Table 1: Number of salvage treatments for each attempt.

Antibiotic regimenTreatment attempt
23456

QUAD (PPI + metronidazole + bismuth + tetracycline)74241283
PAL (PPI + amoxicillin + levofloxacin)26251212
PAC (PPI + amoxicillin + clarithromycin)101
SEQ (PPI + amoxicillin followed by PPI + metronidazole + clarithromycin)12
PMC (PPI + metronidazole + clarithromycin)2
QUAD2 (PPI + clarithromycin + levofloxacin + bismuth)1
PCL (PPI + clarithromycin + levofloxacin)1

PPI: proton pump inhibitor given twice daily. Doses for metronidazole were 500 mg qid for bismuth quadruple therapy (QUAD and QUAD2) and 500 mg BID for PPI triple (PMC) or sequential therapy (SEQ). Bismuth was prescribed as peptobismol 2 tablets qid, tetracycline as 500 mg qid, amoxicillin as 1000 mg bid, levofloxacin as 500 mg daily, and clarithromycin as 500 mg bid. Treatment duration was 14 days for attempts 3–6 except for sequential (SEQ), which was 10 days (5 days for part 1 and 5 for part 2). For attempt 2, duration varied from 7 days in 2 cases, 10 days in 2 cases, and 14 days in all remaining cases.