The Clinical Significance of Acid Rebound in Functional Dyspepsia

Overview

Proton pump inhibitors (PPI) have been shown to cause acid reflux related symptoms at withdrawal in healthy volunteers, a phenomenon known as Rebound Acid Hyper Secretion. Whether this also applies for patients with dyspeptic symptoms but without true reflux disease (functional dyspepsia) treated with PPI is unknown. If this is the case, it could lead to an unfortunate long term use of PPI, since the acid rebound renders withdrawal too difficult. This is a single centre, randomized, double-blinded, placebo-controlled cross over study. Study period is 12 weeks per study subject. Study subjects are referred to the study from General Practitioner (GP) and the gastroenterology department or endoscopy clinic of the investigational centre. The study population consists of patients who seek their GP because of dyspepsia without alert signs, and whom the GP may consider starting on PPI. Out patients referred to the gastroenterology department or endoscopy clinic of the investigational centre because of dyspepsia without specific exclusion criteria are also invited to participate. Baseline interview, upper endoscopy and pH monitoring are performed one week before inclusion to exclude patients with GERD. Helicobacter Pylori (Hp.) status is assessed by Helicobacter Urease Test (HUT). Hp. positive subjects without ulcus are not excluded. Patients with a positive pH monitoring will not be included in the analysis regarding the primary endpoint (Development of GERD) but will be included in the analysis regarding one of the secondary endpoints (Effect of PPI on Functional Dyspepsia). Study subjects are randomized to either pantoprazol followed by cross over to placebo or to placebo. Escape medication in the form of Gaviscon can be used on demand. Internet based questionnaires are answered weekly. Questionnaires consist of the Gastrointestinal Symptom rating Scale (GSRS) in combination with items assessing postprandial fullness and items assessing the Montreal Criteria for Gastro Esophageal Reflux Disease (GERD). Compliance to protocol is assessed at hospital visits every fourth week. At the end of study endoscopy and pH monitoring are repeated.