Eradication of <i>Helicobacter pylori</i>: Are Rifaximin-Based Regimens Effective?

Abstract

Rifaximin is a non-absorbed semisynthetic rifamycin derivative with a broad spectrum of antibacterial activity including Gram-positive and Gram-negative bacteria, both aerobes and anaerobes. Although originally developed for the treatment of infectious diarrhea, the appreciation of the pathogenic role of gut bacteria in several organic and functional gastrointestinal diseases has increasingly broadened its clinical use. Being the antibiotic active against Helicobacter pylori, even towards clarithromycin-resistant strain, and being the primary resistance very rare, several investigations explored its potential use for eradication of the microorganism. Rifaximin alone proved to be effective, but even the highest dose (1,200 mg daily) gave a cure rate of only 30%. Dual and triple therapies were also studied, with the better results obtained with rifaximin-clarithromycin and rifaximin-clarithromycin-esomeprazole combinations. However, the eradication rates (60–70%) obtained with these regimens were still below the standard set by the Maastricht Consensus guidelines. Although rifaximin-based eradication therapies are promising, new antimicrobial combinations (with and without proton pump inhibitors) need to be explored in well-designed clinical trials including a large cohort of H. pylori-infected patients. The remarkable safety of rifaximin will allow high-dose regimens of longer duration (e.g. 10 or 14 days) to be tested with confidence in the hope of achieving better eradication rates. A drawback of rifaximin could be its inability to reach sufficiently high concentrations in the gastric mucus layer under and within which H. pylori is commonly located and this would likely affect eradication rate. Taking these considerations into account, bioadhesive rifaximin formulations able to better and persistently cover gastric mucosa, or combination with mucolytic agents, such as pronase or acetylcysteine, need to be evaluated in order to better define the place of this antibiotic in our therapeutic armamentarium.

<p>Alternative eradication regimens for <em>Helicobacter pylori</em> infection in Indonesian regions with high metronidazole and levofloxacin resistance</p>

“…Among the several alternative drugs tested in the current study, the rate of resistance was highest to rifaximin; this finding is in agreement with a previous study showing that rifaximin-based triple therapy did not achieve acceptable H. pylori cure rates 55,56. However, rifaximin is a promising H. pylori drug due to poor absorbance in the blood, which can minimize adverse effects, and its higher bioavailability in the gastrointestinal tract than that of other antibiotics 57.…”

The role of small intestinal bacterial overgrowth in Parkinson's disease

“…The antibiotic therapy for HP eradication used in these studies would have also treated a concomitant SIBO, as also discussed by Pierantozzi and colleagues . However, in our study, the likelihood that rifaximin monotherapy would have affected HP is very low …”

Effective therapeutic regimens in two South Asian countries with high resistance to major Helicobacter pylori antibiotics

“…We should mention that the poor cure rate of rifaximin was probably due to its use as a single regimen; however, triple therapy of rifaximin together with a proton pump inhibitor and levofloxacin or clarithromycin also led to a poor cure rate in clinical studies, ranging from 30 to 58% [65]. Importantly, rifaximin had high safety ratings because it is poorly absorbed in the stomach, thus it barely approaches H. pylori, which lives under the gastric mucus and epithelium [66]. This safety feature may be useful for infection in children as described by a clinical trial in Russian children reporting an 85.4% cure rate; however, this may not be sufficient evidence due to the small number of subjects (41 patients), and the regimen included bismuth subcitrate and furazolidone [67].…”