Do Japanese and Swedish Peptic Ulcer Patients Respond Differently to Helicobacter pylori Eradication Therapies and What Are Their Histological Features?

BACKGROUND: As a consequence of gastric histological differences, Japanese and Swedish peptic ulcer (PU) patients may respond differently to Helicobacter pylori eradication therapies. METHODS: The study was single-blind and compared four eradication therapies in Japanese and Swedish patients with healed gastric (GU) or duodenal (DU) ulcer. Swedish patients received either (a) omeprazole+clarithromycin (OC, where O = 20 mg, C = 500 mg) for 2 weeks, or triple therapy with (b) omeprazole + amoxicillin + clarithromycin (OAC-L where O = 20mg, A = 1 g, C = 250 mg); (c) OAC-H (where O = 20 mg, A-1 g, C-500 mg); or (d) omeprazole + metronidazole + clarithromycin (OMC, where O = 20 mg, M = 400 mg, C = 250 mg) for 1 week. Antibiotic doses were weight-adjusted downwards in Japanese patients. H. pylori was assessed using the urea breath test (UBT), histology and culture pre-entry, with UBT being repeated 4 and 8 weeks after stopping treatment. Histology and culture were repeated if the UBT was positive post-therapy. RESULTS: Recruitment included 120 patients from Japan (43 GU, 61 DU, 16 GU+DU) and 120 from Sweden (119 DU, 1 GU+DU). There were 26 exclusions from a FAS analysis due to H. pylori negativity (14), no drug administration (7) or no data after visit 1 (5). Eradication rates (FAS) from Japan were (a) 63%, (b) 93%, (c) 96% or (d) 96%, and for Sweden (a) 92%, (b) 86%, (c) 93% or (d) 96%. Dual therapy was less effective in patients with gastric atrophy associated with GU disease. Tolerability was good in all treatment groups, with no serious adverse events. CONCLUSION: Triple therapies were safe and effective for H. pylori eradication in Japanese and Swedish peptic ulcer patients. Dual therapy was significantly less effective in the Japanese patients, half of whom had a history of GU and more abnormal histology than in the Swedish patients, all of whom had DU.