Empiric therapies for Helicobacter pylori infections

Community prevalence of Helicobacter pylori and dyspepsia and efficacy of triple therapy in a rural district of eastern Uganda

Background

Helicobacter pylori (H. pylori) infection and chronic dyspepsia represent significant medical burdens in the developing world. An accurate assessment of the prevalence of chronic dyspepsia, as well as of the effectiveness of population-based screening and eradication of H. pylori are warranted.

Objectives

We determined the prevalence of H. pylori and chronic dyspepsia within the general adult population in a region of eastern Uganda. Independent predictors of H. pylori infection were assessed. Finally, we evaluated the efficacy of standard triple therapy on H. pylori eradication.

Methods

Of 400 randomly selected adult residents in eastern Uganda, 376 were administered a validated, chronic dyspepsia questionnaire and provided a stool sample for H. pylori testing. H. pylori-positive participants were given standard triple therapy and monitored for medication adherence. The efficacy of triple therapy on H. pylori eradication was determined by fecal antigen testing after treatment. Log-linear and logistic regression analyses identified predictors of H. pylori positivity and eradication failure.

Results

H. pylori prevalence within the study population was 48%. The prevalence of chronic dyspepsia was 87%. The presence or severity of dyspepsia did not predict H. pylori infection. However, a higher level of education was an independent predictor of H. pylori infection. Standard triple therapy resulted in ∼90% eradication. Missing at least four doses of any of the triple therapy medications over the 14-day course predicted eradication failure.

Conclusions

In our study population, chronic dyspepsia did not predict H. pylori infection, though clinical suspicion for this prevalent pathogen should nonetheless remain high. Population-based screening and adherence to triple therapy are effective at eradicating H. pylori within this region.

Persister cells as a possible cause of antibiotic therapy failure in Helicobacter pylori

Background and Aim

Due to the failure of antibiotic treatment and recurrence of infection in patients with Helicobacter pylori, this study was designed to find the possible cause of treatment failure and recurrence of the H. pylori infections in Ilam, Iran.

Methods

One hundred patients with specific symptoms of H. pylori infection were selected, and after taking a biopsy specimen, identification of H. pylori, antibiotic susceptibility assay, and persister cell assay were performed. In addition, after treatment, patients with persister cells were followed for possible recurrence of infection. Furthermore, an antibiotic susceptibility assay was performed.

Results

Our results demonstrated that, among 100 patients, 50% (n = 50) showed positive results for the existence of H. pylori. Among the susceptible isolates, 18% (n = 9) were persister cells that were sensitive to clarithromycin as confirmed by a 5 folds higher than the Minimal Inhibitory Concentration (MIC) of clarithromycin. The data were confirmed by following up the suspected patients.

Conclusion

Our results demonstrated that persister cells in H. pylori infections may be responsible to recurrent infection and antibiotic treatment failure. However, more research is needed to obtain more information in this area.

Houston Consensus Conference on Testing for Helicobacter pylori Infection in the United States

Despite guidelines for detection and treatment of Helicobacter pylori infection, recommendations to test patients before and after therapy are commonly not followed in the United States. At the Houston Consensus Conference, 11 experts on management of adult and pediatric patients with H pylori, from different geographic regions of the United States, met to discuss key factors in diagnosis of H pylori infection, including identification of appropriate patients for testing, effects of antibiotic susceptibility on testing and treatment, appropriate methods for confirmation of infection and eradication, and relevant health system considerations. The experts divided into groups that used a modified Delphi panel approach to assess appropriate patients for testing, testing for antibiotic susceptibility and treatment, and test methods and confirmation of eradication. The quality of evidence and strength of recommendations were evaluated using the GRADE system. The results of the individual workshops were presented for a final consensus vote by all panel members. After the Expert Consensus Development meeting, the conclusions were validated by a separate panel of gastroenterologists, who assessed their level of agreement with each of the 29 statements developed at the Expert Consensus Development. The final recommendations are provided, on the basis of the best available evidence, and provide consensus statements with supporting literature to implement testing for H pylori infection at health care systems across the United States.

Helicobacter pylori eradication rates of concomitant and sequential therapies in Korea

BACKGROUND

The efficacy of the standard triple therapy for Helicobacter pylori eradication has decreased to an unacceptable level. We aimed to compare the efficacy of sequential and concomitant therapies as for the first-line treatments for H. pylori eradication and analyzed the effect of clarithromycin resistance on the eradication rates.

MATERIALS AND METHODS

Four hundred and seventy-eight patients with H. pylori infection were randomly assigned to either concomitant therapy (amoxicillin 1000 mg with clarithromycin 500 mg, metronidazole 500 mg, and pantoprazole 40 mg twice daily for 10 days) or sequential therapy (amoxicillin 1000 mg with pantoprazole 40 mg twice daily for 5 days, followed by clarithromycin 500 mg with metronidazole 500 mg and pantoprazole 40 mg twice daily for 5 days). The success of the eradication was evaluated 4-5 weeks after treatment completion. To evaluate the efficacy of the two regimens according to clarithromycin sensitivity, dual-priming oligonucleotide-based multiplex-polymerase chain reaction was also performed in the final third of the enrolled study populations.

