One week triple therapy with omeprazole, clarithromycin and tinidazole for Helicobacter pylori: differing efficacy in previously treated and untreated patients.

BACKGROUND: Triple therapy with omeprazole, clarithromycin, and tinidazole (OCT) has been found to be highly effective against Helicobacter pylori infection. However, its efficacy as a second line regimen for patients who failed metronidazole-based triple therapy has not been evaluated. AIM: The aim of this study was to evaluate the efficacy of low-dose, short-term OCT therapy in an Israeli population, and to compare results obtained in previously treated and untreated patients. METHODS: Patients with duodenal or gastric ulcers and chronic antral gastritis with H. pylori infection as assessed by rapid urease test and/or 14C urea breath test (14C-UBT), were studied. All patients received omeprazole 20 mg b.d., clarithromycin 250 mg b.d. and tinidazole 500 mg b.d. for 7 days. Eradication was assessed by 14C-UBT 4 weeks after treatment. RESULTS: One hundred and fourty-four patients (M/F = 81/63) were enrolled (mean age 48.1 years, range 12-78). Eradication of H. pylori was significantly different between patients who were initially treated with this regimen (90/94, 96%) and patients who had previously failed to eradicate H. pylori with standard triple therapy (27/50, 54%). Moreover, the eradication rate was significantly decreased in patients with more than one previous failure (9/22, 41%) compared to that in patients with only one failure (18/29, 62%). No other differences such as age, gastric pathology, ethnic origin, smoking habits, or pre-treatment urease activity were found to influence the eradication rate. CONCLUSIONS: One-week low-dose triple therapy with OCT is highly effective as an initial therapy in eradicating H. pylori infection. The efficacy is significantly lower when given as a second line treatment in patients who have previously failed to eradicate H. pylori with bismuth-based standard triple therapy.