Effect of ranitidine and amoxicillin plus metronidazole on the eradication of Helicobacter pylori and the recurrence of duodenal ulcer.

Background: Persistent infection with Helicobacter pylori is associated with the recurrence of duodenal ulcer. Whether the efficacy of bismuth therapy in reducing the rate of recurrence of duodenal ulcer is due to its antimicrobial effects on H. pylori or to a direct protective action on the mucosa is still a matter of debate.
Methods: To study the effect of the eradication of H. pylori on the recurrence of duodenal ulcer, we treated 104 patients with H. pylori infection and recurrent duodenal ulcer with either amoxicillin (750 mg three times daily) plus metronidazole (500 mg three times daily) or identical-appearing placebos, given orally for 12 days. All patients also received ranitidine (300 mg each night) for 6 or 10 weeks. Endoscopy was performed before treatment and periodically during follow-up for up to 12 months after healing.
Results: Among the 52 patients given antibiotics, H. pylori was eradicated in 46, as compared with 1 of the 52 given placebo (89 percent vs. 2 percent, P < 0.001). After six weeks, the ulcers were healed in 48 patients given antibiotics and 39 given placebo (92 percent vs. 75 percent, P = 0.011). Side effects, mainly diarrhea, occurred in 15 percent of the patients given antibiotics. Among the patients followed up for 12 months, duodenal ulcers recurred in 4 of 50 patients given antibiotics and 42 of 49 given placebo (8 percent vs. 86 percent, P < 0.001). Ulcers recurred in 1 of 46 patients in whom H. pylori had been eradicated, as compared with 45 of 53 in whom H. pylori persisted (2 percent vs. 85 percent, P < 0.001).
Conclusions: In patients with recurrent duodenal ulcer, eradication of H. pylori by a regimen that does not have any direct action on the mucosa is followed by a marked reduction in the rate of recurrence, suggesting a causal role for H. pylori in recurrent duodenal ulcer.