Review article: alternative antibacterial agents for Helicobacter pylori eradication

Empirical vs. Susceptibility-Guided Treatment of Helicobacter pylori Infection: A Systematic Review and Meta-Analysis

Background

Treating Helicobacter pylori infection according to antibiotic resistance has been frequently recommended. However, information on its real effectiveness is scarce.

Aim

The aim of this study is to perform a meta-analysis comparing empirical vs. susceptibility-guided treatment of H. pylori.

Methods

Selection of studies: Studies comparing empirical versus susceptibility-guided treatment were selected. Search strategy: electronic and manual up to August 2021. Data synthesis: by intention-to-treat (random-effects model).

Results

Overall, 54 studies were included (6,705 patients in the susceptibility-guided group and 7,895 in the empirical group). H. pylori eradication rate was 86 vs. 76%, respectively (RR: 1.12; 95% CI: 1.08-1.17; I 2: 83%). Similar results were found when only RCTs were evaluated (24 studies; RR: 1.16; 95% CI: 1.11-1.22; I 2: 71%) and when susceptibility testing was assessed by culture (RR: 1.12; 95% CI: 1.06-1.18) or PCR (RR: 1.14; 95% CI: 1.05-1.23). For first-line treatments (naïve patients; 30 studies), better efficacy results were obtained with the susceptibility-guided strategy (RR: 1.15; 95% CI: 1.11-1.20; I 2: 79%). However, for empirical first-line quadruple regimens, in particular (both with and without bismuth, excluding the suboptimal triple therapies), not based on CYP2C19 gene polymorphism, no differences in efficacy were found compared with the susceptibility-guided group (RR: 1.04; 95% CI: 0.99-1.09); this lack of difference was confirmed in RCTs (RR: 1.05; 95% CI: 0.99-1.12). For rescue therapies (13 studies, most 2nd-line), similar results were demonstrated for both strategies, including all studies (RR: 1.09; 95% CI: 0.97-1.22; I 2: 82%) and when only RCTs were considered (RR: 1.15; 95% CI: 0.97-1.36).

Conclusion

The benefit of susceptibility-guided treatment over empirical treatment of H. pylori infection could not be demonstrated, either in first-line (if the most updated quadruple regimens are prescribed) or in rescue therapies.

Empirical or susceptibility-guided treatment for Helicobacter pylori infection? A comprehensive review

Although susceptibility-guided therapy is frequently recommended for Helicobacter pylori infection, the evidence available to date supporting this strategy is limited. The aim of the present article is to review the advantages and limitations of the susceptibility-guided and the empirical strategies to treat this infection. We performed a bibliographic search to identify studies investigating H. pylori susceptibility-guided therapy. Culture is not the only way to assess antibiotic resistance, as different polymerase chain reaction-based approaches have been developed as alternative methods. For detecting H. pylori antimicrobial resistance, a molecular approach based on a stool sample might enable more convenient, time-saving methods. Unfortunately, the antimicrobial susceptibility cannot be obtained in all cases. Furthermore, antibiotic susceptibility testing in clinical practice yields useful information only for a few antibiotics: clarithromycin, metronidazole, and quinolones. In addition, susceptibility towards clarithromycin and metronidazole in vitro does not necessarily lead to eradication in vivo. In the case of H. pylori therapy failure, we should not re-administer any of the antibiotics against which H. pylori has probably become resistant. Our updated meta-analysis showed that susceptibility-guided treatment is not better than empirical treatment of H. pylori infection in first-line therapy if the most updated quadruple regimens are empirically prescribed, and similar efficacy results were also demonstrated with the two strategies for second-line therapy. Cumulative H. pylori eradication rate with several successive rescue therapies empirically prescribed reaches almost 100%. Finally, the studies that have evaluated the cost-effectiveness of the susceptibility-guided treatment have achieved contradictory results. In summary, we can conclude that the evidence is too limited to support the generalized use of susceptibility-guided therapy for H. pylori treatment in routine clinical practice, either as first-line or as rescue treatment. Nevertheless, it would be recommended that susceptibility tests are performed routinely, even before prescribing first-line treatment, in specialized centers with an interest in H. pylori management.

Analysis of Correlation between the Seven Important Helicobacter pylori (H. pylori) Virulence Factors and Drug Resistance in Patients with Gastritis

The aim of this study is to evaluate the association between seven important H. pylori virulence factors and antibiotic resistance in patients with gastritis. H. pylori strains isolated from 33 patients with gastritis were examined. Antimicrobial susceptibilities were tested by GenoType® HelicoDR (Hain Life Science, Germany) test kit and RT-PCR. The virulence-factors were determined using conventional PCR. 39% of patients were resistant for clarithromycin and 27% of patients were resistant for fluoroquinolone. 15% of patients were resistant to both clarithromycin and fluoroquinolone. The H. pylori vacA m1/s2 genotype was the most frequent allelic combination. Patients were possessed the vacA s1, m1 (6.1%); s1, m2 (6.1%); s2, m1 (15.1%); and s2, m2 (3.0%) genotypes. 94% of patients with gastritis were positive for H. pylori napA gene. Also, there were no dupA gene-positive gastritis patients. There was no significant correlation between the vacA, cagA, oipA, hpaA, babA, napA, dupA, ureA, ureB virulence genes, clarithromycin, and fluoroquinolone resistance. Herein, we report that the relationship between the H. pylori napA gene and gastritis. Although we found a correlation between H. pylori virulence factor and clinical outcome, there is a need for further studies to enlighten the relation between H. pylori virulence genes and antibiotic resistance.

Systematic review: Would susceptibility-guided treatment achieve acceptable cure rates for second-line Helicobacter pylori therapy as currently practiced?

BACKGROUND

Susceptibility-guided treatment has been proposed as a way to improve Helicobacter pylori eradication rates. Evidence on its efficacy for rescue therapy is very scarce. The aim of this study was to indirectly assess the applicability and effectiveness of susceptibility-guided treatment by evaluating (a) the rate of acceptance of endoscopy, (b) its success in detecting resistances, and (c) infection cure rates in patients harboring strains found to be susceptible to the antibiotics administered in clinical trials in which the efficacy of second-line treatments was reported.

