Related Experiment Video
Updated: Jan 9, 2026

Gastric Mucosa Quantitative Polymerase Chain Reaction Analysis for Detecting Helicobacter pylori and Antibiotic Resistance
Published on: March 7, 2025
Comparison between optimized bismuth quadruple therapy and standard clarithromycin-based triple therapy for
Patricio Andrés Medel-Jara1,2,3, Gonzalo Latorre4, Eduardo Fuentes-Lopez5
1Facultad de Medicina, Programa de Doctorado en Epidemiología, Pontificia Universidad Católica de Chile, Santiago, Chile.
Background:
Helicobacter pylori eradication reduces the risk of peptic ulcer disease and gastric cancer. In Chile, the effectiveness of standard triple therapy has dropped below 80%. We compared optimized bismuth quadruple therapy: esomeprazole 40 mg three times a day, amoxicillin 1 gr three times a day, metronidazole 500 mg three times a day, and bismuth subsalicylate 369 mg three times a day for 14 days, and standard triple therapy omeprazole 20 mg twice a day, amoxicillin 1 gr twice a day, and clarithromycin 500 mg twice a day for 14 days in a Chilean population.
Methods:
Randomized double-blind clinical trial. 127 treatment-naïve individuals with confirmed active H. pylori were recruited. The primary outcome was successful H. pylori eradication, at least 4 weeks post-treatment. We assessed H. pylori resistance to clarithromycin and participants' CYP2C19 genotype/phenotype. We compared eradication success between the groups using intention-to-treat and per-protocol analyses. The trial adhered to CONSORT guidelines. NTC-Number: NCT05664685 (trial completed).
Findings:
127 participants were recruited and randomized (64 standard triple therapy, 63 optimized bismuth quadruple therapy). Men were 44% (56/127), and the mean age was 48 (standard deviation: 14.2) in the sample. Baseline characteristics between the two groups were similar. In intention-to-treat analysis, optimized bismuth quadruple therapy had a significantly higher eradication rate versus standard triple therapy: 95% (60/63) [95% CI 86%-99%] vs. 81% (52/64) [70%-89%], p = 0.033. Adverse events were comparable: optimized bismuth quadruple therapy 67% (42/63) [54%-77%] vs. standard triple therapy 66% (42/64) [53%-76%], p = 1.00. There was no difference in baseline clarithromycin resistance or CYP2C19 polymorphisms.
Interpretation:
Optimized bismuth quadruple therapy eradication is higher than standard triple therapy in treatment-naïve individuals with active H. pylori, without difference in adverse events or adherence. Optimized bismuth quadruple therapy is a reliable and safe empiric eradication therapy, especially in areas with high clarithromycin resistance.
Funding:
FONDECYT (1230504 AR); ANID-FONDAP (152220002 AR); Horizon 2020 program of European Union (825832 AR); ANID-FONDAP (15130011).
Related Concept Videos
Treating Helicobacter pylori in Peptic Ulcers: Antimicrobial Therapy
Peptic Ulcer Disease IV: Management
The therapeutic approach involves ensuring adequate rest, implementing drug therapy, promoting smoking cessation, making dietary modifications, and emphasizing long-term follow-up care.
Pharmacological management
The prevailing therapy for peptic ulcers involves a combination of managing the patient's current...
Peptic Ulcer Disease III: Clinical Manifestations and Diagnostic Studies
Few clinical manifestations differentiate gastric ulcers from duodenal ulcers. Distinctions in the location, timing, and pain relief are crucial for healthcare providers in differentiating between gastric and duodenal ulcers during clinical assessments.
Pulmonary Tuberculosis V
Latent tuberculosis infection occurs when TB bacteria are present in a person's body, but are not causing illness or symptoms. It is not contagious, and preventive treatment is crucial to avoid the...
Gastritis III: Clinical Manifestations and Management
Clinical manifestations of acute gastritis
The patient with acute gastritis may have a rapid onset of symptoms, such as epigastric pain or discomfort, dyspepsia, anorexia, hiccups, or nausea and vomiting, which can last from a few hours to a few days. Erosive or hemorrhagic gastritis may cause bleeding, which may manifest as blood in vomit or as...
Acid Suppressive Drugs for Peptic Ulcer Disease: Histamine H2-Receptor Antagonists

