Omeprazole, amoxycillin and metronidazole for the cure of Helicobacter pylori infection.

OBJECTIVE

In two studies, different regimens of omeprazole-amoxycillin-metronidazole were assessed for the eradication of Helicobacter pylori.

DESIGN

Randomized, international, multicentre studies with parallel groups.

SETTING

The studies were performed at centres in Canada, Czech Republic, France, Germany, Hungary, Sweden and UK.

PARTICIPANTS AND INTERVENTIONS: H. pylori-positive patients with duodenal ulcer disease (active or in remission) were randomized to 7-day treatment with: omeprazole 40 mg once daily, amoxycillin 500 mg three times daily and metronidazole 400 mg three times daily (OAMtid; n = 242); omeprazole 20 mg twice daily, amoxycillin 1000 mg twice daily and metronidazole 800 mg twice daily (OAM800; n = 247); or omeprazole 20 mg twice daily, amoxycillin 1000 mg twice daily and metronidazole 400 mg twice daily (OAM400; n = 127).

MAIN OUTCOME MEASURES: Eradication of H. pylori.

RESULTS

Intention-to-treat analysis revealed H. pylori eradication rates of 76% (184/242) with OAMtid, 80% (198/247) with OAM800, and 76% (97/127) with OAM400. There was considerable variation in the levels of primary resistance to metronidazole in different countries. The overall eradication rate in patients infected with metronidazole-sensitive H. pylori strains was 85% (313/370), compared with 60% (56/94) in patients harbouring metronidazole-resistant strains (P<0.001). All regimens were generally well tolerated, with mild adverse events occurring in 4-26% of patients (mainly diarrhoea, reversible increase in liver enzymes and headache).

CONCLUSION

The OAM combination is effective in curing H. pylori infection. Primary metronidazole resistance may reduce its effectiveness, but an increased daily dosing of metronidazole may partly overcome this problem.