Background and aim: Eradication rates of Helicobacter pylori following standard triple therapy are declining worldwide, but high-dose proton pump inhibitor-based triple therapy (HD-PPI-TT) and sequential therapy (ST) have demonstrated higher cure rates. We aimed to compare the efficacy and tolerability of HD-PPI-TT and ST in H. pylori-associated functional dyspepsia (FD).

Methods: One hundred and twenty H. pylori-associated functional dyspepsia patients were randomized to receive 10-day HD-PPI-TT (60 mg lansoprazole/500 mg clarithromycin/1 g amoxicillin, each administered twice daily for 10 days) or 10-day ST (30 mg lansoprazole/1 g amoxicillin, each administered twice daily for 5 days followed by 30 mg lansoprazole/500 mg clarithromycin/400 mg metronidazole, each administered twice daily for 5 days). H. pylori status was determined in post-treatment week 4 by ¹⁴ C-urea breath test. Eradication and antibiotic resistance rates, dyspeptic symptoms, drug compliance, and adverse effects were compared.

Results: Intention-to-treat eradication rates were similar in the ST and HD-PPI-TT groups (85% vs. 80%; P = 0.47). However, the eradication rate was significantly higher following ST compared with HD-PPI-TT in per protocol analysis (94.4% vs. 81.4%; P = 0.035). ST achieved higher cure rates than HD-PPI-TT in clarithromycin-resistant H. pylori strains (100% vs. 33.3%; P = 0.02). Treatment compliance was similar in the HD-PPI-TT and ST groups, although nausea and dizziness were more common in the ST group.

Conclusions: Sequential therapy achieved better H. pylori eradication than HD-PPI-TT in patients with FD. However, the eradication rate for ST fell from 94.4% in per protocol to 85% in intention-to-treat analysis. Adverse effects might result in poorer compliance and compromise actual ST efficacy