A Better Cure Rate with 800 mg than with 400 mg Clarithromycin Regimens in One-Week Triple Therapy for <i>Helicobacter pylori </i>Infection in Cigarette-Smoking Peptic Ulcer Patients

<i>Background/Aims:</i> In <i>Helicobacter pylori</i> eradication therapy, using a proton pump inhibitor plus amoxicillin and clarithromycin (PPI/AC regimen), the impact of the clarithromycin dose and smoking on efficacy is conflicting. Here, we compared the efficacy of 400 and 800 mg of clarithromycin in the regimen in relation to smoking in patients with peptic ulcer disease. <i>Methods:</i> We studied 601 <i>H. pylori</i>-positive patients with peptic ulcer disease who had received amoxicillin 750 mg and clarithromycin 200 or 400 mg together with lansoprazole 30 mg b.i.d. <i>Results:</i> 305 patients were treated with a regimen containing 400 mg of clarithromycin (C400 group), and 296 patients with a regimen containing 800 mg (C800 group). Overall cure rates between the two groups were not significantly different, but the cure rate in the C800 group was significantly better than that in the C400 group among patients infected with clarithromycin-sensitive strains (p = 0.03). This difference could be attributed to differences among smokers versus non-smokers: the cure rate among smokers in the C800 group (91.0%) was better than that in the C400 group (80.0%, p = 0.003). <i>Conclusions:</i> 800 mg of clarithromycin is recommended in the PPI/AC regimen for patients who smoke and are infected with clarithromycin-sensitive <i>H. pylori</i>.