BACTERICIDAL ACTIVITY OF LANSOPRAZOLE AND OMEPRAZOLE AGAINST HELICOBACTER-PYLORI IN-VITRO

The minimum inhibitory concentrations of 39 Helicobacter pylori strain s against antibiotics (ampicillin. tetracycline, metronidazole), collo idal bismuth subcitrate and proton pump inhibitors were assessed by th e agar dilution method. 20.5% of the strains were metronidazole resist ent. The comparison of the bactericidal action of omeprazole and lanso prazole in a killing curve assay showed a dose-dependent reduction of viable bacteria after 24 h, lansoprazole being more effective than ome prazole. Under varying pH conditions, the antibacterial activity of la nsoprazole was limited to a pH range of 6-7, reducing bacterial number s up to 4 logarithmical steps within 24 h.