Omeprazole once or twice daily with clarithromycin and metronidazole for Helicobacter pylori

Triple therapy for one week with omeprazole, clarithromycin and metronidazole (OCM) is accepted worldwide as a first line therapy for Helicobacter pylori eradication. It is unclear whether omeprazole needs to be given once or twice daily.

To assess the efficacy and safety of these regimens in a single-centre, Canadian practice.

Histologically proven H pylori-positive patients were treated for seven days with clarithromycin 250 mg bid and metronidazole 500 mg bid, and randomly allocated to omeprazole 20 mg either once or twice daily in this open, cohort study. Endoscopy with histology (two antrum and two body biopsies, Giemsa stain) was done four weeks or longer after the pills were completed to assess H pylori eradication.

Whether omeprazole was given once or twice daily, eradication was high and the same in both arms. All-patients-treated eradication was 85% (39 of 46 in the omeprazole once daily group and 41 of 48 in the omeprazole twice daily group) and intent-to-treat eradication was 80% (39 of 49 in the omeprazole once daily group and 41 of 51 in the omeprazole twice daily group). Side effects were frequently seen, suffered by 65% to 69% of patients treated. However, these were mild and compliance was high, with 94% of patients taking all of their pills. Mild side effects included loose stools, taste disturbance, nausea, headache and upper or lower gastrointestinal gas. Only one patient (1%) from the omeprazole once daily arm stopped taking metronidazole due to excessive perspiring.

In this community practice, OCM triple therapy was effective whether omeprazole was given once or twice daily. For those with financial constraint, omeprazole 20 mg once daily can be considered. The regimens were well tolerated without serious adverse events.