METHODS

A systematic review of studies evaluating second-line H pylori treatment was carried out in multiple databases. Studies reporting antibiotic susceptibility evaluation and/or cure rates in patients harboring sensitive and resistant strains were selected. Data were extracted in duplicate.

RESULTS

The systematic review identified 36 eligible studies. Acceptance was evaluated in only one study of 60 patients, of whom only 38 agreed to endoscopy. Among the 2890 patients who received endoscopy and culture, resistances were finally determined in 86.5%. Cure rate was 72.5% in the 113 patients harboring a clarithromycin-susceptible strain after previous clarithromycin treatment, 93.5% in the 765 patients harboring a metronidazole-susceptible strain, and 83.8% in the 192 patients harboring a levofloxacin-susceptible strain. No studies with repeated administration of levofloxacin or metronidazole were found.

CONCLUSION

Even if the culture shows a clarithromycin-sensitive strain, repeating clarithromycin after a first failure should be discouraged. Susceptibility-guided treatment alone did not achieve adequate cure rates for rescue therapies. Additional measures are needed to design rescue treatments that consistently achieve excellent cure rates.

Rifabutin Containing Triple Therapy and Rifabutin with Bismuth Containing Quadruple Therapy for Third-Line Treatment of Helicobacter pylori Infection: Two Pilot Studies

AIM

To evaluate the therapeutic gain of the addition of bismuth to a rifabutin containing triple therapy with amoxicillin and pantoprazole at standard dosages for the treatment of third-line Helicobacter pylori infection after a preliminary susceptibility test.

METHODS

Two separate groups of patients in two pilot studies which were carried out simultaneously. One group was treated with rifabutin 150 mg b.i.d., pantoprazole 20 mg b.i.d., and amoxicillin 1 g b.i.d. for 10 days and the other group with rifabutin 150 mg b.i.d., pantoprazole 20 mg b.i.d., amoxicillin 1 g b.i.d., and bismuth subcitrate 240 mg b.i.d. for 10 days. All patients underwent to culture and susceptibility testing prior to their inclusion in the study. A successful outcome was confirmed with an Urea Breath test performed 8 weeks after the end of treatment. A blood cell count was performed for all patients at the start and after 5 days of treatment since rifabutin has been shown to inhibit the growth of leucocytes.

RESULTS

Twenty-nine patients were recruited in the pantoprazole, amoxicillin, rifabutin group and 30 in the pantoprazole, amoxicillin, rifabutin, and bismuth subcitrate group. All patients had a positive H. pylori culture and the susceptibility test used showed H. pylori sensitivity to rifabutin and amoxicillin. H. pylori eradication during follow-up was 18/27 (66.7%, 95% CI: 47.7-85.7%) in the pantoprazole, amoxicillin, rifabutin group and 28/29 (96.6%, 95% CI: 89.5-100.0%) in the pantoprazole, amoxicillin, rifabutin, and bismuth subcitrate group. Both treatments were well-tolerated with no reported side effects. Blood cell count remained normal in all patients.

CONCLUSION

The addition of bismuth subcitrate to a triple therapy that includes proton pump inhibitors, amoxicillin, and rifabutin in patients who are treated for the third time for H. pylori infection resulted in a 30% therapeutic gain.

Ten-Day versus 14-Day Levofloxacin-Containing Triple Therapy for Second-Line Anti-Helicobacter pylori Eradication in Taiwan

Second-line Helicobacter pylori (H. pylori) eradication with fluoroquinolone-containing triple therapy is one of the recommended treatment options, but neither 7-day nor 10-day regimens provide >90% success rates. The current retrospective study aimed to clarify the effects of 10-day and 14-day levofloxacin-containing triple therapies for second-line H. pylori eradication in a Taiwanese cohort and to evaluate the potential clinical factors influencing eradication. A total of 200 patients who failed H. pylori eradication using the standard triple therapy were prescribed with either a 10-day (EAL-10) or a 14-day (EAL-14) levofloxacin-containing triple therapy group (levofloxacin 500 mg once daily, amoxicillin 1 g twice daily, and esomeprazole 40 mg twice daily). Follow-up studies to assess treatment response were carried out 8 weeks later. Eradication rates attained by EAL-10 and EAL-14 were 75.6%; 95% CI = 63.9-85.3% and 92.5%; 95% CI = 84.5-98.1%, P = 0.002 in the per protocol analysis and 68%; 95% CI = 56.6-78.5% and 86%; 95% CI = 76.8-93.4%, P = 0.002 in the intention-to-treat analysis. The duration of H. pylori therapy is the independent risk factor of H. pylori eradication (P = 0.003). In conclusion, 14-day levofloxacin-containing triple therapy can provide a >90% H. pylori eradication rate, but 10-day treatment duration may be suboptimal. The longer duration of H. pylori therapy (14 days) is the independent risk factor.

Levofloxacin/amoxicillin-based schemes vs quadruple therapy for Helicobacter pylori eradication in second-line

Worldwide prevalence of Helicobacter pylori (H. pylori) infection is approximately 50%, with the highest being in developing countries. We compared cure rates and tolerability (SE) of second-line anti-H. pylori levofloxacin/amoxicillin (LA)-based triple regimens vs standard quadruple therapy (QT). An English language literature search was performed up to October 2010. A meta-analysis was performed including randomized clinical trials comparing 7- or 10-d LA with 7-d QT. In total, 10 articles and four abstracts were identified. Overall eradication rate in LA was 76.5% (95% CI: 64.4%-97.6%). When only 7-d regimens were included, cure rate was 70.6% (95% CI: 40.2%-99.1%), whereas for 10-d combinations, cure rate was significantly higher (88.7%; 95% CI: 56.1%-109.9%; P < 0.05). Main eradication rate for QT was 67.4% (95% CI: 49.7%-67.9%). The 7-d LA and QT showed comparable efficacy [odds ratio (OR): 1.09; 95% CI: 0.63-1.87], whereas the 10-d LA regimen was significantly more effective than QT (OR: 5.05; 95% CI: 2.74-9.31; P < 0.001; I(2) = 75%). No differences were reported in QT eradication rates among Asian and European studies, whereas LA regimens were more effective in European populations (78.3% vs 67.7%; P = 0.05). Incidence of SE was lower in LA therapy than QT (OR: 0.39; 95% CI: 0.18-0.85; P = 0.02). A higher rate of side effects was reported in Asian patients who received QT. Our findings support the use of 10-d LA as a simple second-line treatment for H. pylori eradication with an excellent eradication rate and tolerability. The optimal second-line alternative scheme might differ among countries depending on quinolone resistance.

