Pre-treatment with proton pump inhibitors decreases the success of primary Helicobacter pylori eradication using a vonoprazan-based regimen

The influence of pretreatment with PPI on Helicobacter pylori eradication: A systematic review and meta-analysis

BACKGROUND

In this meta-analysis, we aimed to comprehensively investigate the impact of pretreatment with proton pump inhibitor (PPI) on Helicobacter pylori (H. pylori) eradication and provide novel inspiration to clinical practice.

METHODS

Relevant studies were selected through PubMed, Embase, and Cochrane Library from inception to March 2021. Two reviewers performed the selection independently. The primary outcome of the meta-analysis was the eradication rate. A modified Jadad scale was used to evaluate literature quality quantitatively.

RESULTS

Ten studies were included in this research. The results showed no significant difference between PPI pretreatment and standard treatment on eradication of H. pylori [relative risk (RR): 1.17, 95% confidence interval (95% CI): 0.0.73-1.88]. There was no significant difference between the PPI pretreatment group and the standard therapy group for conventional triple therapy, PPI and amoxicillin and clarithromycin (RR: 1.29, 95% CI: 0.60-2.77). Similar results were obtained in the therapy strategy of PPI and amoxicillin and metronidazole (RR: 3.01, 95% CI: 0.62-14.74). Interestingly, for the therapy regimen of PPI and clarithromycin and metronidazole, PPI pretreatment indicated superiority on H. pylori eradication rate (RR: 0.48, 95% CI: 0.23-0.97, P < .05).

CONCLUSION

PPI pretreatment did not affect the H. pylori eradication rates, regardless of the various types of bacteriostatic antibiotic, except the therapy regimen of PPI and clarithromycin and metronidazole.

Is a Potassium-Competitive Acid Blocker Truly Superior to Proton Pump Inhibitors in Terms of Helicobacter pylori Eradication?

Vonoprazan (VPZ), a new potassium-competitive acid blocker, has been approved and used for Helicobacterpylori eradication in Japan. To date, many studies, as well as several systematic reviews and meta-analyses (MAs), have compared VPZ-based 7-day triple therapy with proton pump inhibitor (PPI)-based therapy. An MA of randomized controlled trials (RCTs) comparing first-line VPZ- with PPI-based triple therapy, the latter featuring amoxicillin (AMPC) and clarithromycin (CAM), found that approximately 30% of patients hosted CAM-resistant H. pylori; however, the reliability was poor because of high heterogeneity and a risk of selection bias. VPZ-based triple therapy is superior to PPI-based triple therapy for patients with CAM-resistant H. pylori, but not for those with CAM-susceptible H. pylori. An MA of non-RCTs found that second-line VPZ-based triple therapies were slightly (~2.6%) better than PPI-based triple therapies (with AMPC and metronidazole). However, the reliability of that MA was also low because of selection bias, confounding variables and a risk of publication bias; in addition, it is difficult to generalize the results because of a lack of data on antibiotic resistance. VPZ-based triple therapy (involving AMPC and sitafloxacin) was more effective than PPI-based triple therapy in a third-line setting, but a confirmatory RCT is needed. Non-RCT studies indicated that VPZ-based triple therapy involving CAM and metronidazole may be promising. Any further RCTs must explore the antibiotic-resistance status when evaluating the possible superiority of a potassium-competitive acid blocker.

Impact of body size on first-line Helicobacter pylori eradication success using vonoprazan and amoxicillin dual therapy

BACKGROUND

As a first-line therapy for Helicobacter pylori, dual therapy with vonoprazan and amoxicillin (VA-dual) provides an eradication rate similar to that of vonoprazan-based triple therapy. As the factors associated with the eradication rate of H. pylori with VA-dual are unknown,we investigated them in this study.

MATERIALS AND METHODS

Overall, 163 patients diagnosed with H. pylori infection received VA-dual (vonoprazan 20 mg twice daily and amoxicillin 750 mg twice daily for 7 d). The association between successful H. pylori eradication and the following patient clinical factors was analyzed: sex, age, height, weight, body surface area (BSA), body mass index (BMI), history of early gastric carcinoma and peptic ulcer, comorbidity of cirrhosis, alcohol consumption habit, smoking habit, common use of proton pump inhibitors, and concomitant use of drugs that are substratesof cytochrome P450 (CYP) 3A4. The association between post-eradication adverse events and clinical factors was analyzed retrospectively.

