BackgroundPatients using low-dose aspirin (LDA) have an increased risk of gastroduodenal mucosal lesions and upper gastrointestinal symptoms. We aimed to clarify the efficacy of rabeprazole for preventing peptic ulcer, esophagitis, and gastrointestinal symptoms associated with LDA.MethodsPatients with a history of peptic ulcers who were receiving LDA for cardiovascular or cerebrovascular disease were randomly assigned to receive rabeprazole at 10 mg daily, rabeprazole at 20 mg daily, or gefarnate (a cytoprotective anti-ulcer agent) at 50 mg twice daily. The primary endpoint was the development of gastric and/or duodenal ulcer at 12 weeks. The modified Lanza score (MLS) and gastrointestinal symptoms were evaluated at baseline and at 12 weeks.ResultsThe full analysis set comprised 261 patients (rabeprazole 10 mg: n = 87, rabeprazole 20 mg: n = 89, gefarnate 100 mg: n = 85). The cumulative incidences of gastroduodenal ulcers at 12 weeks in the 10 mg rabeprazole group, 20 mg rabeprazole group, and gefarnate group were 7.4, 3.7, and 26.7 %, respectively (rabeprazole group 5.5 % vs. gefarnate group 26.7 %, hazard ratio [HR] 0.179; 95 % confidence interval [CI] 0.082–0.394; p < 0.0001). The proportions of patients with an MLS of ≥1 and erosive esophagitis were significantly lower in the rabeprazole group than in the gefarnate group at 12 weeks (gastric lesions 33.5 vs. 62.4 %, p < 0.0001; duodenal lesions 5.7 vs. 24.7 %, p < 0.0001; erosive esophagitis 5.8 vs. 19.4 %, p < 0.0001). Rabeprazole was significantly more effective than gefarnate for the resolution and prevention of gastrointestinal symptoms (resolution 53.6 vs. 25.0 %, p = 0.017; occurrence 9.2 vs. 28.3 %, p = 0.0026).ConclusionsRabeprazole is more effective than gefarnate for reducing the risk of recurrence of peptic ulcer, esophagitis, and gastrointestinal symptoms in LDA users.