Review article: rifabutin in the treatment of refractory Helicobacter pylori infection

BACKGROUND

Even with the current most effective treatment regimens, a relevant proportion of patients will fail to eradicate Helicobacter pylori infection.

AIM

To evaluate the role of rifabutin in the treatment of H. pylori infection.

METHODS

Bibliographical searches were performed in MEDLINE. Data on the efficacy of rifabutin-containing regimens on H. pylori eradication were combined and meta-analysed using the generic inverse variance method.

RESULTS

Rifabutin shows good in vitro activity against H. pylori. Mean H. pylori rifabutin resistance rate (calculated from 11 studies including 2982 patients) was 1.3% (95% confidence interval = 0.9-1.7%). When only studies including patients naïve to H. pylori eradication treatment were considered, this figure was even lower (0.6%). On the other hand, higher values of rifabutin resistance were calculated (1.59%) when only post-treatment patients were considered. Overall, mean H. pylori eradication rate (intention-to-treat analysis) with rifabutin-containing regimens (1008 patients) was 73% (67-79%). Respective cure rates for second-line (223 patients), third-line (342 patients) and fourth/fifth-line (95 patients) rifabutin therapies were 79% (67-92%), 66% (55-77%) and 70% (60-79%) respectively. For treating H. pylori infection, almost all studies have administered rifabutin 300 mg/day; this dose seems to be more effective than 150 mg/day. The ideal length of treatment remains unclear, but 10- to 12-day regimens are generally recommended. The mean rate of adverse effects was 22% (19-25%). Myelotoxicity is the most significant, although this complication was rare. Until now, all patients have recovered of leucopenia uneventfully in a few days, and there have been no reports of infection or other adverse outcomes related to it.

CONCLUSION

Rifabutin-containing rescue therapy constitutes an encouraging strategy after multiple (usually three) previous eradication failures with key antibiotics such as amoxicillin, clarithromycin, metronidazole, tetracycline and levofloxacin.

Dual therapy trial using esomeprazole and amoxicillin as third-line rescue therapy for Helicobacter pylori infection

BACKGROUND/AIMS

The purpose of this study was to evaluate the efficacy and tolerability of dual therapy consisting of esomeprazole and amoxicillin as a rescue therapy for Helicobacter pylori infection.

METHODS

From December 2009 to August 2010, 21 patients who experienced two consecutive eradication failures were included. They received esomeprazole (40 mg, b.i.d.) and amoxicillin (1,000 mg, b.i.d.) for 14 days as a third eradication regimen. Compliance and side effects were determined from an interview. H. pylori status was evaluated using the (13)C urea breath test at least 6 weeks after treatment.

RESULTS

The mean age of the patients was 59 years and included 52% males. Indications for treatment were functional dyspepsia (61.9%), peptic ulcer disease (28.6%), and gastric adenoma (9.5%). H. pylori was eradicated in 14 of 21 (66.7%) patients. Minor side effects were reported in three of the 21 patients (14.3%). These side effects consisted mainly of nausea and epigastric discomfort.

CONCLUSIONS

A 2-week course of dual therapy failed to show satisfactory results in third-line H. pylori eradication, but it was very safe and tolerable. Therefore, dual therapy constitutes an encouraging empirical strategy for the elderly and infirm patients with multiple previous eradication failures.

The evolution of Helicobacter pylori antibiotics resistance over 10 years in Beijing, China

OBJECTIVES

To evaluate Helicobacter pylori antibiotics resistance evolution from 2000 to 2009 to amoxicillin, clarithromycin, metronidazole, tetracycline, levofloxacin and moxifloxacin in Beijing, China.

METHODS

A total of 374 H. pylori strains isolated from 374 subjects who had undergone upper gastrointestinal endoscopy from 2000 to 2009 were collected and examined by E-test method for antibiotics susceptibility.

RESULTS

The average antibiotics resistance rates were 0.3% (amoxicillin), 37.2% (clarithromycin), 63.9% (metronidazole), 1.2% (tetracycline), 50.3% (levofloxacin) and 61.9% (moxifloxacin). Overall resistance to clarithromycin, metronidazole, and fluoroquinolone increased annually (from 14.8 to 65.4%, 38.9 to 78.8%, and 27.1 to 63.5%, in 2000 or 2006-2007 to 2009, respectively). The secondary resistance rates were much higher than primary rates to these antibiotics, which also increased annually in recent 10 years.

CONCLUSIONS

The trend of clarithromycin, metronidazole, and fluoroquinolone resistance of H. pylori increased over time and the resistance to amoxicillin and tetracycline was infrequent and stable in Beijing. Clarithromycin, metronidazole, and fluoroquinolone should be used with caution for H. pylori eradication treatment.

