Evaluation of short‐term low‐dose triple therapy for the eradication of Helicobacter pylori by factorial design in a randomized, double‐blind, controlled study

Abstract

Studies demonstrating the efficacy of short-term low-dose triple therapies including omeprazole (O), clarithromycin (C) and a nitroimidazole (tinidazole, T) for Helicobacter pylori eradication have largely been open and uncontrolled, and have not assessed antibiotic sensitivity. Simpler regimens using the component drugs have not been evaluated. To evaluate the OCT regimen in a randomized, controlled trial, testing for pre- and post-treatment antibiotic resistance and comparing, in a factorial design, the OCT regimen with simpler combinations of its components. One hundred and twenty-eight patients (68 males, 60 females, age 22–80 years, mean 53 years) with H. pylori gastritis were randomly assigned to one of the following four treatment groups: (C) clarithromycin 250 mg b.d.; (OC) omeprazole 20 mg o.d. + clari-thromycin 250 mg b.d.; (CT) clarithromycin 250 mg b.d. + tinidazole 500 mg b.d.; (OCT) omeprazole 20 mg q.d.s. + clarithromycin 250 mg b.d. + tinidazole 500 mg b.d. The drugs were administered for 1 week. Medical interview, upper gastrointestinal endoscopy (with four antral and four corpus biopsies) and the ¹³C-urea breath test were carried out for all patients prior to and 4 weeks after treatment. Biopsy specimens were used for the urease test, histology, and culture and sensitivities. All but one patient completed treatment. Side-effects were rare and mild in all groups. The eradication rate was 93.8% in group OCT, 59.4% in group CT, 31.3% in group OC and 6.3% in group C. Pre-treatment metronidazole resistance was 12.8%, clarithromycin 1.1% and, to both antibiotics, 2.1%. In patients with pre-treatment metronidazole resistance, the eradication rate was 75% in group OCT and 33% in group CT. Post-treatment resistance to clarithromycin was induced in 28.5% of the failures in group C, but in none of group OC. Resistance to both antibiotics occurred in 22.2% of the failures in group CT and in none of group OCT. (i) The high efficacy of the OCT regimen is proved and each of the individual components of the regimen is essential to the result, possibly via a synergistic effect. (ii) Pre-treatment metronidazole resistance is scarcely relevant to the outcome. (iii) Acquired resistance is essentially nil if omeprazole is part of the regimen.