RESUMO
BACKGROUND/AIMS: There have been few studies on the efficacy of proton pump inhibitors and the doses required to treat dyspeptic symptoms observed in clinical practice. The aim of this study was to compare the efficacy of different doses of omeprazole and different administration methods in Helicobacter pylori-negative, dyspeptic patients. METHODS: Patients with chronic upper abdominal symptoms within the previous 3 months were randomly divided into three groups: a daily, omeprazole 20 mg treatment group (OPZ20, n=61); a daily, omeprazole 10 mg treatment group (OPZ10, n=72); and an on-demand omeprazole 20 mg treatment group (on-demand, n=62). After 4 weeks of administration of the drug, symptom improvement rates were evaluated based on the Overall Global Severity score. RESULTS: The rates of symptom improvement after 4 weeks of treatment were 65.6% (40/61) in the OPZ20 group, 47.2% (34/72) in the OPZ10 group, and 50.0% (31/62) in the on-demand group. The OPZ20 group exhibited a significantly higher improvement rate (p=0.034) than the OPZ10 group. The OPZ20 group had significant improvements in regurgitation, postprandial fullness, vomiting, and bloating compared with the OPZ10 group. CONCLUSIONS: Daily treatment with 20 mg of omeprazole was efficient in treating upper abdominal symptoms. Trial registration: ClinicalTrials.gov, number UMIN000002621.