RESULTS

Successful H. pylori eradication was associated with a lower BSA (eradication rate: 90.8% in patients with BSA <1.723 vs. 79.6% in those with BSA ≥1.723; p = 0.045). The incidence of adverse events was higher in women than in men (adverse events: 40.0% in women vs. 19.4% in men; p = 0.004).

CONCLUSIONS

Successful H. pylori eradication with VA-dual was associated with the small body size of patients. This therapy may have to be adjusted per body size.

High Body Mass Index Is Correlated with the Success of Vonoprazan-Based Second-Line Therapy for Helicobacter Pylori Infection

Eradication of Helicobacter pylori (Hp) is necessary for preventing peptic ulcers and stomach cancer. The potassium-competitive acid blocker vonoprazan is a gastric acid secretion inhibitor that improves the success rate of Hp eradication through its immediate and persistent inhibition of acid excretion. In Japan, first-line treatment involves a regimen in which vonoprazan is combined with amoxicillin and clarithromycin, while second-line treatment involves vonoprazan combined with amoxicillin and metronidazole. However, in contrast to the vonoprazan-based first-line therapy, no studies have investigated the factors influencing the success of vonoprazan-based second-line therapy. In this study, we therefore aimed to investigate factors related to the success of vonoprazan-based second-line therapy. We analyzed the association between the success of Hp eradication and patient factors including metronidazole/amoxicillin minimal inhibitory concentrations (MICs). MICs were measured using the Hp isolated from each patient. A receiver operating characteristic (ROC) analysis was conducted to examine continuous variables and eradication success. We reviewed the records of 33 patients (age: 34-79 years, male/female: 22/11, and body mass index (BMI): 16.1-28.8 kg/m²) who underwent vonoprazan-based second-line therapy after failure of first-line therapy at seven Japanese facilities between October 2018 and June 2019. The eradication success rate was 81.8% (27/33). ROC analysis revealed an area under the curve and BMI cutoff value of 0.796 and 23.8 kg/m², respectively. The eradication success rate was higher in patients with high BMI than in those with low BMI (p = 0.007). Our findings indicate that higher BMI is correlated with the success of vonoprazan-based second-line therapy.

Role of Vonoprazan in Helicobacter pylori Eradication Therapy in Japan

Complete eradication of Helicobacter pylori is important for preventing the development of gastric cancer. The outcome of H. pylori eradication therapy is mainly dependent on bacterial susceptibility to antimicrobial agents and potent neutralization of intragastric pH across 24 h, especially when using acid-sensitive antimicrobial agents such as clarithromycin (CLR), amoxicillin and sitafloxacin. However, conventional regimens comprising twice-daily doses (bid) of proton pump inhibitors (PPIs) are generally insufficient for maintaining the required gastric acid secretion for 24 h for successful eradication in all H. pylori-positive patients. Further, the increasing prevalence of CLR-resistant strains with each year has led to a decrease in eradication rates of first-line PPI- and CLR-containing therapies in developed countries, including Japan. In 2015, the potassium-competitive acid blocker vonoprazan (VPZ) became clinically available in Japan. VPZ competitively inhibits H⁺/K⁺-ATPase activity more potently than PPIs (e.g., omeprazole, lansoprazole, rabeprazole, pantoprazole, and esomeprazole). Therefore, a VPZ-containing H. pylori eradication regimen is expected to increase the eradication rate compared with conventional regimens containing a standard dose of PPI. In fact, a recent meta-analysis that investigated the efficacy of first-line eradication therapy showed that a VPZ-containing regimen achieved a higher eradication rate than a PPI-containing regimen. While the Maastricht V/Florence Consensus Report recommends selecting a bismuth or non-bismuth quadruple therapy and concomitant therapy for patients living in areas with high prevalence of CLR resistance, a VPZ-containing regimen demonstrates effectiveness for patients infected with CLR-resistant strains and patients living in areas where the prevalence of CLR-resistant strains is >15%. As a next step, studies are needed to determine the factors affecting the clinical outcome of VPZ-containing therapy and optimal VPZ-containing alternative regimens for tailored treatments. In this review, we summarize the advantages and disadvantages of VPZ in H. pylori eradication therapy.