greater effect on treatment efficacy than nitroimidazole resistance. Metronidazole resistance reduced efficacy by 26% in triple therapies containing a nitroimidazole, tetracycline and bismuth, while efficacy was reduced by only 14% when a gastric acid inhibitor was added to the regimen. Quadruple therapies containing both clarithromycin and metronidazole were the most efficacious; >80% of H. pylori infections were consistently eradicated with these regimens.

CONCLUSIONS

Drug resistance was a strong predictor of efficacy across triple therapies for the eradication of H. pylori in adults. Resistance to either clarithromycin or metronidazole, but not both simultaneously, may be overcome by using quadruple therapies, especially those containing both clarithromycin and metronidazole.

Treatment of Helicobacter pylori

Triple therapy, consisting of two antibiotics, clarithomycin and amoxicillin or metronidazole in combination with a proton pump inhibitor (PPI) has become the first-line option for infection with Helicobacter pylori and has been recommended at several consensus conferences. In clinical practice, approximately 20% of patients will fail to obtain H. pylori eradication with the recommended treatment regimens. Major causes of treatment failure are insufficient patient compliance and antibiotic resistance. Because of antibiotic resistance, bismuth-based quadruple therapy has also become a first-line regimen in areas with exceedingly high rates of clarithromycin and metronidazole resistance, and is the preferred second-line option otherwise. Triple therapies based on levofloxacin and/or rifabutin mainly with combination of amoxicillin are options if multiple eradication failure occurs. However, following therapy failure beyond a second treatment attempt requires antibiotic resistance testing. New drugs and adjuvant agents have been reported but their efficacy needs further evaluation.

2-week triple therapy for Helicobacter pylori infection is better than 1-week in clinical practice: a large prospective single-center randomized study

BACKGROUND

Proton pump inhibitor (PPI)-based triple therapies are considered the standard regimens for Helicobacter pylori eradication, but the optimal duration of these regimens is still controversial. The aim of this study was to compare the efficacy of 1-week versus 2-week triple therapies in H. pylori-positive patients.

MATERIALS AND METHODS

A total of 486 consecutive H. pylori-positive patients were randomized to receive omeprazole, 20 mg b.i.d., clarithromycin 500 mg b.i.d., and either amoxicillin 1 g b.i.d. or metronidazole 500 mg b.i.d. for 1 or 2 weeks. Upper gastrointestinal endoscopy and histology were performed at entry and 2 months after the end of therapy. H. pylori status was defined according to histology and urea breath test.

RESULTS

At intention-to-treat analysis, 2-week therapy with omeprazole, amoxicillin, and clarithromycin achieved a significantly higher eradication rate than 1- or 2-week regimens with metronidazole (70% versus 52%, p = .003, versus 56%, p < .01) and the same therapy for 1-week (70% versus 57%, p = .05). At per-protocol analysis, 2-week therapy with omeprazole, amoxicillin, and clarithromycin showed a significantly higher eradication rate than 1-week of amoxicillin and metronidazole (77% versus 62%; p = .03) but no difference with 1-week same regimen (66%) or 2-week metronidazole and clarithromycin regimen (72%). Compliance and tolerability were good for all regimens.

CONCLUSIONS

Two-week therapies, independently of antibiotic combination, lead to a significant increase of H. pylori eradication rate compared to 1-week therapies, with same compliance and tolerability, even if, taking account of low-eradication rates, one must question whether the triple therapy should still be used.

Alaska sentinel surveillance for antimicrobial resistance in Helicobacter pylori isolates from Alaska native persons, 1999-2003

BACKGROUND

Previous studies in Alaska have demonstrated elevated proportions of antimicrobial resistance among Helicobacter pylori isolates.

MATERIALS AND METHODS

We analyzed H. pylori data from the Centers for Disease Control and Prevention (CDC)'s sentinel surveillance in Alaska from July 1999 to June 2003 to determine the proportion of culture-positive biopsies from Alaska Native persons undergoing routine upper-endoscopy, and the susceptibility of H. pylori isolates to metronidazole [minimum inhibitory concentration (MIC) of > 8 g metronidazole/mL), clarithromycin (MIC > or = 1), tetracycline (MIC > or = 2) and amoxicillin (MIC > or = 1)] using agar dilution.

RESULTS

Nine-hundred sixty-four biopsy specimens were obtained from 687 participants; 352 (51%) patients tested culture positive. Mean age of both culture-positive and culture-negative patients was 51 years. Metronidazole resistance was demonstrated in isolates from 155 (44%) persons, clarithromycin resistance from 108 (31%) persons, amoxicillin resistance from 8 (2%) persons, and 0 for tetracycline resistance. Metronidazole and clarithromycin resistance varied by geographic region. Female patients were more likely than male subjects to show metronidazole resistance (p < .01) and clarithromycin resistance (p = .05).

CONCLUSIONS

Resistance to metronidazole and clarithromycin is more common among H. pylori isolates from Alaska Native persons when compared with those from elsewhere in the USA.

Effectiveness of antiinfectives

BACKGROUND

Helicobacter pylori is one of the most common infections of mankind, with persistent colonization causing significant morbidity and mortality.

TREATMENT

First-line therapy, consisting of 7-day treatment with a proton pump inhibitor or ranitidine bismuth citrate, amoxicillin and clarithromycin, with second-line therapy, consisting of a proton pump inhibitor, bismuth, metronidazole, and tetracycline, in the case of failure, is chosen as the most cost-effective method of H. pylori eradication.

CONCLUSION

The effectiveness of these antiinfectives is limited by lack of compliance with treatment regimens, and increasing antibiotic resistance.

High rate of Helicobacter pylori eradication with sequential therapy in elderly patients with peptic ulcer: a prospective controlled study

BACKGROUND

Helicobacter pylori eradication rates with triple therapies are decreasing, and few data in elderly patients are available. A 10-day sequential regimen succeeded in curing such H. pylori infection in unselected patients.

AIM

To compare this sequential regimen and the standard triple therapy for H. pylori eradication in geriatric patients with peptic ulcer.

METHODS

Overall, 179 H. pylori-infected patients with peptic ulcer were enrolled (mean age: 69.5 years; range: 65-83). Patients were randomized to 10-day sequential therapy (rabeprazole 20 mg b.d. plus amoxicillin 1 g b.d. for the first 5 days, followed by rabeprazole 20 mg, clarithromycin 500 mg and tinidazole 500 mg, all b.d., for the remaining 5 days) or standard 7-day triple regimen (rabeprazole 20 mg, clarithromycin 500 mg and amoxicillin 1 g, all b.d.). Helicobacter pylori status was assessed by histology and rapid urease test at baseline and 4-6 weeks after completion of treatment.

