Drugs for improving esophageal mucosa defense: where are we now and where are we going?

Abstract

In the past, the attention of physiologists and doctors has been mainly focused on the key role of acid in the pathogenesis of gastroesophageal reflux disease (GERD), but increasing evidence that 20-40% of reflux patients respond not at all or only partially to proton pump inhibitors (PPIs) has underlined the concept that factors other than acid are implicated in its development and the elicitation of symptoms. Among these, impaired mucosal integrity, particularly in most patients with non-erosive reflux disease, has recently been reincluded and the reinforcement of defensive mechanisms and/or its protection has been reappointed as a renewed therapeutic target for the management of GERD patients. In this review we will summarize the existing knowledge of the old and novel compounds able to produce this therapeutic effect, including sucralfate, alginate-based drugs, and a new medical device consisting of hyaluronic acid and chondroitin sulfate dispersed in a bioadhesive carrier, together with the potential indications for their use. It is to be stressed, however, that, although these compounds may represent a real alternative to PPI therapy in GERD, the combination of mucosal protection with acid suppression may help manage many cases with a partial or unsatisfactory response to PPIs alone.

Keywords: Gastroesophageal reflux disease; histology; impedance-pH monitoring; mucosal integrity; non-erosive reflux disease.

Figure 1

Main pathogenetic factors implicated in gastroesophageal reflux disease

Figure 2

Pathophysiological heterogeneity of non-erosive reflux disease (NERD) by means of 24-h impedance-pH monitoring: the NERD umbrella concept

Figure 3

Expression of microscopic esophagitis in the various forms of gastroesophageal reflux disease, functional heartburn and controls NERD, non-erosive reflux disease