Background: After each treatment for Helicobacter pylori infection there is an eradication failure rate ranging from 5 to 50%. Thus, the best therapy schedule and treatment regimen sequence have still to be identified.
Methods: Patients with H. pylori infection were randomized to receive either a 1-week triple therapy of omeprazole 20 mg b.d., clarithromycin 250 mg b.d. and tetracycline 500 mg b.d. (OCT; 78 patients) or a 2-week dual therapy of omeprazole 20 mg b.d. and amoxycillin 1 g b.d. (OA; 75 patients). H. pylori infection at entry and eradication 4-6 weeks after therapy had ended were assessed by rapid urease test and histology on biopsies from the antrum and the corpus. When eradication did not occur with either the OCT or OA regimens, patients were switched over to the OA or OCT therapy, respectively. Eradication in these patients was assessed 4-6 weeks after conclusion of treatment by a further endoscopy.
Results: H. pylori eradication was achieved in 67.9% (95% CI = 57.6-78.3%) of patients treated with the OCT regimen and in 75.7% (95% CI = 65.9-85.5%) of patients treated with the OA therapy (chi 2 = 1.11; P = 0.29). Moreover, H. pylori eradication was achieved in 39.1% (95% CI = 19.2-59.1%) of patients re-treated with the OA regimen and in 88.9% (95% CI = 74.4-100%) of patients re-treated with the OCT therapy (chi 2 = 8.52; P = 0.003). Thus, the overall success rate 'per protocol' analysis in our study was 81.6% (95% CI = 72.9-90.3%) for the triple and dual therapy sequence and 97.3% (95% CI = 93.6-100%) for dual followed by triple therapy (chi 2 = 8.14; P = 0.004).
Conclusions: Our data found that H. pylori eradication with OA therapy after OCT therapy failure was poor, while that obtained with OCT after OA therapy was good.