RESULTS

The sequential regimen achieved eradication rates significantly higher in comparison with the standard regimen at both intention-to-treat (94% vs. 80%; P = 0.008) and per-protocol (97% vs. 83%; P = 0.006) analyses. In both treatment groups, compliance to the therapy was high (> 95%), and the rate of mild side-effects was similarly low (< 12%). At repeated upper endoscopy, peptic ulcer lesions were healed in 97% patients, without a statistically significant difference between the sequential regimen and the standard triple therapy.

CONCLUSIONS

In elderly patients with peptic ulcer disease, the 10-day sequential treatment regimen achieved significantly higher eradication rates in comparison with standard triple therapy.

Increased activity of Pgp multidrug transporter in patients with Helicobacter pylori infection

AIM: To determine whether local antibiotic resistance involves P-glycoprotein (Pgp)-mediated active drug out-pumping during Helicobacter pylori (H pylori) infection treatment with classic antibiotic therapy.

METHODS: Pgp activity was determined in gastric mucosa biopsy specimens obtained from 53 patients with pathohistologically verified gastritis and microbiologically confirmed H pylori infection, and compared with the Pgp activity in 12 control subjects with normal endoscopic findings. The H pylori positive patients were treated with short-term 7-d therapy consisting of two antibiotics (amoxicillin and azithromycin/metronidazole and clarithromycin) and a proton pump inhibitor. Pgp activity was determined by flow cytometry in the test of rhodamine dye efflux and quantified as mean fluorescence ratio (RMF).

RESULTS: Upon the first cycle, H pylori was successfully eradicated in 20 patients, whereas therapy was continued in 33 patients. In the course of antibiotic therapy, RMF increased (P<0.05) and gastric cells showed higher rhodamine dye efflux. The mean pre-treatment RMF values were also higher (P<0.0001) in patients with multiple therapeutic failure than in those with successful H pylori eradication and control subjects.

CONCLUSION: Pgp might be one of the causes of therapy failure in patients with H pylori and antibiotic therapy could be chosen and followed up on the basis of the Pgp transporter local activity.

Rifabutin- and furazolidone-based Helicobacter pylori eradication therapies after failure of standard first- and second-line eradication attempts in dyspepsia patients

BACKGROUND

Optimal management approach is not well defined for subjects who fail initial first- and second-line Helicobacter pylori eradication attempts and are dealt on a case-by-case basis by the specialists.

AIM

To evaluate the efficacy and safety of standard and 'rescue' eradication therapies at primary and secondary care levels.

METHODS

H. pylori infected dyspepsia patients referred to our C13 urea breath testing laboratory between January 1999 to February 2002 were included. Eradication failure at secondary care level was treated using strategies including antibiotic sensitivity testing and the use of rifabutin- and furazolidone-based therapies.

RESULTS

3280 patients received standard first-line eradication therapy, which was successful in 2530 (77%) patients. Second-line therapy (bismuth-based 'quadruple') or triple therapy (altering constituent antibiotics) was successful in 56% of 270 treated patients. Subsequent eradication attempts using rifabutin-based (n = 34) and furazolidone-based (n = 10) regimens were successful in 38% and 60% patients respectively. H. pylori eradication rates were significantly different for guidelines compliant (94.8%) and non-compliant (82%) groups (P = 0.0001). H. pylori eradication rates for non-ulcer dyspepsia (40%) and peptic ulcer disease (36%) were not significantly different.

CONCLUSIONS

Available H. pylori eradication therapies remain very effective and compliance to guidelines achieves high success rates. Furazolidone-based 'rescue' regimen achieved high eradication rates after failure of the standard first-line, second-line and rifabutin-based therapies.

Rank order of success favors longer duration of imidazole-based therapy for Helicobacter pylori in duodenal ulcer disease: a randomized pilot study

BACKGROUND

Studies on eradication therapy in developing countries have shown a success rate of 70-85%, which is suboptimal. Duration of therapy may be an important factor dictating eradication success in such regions.

AIMS

The study was undertaken to evaluate the effect of increasing the treatment period on eradication of Helicobacter pylori in duodenal ulcer disease.

METHODS

A randomized trial was carried out in which 64 consecutive H. pylori-infected patients with duodenal ulcer disease were enrolled. The patients were randomized to one of the three trial arms. Therapy consisted of lansoprazole 30 mg twice a day (b.i.d.), amoxycillin 1 g b.i.d. and tinidazole 500 mg b.i.d. The treatment period was 1 week in group I, 2 weeks in group II and 3 weeks in group III. At inclusion, patients underwent endoscopy and the presence of H. pylori was documented by a positive urease test and C14 urea breath test. Four weeks after completion of eradication therapy, the patients were subjected to repeat endoscopy to assess ulcer healing and tests for H. pylori infection.

RESULTS

Sixty-four patients (55 male and nine female; mean age 35.5 years) were enrolled in each group. The H. pylori eradication rate for group I (1 week of therapy) was 47.6%, that for group II (2 weeks of therapy) was 80%, and that for group III (3 weeks of therapy) was 91.3% (p =.003). The ulcer healing rates were 71.4, 80 and 95.6% in groups I, II and III, respectively (p =.09).

CONCLUSIONS

The 3-week regimen significantly improved the eradication rate as compared with the 1-week regime. Increasing the duration of therapy significantly improved the chances of eradication of H. pylori in duodenal ulcer disease.

Metronidazole-resistant Helicobacter pylori is more prevalent in patients with nonulcer dyspepsia than in peptic ulcer patients in a multiethnic Asian population

The trend of increasing prevalence of antibiotic resistance among Helicobacter pylori strains has been suggested as a cause of the failure of treatment of H. pylori infections. In this study, 120 of 211 antral biopsy specimens from patients with dyspeptic symptoms were found to harbor H. pylori. The isolates from the 120 specimens were tested by the agar dilution method, and 38 (31.7%) were found to be metronidazole resistant. Among the 211 subjects, 81 of 115 (70.4%) patients with peptic ulcer (PU) were infected with H. pylori, whereas 39 of 96 (40.6%) patients with nonulcer dyspepsia (NUD) were infected with H. pylori. Interestingly, significantly more NUD patients than PU patients harbored metronidazole-resistant H. pylori (22 of 39 [56.4%] and 16 of 81 [19.8%], respectively; P < 0.001). A similar pattern was also observed among NUD patients of different ethnicities but not between male and female patients (23 of 78 [29.5%] and 15 of 42 [35.7%], respectively; P = 0.54). In the posttreatment follow-up, five of six patients who had positive urea breath test results, indicating treatment failure, were NUD patients. Of these, four harbored metronidazole-resistant H. pylori strains. This further illustrates the relevance of metronidazole-resistant H. pylori in NUD patients. The significantly higher percentage of metronidazole-resistant H. pylori isolates in NUD patients may be attributed to the protection offered by the mucus layer of the nonulcerated stomach to the bacteria that reside below it, resulting in organism exposure to sublethal concentrations of metronidazole and leading to the induction of metronidazole resistance. The results demonstrate that the H. pylori isolates colonizing NUD patients are more likely to be resistant to metronidazole. It will therefore be useful to reevaluate the use of metronidazole in the treatment of NUD patients infected with H. pylori.

