Comparison of Amoxicillin–Metronidazole Plus Famotidine or Lansoprazole for Amoxicillin–Clarithromycin–Proton Pump Inhibitor Treatment Failures for Helicobacter pylori Infection

Abstract

Background: Proton pump inhibitor–amoxicillin–metronidazole is recommended as second-line Helicobacter pylori therapy in Japan. The authors assessed the efficacy and safety of second-line eradication using the H₂-receptor antagonist famotidine as a substitute for proton pump inhibitor.

Materials and methods: Sixty-one patients who failed in first-line H. pylori eradication using proton pump inhibitor–clarithromycin–amoxicillin were randomly assigned to either second-line therapy including metronidazole: a 7-day course of lansoprazole 30 mg, amoxicillin 750 mg, and metronidazole 250 mg, b.i.d. (lansoprazole group); or a 7-day course of famotidine 40 mg, amoxicillin 750 mg, and metronidazole 250 mg, b.i.d. (famotidine group). Eradication was assessed for each group at least 4 weeks after completing eradication therapy. Drug susceptibility test was performed using 57 strains in pretreatment to clarithromycin, metronidazole, and amoxicillin.

Results: Prior to second-line H. pylori eradication, the rate of resistance to clarithromycin was high at 84% (48/57). Similarly, resistance to metronidazole was low at 5.3% (3/57); however, no amoxicillin-resistant strains were found.

The eradication rates for both lansoprazole and famotidine treatment groups were high at 97% (29/30) and 94% (29/31), respectively.

Conclusions: Famotidine treatment including metronidazole–amoxicillin as second-line therapy provided a high eradication rate similar to lansoprazole therapy. Famotidine is therefore expected to serve as a useful H. pylori eradication regimen in patients with proton pump inhibitor allergy, an economic benefit in terms of reduced health-care costs is also anticipated.