THERAPEUTIC SUBSTANCES

BACKGROUND/AIMS: To test the impact of vitamin C supplementation on triple therapy for H. pylori eradication. METHODOLOGY: A total of 171 H. pylori-infected patients were randomized to receive different one-week triple therapies, including 20 mg omeprazole, 1 g amoxicillin, plus the following twice daily: (1) 250 mg clarithromycin (C250 group, n=55); (2) 250 mg clarithromycin and 500 mg vitamin C (V-C250 group, n=61); (3) 500 mg clarithromycin (C500 group, n=55). Six weeks after treatment, the success of H. pylori eradication was assessed by a 13C-urea breath test. Each collected H. pylori strain was defined as either clarithromycin susceptible or resistant by E-test. RESULTS: The demographic background, clarithromycin susceptibility of H. pylori, and drug compliance were similar among the three groups (p=NS). For clarithromycin susceptible infection, the V-C250 group had a higher eradication rate than the C250 group (ITT: 85% vs. 68% and PP: 90% vs. 73%, p = 0.03), but had an equivalent rate to the C500 group (p=NS). For clarithromycin resistant infection, all three groups had a similarly poor eradication rate of less than 34%. CONCLUSIONS: Adding vitamin C to one-week triple therapy can reduce the dosage of clarithromycin, but preserve the high eradication efficacy for clarithromycin susceptible H. pylori infection.