Aging and upper gastrointestinal disorders

The prevalence of upper gastrointestinal (GI) diseases is increasing in subjects aged 65 years and over. Pathophysiological changes in esophageal functions that occur with aging may, at least in part, be responsible for the high prevalence of gastro-esophageal reflux disease (GERD) in old age. GERD symptoms are different in the elderly compared to young or adult patients; moreover, esophagitis is a more severe disease in the elderly than in young subjects, relapse occurring in a high percentage of cases in those elderly patients who are not in maintenance therapy with antisecretories. In old age, PPIs are more effective than H2-blockers in healing and reducing the relapse of esophagitis; PPI therapy is well tolerated and very effective even in elderly subjects with concomitant diseases and treatments. Discontinuing maintenance treatment with PPIs after 6 months is associated with a significant increase in the relapse rate. The incidence of gastric and duodenal ulcers and their bleeding complications is increasing in old-aged populations worldwide. Approximately 53-73% of elderly peptic ulcer patients are Helicobacter pylori positive; however, the percentage of H. pylori-positive elderly patients who are treated for their infection remains very low. We now have data that demonstrate the benefit of curing H. pylori infection in elderly patients with H. pylori-associated peptic ulcer disease and severe chronic gastritis. One-week PPI-based triple therapy regimens including clarithromycin, amoxycillin and/or nitroimidazoles are highly effective and well tolerated in elderly patients. Low doses of both PPIs and clarithromycin (in combination with standard doses of amoxycillin or nitroimidazoles) are sufficient. Almost 40% of GU and 25% of DU in the elderly patients are associated with the use of NSAID and/or aspirin. Several strategies are available to prevent NSAID-related peptic ulcers, i.e. the use of low doses and/or less damaging NSAIDs, the use of coxibs, gastroprotection with antisecretory drugs, the eradication of H. pylori infection in infected patients as well as educational programs to reduce inappropriate prescriptions. Strategies for subgroups of patients that will take account of the GI and non-GI risks, i.e. disability, co-morbidity and friality of patients, according to a comprehensive geriatric assessment are recommended.

Pantoprazole based therapies in Helicobacter pylori eradication: a systematic review and meta-analysis

AIM

To perform a systematic review on the efficacy of pantoprazole based therapies in Helicobacter pylori eradication, and to conduct a meta-analysis comparing the efficacy of pantoprazole and other proton pump inhibitors (PPIs) when co-prescribed with antibiotics.

METHODS

Studies evaluating pantoprazole combined with antibiotics were considered. Only randomized clinical trials comparing pantoprazole and other PPIs when co-prescribed with antibiotics, and differing only in the PPI (pantoprazole vs other), were eligible for inclusion in the meta-analysis. Bibliographical searches in several electronic databases, and manual search of abstracts from congresses, were conducted. The percentage (weighted mean) of patients with eradication success was calculated. Meta-analysis was performed combining the odds ratios (ORs) of the individual studies in a global OR.

RESULTS

The mean eradication rate with pantoprazole plus clarithromycin for 14 days was 60%. Cure rates with 7 day pantoprazole based triple regimens were higher: pantoprazole, amoxicillin and clarithromycin (78%); pantoprazole, clarithromycin and nitroimidazole (84%); and pantoprazole, amoxicillin and nitroimidazole (74%). Twelve studies comparing pantoprazole and other PPIs were selected for the meta-analysis, including 534 and 603 patients, respectively. The mean eradication rate for H. pylori using pantoprazole plus antibiotics was 83%, and 81% when other PPIs were used (OR = 1; 95% confidence interval (CI) from 0.61 to 1.64). When sub-analysis was performed, including only studies comparing pantoprazole with omeprazole, or pantoprazole with lansoprazole, differences were also statistically non-significant. The meta-analysis of the six studies prescribing equivalent doses of all PPIs demonstrated similar results with pantoprazole and with other PPIs (OR = 1.07; 95% CI from 0.71 to 1.62), the results being statistically homogeneous.

CONCLUSIONS

Pantoprazole achieves similar cure rates to those of omeprazole and lansoprazole when co-prescribed with antibiotics for the eradication of H. pylori infection.

Eradication of Helicobacter pylori by 7-day triple-therapy regimens combining pantoprazole with clarithromycin, metronidazole, or amoxicillin in patients with peptic ulcer disease: results of two double-blind, randomized studies

AIM

To compare the short-term (7-day) safety and efficacy of two triple-therapy regimens using pantoprazole with those of two dual-therapy regimens (one with pantoprazole and one without), for Helicobacter pylori eradication in patients with peptic ulcer disease.

METHODS

H. pylori infection was identified by rapid urease (CLOtest), and confirmed by histology and culture. Patients were enrolled into one of two randomized, double-blind, multicenter, parallel-group studies. In study A, patients received oral pantoprazole 40 mg, clarithromycin 500 mg, and metronidazole 500 mg (PCM); pantoprazole, clarithromycin and amoxicillin 1000 mg (PCA); or pantoprazole and clarithromycin (PC). In study B, patients received PCM, PCA, PC, or clarithromycin and metronidazole without pantoprazole (CM). Treatments were given twice daily for 7 days. H. pylori status after therapy was assessed by histology and culture at 4 weeks after completing the course of study treatment. Modified intent-to-treat (MITT; each study: n = 424, n = 512) and per-protocol (PP; each study: n = 371, n = 454) populations were analyzed. The MITT population comprised all patients whose positive H. pylori status was confirmed by culture and histology; the PP population comprised patients who also complied with > or = 85% of study medication doses.

RESULTS

A total of 1016 patients were enrolled. Cure rates among patients with clarithromycin-susceptible H. pylori strains were 82 and 86% for PCM, and 72 and 71% for PCA, in studies A and B, respectively. Cure rates among patients with metronidazole-susceptible H. pylori strains were 82 and 87% for PCM, and 71 and 69% for PCA, in studies A and B, respectively. The combined eradication rates observed with the PCM regimen were superior to those of all other regimens tested. Side-effects were infrequent and mild.

