Cure of Helicobacter pylori infection in elderly patients: comparison of low versus high doses of clarithromycin in combination with amoxicillin and pantoprazole.

Background: Advancing age may influence clarithromycin's pharmacokinetics. No studies have yet compared the effects of different dosages of clarithromycin in combination with a proton pump inhibitor and amoxicillin in elderly patients.

Aim: To compare the efficacy and tolerability of clarithromycin 250 mg vs. clarithromycin 500 mg twice daily (b.d.) in combination with pantoprazole and amoxicillin in elderly patients.

Methods: One hundred and fifty-four elderly patients with H. pylori-associated ulcer disease or chronic gastritis were consecutively randomized to receive pantoprazole 40 mg daily plus amoxicillin 1 g, and either clarithromycin 250 mg b.d. (PAC 250) or clarithromycin 500 mg b.d. (PAC 500). Two months after therapy, endoscopy and gastric biopsies were repeated.

Results: The cure rates of H. pylori infection in the PAC 250 and PAC 500 groups were, respectively, 83% and 79% (ITT analysis) and 94% and 88% (PP analysis) (P=N.S.). Significant decreases in chronic gastritis activity both in the body (P < 0.00001) and the antrum (P < 0.0001) of the stomach were found in H. pylori-cured patients, independently of clarithromycin dosage. Four patients in PAC 250 (5%) and seven in PAC 500 (9%) reported adverse events (P=N.S.). One patient in PAC 250 (25%) and three in PAC 500 (43%) discontinued the study because of these drug-related side-effects (P=N.S.).

Conclusions: In elderly patients, 1-week triple therapy with a proton pump inhibitor, amoxicillin and clarithromycin is a highly effective and well tolerated anti-H. pylori treatment. With this combination, clarithromycin at the lower dose of 250 mg b.d. achieved excel- lent cure rates and minimized adverse events and costs.