Objective: Combinations of omeprazole plus two antibiotics for seven days have repeatedly been studied and high Helicobacter pylori eradication rates have been obtained, ranging from 80% and 90% in our country. Our objective was to verify whether length of such therapies (with omeprazole, metronidazole and clarithromycin or amoxicillin) can be shortened to five days with no loss of efficacy.
Design: randomized clinical trial.
Patients: forty-eight consecutive patients with duodenal ulcer were prospectively studied. The exclusion criteria were previous administration of antibiotics, bismuth or gastroerosive drugs, and associated diseases. During the initial endoscopy biopsy specimens from antrum and corpus were obtained (haematoxylin-eosin). Two therapies were administered for five days: omeprazole (20 mg/12 h) and clarithromycin (500 mg/12 h) plus metronidazole (500 mg/12 h) (n = 24) or amoxicillin (1 g/12 h) (n = 24). One month after therapy was completed a new endoscopy was performed, biopsy specimens were obtained, and the 13C-urea breath test was performed. Compliance of therapy was assessed by questioning the patient and counting the residual medication.
Data analysis: multiple logistic regression and "intention-to-treat" analysis.
Outcome variable: eradication was defined as the absence of H. pylori by all diagnostic methods.
Results: Mean age +/- SD was 48 +/- 10 years, 73% were males. Twenty-three patients in each group completed the protocol and the distribution of investigated parameters was similar in both groups. Eradication was obtained in 91.7% (95% CI = 74%-98%) in the metronidazole group and 70.8% (51%-85%) in the amoxicillin group (chi 2 = 2.19; p = 0.13). In the multivariate analysis, OR for the effect of type of therapy on eradication was 4.5 (CI = 0.83-24.7; p = 0.077). No relevant secondary effects were reported. The most common secondary effect was a metallic taste of medication, which was perceived by half of patients in each group.
Conclusion: The combination of omeprazole, clarithromycin, and metronidazole for only five days has a high eradicating efficacy (approximately 90%), similar to that obtained in previous studies with seven days of therapy. Nevertheless, the association of omeprazole, clarithromycin, and amoxicillin should probably be administered at least for one week to reach an optimal eradicating efficacy.