Alginate antacid reduces GERD symptoms in partial responders to PPIs updated

Patients with persistent symptoms of gastro-oesophageal reflux disease (GERD) despite proton pump inhibitor (PPI) therapy may obtain relief with alginate antacid, an old agent emerging as a promising treatment option due to the finding of a novel mechanism of the disease.

“Recent evidence suggests that an unbuffered acid pocket forms at the proximal stomach during the postprandial period. In patients with GERD, this acid pocket is larger and longer in length, and is the major source of acid reflux,” said Professor Justin Wu of the Chinese University of Hong Kong, who spoke at the 21st Hong Kong Medical Forum. [Neurogastroenterol Motil 2009;21:725-e42; Am J Gastroenterol 2007;102:2633-2641; Gut 2009;58:904-909; Gut 2010;59:441-451]

“Alginate antacid forms a physical barrier at the gastro-oesophageal junction, which blocks acid reflux. It also neutralizes and distally displaces the acid pocket,” he continued. “In contrast, regular antacid sinks to the distal stomach after ingestion, and is therefore not very effective in blocking reflux.” [Aliment Pharmacol Ther 2013;37:1093-1102; Aliment Pharmacol Ther 2011;34:59-66]

In patients with persistent GERD symptoms despite once-daily standard PPI therapy, adding alginate antacid (10 mL four times daily) significantly reduced the frequency and severity of heartburn vs placebo (change in Heartburn Reflux Dyspepsia Questionnaire score, 2.8 vs 2.0; p=0.02). “Patients receiving add-on alginate antacid also reported significant reductions in the frequency of regurgitation [p=0.04] and night-time symptoms [p<0.01],” Wu noted. [Aliment Pharmacol Ther 2016;43:899-909]

An earlier study of Japanese patients with non-erosive reflux disease similarly showed a significantly higher rate of complete resolution of heartburn for ≥7 consecutive days in patients receiving sodium alginate added to omeprazole vs omeprazole alone (57 vs 26 percent; p<0.05). [Dis Esophagus 2012;25:373-380]

“The conventional approach of treating PPI poor responders was to double the PPI dose or increase the frequency of dosing to twice daily. Perhaps alginate antacid can serve equally well as adjuvant therapy in these patients,” Wu suggested.

Inadequate response to PPIs is an unmet need in GERD treatment, with 16 and 13 percent of patients still experiencing heartburn and regurgitation, respectively, at 5 years. [JAMA 2011;305:1969-1977] “Asians with GERD have lower rates of response to PPIs than Western populations,” pointed out Wu. [BMC Gastroenterol 2014;14:156]

Although laparoscopic anti-reflux surgery (LARS) provides comparable control of acid-related symptoms, 11 percent of patients were found to have dysphagia at 5 years post-LARS, while 40 percent had bloating and 57 percent had flatulence. [JAMA 2011;305:1969-1977] “These symptoms may be equally bothersome, and the rate of PPI use is high after anti-reflux surgery,” said Wu. “Furthermore, large-scale studies have highlighted safety issues with long-term PPI use, such as fractures, PPI-clopidogrel interactions, and Clostridium difficile colitis.”