Age-dependent eradication of Helicobacter pylori with dual therapy

Background: Combined treatment using an acid-inhibiting drug with antibiotics can cure Helicobacter pylori infection. However, eradication rates are highly variable, especially if a proton pump inhibitor is used with amoxycillin. Therefore it is important to define factors/predictors of the clinical outcome. Methods: In a single-blind study, 60 H. pylori-positive patients prospectively matched for diagnosis (erosive gastritis, duodenal and gastric ulcer), age (above and below 50 years) and smoking habits were randomly treated (each group n = 20) for 2 weeks with amoxycillin (1 mg b.d.) and either omeprazole (20 mg b.d.), lansoprazole (30 mg b.d.) or ranitidine (300 mg b.d.). Intragastric pH and plasma levels of the administered drugs were monitored over a dosing interval of 12 h. Results: The overall eradication rates were 45% (intention-to-treat, ITT, 27/60) or 47% (per protocol 27/58); they did not differ (ITT) between omeprazole (50%), lansoprazole (40%) and ranitidine (45%). Median pH and time at which intragastric pH was above 4 was slightly lower for ranitidine (4.0 ± 1.7; 51 ± 25%) than for omeprazole (5.4 ± 1.1; 77 ± 25%; P < 0.05) or lansoprazole (4.4 ± 1.6; 68 ± 32%). Plasma concentrations of amoxycillin were comparable in all three treatment groups. Post-treatment H. pylori status was not dependent on those levels, or the drug-induced extent or duration of increased intragastric pH. However, H. pylori-eradicated patients were significantly (P < 0.05) older (56 ± 13 years) than patients still H. pylori-positive (47 ± 14 years). In addition, in patients older than 50 years (n = 33), eradication was higher (P < 0.01) than in patients (n = 25) below 50 years (65 vs. 24%). Eradication rate was highest (75–83%) in subgroups of patients (>50 years and history of peptic ulcer or smokers). Neither activity/grade of peptic ulcer or erosive gastritis nor initial diagnosis were predictors for clinical outcome. Conclusion: The age of patients must be regarded as a major determinant of H. pylori eradication rate and may represent an important factor contributing to the highly variable clinical results.