CONCLUSIONS

PCM had the highest overall eradication rate in these two studies examining 7-day treatment regimens. All regimens were safe and well tolerated.

Role of antibiotic sensitivity testing before first-line Helicobacter pylori eradication treatments

BACKGROUND

The resistance of Helicobacter pylori to antibiotics has been advocated as a major cause of treatment failure, and antimicrobial sensitivity testing has been proposed to improve efficacy; however, its role before first-line therapy has not been investigated in detail.

AIM

To assess whether antimicrobial sensitivity testing improves the eradication rate of first-line anti-Helicobacter treatments and to compare the effectiveness of ranitidine bismuth citrate and omeprazole in the presence of H. pylori resistance to antibiotics.

METHODS

Two hundred and forty-two patients were assigned to either empirical or antimicrobial sensitivity testing-based treatment; within each group, subjects were further randomized to receive ranitidine bismuth citrate, 400 mg b.d., tinidazole, 500 mg b.d., and clarithromycin, 500 mg b.d., or omeprazole, 20 mg b.d., clarithromycin, 500 mg b.d., and amoxicillin, 1 g b.d., for 1 week, with substitution of the resistant antibiotic in the antimicrobial sensitivity testing-based treatment group.

RESULTS

Eradication rates were 67% [confidence interval (CI), 55-79%] in the empirical treatment group and 76% (CI, 65-87%) in the antimicrobial sensitivity testing-based group (P=N.S.). The overall success rate was 60% (CI, 51-69%) with omeprazole and 82% (CI, 73-91%) with ranitidine bismuth citrate (P<0.03); the latter overcame antibiotic resistance in 12 of 15 strains vs. zero of eight strains by omeprazole.

CONCLUSIONS

Antimicrobial sensitivity testing before first-line treatment does not improve the eradication rate, which is greater when ranitidine bismuth citrate is included in the treatment.

Molecular mechanism of the resistance of Helicobacter pylori to clarithromycin

AIM

To investigate the resistance mechanism of Hp to clarithromycin.

METHODS

With E-test method, we examined the minimal inhibitory concentration (MIC) to clarithromycin of 35 Hp clinical isolates. Resistance strains were defined when MIC≥8 mg/L. Extract the DNA from the bacteria with the phenol-chloroform extraction method. Then amplify the fragments from 2 047 to 2 347 of 23 S rRNA gene. Gene sequence of the PCR products was analyzed to observe the mutation in the resistant Hp strains.

RESULTS

Compared with susceptible strains, No13 strain contained one point mutation (T2289C), No17 had two point mutations (G2224A, T2289C) and No22 strain had 3 point mutations (G2224A, C2245T, T2289C).The MICs of the 3 resistant Hp isolates were as follows: No13 of 8.0 mg/L, No17 of 64 mg/L, No22 of >256 mg/L. With increase of the resistance of Hp strains, the number of point mutations increased.

CONCLUSION

The point-mutations at 23 S rRNA gene responsible for Hp resistance to clarithromycin have not been reported in literature either at home or abroad, demonstrating that different mechanism of Hp resistance to clarithromycin exists in different regions.

Pantoprazole: an update of its pharmacological properties and therapeutic use in the management of acid-related disorders

Pantoprazole (Protonix) is an irreversible proton pump inhibitor (PPI) that reduces gastric acid secretion. In combination with two antimicrobial agents (most commonly metronidazole, clarithromycin or amoxicillin) for 6-14 days, pantoprazole 40 mg twice daily produced Helicobacter pylori eradication rates of 71-93.8% (intent-to-treat [ITT] or modified ITT analysis) in patients without known antibacterial resistance. Pantoprazole-containing triple therapy was at least as effective as omeprazole- and similar in efficacy to lansoprazole-containing triple therapy in large trials. In the treatment of moderate to severe gastro-oesophageal reflux disease (GORD), oral pantoprazole 40 mg/day was as effective as other PPIs (omeprazole, omeprazole multiple unit pellet system, lansoprazole and esomeprazole) and significantly more effective than histamine H(2)-antagonists. Pantoprazole 20 mg/day provided effective mucosal healing in patients with GORD and mild oesophagitis. Intravenous pantoprazole 40 mg/day can be used in patients who are unable to take oral medication. Oral pantoprazole 20-40 mg/day for up to 24 months prevented relapse in most patients with healed GORD. According to preliminary data, oral pantoprazole 20 or 40 mg/day was effective at healing and preventing non-steroidal anti-inflammatory drug (NSAID)-related ulcers, and intravenous pantoprazole was at least as effective as intravenous ranitidine in preventing ulcer rebleeding after endoscopic haemostasis. Oral or intravenous pantoprazole up to 240 mg/day maintained target acid output levels in most patients with hypersecretory conditions, including Zollinger-Ellison syndrome. Oral and intravenous pantoprazole appear to be well tolerated in patients with acid-related disorders in short- and long-term trials. Tolerability with oral pantoprazole was similar to that with other PPIs or histamine H(2)-antagonists in short-term trials. Formal drug interaction studies have not revealed any clinically significant interactions between pantoprazole and other agents. In conclusion, pantoprazole is an effective agent in the management of acid-related disorders. As a component of triple therapy for H. pylori eradication and as monotherapy for the healing of oesophagitis and maintenance of GORD, pantoprazole has shown similar efficacy to other PPIs and greater efficacy than histamine H(2)-antagonists. Limited data suggest that it is also effective in Zollinger-Ellison syndrome and in preventing ulcer rebleeding. Pantoprazole is well tolerated with minimal potential for drug interactions. The availability of pantoprazole as both oral and intravenous formulations provides flexibility when the oral route of administration is not appropriate. Thus, pantoprazole is a valuable alternative to other PPIs in the treatment of acid-related disorders.

Impact of clarithromycin resistance and CYP2C19 genetic polymorphism on treatment efficacy of Helicobacter pylori infection with lansoprazole- or rabeprazole-based triple therapy in Japan

OBJECTIVE

Helicobacter pylori treatment failure is thought to be due mainly to polymorphic cytochrome P450 2C19 (CPY2C19) genetic polymorphism, associated with proton pump inhibitor metabolism, and antimicrobial susceptibility. This report has ascertained which was more important, CPY2C19 polymorphism or antimicrobial susceptibility, when using 1-week lansoprazole-based or rabeprazole-based triple therapy in Japan.

