The effectiveness of omeprazole, clarithromycin and tinidazole in eradicating Helicobacter pylori in a community...

Helicobacter pylori screening and treatment has been proposed as a cost-effective method of preventing gastric cancer.

To assess, in a randomized controlled trial, the efficacy of therapy in eradicating H. pylori as part of a screening programme, and to report the adverse events associated with this strategy.

Subjects between the ages of 40-49 years were randomly selected from the lists of 36 primary care centres. Participants attended their local practice and H. pylori status was determined by 13C-urea breath test. Infected subjects were randomized to receive omeprazole 20 mg b.d., clarithromycin 250 mg b.d. and tinidazole 500 mg b.d. for 7 days (OCT) or identical placebos. Eradication was determined by a 13C-urea breath test 6 months and 2 years after the first visit. Successful eradication was defined as two negative 13C-urea breath tests or one negative and one missing test. Adverse events and compliance were assessed at the 6-month visit.

A total of 32 929 subjects were invited to attend, 8407 were evaluable, and 2329 (28%) of these were H. pylori-positive. A total of 1161 subjects were randomized to OCT and 1163 to placebo; over 80% returned for a repeat 13C-urea breath test on at least one occasion. The eradication rates in those allocated to OCT were as follows: intention-to-treat, 710 out of 1161 (61%; 95% confidence interval: 58-64%); evaluable 710 out of 967 (73%; 95% CI: 71-76%); took all medication 645 out of 769 (84%; 95% CI: 81-87%). Adverse events occurred in 45% of the treatment group and in 18% of the placebo group (relative risk 2.5; 95% CI: 2.1-2.9). Compliance, male gender, no antibiotic prescription in the subsequent 2 years and experiencing a bitter taste with the medication were independently associated with treatment success.

The OCT regimen has an eradication rate of 61% in intention-to-treat analysis and is therefore less successful in treating H. pylori as part of a screening programme compared with hospital studies in dyspeptic patients.