AIM: To compare the clinical efficacy of the secondgeneration H2 RA lafutidine with that of lansoprazole in Japanese patients with mild gastroesophageal reflux disease(GERD). METHODS: Patients with symptoms of GERD and a diagnosis of grade A reflux esophagitis(according to the Los Angeles classification) were randomized to receive lafutidine(10 mg, twice daily) or lansoprazole(30 mg, once daily) for an initial 8 wk, followed by maintenance treatment comprising half-doses of the assigned drug for 24 wk. The primary endpoint was the frequency and severity of heartburn during initial and maintenance treatment. The secondary endpoints were the sum score of questions 2 and 3 in the Gastrointestinal Symptom Rating Scale(GSRS), and the satisfaction score.RESULTS: Between April 2012 and March 2013, a total of 53 patients were enrolled, of whom 24 and 29 received lafutidine and lansoprazole, respectively. After 8 wk, the frequency and severity of heartburn was significantly reduced in both groups. However, lafutidine was significantly inferior to lansoprazole with regard to the severity of heartburn during initial and maintenance treatment(P = 0.016). The sum score of questions 2 and 3 in the GSRS, and satisfaction scores were also significantly worse in the lafutidine group than the lansoprazole group(P = 0.0068 and P = 0.0048, respectively).CONCLUSION: The clinical efficacy of lafutidine was inferior to that of lansoprazole, even in Japanese patients with mild GERD. AIM: To compare the clinical efficacy of the second generation H2 RA lafutidine with that of lansoprazole in Japanese patients with mild gastroesophageal reflux disease (GERD). METHODS: Patients with symptoms of GERD and a diagnosis of grade A reflux esophagitis (according to the Los Angeles classification) were randomized to receive lafutidine (10 mg, twice daily) or lansoprazole (30 mg, once daily) for an initial 8 wk, followed by maintenance treatment comprising half-doses of the assigned drug for 24 wk. The primary endpoint was the frequency and severity of heartburn during initial and maintenance treatment. The secondary endpoints were the sum score of questions 2 and 3 in the Gastrointestinal Symptom Rating Scale (GSRS), and the results score.RESULTS: Between April 2012 and March 2013, a total of 53 patients were enrolled, of whom 24 and 29 received lafutidine and lansoprazole, respectively. After 8 wk, the frequency and severity of heartburn was significantly reduced in both grou ps. However, lafutidine was significantly inferior to lansoprazole with regard to the severity of heartburn during initial and maintenance treatment (P = 0.016). The sum score of questions 2 and 3 in the GSRS, and satisfaction scores were also significantly worse in the lafutidine group than the lansoprazole group (P = 0.0068 and P = 0.0048, respectively). CONCLUSION: The clinical efficacy of lafutidine was inferior to that of lansoprazole, even in Japanese patients with mild GERD.