RESULTS

The eradication rates with concomitant or sequential therapy were 81.9% and 76.6% (P = .153) in intention-to-treat analysis, and 93.4% and 84.8% (P = .004) in per-protocol analysis, respectively. Among the 156 patients for whom dual-priming oligonucleotide-based multiplex-polymerase chain reaction was performed, 17.9% were clarithromycin resistant, and the efficacy of concomitant therapy was better than sequential therapy in the clarithromycin-resistant strains (100% vs 58.3%, P = .010).

CONCLUSION

Concomitant therapy was superior to sequential therapy as the first-line treatment for H. pylori eradication, especially in clarithromycin-resistant strains in Korea.

Nitroimidazoles: Molecular Fireworks That Combat a Broad Spectrum of Infectious Diseases

Infectious diseases claim millions of lives every year, but with the advent of drug resistance, therapeutic options to treat infections are inadequate. There is now an urgent need to develop new and effective treatments. Nitroimidazoles are a class of antimicrobial drugs that have remarkable broad spectrum activity against parasites, mycobacteria, and anaerobic Gram-positive and Gram-negative bacteria. While nitroimidazoles were discovered in the 1950s, there has been renewed interest in their therapeutic potential, particularly for the treatment of parasitic infections and tuberculosis. In this review, we summarize different classes of nitroimidazoles that have been described in the literature in the past five years, from approved drugs and clinical candidates to examples undergoing preclinical or early stage development. The relatively "nonspecific" mode of action and resistance mechanisms of nitromidazoles are discussed, and contemporary strategies to facilitate nitroimidazole drug development are highlighted.

Managing Helicobacter pylori in college health, with special considerations for international students

OBJECTIVE

Helicobacter pylori infection is the major cause of dyspepsia, peptic ulcer disease, and gastric cancer. This paper will make specific recommendations for a diagnostic and treatment strategy tailored to the international student population.

PARTICIPANTS/METHODS

This paper is a case report and narrative review based on recent international epidemiologic studies and consensus conference recommendations identified in MEDLINE.

RESULTS

In the nations (mostly Asian) that send the largest number of students to the United States, the prevalence of H. pylori is generally 60% to 80%, whereas the prevalence in the United States is about 25%. The patterns of antibiotic resistance in those countries are also different than that in the general US population.

CONCLUSIONS

Health care providers should have a higher index of suspicion for Helicobacter infection among international students with dyspepsia and need to use a different treatment regimen than is standard for the general US population.

Beyond Maastricht IV: are standard empiric triple therapies for Helicobacter pylori still useful in a South-European country?

Background

Empiric triple treatments for Helicobacter pylori (H. pylori) are increasingly unsuccessful. We evaluated factors associated with failure of these treatments in the central region of Portugal.

Methods

This single-center, prospective study included 154 patients with positive ¹³C-urea breath test (UBT). Patients with no previous H. pylori treatments (Group A, n = 103) received pantoprazole 40 mg 2×/day, amoxicillin 1000 mg 12/12 h and clarithromycin (CLARI) 500 mg 12/12 h, for 14 days. Patients with previous failed treatments (Group B, n = 51) and no history of levofloxacin (LVX) consumption were prescribed pantoprazole 40 mg 2×/day, amoxicillin 1000 mg 12/12 h and LVX 250 mg 12/12 h, for 10 days. H. pylori eradication was assessed by UBT 6–10 weeks after treatment. Compliance and adverse events were assessed by verbal and written questionnaires. Risk factors for eradication failure were determined by multivariate analysis.

Results

Intention-to-treat and per-protocol eradication rates were Group A: 68.9% (95% CI: 59.4–77.1%) and 68.8% (95% CI: 58.9–77.2%); Group B: 52.9% (95% CI: 39.5–66%) and 55.1% (95% CI: 41.3–68.2%), with 43.7% of Group A and 31.4% of Group B reporting adverse events. Main risk factors for failure were H. pylori resistance to CLARI and LVX in Groups A and B, respectively. Another independent risk factor in Group A was history of frequent infections (OR = 4.24; 95% CI 1.04–17.24). For patients with no H. pylori resistance to CLARI, a history of frequent infections (OR = 4.76; 95% CI 1.24–18.27) and active tobacco consumption (OR = 5.25; 95% CI 1.22–22.69) were also associated with eradication failure.

Conclusions

Empiric first and second-line triple treatments have unacceptable eradication rates in the central region of Portugal and cannot be used, according to Maastricht recommendations. Even for cases with no H. pylori resistance to the used antibiotics, results were unacceptable and, at least for CLARI, are influenced by history of frequent infections and tobacco consumption.

A comparison between 15-day sequential, 10-day sequential and proton pump inhibitor-based triple therapy for Helicobacter pylori infection in Korea

OBJECTIVE

The eradication rate of 10-day sequential therapy for Helicobacter pylori (H. pylori) infection was not satisfactory in Korea, probably due to antibiotic resistance. To compare the treatment efficacy of 15-day and 10-day sequential therapy of conventional 7-day proton pump inhibitor (PPI) triple therapy for the treatment of H. pylori infection.

