Gaviscon Double Action Liquid (antacid & alginate) is more effective than antacid in controlling post‐prandial oesophageal acid exposure in <scp>GERD</scp> patients: a double‐blind crossover study

<jats:title>Summary</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Recent studies have shown that Gaviscon Double Action Liquid (a combination alginate‐antacid) administered post‐prandially co‐localises with the acid pocket, the ‘reservoir’ for post‐prandial acid reflux.</jats:p></jats:sec><jats:sec><jats:title>Aim</jats:title><jats:p>To compare the effectiveness of Gaviscon Double Action Liquid to an equivalent strength antacid without alginate in controlling post‐prandial acid reflux in <jats:styled-content style="fixed-case">GERD</jats:styled-content> patients.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Fourteen GERD patients undertook two 3.5‐h high‐resolution manometry/<jats:styled-content style="fixed-case">pH</jats:styled-content>‐impedance studies during which they ate a standardised meal. In a double‐blinded randomised crossover design they then took Gaviscon or CVS brand antacid, each with ~18 mmol/L acid neutralising capacity. The primary outcome was distal oesophageal acid exposure; secondary outcomes were number of reflux events, proximal extent of reflux, nadir <jats:styled-content style="fixed-case">pH</jats:styled-content> of the refluxate, mechanism of reflux and reflux symptoms scored with a validated instrument.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Ten patients completed the study. Gaviscon studies had significantly less distal oesophageal acid exposure and greater nadir refluxate <jats:styled-content style="fixed-case">pH</jats:styled-content> in the 30–150 min post‐prandial period than antacid studies. There were no differences in the number of reflux events (acid or weakly acidic) or the number of proximal reflux events (15–17 cm above the LES) with either study medication.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>Gaviscon Double Action Liquid is more effective than an antacid without alginate in controlling post‐prandial oesophageal acid exposure. However, the number and spatial distribution of reflux events within the oesophagus are similar. This suggests that Gaviscon main effectiveness relates to its co‐localisation with and displacement/neutralisation of the post‐prandial acid pocket, rather than preventing reflux.</jats:p></jats:sec>