Second-line rescue therapy of helicobacter pylori infection

Helicobacter pylori infection is the main known cause of gastritis, gastroduodenal ulcer disease and gastric cancer. After more than 20 years of experience in H. pylori treatment, however, the ideal regimen to treat this infection has still to be found. Nowadays, apart from having to know well first-line eradication regimens, we must also be prepared to face treatment failures. Therefore, in designing a treatment strategy we should not focus on the results of primary therapy alone, but also on the final (overall) eradication rate. The choice of a 'rescue' treatment depends on which treatment is used initially. If a first-line clarithromycin-based regimen was used, a second-line metronidazole-based treatment (quadruple therapy) may be used afterwards, and then a levofloxacin-based combination would be a third-line 'rescue' option. Alternatively, it has recently been suggested that levofloxacin-based 'rescue' therapy constitutes an encouraging second-line strategy, representing an alternative to quadruple therapy in patients with previous PPI-clarithromycin-amoxicillin failure, with the advantage of efficacy, simplicity and safety. In this case, quadruple regimen may be reserved as a third-line 'rescue' option. Finally, rifabutin-based 'rescue' therapy constitutes an encouraging empirical fourth-line strategy after multiple previous eradication failures with key antibiotics such as amoxicillin, clarithromycin, metronidazole, tetracycline, and levofloxacin. Even after two consecutive failures, several studies have demonstrated that H. pylori eradication can finally be achieved in almost all patients if several 'rescue' therapies are consecutively given. Therefore, the attitude in H. pylori eradication therapy failure, even after two or more unsuccessful attempts, should be to fight and not to surrender.

Second-line levofloxacin-based triple schemes for Helicobacter pylori eradication

BACKGROUND

The recommended second-line therapy for Helicobacter pylori (H. pylori) eradication is a quadruple regimen that fails in up to 30% of patients. Several recent studies suggest levofloxacin-based triple therapies as an alternative rescue treatment. However, dosage and length of levofloxacin-based regimens have not been established.

AIM

To compare the efficacy and tolerability of four second-line levofloxacin-based schemes for H. pylori eradication.

METHODS

One hundred and sixty patients (aged 18-70 years, 72 male patients) who were H. pylori positive after standard triple therapies were randomised to receive esomeprazole 20mg b.d. and amoxicillin 1g b.d. plus levofloxacin 500 mg o.d., for 7 or 10 days (Groups A and B) or levofloxacin 500 mg b.d. for 7 days or 10 days (Groups C and D). H. pylori status was assessed by 13-C Urea Breath Test or rapid urease test, before and 6 weeks after therapy. Incidence of side effects was evaluated by a questionnaire.

RESULTS

No dropouts were observed. Eradication of H. pylori infection was successful in: 65% of patients in Group A; 90% in Group B; 70% in Group C; 85% in Group D. Based upon duration of treatment, eradication rates were: 67.5% in 7 days groups and 87.5% in 10 days groups (p=0.004). Dosage of levofloxacin did not affect the eradication rates (77.5% both in the once daily and twice daily groups). Mild adverse events were reported overall in 16% of patients (22.5% in 7 days groups; 27.5% in 10 days groups; p=0.58; 12% in the once daily group; 32.5% in the twice daily group; p=0.04).

CONCLUSIONS

10 days levofloxacin-based second-line regimens were effective in curing H. pylori infection in more than 85% of patients with a lower incidence of adverse effects in levofloxacin single-dosage scheme. The 10 days levofloxacin-based regimens were more effective than 7 days course of treatment showing that duration of therapy is the crucial factor affecting eradication rate.

Meta-analysis: the effect of supplementation with lactoferrin on eradication rates and adverse events during Helicobacter pylori eradication therapy

BACKGROUND

Recent evidence shown that lactoferrin could exert an antimicrobial effect against Helicobacter pylori both in vitro and in vivo models. To systematically evaluate whether adding lactoferrin to H. pylori eradication regimens could improve eradication rates and reduce side-effects during anti-H. pylori treatment.

MATERIALS AND METHODS

Eligible articles were identified by searches of electronic databases. We included all randomized trials comparing lactoferrin supplementation to placebo or no treatment during anti-H. pylori regimens. Statistical analysis was performed with Review Manager 5.0.10. Subanalysis/Sensitivity analysis was also performed.

RESULTS

We identified nine randomized trials (n = 1343). Pooled H. pylori eradication rates were 86.57% (95% confidence interval (CI) = 83.99-89.15%) and 74.44% (95% CI = 71.14-77.74%) for patients with or without lactoferrin by intention-to-treat analysis, respectively, the odds ratio (OR) was 2.26 (95% CI = 1.70-3.00); the occurrence of total side-effects was 9.05% (95% CI = 6.83-11.27%) and 16.28% (95% CI = 13.43%-19.13%) for groups with or without lactoferrin, especially for nausea, the summary OR was 0.15 (95% CI = 0.04-0.54).

CONCLUSIONS

Our review suggests that supplementation with lactoferrin could be effective in increasing eradication rates of anti-H. pylori therapy, and could be considered helpful for patients with eradication failure. Furthermore, lactoferrin shows a positive impact on H. pylori therapy-related side-effects.

“Rescue” regimens after Helicobacter pylori treatment failure

Helicobacter pylori (H pylori) infection is the main cause of gastritis, gastroduodenal ulcer disease, and gastric cancer. After more than 20 years of experience in H pylori treatment, in my opinion, the ideal regimen to treat this infection is still to be found. Currently, apart from having to know first-line eradication regimens well, we must also be prepared to face treatment failures. Therefore, in designing a treatment strategy we should not focus on the results of primary therapy alone, but also on the final (overall) eradication rate. The choice of a “rescue” treatment depends on which treatment is used initially. If a clarithromycin-based regimen was used initially, a subsequent metronidazole-based treatment (quadruple therapy) may be used afterwards, and then a levofloxacin-based combination would be a third “rescue” option. Alternatively, it has recently been suggested that levofloxacin-based rescue therapy constitutes an encouraging second-line strategy, representing an alternative to quadruple therapy in patients with previous PPI-clarithromycin-amoxicillin failure, with the advantage of efficacy, simplicity and safety. In this case, a quadruple regimen may be reserved as a third-line rescue option. Finally, rifabutin-based rescue therapy constitutes an encouraging empirical fourth-line strategy after multiple previous eradication failures with key antibiotics such as amoxicillin, clarithromycin, metronidazole, tetracycline, and levofloxacin. Even after two consecutive failures, several studies have demonstrated that H pylori eradication can finally be achieved in almost all patients if several rescue therapies are consecutively given. Therefore, the attitude in H pylori eradication therapy failure, even after two or more unsuccessful attempts, should be to fight and not to surrender.