DESIGN

An open, randomized, parallel group study.

SETTING

One hundred and forty-five subjects with H. pylori-positive gastritis or peptic ulcers were randomly assigned to receive 30 mg lansoprazole twice daily (LAC group), 10 mg rabeprazole twice daily (RAC20 group), or 20 mg rabeprazole twice daily (RAC40 group), with 1000 mg amoxicillin twice daily and 400 mg clarithromycin twice daily for 1 week. Antimicrobial resistance testing was performed by E-test. More than 4 weeks after completion of treatment, H. pylori status was assessed by 13C-urea breath test, histology, and culture.

RESULTS

Cure rates expressed as intention-to-treat and per-protocol analyses, respectively, were 79.6 and 83.0% with LAC, 85.4 and 89.1% with RAC20, and 83.3 and 88.9% with RAC40. In the case of clarithromycin-sensitive strains, the cure rates were more than 97%, regardless of CPY2C19 polymorphism. However, treatment succeeded in only one out of 16 clarithromycin-resistant strains.

CONCLUSIONS

The key to successful eradication of H. pylori, using lansoprazole or rabeprazole with clarithromycin and amoxicillin, is clarithromycin susceptibility, not CPY2C19 polymorphism.

Review article: an approach to Helicobacter pylori infection in the elderly

The prevalence of Helicobacter pylori infection increases with age world-wide, reaching levels of 40-60% in asymptomatic elderly subjects and over 70% in elderly patients with gastroduodenal diseases. However, the percentage of H. pylori-positive elderly patients who are treated for their infection remains very low. Data are now available that demonstrate the benefit of curing H. pylori infection in elderly patients with H. pylori-associated peptic ulcer disease and severe chronic gastritis. Furthermore, the cure of H. pylori may prevent the progression of intestinal metaplasia and gastric atrophy. New studies are needed to clarify the role of eradication in elderly patients with non-ulcer dyspepsia and gastro-oesophageal reflux disease and in those who use non-steroidal anti-inflammatory drugs. H. pylori infection may be easily diagnosed by histological evaluation, rapid urease test or culture performed on gastric biopsies taken during endoscopy. However, the biopsy site must be carefully selected in elderly patients. For non-invasive monitoring of H. pylori infection after treatment, the 13C-urea breath test has significantly higher accuracy than serology in the elderly; further studies are needed to clarify the role of the H. pylori stool antigen test in old age. One-week proton pump inhibitor-based triple therapy regimens, including clarithromycin, amoxicillin and/or nitroimidazoles, are highly effective and well tolerated in elderly patients. Low doses of both proton pump inhibitors and clarithromycin (in combination with standard doses of amoxicillin or nitroimidazoles) are sufficient. Low compliance and antibiotic resistance are the main factors related to treatment failure in old age.

Review article: treatment of Helicobacter pylori infection and factors influencing eradication

Currently available Helicobacter pylori eradication therapies are considered very effective and safe. The most recent eradication guidelines proposed in the Maastricht 2-2000 Consensus Report recommend the use of proton pump inhibitors (standard b.d.) along with clarithromycin (500 mg b.d.) and amoxycillin (1000 mg b.d.) or metronidazole (500 mg b.d.) for a minimum of 7 days. The combination of amoxycillin and clarithromycin is preferred because it may favour best results with a second-line proton pump inhibitor quadruple therapy. The recommended second-line therapy includes a combination of a proton pump inhibitor (standard b.d.) with bismuth salt (subsalicylate/subcitrate 120 mg q.d.s.), metronidazole (500 mg t.d.s.), and tetracycline (500 mg q.d.s.) for a minimum of 7 days. Extended proton pump inhibitor-based triple therapy can be used if bismuth is not available. Specialists should manage subsequent failures. Based on direct and indirect evidence from well-designed studies and clinical experience, eradication is recommended in gastric and duodenal ulcers, MALToma, atrophic gastritis, postgastric cancer resection, and in first-degree relatives of gastric cancer patients. The most common reason for treatment failure is poor compliance with eradication guidelines. Antibiotic resistance may be a significant factor in certain geographical areas. Proton pump inhibitors are an integral part of the eradication regimens as proved by meta-analyses of clinical trials. Novel agents used in secondary failure are few and depend on the use of new antibiotics. The role of H. pylori-specific antibiotics, probiotics, and vaccines is not established as yet. Widespread acceptance of the eradication guidelines should be regarded as the single most important factor in eradication success.

Helicobacter pylori-associated peptic ulcer disease in older patients: current management strategies

The incidence of peptic ulcer and its severe complications, i.e. bleeding or perforation, is increasing in elderly patients worldwide. The prevalence of Helicobacter pylori infection in patients with peptic ulcer aged over 65 years has been reported to range from 58 to 78%. However, in elderly patients hospitalised for ulcer disease, the rate of diagnostic screening or treatment for H. pylori infection was less than 60%, and only 50 to 73% of patients who had a positive H. pylori test were treated with antibacterials. The eradication of H. pylori infection is known to be of proven benefit for elderly patients with H. pylori-associated ulcer disease. Significant improvement of the clinical outcome, and reduction of ulcer recurrences, symptoms and histological signs of ulcer-associated chronic gastritis activity, as well as decreased costs in elderly healthcare, all result from successful therapy. Proton pump inhibitor (PPI)-based triple therapy regimens including clarithromycin, amoxicillin and/or nitroimidazoles are highly effective and well tolerated in elderly patients, particularly if therapy is of a short duration and low doses of both the PPI and clarithromycin are used. Resistance of H. pylori to antibacterials and low compliance are the major reasons for treatment failure. Surveillance of H. pylori susceptibility to antibacterials at the regional level and enhanced compliance programmes give promising results that suggest new approaches to anti-H. pylori treatment, especially in elderly patients. The role of H. pylori infection in nonsteroidal anti-inflammatory drug (NSAID)-related peptic ulcer still remains controversial. At present, no clear evidence supports the testing and treatment of H. pylori infection for the prevention of drug-related peptic ulcer in elderly patients receiving an NSAID or aspirin (acetylsalicylic acid). After therapy, elderly patients with peptic ulcer may be re-evaluated by invasive methods, i.e. endoscopy and gastric biopsies. or by noninvasive methods. In elderly patients, the 13C-urea breath test demonstrated significantly higher sensitivity, specificity and diagnostic accuracy for detecting H. pylori infection than anti-H. pylori antibodies.

