SHORT-DURATION THERAPY FOR HELICOBACTER-PYLORI IN WESTERN-AUSTRALIA -THE IMPACT OF METRONIDAZOLE RESISTANCE

Background: Limited Australian data are available on either short dura tion therapy for Helicobacter pylori infection, or the impact of metro nidazole resistance on the outcome of treatment. Aim: To compare the e fficacy of two treatment regimens and determine the influence metronid azole resistance has on clearing H. pylori infection. Methods: Eighty patients with H. pylori infection proven at upper gastrointestinal end oscopy, none of whom had previously received therapy for H. pylori, we re randomised to one week therapy with either bismuth subcitrate one t ablet qid, tetracycline 500 mg qid and metronidazole 400 mg tds (BTM), or lansoprazole 30 mg bd, amoxycillin 500 mg qid and metronidazole 40 0 mg tds (LAM). Effectiveness of therapy was measured by C14-urea brea th test at six weeks. Results: On an intention-to-treat basis, clearan ce of infection was achieved in 17 of 32 (53%; 95% CI: 35-71%) evaluab le patients receiving BTM and 32 of 46 (70%, 54-82%) patients receivin g LAM (p = 0.16). Metronidazole resistance was found in 32 of 65 (49%) patients in whom H. pylori was isolated by culture. On a per-protocol basis, of patients who had metronidazole sensitive strains of H. pylo ri 23 of 24 (96%) cleared infection after therapy with either BTM or L AM, compared with 14 of 24 (58%) who were metronidazole resistant (p = 0.004). Clarithromycin resistance was not found in 45 patients tested . Conclusions: In Western Australia clearance rates of H. pylori infec tion, after one week of BTM or LAM, are lower than in other published series. The high incidence of metronidazole resistance is the main det erminant of our relatively poor eradication rates.