Empirical rescue therapy after Helicobacter pylori treatment failure: a 10-year single-centre study of 500 patients

BACKGROUND

Several 'rescue' therapies have been recommended to eradicate Helicobacter pylori, but they still fail in >20% of the cases, and these patients constitute a therapeutic dilemma.

AIM

To evaluate the efficacy of different 'rescue' therapies empirically prescribed during 10 years to 500 patients in whom at least one eradication regimen had failed to cure H. pylori infection.

DESIGN

Prospective single-centre study.

PATIENTS

Consecutive patients in whom at least one eradication regimen had failed.

INTERVENTION

Rescue regimens included: (i) quadruple therapy with omeprazole-bismuth-tetracycline-metronidazole; (ii) ranitidine bismuth citrate-tetracycline-metronidazole; (iii) omeprazole-amoxicillin-levofloxacin; and (iv) omeprazole-amoxicillin-rifabutin. Antibiotic susceptibility was unknown (rescue regimens were chosen empirically).

OUTCOME

Eradication was defined as a negative (13)C-urea breath test 4-8 weeks after completing therapy.

RESULTS

Five hundred patients were included (76% functional dyspepsia, 24% peptic ulcer). Compliance rates with first-, second- and third-line regimens were 92%, 92%, and 95%, respectively. Adverse effects were reported by 30%, 37%, and 55% of the patients receiving second-, third-, and fourth-line regimens. Overall, H. pylori cure rates with the second-, third-, and fourth-line rescue regimens were 70%, 74%, and 76%, respectively. Cumulative H. pylori eradication rate with four successive treatments was 99.5%.

CONCLUSION

It is possible to construct an overall treatment strategy to maximize H. pylori eradication, on the basis of administration of four consecutive empirical regimens; thus, performing bacterial culture even after a second or third eradication failure may not be necessary.

Rational prescription of drugs within similar therapeutic or structural class for gastrointestinal disease treatment: Drug metabolism and its related interactions

AIM: To review and summarize drug metabolism and its related interactions in prescribing drugs within the similar therapeutic or structural class for gastrointestinal disease treatment so as to promote rational use of medicines in clinical practice.

METHODS: Relevant literature was identified by performing MEDLINE/Pubmed searches covering the period from 1988 to 2006.

RESULTS: Seven classes of drugs were chosen, including gastric proton pump inhibitors, histamine H₂-receptor antagonists, benzamide-type gastroprokinetic agents, selective 5-HT₃ receptor antagonists, fluoroquinolones, macrolide antibiotics and azole antifungals. They showed significant differences in metabolic profile (i.e., the fraction of drug metabolized by cytochrome P450 (CYP), CYP reaction phenotype, impact of CYP genotype on interindividual pharmacokinetics variability and CYP-mediated drug-drug interaction potential). Many events of severe adverse drug reactions and treatment failures were closely related to the ignorance of the above issues.

CONCLUSION: Clinicians should acquaint themselves with what kind of drug has less interpatient variability in clearance and whether to perform CYP genotyping prior to initiation of therapy. The relevant CYP knowledge helps clinicians to enhance the management of patients with gastrointestinal disease who may require treatment with polytherapeutic regimens.

Efficacy of rifabutin-based triple therapy in Helicobacter pylori infected patients after two standard treatments

BACKGROUND AND AIM

Even with the current most effective treatment regimens for Helicobacter pylori infection, a considerable number of patients will be resistant to eradication. The aim of the present study was to evaluate the H. pylori eradication rate in patients resistant to standard therapies when treated with a triple therapy of pantoprazole, rifabutin and amoxicillin.

METHODS

Ninety-two consecutive patients diagnosed with H. pylori infection resistant to two previous treatment regimens were treated with pantoprazole, rifabutin and amoxicillin for 10 days. The persistence or eradication of H. pylori was determined by a 13C-urea breath test performed 4 weeks after the treatment.

RESULTS

Per protocol eradication was achieved in 62.2% of patients and the intention-to-treat eradication was 60.8%. Only two patients were excluded for adverse events related to the treatment.

CONCLUSIONS

The eradication rate is acceptable as a third-line therapy, particularly in centers with high cure rate for first line therapy. Another important value of this study is the good tolerance for the treatment observed in our patients. It is possible that rifabutin-based triple therapy may be of use in hospital centers that do not have disposable culture and susceptibility methods against H. pylori.

Role of the preliminary susceptibility testing for initial and after failed therapy of Helicobacter pylori infection with levofloxacin, amoxicillin, and esomeprazole

BACKGROUND

Levofloxacin has been proposed as an alternative to classic therapy in secondary resistance to Helicobacter pylori.

AIM

To evaluate primary and secondary resistance of H. pylori to levofloxacin, and to test the role of susceptibility test on the efficacy of levofloxacin-based triple therapy.

METHODS

Eighty consecutive dyspeptic patients with positive (13)C-urea breath test never treated were randomly allocated into group A(1) (40 patients) and group B(1) (39 patients). Eighty-three patients already treated unsuccessfully with positive (13)C-urea breath test were divided into group A(2) (51 patients) and group B(2) (32 patients). Patients in group A(1) and group A(2) underwent upper gastrointestinal endoscopy for H. pylori susceptibility test to amoxicillin, clarithromycin, tinidazole, rifabutin, and levofloxacin. These patients were treated with levofloxacin (500 mg b.i.d.), amoxicillin (1 g b.i.d.) and esomeprazole (20 mg b.i.d.) for 10 days if sensitive to these two antibiotics. If H. pylori was found resistant to amoxicillin and/or levofloxacin the treatment was based on the indications of the susceptibility test. Patients in group B(1) and group B(2) were treated empirically with levofloxacin, amoxicillin, and esomeprazole at the same dose and duration as group A. All patients underwent (13)C-urea breath test 2 months after the end of therapy.

