Efficacy and safety of omeprazole in Japanese patients with nonerosive reflux disease

BACKGROUND: There is increasing awareness of nonerosive reflux disease (NERD) as a disease requiring treatment in Japan. This randomized, double-blind, placebo-controlled, parallel-group study was conducted to investigate the efficacy and safety of omeprazole 10 mg and 20 mg once daily in Japanese patients with NERD. METHODS: Patients with heartburn for at least 2 days a week during the month before entry into the study and no endoscopic signs of a mucosal break (grade M or N according to Hoshihara's modification of the Los Angeles classification) were randomly assigned to one of three groups (omeprazole 10 mg or 20 mg, or placebo) once daily for 4 weeks. RESULTS: Overall, 355 patients were enrolled, of whom 284 were randomly assigned to one of the three groups (omeprazole 10 mg, n = 96; omeprazole 20 mg, n = 93; placebo, n = 95). The rate of complete resolution of heartburn in week 4 was significantly higher in patients treated with omeprazole 10 mg 32.3%, 95% confidence interval (CI), 22.9%-41.6%] or 20 mg (25.8%, 95% CI, 16.9%-34.7%) than in the placebo group (12.0%, 95% CI, 5.3%-18.6%). No significant difference between the two omeprazole groups was observed. The rate of complete resolution of heartburn by omeprazole was similar between patients with grade M and those with grade N esophagus. Omeprazole also increased the rate of sufficient relief from heartburn. Omeprazole was well tolerated. CONCLUSIONS: Omeprazole 10 mg or 20 mg once daily is effective and well tolerated in patients with NERD regardless of their endoscopic classification.