Failure of a 1-day high-dose quadruple therapy for cure of Helicobacter pylori infection

Background: The optimal duration of treatment for eradication of Helicobact er pylori has still to be defined. A 1-day high-dose quadruple therapy with a combination of amoxycillin (or tetracycline), metronidazole, a bismuth s alt and a proton pump inhibitor has led to eradication rates of 57-77%, In view of the high frequency of metronidazole-resistant strains of H, pylori in Europe, we hypothesized that by using clarithromycin in place of metroni dazole and by increasing the dose of proton pump inhibitor, the efficacy of a 1-day high-dose quadruple therapy could be improved. Methods: Patients were randomized to receive either amoxycillin 1000 mg b.d ., clarithromycin 500 mg b.d. and lansoprazole 30 mg b.d. for 7 days, or am oxycillin 2000 mg q.d.s., clarithromycin 500 mg q.d.s., lansoprazole 30 mg t.d.s. and bismuth subcitrate 240 mg q.d.s. for 1 day. Results: It was originally intended to include 100 patients. The first plan ned interim analysis performed after follow-up was completed for 30 patient s revealed H, pylori eradication rates of 80% (12/15) in the 7-day triple t herapy group and 20% (3/15) in the 1-day quadruple therapy group, the diffe rence being highly significant (P = 0.003). Because the efficacy of the 1-d ay treatment was so low, the study was stopped for ethical reasons. Eleven patients who failed with the 1-day treatment were re-treated with the 7-day triple therapy: the eradication rate was 91% (10/11). Conclusions: One-day high-dose quadruple therapy with amoxycillin, clarithr omycin, lansoprazole and bismuth subcitrate is dramatically less effective than the classic 7-day triple therapy with the same antibiotics.