RESULTS

The antibiotic resistance of H. pylori strains in group A(1) and group A(2) was (%): amoxicillin: 2.4, 10; clarithromycin: 21.9, 43.1; tinidazole: 31.7, 70; rifabutin: 2.4, 4; and levofloxacin: 9.7, 12.2, respectively. In group A(1) with susceptibility test-driven therapy, eradication was 97.2%, and in group B(1) with empirical treatment, 94.1% (n.s.). In group A(2) with susceptibility test, eradication was 97.5%, whereas in group B(2) with empirical treatment 81.2% (p < .01).

CONCLUSION

Primary and secondary resistance of H. pylori to levofloxacin is approximately 10% of the tested strains. The susceptibility test does not influence therapeutic outcome of triple therapy with amoxicillin and levofloxacin in patients never treated, while it is determinant for patients who were previously treated without success.

Bovine lactoferrin for Helicobacter pylori eradication: an open, randomized, multicentre study

BACKGROUND

Cure rates for eradication of Helicobacter pylori appear to be decreasing, thus more effective therapies must be identified.

AIM

To evaluate the efficacy of bovine lactoferrin in the treatment of H. pylori infection.

METHODS

In a multicentered prospective study, 402 (mean age 52.4, range 19-84 years) H. pylori-positive patients were assigned to one of three regimens: group A - esomeprazole 20 mg b.d., clarithromycin 500 mg b.d. and tinidazole 500 mg b.d. for 7 days; group B - lactoferrin 200 mg b.d. for 7 days followed by the same schedule of group A; group C - esomeprazole 20 mg b.d., clarithromycin 500 mg b.d. and tinidazole 500 mg b.d. plus lactoferrin 200 mg b.d. for 7 days.

RESULTS

Of the 402 patients, 389 completed the study. Six patients were discontinued due to side effects, one patient in group B died and six patients were lost to follow up. The eradication rate (intention-to-treat analysis) was 77% in group A (105/136), 73% in group B (97/132) and 90% in group C (120/134) (chi(2)-test P < 0.01). The incidence of side effects was 9.5% in group A, 9% in group B and 8.2% in group C (chi(2)-test P = 0.1).

CONCLUSION

This study demonstrates that bovine lactoferrin is an effective adjuvant to 7-day triple therapy for eradication of H. pylori infection.

Helicobacter pylori "rescue" therapy after failure of two eradication treatments

Nowadays, apart from having to know well first-line eradication regimens, we must also be prepared to face Helicobacter pylori treatment failures. Therefore, in designing a treatment strategy we should not focus on the results of primary therapy alone, but also on the final--overall--eradication rate. After failure of a combination of proton pump inhibitor (PPI), amoxicillin, and clarithromycin, the use of empirical quadruple therapy (PPI-bismuth-tetracycline-metronidazole), has been generally used as the optimal second-line therapy. Even after two consecutive failures, several studies have demonstrated that H. pylori eradication can finally be achieved in almost all patients if several "rescue" therapies are consecutively given. It seems that performing culture even after a second eradication failure may not be necessary, as it is possible to construct an overall strategy to maximize H. pylori eradication, based on the different possibilities of empirical treatment (when antibiotic susceptibilities are unknown). Thus, if one does not want to perform culture before the administration of the third treatment after failure of the first two, different empirical treatments exist, including regimens based on: 1, amoxicillin (amoxicillin-PPI at high doses); 2, amoxicillin plus tetracycline (PPI-bismuth-tetracycline-amoxicillin, or ranitidine-bismuth-citrate-tetracyline-amoxicillin); 3, rifabutin (rifabutin-amoxicillin-PPI); 4, levofloxacin (levofloxacin-amoxicillin-PPI); and 5, furazolidone (furazolidone-bismuth-tetracycline-PPI).

A 10-day levofloxacin-based triple therapy in patients who have failed two eradication courses

BACKGROUND

A standard third-line treatment is lacking, and European guidelines recommend performing culture in these patients. However, the use of this procedure as 'routine practice' is definitively not feasible.

AIM

To evaluate the eradication rate of a 10-day levofloxacin-based triple therapy in patients who have failed two eradication courses for Helicobacter pylori.

METHODS

A total of 151 patients with persistent Helicobacter pylori infection after two treatments were studied. Patients were considered positive if two of three endoscopic tests were positive. Susceptibility testing was also performed. Patients received a standard dose of proton-pump inhibitors twice daily, levofloxacin 250 mg twice daily and amoxicillin 1 g twice daily, for 10 days. Endoscopic follow-up was carried out 4-6 weeks after the end of eradication therapy.

RESULTS

About 76% (95% CI: 68.8-82.3), and 85% (95% CI: 77.5-89.7) of patients were eradicated according to intention-to-treat and per-protocol analysis, respectively. Eradication rates of the strains showed as 92% (95% CI: 83.2-96.7) of those resistant to both metronidazole and clarithromycin but susceptible to levofloxacin.

CONCLUSIONS

In patients who failed previous regimens, the 10-day levofloxacin-based triple therapy is safe and effective, allowing eradication in almost 80% of the patients.

Treatment of Helicobacter pylori in Pediatrics

Helicobacter pylori (H. pylori) is among the most common bacterial infections in humans. In 1982, H. pylori was discovered by Marshal and Warren, demonstrating an association between H. pylori and ulcer disease. H. pylori is a gram-negative, S-shaped rod that produces enzymes like urease, catalase and oxidase. The mechanism of acquisition and transmission of H. pylori is unclear, although the most likely mode of transmission is fecal-oral and oral-oral. The mode of transmission is supported by studies that demonstrate viable H. pylori organisms can be cultured from the stool or vomitus of infected patients. Risk factors such as minimal education and low socio-economic status during childhood affect the prevalence. Children infected with H. pylori develop histologic chronic active gastritis despite the fact that they are generally asymptomatic. A small percentage of these children will go on to develop peptic ulcer disease, and even gastric cancer. In contrast, the association of abdominal pain and H. pylori infection remains controversial. In the year 2000, the North American Society of Pediatric Gastroenterology guidelines on H. pylori reported that there is no evidence demonstrating a link between H. pylori-associated gastritis and abdominal pain, except in rare cases in which gastric or duodenal ulcer disease is present. Currently, treatment with a combination of two antimicrobial agents in conjunction with a proton pump inhibitor (PPI) continues to be recommended for the treatment of H. pylori associated peptic ulcer disease.