METHODS

A total of 332 patients with H. pylori infection were randomly assigned to receive either 7-day PPI triple therapy, 10-day sequential therapy or 15-day sequential therapy. Eradication rate, drug compliance, and adverse events were compared among the three regimens.

RESULTS

The eradication rates by intention-to-treat analysis were 64.3% (95% CI: 55.5-73.2; 74 of 115 patients), 72.1% (95% CI: 63.6-80.5; 80 of 111 patients), and 80.2% (95% CI: 72.5-87.9; 85 of 106 patients) in the 7-day PPI triple, 10-day and 15-day sequential therapy groups, respectively (p = 0.032). The eradication rates by per-protocol analysis were 68.5% (95% CI: 59.6-77.4; 74 of 108 patients), 78.4% (95% CI: 70.3-86.5; 80 of 102 patients), and 89.5% (95% CI: 83.2-95.8; 85 of 95 patients) in the 7-day PPI triple, 10-day and 15-day sequential therapy groups, respectively (p = 0.001). There were no statistically significant differences between the three eradication therapy groups in regard to drug compliance and adverse events.

CONCLUSION

The 15-day sequential therapy demonstrated improved eradication efficacy compared with 7-day PPI triple and 10-day sequential therapy in Korea.

Rational Helicobacter pylori therapy: evidence-based medicine rather than medicine-based evidence

Data are available such that choice of Helicobacter pylori therapy for an individual patient can be reliably predicted. Here, treatment success is defined as a cure rate of 90% or greater. Treatment outcome in a population or a patient can be calculated based on the effectiveness of a regimen for infections with susceptible and with resistant strains coupled with the knowledge of the prevalence of resistance (ie, based on formal measurement, clinical experience, or both). We provide the formula for predicting outcome and we illustrate the calculations. Because clarithromycin-containing triple therapy and 10-day sequential therapy are now only effective in special populations, they are considered obsolete; neither should continue to be used as empiric therapies (ie, 7- and 14-day triple therapies fail when clarithromycin resistance exceeds 5% and 15%, respectively, and 10-day sequential therapy fails when metronidazole resistance exceeds 20%). Therapy should be individualized based on prior history and whether the patient is in a high-risk group for resistance. The preferred choices for Western countries are 14-day concomitant therapy, 14-day bismuth quadruple therapy, and 14-day hybrid sequential-concomitant therapy. We also provide details regarding the successful use of fluoroquinolone-, rifabutin-, and furazolidone-containing therapies. Finally, we provide recommendations for the efficient development (ie, identification and optimization) of new regimens, as well as how to prevent or minimize failures. The trial-and-error approach for identifying and testing regimens frequently resulted in poor treatment success. The described approach allows outcome to be predicted and should simplify treatment and drug development.

Eradication of Helicobacter pylori infection: Which regimen first?

Helicobacter pylori (H. pylori) is a well-known human pathogen that plays an essential role in the pathogenesis of chronic gastritis, peptic ulcer disease, and gastric malignancies. Although H. pylori is susceptible to several antimicrobials, this infection has proven challenging to cure because of the increasing prevalence of bacterial strains that are resistant to the most commonly used antimicrobials, particularly clarithromycin. An effective (i.e., > 90%) first-line therapy is mandatory for avoiding supplementary treatments and testing, and more importantly for preventing the development of secondary resistance. This study reviews the recent literature on first-line therapies for H. pylori. The eradication rates following standard triple therapy (a proton pump inhibitor plus amoxicillin and clarithromycin) for H. pylori infection are declining worldwide. Several first-line strategies have been proposed to increase the eradication rate, including extending the treatment duration to 14 d, the use of a four-drug regimen (bismuth-containing quadruple, sequential, and concomitant treatments), and the use of novel antibiotics, such as fluoroquinolones. However, the efficacy of these regimens is controversial. A first-line eradication regimen should be based on what works best in a defined geographical area and must take into account the prevalence of antimicrobial resistance in that region.

Helicobacter pylori: usefulness of an empirical fourth-line rifabutin-based regimen

Helicobacter pylori represents the major cause of gastric cancer, gastric lymphoma and peptic ulcer diseases. In some cases, the infection persists even after three rounds of treatment. The evaluated article reports on the efficacy of an empirical multicenter, prospective fourth‑line rescue study with rifabutin in patients with three consecutive eradication failures. A total of 100 patients (31% peptic ulcer and 69% functional dyspepsia) were included to receive a fourth‑line with rifabutin (150 mg twice daily [b.i.d.]), amoxicillin (1 g b.i.d.) and a proton‑pump inhibitor (standard dose b.i.d.) for 10 days. The end point was H. pylori eradication, determined by (13)C-urea breath test 4-8 weeks after therapy. H. pylori eradication was achieved in approximately 50% of patients. Adverse events (mainly metallic taste, nausea and diarrhea) were reported in 30 patients. Thus, a fourth-line rifabutin-based rescue therapy constitutes a valid strategy after multiple previous H. pylori eradication failures with key antibiotics, such as clarithromycin, metronidazole, tetracycline and levofloxacin.