Meta-analysis: four-drug, three-antibiotic, non-bismuth-containing "concomitant therapy" versus triple therapy for Helicobacter pylori eradication

Role of Helicobacter pylori infection in gastric carcinogenesis: Current knowledge and future directions

Helicobacter pylori (H. pylori) plays a role in the pathogenesis of gastric cancer. The outcome of the infection depends on environmental factors and bacterial and host characteristics. Gastric carcinogenesis is a multistep process that is reversible in the early phase of mucosal damage, but the exact point of no return has not been identified. Therefore, two main therapeutic strategies could reduce gastric cancer incidence: (1) eradication of the already present infection; and (2) immunization (prior to or during the course of the infection). The success of a gastric cancer prevention strategy depends on timing because the prevention strategy must be introduced before the point of no return in gastric carcinogenesis. Although the exact point of no return has not been identified, infection should be eradicated before severe atrophy of the gastric mucosa develops. Eradication therapy rates remain suboptimal due to increasing H. pylori resistance to antibiotics and patient noncompliance. Vaccination against H. pylori would reduce the cost of eradication therapies and lower gastric cancer incidence. A vaccine against H. pylori is still a research challenge. An effective vaccine should have an adequate route of delivery, appropriate bacterial antigens and effective and safe adjuvants. Future research should focus on the development of rescue eradication therapy protocols until an efficacious vaccine against the bacterium becomes available.

Current Helicobacter pylori treatment in 2014

Helicobacter pylori is one of the most commonly seen bacterium worldwide. It’s in the etiology of multiple gastrointestinal diseases, ranging from gastritis to gastric carcinoma. The antimicrobial therapies, which are frequently prescribed empirically, are losing their effectivity as a result of the increasing antimicrobial resistance. As the standard triple therapy is now left especially in areas with high-clarithromycin resistance due to decreased eradication rates, quadruple therapies are recommended in most regions of the world. Alternatively, concomitant, sequential and hybrid therapies are used. There is still a debate going on about the use of levofloxacin-based therapy in order to prevent the increase in quinolone resistance. If no regimen can achieve the desired eradication rate, culture-guided individualized therapies are highly recommended. Probiotics, statins and n-acetylcysteine are helpful as adjuvant therapies in order to increase the effectiveness of the eradication therapy. Herein, we focused on different eradication regimens in order to highlight the current Helicobacter pylori treatment.

Optimizing clarithromycin-containing therapy for Helicobacter pylori in the era of antibiotic resistance

The efficacy of triple therapy for Helicobacter pylori infection has dramatically declined over the last decade, largely related to increasing clarithromycin resistance rates. From a microbiological standpoint, bismuth quadruple therapy is the ideal replacement since it combines drugs for which resistance does not impair its efficacy. Nonetheless, several obstacles such as availability, complexity or tolerance prevent a general implementation of bismuth quadruple therapy, so non-bismuth quadruple regimens remain the best first-line treatment in clinical practice in many geographical areas. We review the rationale and efficacy of several optimization tools (increasing the length of duration, high-dose acid suppression, probiotics), which have been largely evaluated over the last 5 years to increase the effectiveness of standard triple therapy. Then, we update available evidence on the effectiveness of several non-bismuth quadruple therapies (sequential, concomitant, hybrid, miscellaneous therapy), which have gained interest lately. We also revise evidence on the efficacy of the aforementioned optimization tools for non-bismuth quadruples schemes and, finally we provide a novel regionalized therapeutic algorithm, based on novel formulas recently developed for predicting the outcome of non-bismuth quadruple regimens, upon local antibiotic resistance rates.