In vitro activity of ebrotidine, ranitidine, omeprazole, lansoprazole, and bismuth citrate against clinical isolates ofHelicobacter pylori

Abstract

The aim of this study was to determine the in vitro activity of ranitidine, ebrotidine, bismuth citrate, omeprazole, and lansoprazole against 113 clinical isolates of Helicobacter pylori cultured from gastric biopsies. An agar dilution method using Mueller-Hinton agar plus 7%, horse blood, an inoculum of 10(6) cfu/spot, and incubation in a CO2 incubator for 2 to 5 days was used. The minimum inhibitory concentrations for 50 and 90% of the isolates tested, respectively, were as follows: ranitidine, 1024 and 1024 mg/l; ebrotidine, 64 and 256 mg/l; bismuth citrate, 1 and 4 mg/l; omeprazole, 16 and 16 mg/l; and lansoprazole, 1 and 1 mg/l. Ebrotidine was more active than ranitidine, and lansoprazole was the most active compound against the Helicobacter pylori isolates tested.

Potent Gastric Acid Inhibition in Helicobacter pylori Eradication

“…Thus, while the H 2 receptor antagonists have no intrinsic antibacterial effect against H. pylori, the PPIs have been shown to have, in vitro, a remarkable bactericidal activity, with a minimum inhibitory concentration (MIC) similar to that described for the bismuth salts. [60,61] Nevertheless, it is debatable whether this antibacterial effect also applies in vivo, as the plasma PPI concentration is appreciably lower than that required for achieving an antibacterial effect in vitro. [13,62] Thus, the administration of omeprazole alone renders the detection of H. pylori impossible immediately after concluding therapy in up to 50% of the cases; but when the same diagnostic methods are used 4 weeks after the end of therapy, eradication of H. pylori is only confirmed in less than 5% of the patients.…”

Helicobacter pylori Current Chemotherapy and New Targets for Drug Design

“…Ebrotidine, an H 2 -receptor antagonist which is also known for its gastroprotective effects, has been shown to produce a 50% reduction in the extent of mucosal inflammatory changes elicited by H. pylori-induced mucosal inflammatory responses by interfering with the events propagated by NOS-2 and caspase-3 [297][298][299][300]. Pibutidine Pibutidine is a histamine H 2 -receptor antagonist which has a potent and long lasting anti-secretory effect and has been shown to be useful in the treatment of gastric ulcer whether indomethacininduced or a result of H. pylori infection [292,293] …”