Evolution of Amoxicillin-Based Mono-Antibiotic Regimens for Helicobacter pylori Eradication: From Ineffectiveness to Innovation—A Systematic Review

Mono-antibiotic therapy for <i>Helicobacter pylori</i> (<i>H. pylori</i>) infection minimizes unnecessary antibiotic exposure, reduces disruption of the gut microbiota, and lowers the risk of multidrug resistance. Although resistance of <i>H. pylori</i> to amoxicillin remains extremely low (<3%) worldwide, regular-dose amoxicillin monotherapy achieves eradication rates of less than 30%. Strategies to improve the efficacy of amoxicillin-based mono-antibiotic therapy include elevating intragastric pH with potent acid suppression, increasing the amoxicillin dose, and adding bismuth salts to the treatment regimen. This review evaluates the safety and effectiveness of six amoxicillin-based treatments for <i>H. pylori</i>. All regimens lasted 14 days and were studied in clinical trials published between 1 October 2014, and 1 October 2025. The pooled intention-to-treat and per-protocol eradication rates for each regimen were as follows: Regimen 1: Regular-dose amoxicillin + high-dose proton pump inhibitor (PPI): 84.7% (83/98) and 84.7% (83/98); Regimen 2: High-dose amoxicillin + high-dose PPI: 85.3% (3709/4347) and 89.9% (3692/4109); Regimen 3: Regular-dose amoxicillin + high-dose potassium-competitive acid blocker (PCAB): 86.0% (901/1048) and 91.2% (888/974); Regimen 4: High-dose amoxicillin + high-dose PCAB: 88.2% (1771/2009) and 93.5% (1720/1839); Regimen 5: Regular-dose amoxicillin + high-dose PCAB + bismuth: 84.9% (327/385) and 91.3% (327/358); Regimen 6: High-dose amoxicillin + high-dose PCAB + bismuth: 95.8% (115/120) and 98.4% (115/117). In conclusion, potent acid inhibition, escalation of amoxicillin dosage, and incorporation of bismuth can transform amoxicillin mono-antibiotic therapy from an ineffective approach into a highly effective eradication regimen for <i>H. pylori</i> infection.