Treatment of Helicobacter pylori infection. Indications and regimens: an update

The management of Helicobacter pylori infection is still surrounded by controversy and uncertainties. Indications and correct application of current regimens for Helicobacter pylori infection are still considered a matter of debate. Regarding indications, only peptic ulcer and mucosa associated lymphoid tissue lymphoma are considered clear indications for treatment. In other conditions, such as atrophic gastritis, post gastric cancer resection, first-degree relatives of gastric cancer patients, dyspeptic patients, patients with gastro-oesophageal reflux disease and non-steroidal anti-inflammatory drug users, the value of Helicobacter pylori eradication is still controversial. The regimens for first-line and second-line treatment of Helicobacter pylori infection have been recommended by the Maastricht 2 Consensus Report. Although all the treatments are considered to be effective, physicians still do not agree on what first-line regimen should be used. Furthermore, a consensus on the duration of the antibiotic treatment is still lacking, although Maastricht guidelines for treatment of Helicobacter pylori infection recommend a one-week therapy. Also regimens, as a third-line treatment, and methods to improve compliance and clinical outcome are still a matter of debate. All these points will be considered in the present review

Triple therapy with clarithromycin, amoxicillin and omeprazole for Helicobacter pylori eradication in children and adolescents

BACKGROUND

Helicobacter pylori infection presents high prevalence in developing countries, but there are few pediatric assays evaluating antimicrobial treatment.

OBJECTIVE

The aim of this study was to investigate Helicobacter pylori eradication rate using a short regimen (7 and 10 days) of triple therapy with clarithromycin, amoxicillin and omeprazole.

PATIENTS AND METHODS

Twenty-five Hp positive patients who presented severe epigastralgia, were submitted to antimicrobial treatment with amoxicillin (50 mg/kg/day--maximum dose 1 g bid), clarithromycin (30 mg/kg/day--maximum dose 500 mg bid) and omeprazole (0.6 mg/kg/day--maximum dose 20 mg bid) during 7 or 10 days. After 2 months, clinical symptoms were evaluated and gastric biopsies were taken to test Hp eradication.

RESULTS

Overall eradication rate was achieved in 16/25 patients (64%--IC(95% = 45-83%), in 11/15 (73%--IC(95%) = 51-95%) patients who used 10 days therapy course and in 5/10 (50%--IC(95%) = 19-81%) who used 7 days therapy course. Eradication drugs were well accepted and adverse effects were reported in two patients (8%).

CONCLUSIONS

This triple therapy regimen had moderate efficacy (64%). The data suggests that 10 days therapy course achieves better eradication rate (73%) than 7 days course (50%) to treat Hp infection in our population.

Cure of Helicobacter pylori infection in elderly patients: comparison of low versus high doses of clarithromycin in combination with amoxicillin and pantoprazole

BACKGROUND

Advancing age may influence clarithromycin's pharmacokinetics. No studies have yet compared the effects of different dosages of clarithromycin in combination with a proton pump inhibitor and amoxicillin in elderly patients.

AIM

To compare the efficacy and tolerability of clarithromycin 250 mg vs. clarithromycin 500 mg twice daily (b.d.) in combination with pantoprazole and amoxicillin in elderly patients.

METHODS

One hundred and fifty-four elderly patients with H. pylori-associated ulcer disease or chronic gastritis were consecutively randomized to receive pantoprazole 40 mg daily plus amoxicillin 1 g, and either clarithromycin 250 mg b.d. (PAC 250) or clarithromycin 500 mg b.d. (PAC 500). Two months after therapy, endoscopy and gastric biopsies were repeated.

RESULTS

The cure rates of H. pylori infection in the PAC 250 and PAC 500 groups were, respectively, 83% and 79% (ITT analysis) and 94% and 88% (PP analysis) (P=N.S.). Significant decreases in chronic gastritis activity both in the body (P < 0.00001) and the antrum (P < 0.0001) of the stomach were found in H. pylori-cured patients, independently of clarithromycin dosage. Four patients in PAC 250 (5%) and seven in PAC 500 (9%) reported adverse events (P=N.S.). One patient in PAC 250 (25%) and three in PAC 500 (43%) discontinued the study because of these drug-related side-effects (P=N.S.).

CONCLUSIONS

In elderly patients, 1-week triple therapy with a proton pump inhibitor, amoxicillin and clarithromycin is a highly effective and well tolerated anti-H. pylori treatment. With this combination, clarithromycin at the lower dose of 250 mg b.d. achieved excel- lent cure rates and minimized adverse events and costs.

Retreatment of Helicobacter pylori infection after initial treatment failure

OBJECTIVES

Helicobacter pylori treatment regimens fail to cure the infection in at least 10-20% of patients undergoing initial treatment. Retreatment strategies for patients who have failed initial treatment for H. pylori infection remain poorly described.

METHODS

The literature describing the frequency of H. pylori treatment failure and factors leading to failure is reviewed. The role of antibiotic resistance is discussed and clinical studies assessing success rates according to antibiotic resistance are described. Clinical trials evaluating the treatment success rates for a second episode of treatment are discussed.

RESULTS

The literature describing retreatment of failed H. pylori infection remains limited. The existing data support the use of bismuth-based quadruple therapy or ranitidine bismuth citrate (RBC)-based triple therapy as the preferred agents after initial treatment failure.

CONCLUSION

Further studies are needed to better define the optimal second treatment regimen after failed H. pylori treatment.

A systematic comparison of triple therapies for treatment of Helicobacter pylori infection with proton pump inhibitor/ ranitidine bismuth citrate plus clarithromycin and either amoxicillin or a nitroimidazole

BACKGROUND

Triple therapies with proton pump inhibitor/ranitidine bismuth citrate (RBC), clarithromycin (C) and either amoxicillin (A) or a nitroimidazole (I) are widely accepted as treatment for Helicobacter pylori infection. However, it is not clear which of these antibiotic combinations should be preferred.

AIM

To evaluate whether there is a difference in efficacy between triple therapies with proton pump inhibitor/RBC, clarithromycin and either amoxicillin or a nitroimidazole.

METHODS

The literature was examined for randomized trials comparing proton pump inhibitor/RBC-C-A and proton pump inhibitor/RBC-C-I. Studies were grouped according to the type of acid inhibitor used (proton pump inhibitor or RBC) and differences between pooled cure rates were calculated.

RESULTS

Forty-seven studies were identified: seven using RBC, 39 using proton pump inhibitor, one using both. RBC-C-I was somewhat superior to RBC-C-A, although this difference only reached statistical significance in intention-to-treat analysis. Overall, proton pump inhibitor-C-I and proton pump inhibitor-C-A were equally effective, but in nitroimidazole-susceptible strains, proton pump inhibitor-C-I performed better, in nitroimidazole-resistant strains, proton pump inhibitor-C-A performed better. No serious side-effects were reported and pooled drop-out rates were equal.

