Objective To compare prospectively the effectiveness of 1 year's treatment with pantoprazole versus ranitidine in order to prevent relapse after initial cure of reflux oesophagitis, For the first time the influence of the initial Helicobacter pylori status on therapeutic results was also taken into account. Methods In order to cure reflux oesophagitis, 396 patients with Savary/Miller stage II or III reflux oesophagitis were treated with pantoprazole 40 mg once daily for 8 weeks. Those who were H. pylori positive (n = 140) were also given 1 week of eradication treatment with clarithromycin 2 x 250 mg daily, metronidazole 2 x 400 mg daily, and a further 40 mg pantoprazole daily. The 303 patients who were endoscopically cured after the 8-week period were randomized and treated with either pantoprazole 20 mg (n = 199)or ranitidine 150 mg (n = 104) daily in double-blind fashion. The primary objective was to assess the time to endoscopically proven recurrence of reflux oesophagitis, Results In the intention-to-treat (ITT) population, 66.3% (118/178) of the pantoprazole group and 34.0% (32/94) of the ranitidine group showed neither endoscopic nor clinical symptoms of relapse after the 1-year treatment 155] in the pantoprazole group and 39.4% [28/71] in the ranitidine group. In the pantoprazole group, the relapse rate in initially H. pylori-positive patients who underwent eradication was 30.9% (17/55) and in H. pylori-negative patients 29% (29/100). Conclusions Long-term treatment with 20 mg pantoprazole daily to prevent relapse of reflux oesophagitis in ii pylori-negative patients is significantly more effective than 150 mg ranitidine daily, The initial H. pylori eradication treatment does not influence the outcome of the long-term treatment. (C) 2001 Lippincott Williams & Wilkins.