Optimal treatment for Helicobacter pylori infection in patients with dyspeptic syndromes is unclear at the present time since the incidence of H. pylori resistance to metronidazole has increased. Chey and colleagues studied the effect of triple therapy with a proton pump inhibitor, clarithromycin and metronidazole or bismuth subsalicylate for seven days in the treatment of documented H. pylori infection in patients with peptic ulcer disease, a history of peptic ulcer disease or nonulcer dyspepsia.

None of the 112 patients who were enrolled in the study had received previous treatment for H. pylori infection. Patients were randomly assigned to one of two treatment groups. The first group received lansoprazole in a dosage of 30 mg twice a day, clarithromycin in a dosage of 500 mg twice a day, and metronidazole in a dosage of 500 mg twice a day. The second group received the same dosages of lansoprazole and clarithromycin but were given bismuth subsalicylate in a dosage of 524 mg twice a day as the third agent instead of metronidazole. Both treatments lasted seven days.

Both regimens eradicated H. pylori in over 80 percent of patients, with no significant difference between the two groups. The most common side effects reported in the metronidazole-treated group were altered taste (39 percent) and abdominal pain (19 percent); side effects reported in the bismuth subsalicylate-treated group were altered taste (23 percent) and dark stools (23 percent). No patients dropped out of the study because of intolerable side effects.

The authors conclude that both triple regimens are successful in eradicating H. pylori. Both regimens were well-tolerated, and there were no side effects resulting in discontinuation of therapy. The authors suggest that because there is an increasing potential for H. pylori to become resistant to metronidazole, bismuth subsalicylate may be a viable alternative.