Efficacy and safety of twice a day, bismuth-containing quadruple therapy using high-dose tetracycline and metronidazole for second-line Helicobacter pylori eradication

Background/Aims Conventional second-line, bismuth-containing quadruple therapy is administered four times a day. We aimed to evaluate the efficacy and safety of twice a day administration compared to the four times a day therapy. Methods Medical records of consecutive patients with positive C-13-urea breath tests (UBTs) after first-line eradication were reviewed. From December 2018 to June 2019, 100 consecutive C-13-UBT-positive patients received tetracycline 1 g, metronidazole 750 mg, bismuth subcitrate 300 mg, and pantoprazole 20 mg twice a day for one week. The same number of consecutive(13)C-UBT-positive patients before December 2018 was included as controls. The control group received tetracycline 500 mg and bismuth subcitrate 300 mg four times a day, metronidazole 500 mg three times a day, and pantoprazole 20 mg twice a day for one week. Eradication was confirmed based on a C-13-UBT performed in the 5th week after taking quadruple therapy. Results Ninety-eight patients from the twice a day group and 99 patients from the four times a day group were analyzed. The eradication rate did not differ between the twice a day group (92/98, 93.9%) and the four times a day group (92/99, 92.9%). Adverse drug effects were found in 36 patients from the twice a day group and 50 patients from the four times a day group (P = .051). Abdominal pain, discomfort, and distention were more common with four times a day intake (13.1%) than with twice a day intake (4.1%; P = .024). Conclusions We determined for the first time that twice a day intake of bismuth-containing quadruple therapy using 2 g/d of tetracycline, 1.5 g/d of metronidazole, and 600 mg/d of bismuth subcitrate for one week is effective and safe as the conventional four times a day therapy. Twice a day intake decreased abdominal pain, discomfort, and distention.