Bactericidal activity and synergy studies of proton pump inhibitors and antibiotics against Helicobacter pylori in vitro.

The bactericidal activity of the proton pump inhibitors omeprazole and lansoprazole alone and in combination with a beta-lactam or macrolide antibiotic were investigated in vitro. Time-kill curves against Helicobacter pylori NCTC 11637 and a recent clinical isolate revealed significant concentration-dependent killing with all drugs other than amoxycillin. Combinations of proton pump inhibitor and erythromycin showed synergic activity. In contrast, proton pump inhibitor plus amoxycillin showed additive activity against the clinical isolate only. Bactericidal investigations of anti-helicobacter drugs in vitro may suggest optimum treatment strategies for this common infectious disease.