Ranitidine bismuth citrate with either clarithromycin 1 g/day or 1.5 g/day is equally effective in the eradication of H. pylori and healing of duodenal ulcer.

Background: No randomized double-blind studies have been performed to compare clarithromycin 1 g/day with higher doses of the macrolide (1.5 g/day) when combined with ranitidine bismuth citrate (RBC).

Aim: To compare H. pylori eradication and ulcer healing rates of RBC 400 mg b.d. for 4 weeks combined for the first 2 weeks either with clarithromycin 500 mg b.d. (Group A) or clarithromycin 500 mg t.d.s. (Group B).

Methods: Two hundred and seventy-three patients with H. pylori-positive active duodenal ulcer were included. H. pylori infection was detected by CLO-test and histology on antral and corpus biopsies before and at least 4 weeks after the end of therapy. Eradication was assumed if both CLO-test and histology results were negative for H. pylori.

Results: Eradication/healing rates according to intention-to-treat and per protocol analysis were 76/82% and 87/92% for Group A and 78/85% and 88/95% for Group B, respectively (P = N.S.). Adverse events were reported by 7% and 12% of patients in Groups A and B, respectively, and they were generally mild.

Conclusions: RBC in co-prescription with clarithromycin 500 mg b.d. is as effective as RBC plus clarithromycin 500 t.d.s. in eradicating H. pylori and healing duodenal ulcers.