CONCLUSIONS

In general, proton pump inhibitor-C-I and proton pump inhibitor-C-A are equally effective and therefore other factors such as local prevalence of resistant strains, cost of therapy and options for second-line treatment should determine which regimen should be preferred. When using RBC, the RBC-C-I combination is somewhat superior to RBC-C-A.

Do some patients with Helicobacter pylori infection benefit from an extension to 2 weeks of a proton pump inhibitor-based triple eradication therapy?

OBJECTIVES

Seven-day proton pump inhibitor (PPI)-based triple therapies are the first-line anti-Helicobacter pylori regimens; to date, however, there is still no agreement concerning all the predictors of H. pylori cure under these regimens. The aim of this prospective study was to evaluate whether patients with certain pretreatment characteristics may benefit from an extension from 1 to 2 wk of treatment with lansoprazole, amoxycillin, and clarithromycin.

METHODS

A total of 142 patients with H. pylori infection ascertained by means of gastric histopathology and 13C urea breath test (UBT) participated in this study. In all patients H. pylori density was determined at histology both on antral and corpus biopsies, and H. pylori culture with antibiotic susceptibility testing; IgG anti-H. pylori titers were also determined before therapy. Patients were randomized to receive 1-wk versus 2-wk of treatment with lansoprazole (30 mg b.i.d.), clarithromycin (500 mg b.i.d.), and amoxycillin (1 g b.i.d.). The association between eradication and potential predictors was analyzed by means of unconditional logistic regression models and stratified according to the duration of treatment. A stepwise regression analysis was performed to identify variables discriminated between subjects, using eradication status as the dependent variable.

RESULTS

The overall eradication rates for 1- and 2-wk treatments were 74.6% and 85.9% (intention-to-treat analysis) and 81.5% and 89.1% (per-protocol analysis), respectively (p = NS). Multivariate discriminant analysis selected as the variables independently related to eradication cigarette smoking (OR = 3.98), delta of 13C-UBT higher than 35 (OR = 9.21) and IgG anti-H. pylori titer > or = 93 (OR = 0.24) for the whole series of subjects. Stratified analysis according to the duration of therapy selected H. pylori density as the only predictor of eradication in the group treated for 1 wk (OR = 8.11). In contrast, no significant predictors were found in the group treated for 2 wk.

CONCLUSIONS

Patients with a high intragastric bacterial load, as detected by histology (grade 3) or 13C-UBT (delta > 35) may benefit from an extension to 2 wk of triple therapy with lansoprazole, amoxycillin, and clarithromycin.

Role of antimicrobial susceptibility testing on efficacy of triple therapy in Helicobacter pylori eradication

BACKGROUND

Helicobacter pylori treatment failure may be due to resistance to macrolides and 5-nitroimidazoles.

AIM

To test whether a preliminary in vitro susceptibility test of H. pylori to tinidazole and clarithromycin and a consequent specific regimen could improve the eradication rate.

METHODS

A total of 109 consecutive H. pylori-positive patients with dyspeptic symptoms were included. At endoscopy, biopsy from the antrum was obtained for H. pylori culture and antimicrobial susceptibility testing. Fifty-six patients were treated with omeprazole, tinidazole and clarithromycin for 10 days (group OTC) and 53 patients received therapy on the basis of the susceptibility test (group SUSC). Treatment success was evaluated by the 13C-urea breath test 1 month after the end of therapy.

RESULTS

Eight patients dropped out. Overall primary resistance to clarithromycin, tinidazole and both antibiotics was 13%, 33% and 4%, respectively. In group OTC, H. pylori was eradicated in 81% and 75% of patients by per protocol and intention-to-treat analysis, respectively. Per protocol and intention-to-treat eradication rates for group SUSC were 98% and 91% (P < 0.05 vs. group OTC).

CONCLUSIONS

These data show that in H. pylori infection, antibiotic therapy based on the results of culture and susceptibility testing gives, in comparison to standard therapy, a significant improvement in eradication rate.

Prevalence of Helicobacter pylori resistance to antibiotics in Northeast Italy: a multicentre study. GISU. Interdisciplinary Group for the Study of Ulcer

AIMS

To evaluate prevalence of primary Helicobacter pylori antibiotic resistances in Northeast Italy and to identify risk factors associated with this resistance.

MATERIALS AND METHODS

A total of 248 patients undergoing upper gastrointestinal endoscopy were enrolled from 19 Endoscopy Units over a 6-month period. From each patient, 4 gastric biopsies were taken for histology and 2 were sent to the Central Referral Microbiological Laboratory for culture and determination of antibiotic activity against Helicobacter pylori by means of E-test. Strains were considered resistant when minimum inhibitory concentration was >8 microg/ml for metronidazole and >1 microg/ml for clarithromycin. No cut-off value was predefined for amoxycillin.

RESULTS

Culture of Helicobacter pylori was successfully performed in 167 patients. Primary resistance to metronidazole, clarithromycin or amoxycillin was 14.9%, 1.8% and 0%, respectively Patients infected with Helicobacter pylori strains resistant to antibiotics were more frequently females than males (70.3% vs 41.4%), had a significantly lower coffee intake (66.6% vs 86.6%) and lower body mass index (23.7+/-2.6 vs 25.3+/-3.6) than patients with susceptible Helicobacter pylori strains. Age, smoking, alcohol use, family history of Helicobacter pylori infection, concomitant diseases and treatments, endoscopic diagnoses, Helicobacter pylori density and histological activity of chronic gastritis were not associated with antibiotic resistance. Multivariate analysis confirmed that female gender (odds ratio = 2.74, 95% confidence interval = 1.03-7.27) was the only significant risk factor associated with antibiotic resistance.

CONCLUSIONS

In this population, primary Helicobacter pylori resistance to metronidazole was higher than resistance to clarithromycin, and female gender was significantly associated with this resistance. The low prevalence of resistance to metronidazole, clarithromycin and amoxycillin identified in this geographical area suggests that proton pump inhibitor-based triple regimens including these antibiotics may still be used as first line therapies against Helicobacter pylori infection.

Pantoprazole: a new proton pump inhibitor

OBJECTIVE

This paper reviews the pharmacology, clinical efficacy, and tolerability of pantoprazole in comparison with those of other available proton pump inhibitors (PPIs).

METHODS

Relevant English-language research and review articles were identified by database searches of MEDLINE, International Pharmaceutical Abstracts, and UnCover, and by examining the reference lists of the articles so identified. In selecting data for inclusion, the author gave preference to full-length articles published in peer-reviewed journals.

