Effect of Smoking and Histological Gastritis Severity on the Rate of H. pylori Eradication with Omeprazole, Amoxicillin, and Clarithromycin

Background. The combination of omeprazole, amoxicillin, and clarithromycin is a common regimen against Helicobacter pylori. Several recent studies have shown that smoking, high intragastric acidity, and the degree of histological gastritis are associated with H. pylori eradication failure.
Materials and Methods. One hundred and thirty-seven H. pylori –positive patients were treated with a 1-week regimen composed of omeprazole, 20 mg once daily; amoxicillin, 500 mg; and clarithromycin, 200 mg thrice daily. Success of the treatment was evaluated by histology and the ¹³C-urea breath test at least 4 weeks after completion of therapy. Data about age, gender, alcohol intake, smoking habits, and previous proton pump inhibitor intake were collected in patient interviews. We evaluated fasting gastric pH and the degree of histological gastritis before eradication of H. pylori.
Results. The overall eradication of H. pylori at 4 weeks was successful in 98 of 137 patients (72%). On the multivariate analysis, a low grade of inflammation in the antrum ( p ≤ .01; 95% confidence interval CI], 2.34–16.75), low grade of activity in the fundus ( p ≤ .05; 95% CI, 1.31–9.65), and smoking ( p ≤ .05; 95% CI, 1.27–6.82) were the significant independent factors predicting treatment failure.
Conclusions. These findings indicate that H. pylori eradication therapy with omeprazole, amoxicillin, and clarithromycin is less effective in patients who smoke and more effective in patients with high scores of antral inflammation and fundal activity at baseline biopsy.