Trends in peptic ulcer pharmacotherapy

Considering the diseases of the stomach and duodenum, peptic ulcer has been the one with a significant clinical impact. The pathophysiology of peptic ulcer has centred on an imbalance between aggressive and protective factors. The discovery of Helicobacter pylori as a cause of peptic ulcer has changed our approach greatly towards this disease. Despite the decreasing frequency of H. pylori-induced peptic ulcers, peptic ulcer remains a major clinical problem partly because nonsteroidal anti-inflammatory drug (NSAID)-related ulcers and hospital admissions for ulcer complications associated with NSAIDs have increased in frequency. The interaction between H. pylori and NSAIDs is one of the most controversial issues in peptic ulcer. In this article, current concepts of peptic ulcer etiopathogenesis and the management of peptic ulcer according to the etiology were reviewed.

Empirical Helicobacter pylori "rescue" therapy after failure of two eradication treatments

AIM

Even with the current most effective Helicobacter pylori treatment regimens, approximately 20% of patients do not eradicate the infection. Several "rescue" therapies have been recommended, but they still fail to eradicate H. pylori in approximately 20-30% of the cases. Our aim was to evaluate the efficacy of different rescue therapies prescribed to patients in whom two consecutive H. pylori eradication regimens had failed.

METHODS

Design. Prospective single-centre study. Patients. Consecutive patients in whom two eradication regimens had failed to eradicate H. pylori. Intervention. Third eradication regimens included: (1) omeprazole-amoxicillin-clarithromycin for 7 days; (2) quadruple therapy with omeprazole-bismuth-tetracycline-metronidazole for 7 days; (3) omeprazole-amoxicillin-clarithromycin-bismuth for 14 days; and (4) omeprazole-amoxicillin-rifabutin for 14 days. H. pylori antibiotic susceptibility was unknown and, therefore, rescue regimens were chosen empirically. In no case, was the same regimen repeated. Outcome. H. pylori eradication was defined as a negative in 13C-urea breath test 8 weeks after completing the therapy.

RESULTS

Forty-eight patients were included (mean age 45 years, 44% males, 82% with peptic ulcer and 18% with functional dyspepsia). No patient was lost from follow-up. Adverse effects were described in 21% of the patients. One patient receiving omeprazole, amoxicillin and rifabutin was removed from medication due to adverse effects (vomiting). Overall, mean H. pylori eradication with third therapy after failure of two eradication treatments was 34/48 (71%; 95% confidence interval 57-82%) by intention-to-treat and 34/47 (72%; 95% confidence interval 58-83%) by per-protocol.

CONCLUSION

It seems that performing culture even after a second eradication failure may not be necessary, as it is possible to construct an overall strategy to maximise H. pylori eradication, based on the different possibilities of empirical treatment.

'Rescue' therapy with rifabutin after multiple Helicobacter pylori treatment failures

AIM

Eradication therapy with proton pump inhibitor, clarithromycin and amoxicillin is extensively used, although it fails in a considerable number of cases. A 'rescue' therapy with a quadruple combination of omeprazole, bismuth, tetracycline and metronidazole (or ranitidine bismuth citrate with these same antibiotics) has been recommended, but it still fails in approximately 20% of cases. Our aim was to evaluate the efficacy and tolerability of a rifabutin-based regimen in patients with two consecutive H. pylori eradication failures.

DESIGN

Prospective multicenter study.

PATIENTS

Consecutive patients in whom a first eradication trial with omeprazole, clarithromycin and amoxicillin and a second trial with omeprazole, bismuth, tetracycline and metronidazole (three patients) or ranitidine bismuth citrate with these same antibiotics (11 patients) had failed were included.

INTERVENTION

A third eradication regimen with rifabutin (150 mg bid), amoxicillin (1 g bid) and omeprazole (20 mg bid) was prescribed for 14 days. All drugs were administered together after breakfast and dinner. Compliance with therapy was determined from the interrogatory and the recovery of empty envelopes of medications.

OUTCOME

H. pylori eradication was defined as a negative 13C-urea breath test 8 weeks after completing therapy.

RESULTS

Fourteen patients have been included. Mean age +/- SD was 42 +/- 11 years, 41% males, peptic ulcer (57%), functional dyspepsia (43%). All patients took all the medications and completed the study protocol. Per-protocol and intention-to-treat eradication was achieved in 11/14 patients (79%; 95% confidence interval = 49-95%). Adverse effects were reported in five patients (36%), and included: abdominal pain (three patients), nausea and vomiting (one patient), and oral candidiasis (one patient); no patient abandoned the treatment due to adverse effects.

CONCLUSION

Rifabutin-based rescue therapy constitutes an encouraging strategy after multiple previous eradication failures with key antibiotics such as amoxicillin, clarithromycin, metronidazole and tetracycline.

Evaluation of the string test for the detection of Helicobacter pylori

AIM: Helicobacter pylori can be diagnosed by invasive or non-invasive tests but to obtain bacteria for culture and antibiotic susceptibility testing, an upper GI endoscopy is often required. The string test may be a minimally-invasive alternative method of obtaining H. pylori samples. This study evaluates the sensitivity and specificity of the string test in the diagnosis of H. pylori in comparison with endoscopic means of diagnosis.

METHODS: This was a prospective open comparative study of patients with dyspepsia with endoscopy-based tests as gold standard (defined as a positive CLO test and antral histology). Fasting patients swallowed the encapsulated-string (Entero-test Hp), which was withdrawn after 1 h. The gastric juice from the string was plated onto H. pylori-selective media for culture. Helicobacter pylori was identified by typical colony morphology, gram stain and biochemical test results.

