Comparison of One or Two Weeks of Lansoprazole, Amoxicillin, and Clarithromycin in the Treatment of Helicobacter pylori

BACKGROUND: The simplest, most effective, and least expensive Helicobacter pylori therapy remains to be determined. Two weeks of 30 mg lansoprazole bid, 1 gm amoxicillin bid, and 500 mg clarithromycin bid (LAC2) had been shown to be an effective therapy for H. pylori. The aim of this study was to assess whether 1 week of this regimen (LAC1) would have a similar efficacy. MATERIALS AND METHODS: H. pylori-positive patients assessed histologically, by rapid urease test, microbiologically, and by a 13C-urea breath test (13C-UBT) were randomized to receive either LAC1 or LAC2 in a single-center open study. Patients were interviewed 1 to 3 days after completion of therapy to evaluate adverse events and compliance. Efficacy was determined by 13C-UBT at least 4 weeks after antibiotic therapy. RESULTS: Seventy evaluable patients were randomized to receive LAC1 (n = 33) LAC2 (n = 37). Of the 33 LAC1 patients, 30 (91%) were treated successfully (95% confidence interval (CI) = 76-98%), compared with 32 of 37 (86%) in the LAC2 group (95% CI = 71-96%). There was no difference in efficacy between the two groups (Fisher's exact test p = 1.0; 95% CI = -10.3%-19.2%). Patients taking LAC1 experienced significantly fewer severe adverse events than those taking LAC2 (Mann-Whitney U test). One of 64 patients had primary resistance to clarithromycin, and treatment was unsuccessful in this case. Six of the 7 remaining treatment failures developed secondary resistance to clarithromycin. CONCLUSIONS: LAC1 is as effective as LAC2 and is associated with less toxicity. Posttreatment clarithromycin resistance is common in patients who do not experience success with therapy.