RESULTS

Like other PPIs, pantoprazole exerts its pharmacodynamic actions by binding to the proton pump (H+,K+ -adenosine triphosphatase) in the parietal cells, but, compared with other PPIs, its binding may be more specific for the proton pump. Pantoprazole is well absorbed when administered as an enteric-coated, delayed-release tablet, with an oral bioavailability of approximately 77%. It is hepatically metabolized via cytochrome P2C19 to hydroxypantoprazole, an inactive metabolite that subsequently undergoes sulfate conjugation. The elimination half-life ranges from 0.9 to 1.9 hours and is independent of dose. Pantoprazole has similar efficacy to other PPIs in the healing of gastric and duodenal ulcers, as well as erosive esophagitis, and as part of triple-drug regimens for the eradication of Helicobacter pylori from the gastric mucosa. It is well tolerated, with the most common adverse effects being headache, diarrhea, flatulence, and abdominal pain. In clinical studies, it has been shown to have no interactions with various other agents, including carbamazepine, cisapride, cyclosporine, digoxin, phenytoin, theophylline, and warfarin.

CONCLUSIONS

Pantoprazole appears to be as effective as other PPIs. Its low potential for drug interactions may give it an advantage in patients taking other drugs.

Incidence of secondary Helicobacter pylori resistance to antibiotics in treatment failures after 1-week proton pump inhibitor-based triple therapies: a prospective study

BACKGROUND

Antibiotic-resistant Helicobacter pylori strains are becoming increasingly prevalent, although it is not clear to what extent the new resistant organisms will spread.

AIM

To evaluate the incidence of secondary Helicobacter pylori resistance to metronidazole, clarithromycin and/or amoxycillin after one-week proton pump inhibitor based triple therapy failure in patients who were, before therapy infected with Helicobacter pylori strains susceptible to these antibiotics.

PATIENTS AND METHODS

Enrolled in the study were 97 consecutive Helicobacter pylori-positive subjects infected by Helicobacter pylori strains susceptible to metronidazole, clarithromycin and amoxycillin. Activity of tested antibiotics was determined by means of the E-test. Patients were treated for seven days with a proton pump inhibitor, omeprazole 20 mg twice daily or pantoprazole 40 mg once daily, plus clarithromycin 250 mg twice daily and metronidazole 250 mg four times daily; or with a proton pump inhibitor plus amoxycillin 1 g twice daily and clarithromycin 500 mg twice daily. Two months after completion of therapy, endoscopy and gastric biopsies for histology, rapid urease test and culture were repeated.

RESULTS

Four patients were dropped from the study Overall Helicobacter pylori cure rates expressed as both intention-to-treat and per-protocol analyses, were, respectively 80% (40/50) and 81.6% (40/49) with proton pump inhibitor, clarithromycin and metronidazole and 76.6% (36/47) and 81.8% (36/44) with proton pump inhibitor amoxycillin and clarithromycin. No significant differences were observed between the two treatments. Subjects in whom treatment failed were significantly younger and had less active ulcer than cured patients. Of treatment failures, 70.6% (12 out of 17 subjects) de veloped a secondary resistance to metronidazole (35.33% and/or clarithromycin (64.7%). Secondary antibiotic resistance occurred in 77. 8% of treatment failures treated with proton pump inhibitor, clarithromycin and metronidazole and in 62.5% of those treated with proton pump inhibitor, amoxycillin and clarithromycin. Considering all patients treated, the overall incidence of secondary metronidazole and/or clarithromycin resistance after therapy was reported in 12.9% of subjects (12 out of 93 treated patients).

CONCLUSIONS

Secondary Helicobacter pylori resistances to metronidazole and/or clarithromycin occurred in large percentages in patients with treatment failure after the one-week proton pump inhibitor-based triple therapies, proton pump inhibitor, clarithromycin and metronidazole and proton pump inhibitor, amoxycillin and clarithromycin. It is likely that new antibiotics or treatment strategies will be needed in the near future to successfully treat Helicobacter pylori infection.

Rifabutin-based triple therapy after failure of Helicobacter pylori eradication treatment: preliminary experience

Despite continuous improvement of Helicobacter pylori (Hp) eradication therapy, new treatment regimens are necessary if established first-line treatments fail. In the present pilot study, a recently described rifabutin-based triple therapy was evaluated after preceding failure of triple therapy. Rifabutin (150 mg), amoxicillin (1 g), and lansoprazole (30 mg) were administered twice daily for 1 week to 25 patients infected with Hp who had previously failed to respond to eradication treatment and/or who had developed resistance to macrolides and nitroimidazoles. Four patients were lost to follow-up. Eradication rate of rifabutin-based triple therapy was 86% (18/21; per protocol) and 72% (18/25; intention-to-treat). Side effects were minimal. It is concluded that this new drug combination is an effective therapy for Hp strains resistant to clarithromycin or metronidazole; however, rifabutin-based treatment regimens for Hp eradication should be restricted to patients infected with resistant strains.

Pantoprazole versus one-week Helicobacter pylori eradication therapy for the prevention of acute NSAID-related gastroduodenal damage in elderly subjects

AIM

To compare the efficacy of pantoprazole vs. a one-week Helicobacter pylori eradication therapy for the prevention of NSAID-related gastroduodenal damage.

METHODS

Patients over 60 years old with symptoms and/or a history of ulcer who needed NSAID treatment were evaluated by endoscopy. H. pylori positive subjects who had no severe gastroduodenal lesions were randomized to take, concomitantly with NSAID therapy, either: (i) pantoprazole 40 mg daily plus amoxycillin 1 g b.d. and clarithromycin 250 mg b.d. for 1 week (35 subjects, Group PAC) or (ii) pantoprazole 40 mg daily for 1 month (34 subjects, Group P). Endoscopy was repeated after 1 month.

RESULTS

A significantly higher incidence of severe gastroduodenal damage was found in Group PAC than in Group P (29% vs. 9%, P<0.05). The percentages of patients worsened, unchanged and improved after 1 month were, respectively: Group PAC: 46%, 46%, and 9% and Group P: 7%, 65%, and 29% (P<0.0008). The percentage of H. pylori-negative subjects was 89% in Group PAC and 52% in Group P (P=0.0009). The incidence of gastroduodenal damage was higher in Group PAC treatment failures than in cured patients (50% vs. 25.8%, P=ns).

CONCLUSION

One month of pantoprazole was more effective than a proton pump inhibitor-based triple therapy in the prevention of gastroduodenal damage in elderly H. pylori-positive NSAID users.