Failure of optimized dual proton pump inhibitor amoxicillin therapy: What now?

For a decade following the initial description of dual amoxicillin–proton pump inhibitor (PPI) therapy by Unge et al.,[1] investigators attempted to optimize the doses and duration of this regimen in an attempt to reliably achieve >90% cure rates (reviewed in Dore et al.).[2] When given twice daily PPI and amoxicillin cured approximately 62% patients (range 60–64%),[3] and increasing the omeprazole dosage from 20 to 60 mg b.i.d. did not reliably improve outcome.[4] For example, even amoxicillin 750 mg t.i.d. with omeprazole 40 mg b.i.d. or 40 mg t.i.d. for 14 days cured only approximately 80% of cases.[5] Labenz et al.[6] gave 40–80 mg of omeprazole with amoxicillin 500 mg q.i.d. for 2 weeks with 82.8% success. In the USA, dual therapy with 1 g amoxicillin and 30 mg lansoprazole, each given every 8 h produced a 60–70% cure rate[7,8] and even this low cure rate was approved by the Food and Drug Administration (FDA).