Heartburn relief with bicarbonate-rich mineral water: results of the randomised, placebo-controlled phase-III trial STOMACH STILL

Abstract

Objective: We assessed whether the bicarbonate-rich mineral water Staatl. Fachingen STILL is superior over conventional mineral water in relieving heartburn.

Design: Multicentre, double-blind, randomised, placebo-controlled trial STOMACH STILL in adult patients with frequent heartburn episodes since ≥6 months and without moderate/severe reflux oesophagitis. Patients drank 1.5 L/day verum or placebo over the course of the day for 6 weeks. Primary endpoint was the percentage of patients with reduction of ≥5 points in the Reflux Disease Questionnaire (RDQ) score for 'heartburn'. Secondary endpoints included symptom reduction (RDQ), health-related quality of life (HRQOL, Quality of Life in Reflux and Dyspepsia (QOLRAD)), intake of rescue medication and safety/tolerability.

Results: Of 148 randomised patients (verum: n=73, placebo: n=75), 143 completed the trial. Responder rates were 84.72% in the verum and 63.51% in the placebo group (p=0.0035, number needed to treat=5). Symptoms improved under verum compared with placebo for the dimension 'heartburn' (p=0.0003) and the RDQ total score (p=0.0050). HRQOL improvements under verum compared with placebo were reported for 3 of 5 QOLRAD domains, that is, 'food/drink problems' (p=0.0125), 'emotional distress' (p=0.0147) and 'vitality' (p=0.0393). Mean intake of rescue medication decreased from 0.73 tablets/day at baseline to 0.47 tablets/day in week 6 in the verum group, whereas in the placebo group it remained constant during the trial. Only three patients had treatment-related adverse events (verum: n=1, placebo: n=2).

Conclusion: STOMACH STILL is the first controlled clinical trial demonstrating superiority of a mineral water over placebo in relieving heartburn, accompanied by an improved HRQOL.

Trial registration number: EudraCT 2017-001100-30.

Keywords: acid-related diseases; anti-reflux therapy; dyspepsia; gastric diseases; gastroesophageal reflux disease.

Figure 1

Disposition of patients. *Patient excluded from the FAS due to missing documentation of RDQ score at postbaseline visits V3-V5. AE, adverse event; FAS, full-analysis set; RDQ, Reflux Disease Questionnaire; V, visit.

Figure 2

Time course of RDQ score for ‘heartburn’ (full-analysis set, N=146)* Shown are arithmetic mean values with standard deviation. *The full-analysis set includes all randomised patients who received the study drug at least once, and who provided any postbaseline data for the RDQ score used for responder analysis, and who did not violate against inclusion criteria. RDQ, Reflux Disease Questionnaire.

Figure 3

Investigator-assessed effectiveness (A) and tolerability (B) of treatment post baseline—Verbal Rating Scale (full-analysis set, N=146)*. *The full-analysis set includes all randomised patients who received the study drug at least once, and who provided any postbaseline data for the RDQ score used for responder analysis, and who did not violate against inclusion criteria. N/n, number of patients; RDQ, Reflux Disease Questionnaire.