RESULTS: Thirty dyspeptic patients were recruited of whom 21 (70%) were positive for H. pylori according to the gold standard. The sensitivity, specificity, positive predictive value, and negative predictive value for the string test were 38%, 100%, 100% and 41% respectively, and for endoscopic biopsies 81%, 100%, 100%, 69% respectively (P = 0.004). Logistic regression showed that only abundant growth density from endoscopic biopsy cultures to be a predictor of a positive string test (P = 0.018).

CONCLUSION: The string test is an alternative method to endoscopy in obtaining H. pylori but has a low sensitivity compared to endoscopic biopsies.

Alternative and rescue treatment regimens for Helicobacter pylori eradication

Eradication therapy has been incorporated into clinical practice. The regimens currently recommended for first-line treatment include a 2-week bismuth-based triple therapy (mainly in developing countries), a 1 - 2 week proton pump inhibitor (PPI)-based triple therapy and a 1-week ranitidine bismuth citrate (RBC)-based triple therapy. However, these regimens fail to eradicate Helicobacter pylori in up to 20% of patients due to poor compliance, inadequate treatment duration, smoking, old age and bacterial resistance to nitroimidazoles and/or macrolides in particular. Therefore, alternative regimens that avoid nitroimidazoles and/or macrolides or overcome bacterial resistance to these drugs, improve compliance, minimise side effects and/or reduce costs have been evaluated. One-week quadruple therapy, which adds a PPI or histamine receptor 2-blocker to bismuth-based triple therapy, usually achieves an eradication rate of 90% when used as an alternative first-line therapy but the efficacy decreases when used as a rescue therapy. Several new triple therapies that may be used as alternative and/or rescue therapies have been evaluated. Among these are furazolidone-based (furazolidone plus an antibiotic and a bismuth salt, a PPI or RBC), fluoroquinolone-based (levofloxacin or moxifloxacin plus an antibiotic and a PPI) and ecabet sodium-based (ecabet plus two antibiotics) triple therapies. Recently, rifabutin has been used in combination with a PPI and amoxycillin as a rescue therapy, with satisfactory eradication rates. In addition, a number of new antimicrobial agents are currently under investigation in in vitro studies but the clinical values of these agents needs to be confirmed.

Omeprazole, furazolidone, and tetracycline: an eradication treatment for resistant H. pylori in Brazilian patients with peptic ulcer disease

OBJECTIVES

To determine the efficacy of a simple, short-term and low-cost eradication treatment for Helicobacter pylori (H. pylori) using omeprazole, tetracycline, and furazolidone in a Brazilian peptic ulcer population, divided into 2 subgroups: untreated and previously treated for the infection.

PATIENTS AND METHODS

Patients with peptic ulcer disease diagnosed by endoscopic examination and infected by H. pylori diagnosed by the rapid urease test (RUT) and histological examination, untreated and previously unsuccessfully treated by macrolides and nitroimidazole, were medicated with omeprazole 20 mg daily dose and tetracycline 500 mg and furazolidone 200 mg given 3 times a day for 7 days. Another endoscopy or a breath test was performed 12 weeks after the end of treatment. Patients were considered cured of the infection if a RUT and histologic examination proved negative or a breath test was negative for the bacterium.

RESULTS

Sixty-four patients were included in the study. The women were the predominant sex (58%); the mean age was 46 years. Thirty-three percent of the patients were tobacco users, and duodenal ulcer was identified in 80% of patients. For the 59 patients that underwent follow-up examinations, eradication was verified in 44 (75%). The eradication rate for the intention-to-treat group was 69%. The incidence of severe adverse effects was 15%.

CONCLUSION

The treatment provides good efficacy for H. pylori eradication in patients who were previously treated without success, but it causes severe adverse effects that prevented adequate use of the medications in 15% of the patients.

Review article: Helicobacter pylori "rescue" regimen when proton pump inhibitor-based triple therapies fail

Even with the currently most effective treatment regimens, about 10-20% of patients will fail to obtain eradication of Helicobacter pylori infection. Therefore, in designing a treatment strategy, we should not focus on the results of primary therapy alone, but also on the final (overall) eradication rate. The choice of second-line treatment depends on which treatment was used initially, as re-treatment with the same regimen is not recommended. Therefore, it is not necessary to perform culture after the first eradication failure. Assessment of the sensitivity of H. pylori to antibiotics only after failure of the second treatment is suggested in clinical practice. Different possibilities of empirical treatment have been suggested. After failure of proton pump inhibitor-amoxicillin-clarithromycin, quadruple therapy has generally been used. More recently, replacement of the proton pump inhibitor and the bismuth compound by ranitidine bismuth citrate has also achieved good results. After proton pump inhibitor-amoxicillin-nitroimidazole failure, re-treatment with proton pump inhibitor-amoxicillin-clarithromycin has been proven to be effective. Finally, first-line treatment should not combine clarithromycin and metronidazole in the same regimen, because of the problem of resistance to both antibiotics. Recently, rifabutin-based rescue therapies have been shown to constitute an encouraging strategy for eradication failures, as they are effective against H. pylori strains resistant to antibiotics.

Rescue Therapy for Helicobacter pylori

Up to 35% of patients infected with Helicobacter pylori fail to respond to standard anti-H. pylori therapy. With the rising prevalence antimicrobial resistance, the failure rates of conventional proton pump inhibitor-containing triple therapy are expected to increase. Pretreatment antibiotic resistance testing should be done whenever possible to allow for tailoring of the treatment regimens. The data on second-line or rescue therapy are limited and usually are subjected to various biases and confounding factors. Switching between clarithromycin and metronidazole should be considered if repeated courses of proton pump inhibitor-containing triple therapy are used as second-line therapy in the absence of antimicrobial sensitivity testing. The prolongation of therapy duration with proton pump inhibitor, amoxicillin, and clarithromycin is ineffective for clarithromycin-resistant strains. The bismuth-containing quadruple therapy is the best salvage treatment in the absence of pretreatment antibiotic susceptibility. Furazolidone quadruple therapy (where available) and rifabutin triple therapy are salvage therapies of last resort. If these regimens fail, culture and susceptibility testing is required.