Does pretreatment with omeprazole decrease the chance of eradication of Helicobacter pylori in peptic ulcer patients?

OBJECTIVE: It has been reported that pretreatment with omeprazole could decrease the efficacy of Helicobacter pylori eradication. Our aim was to compare the efficacy, safety, and tolerability of the eradicating regimen, omeprazole/amoxicillin/metronidazole. The two antibiotics were scheduled either during the first or during the last 2 wk of omeprazole administration. METHODS: In this prospective controlled study conducted in a single center, 78 symptomatic peptic ulcer patients were treated for 4 wk with omeprazole 40 mg o.m.; the patients were randomly assigned to receive amoxicillin 1 g t.i.d. postprandially and metronidazole 250 mg t.i.d. postprandially, either during the first 2 wk (group A, n = 40) or the last 2 wk of therapy with omeprazole (group B, n = 38). H. pylori status was assessed by culture, histology, urease test, and IgG antibodies. Each patient's course was followed for 1 yr. RESULTS: H. pylori infection was cured in 97.4% of group A (95% CI: 0.84-0.99) and in 89% of group B (95% CI: 0.73-0.96, p = 0.28). Healing was achieved in 80% of the patients in group A (95% CI: 0.63-0.90) and in 75.7% of patients in group B (95% CI: 0.60-0.90, p = 0.60) At 12-month follow-up, 72 patients were evaluated: 37/38 (97%) of patients in group A and 33/33 (100%) in group B were confirmed as cured of the infection (NS). Peptic ulcer healing rate reached 100% in the two groups. Furthermore, between the two groups, there were no significant differences in symptom relief or improvement. Both regimens were well tolerated, and no patient had to be withdrawn from therapy because of an adverse event. Minor side-effects appeared to be similar in the two groups (40% vs. 38%). CONCLUSIONS: This randomized study clearly indicates that omeprazole pretreatment does not significantly reduce the efficacy of eradicating therapy for H. pylori in peptic ulcer patients.