['The major obstacle to 100% effective eradication of Helicobacter pylori infection is represented by antimicrobial-resistant H. pylori strains. This randomized study was designed to evaluate whether regimens based on pretreatment susceptibility testing were more effective and cost saving compared with standard nonsusceptibility testing-based therapy in the eradication of H. pylori infection.', 'We studied 150 consecutive H. pylori-infected dyspeptic subjects. Patients were randomly assigned to omeprazole 20 mg twice daily, clarithromycin 500 mg twice daily, and metronidazole 500 mg twice daily for 7 days or to omeprazole 20 mg twice daily and 2 antimicrobials chosen based on susceptibility testing. H. pylori status was reevaluated 12 weeks after the end of treatment by the (13)C-urea breath test.', 'Susceptibility testing-based regimens led to the following results. (1) Eradication rates were 97.3% (95% confidence interval [CI], 91.2%-99.5%) (71 of 73) and 94.6% (95% CI, 87.6%-98.3%) (71 of 75) in the per-protocol and intention-to-treat analysis, respectively. These were significantly higher (P < 0.005) than eradication rates obtained without susceptibility testing, that is, 79.4% (95% CI, 69.1%-87.6%) (58 of 73) and 77.3% (95% CI, 66.9%-85.7%) (58 of 75) in the per-protocol and intention-to-treat analyses, respectively. (2) There were savings of approximately $5 U.S. per patient compared with standard triple therapy.'] Is pretreatment antimicrobial susceptibility testing cost saving in the eradication of Helicobacter pylori?