Helicobacter Pylori and Its Treatment
Helicobacter pylori (H. pylori) is a gram-negative bacterium that colonizes the gastric mucosa and causes chronic gastritis, which can lead to peptic ulcers, gastric cancer, and other gastrointestinal diseases. The recommended first-line treatment is bismuth quadruple therapy for 14 days to maximize eradication efficacy and overcome increasing antibiotic resistance. 1, 2
What is H. pylori?
- H. pylori is a bacterium that lives in the gastric mucus layer where there is a pH gradient from 2.7 to 2, causing chronic gastritis 1
- It proliferates at pH 5 and survives at pH 4, making it uniquely adapted to the stomach environment 1
- H. pylori infection is responsible for many peptic ulcers and >80% of cases of gastric cancer 1
- It is the third most common cause of cancer death worldwide and is associated with several other gastric and extra-gastric diseases 1
First-Line Treatment Options
Bismuth quadruple therapy is the preferred first-line treatment when antibiotic susceptibility is unknown, consisting of:
In areas with low clarithromycin resistance (<15-20%), triple therapy may be considered:
- PPI twice daily
- Clarithromycin
- Amoxicillin or metronidazole
- Duration: 10-14 days 2
Concomitant (non-bismuth quadruple) therapy is an alternative first-line option:
- PPI twice daily
- Clarithromycin
- Amoxicillin
- Metronidazole
- Duration: 10-14 days 2
Why Bismuth Quadruple Therapy is Preferred
- Clarithromycin resistance has increased globally (from 9% in 1998 to 17.6% in 2008-2009 in Europe), making traditional triple therapy less effective 2
- Bismuth is valuable because bacterial resistance to this compound is extremely rare 2
- Bismuth quadruple therapy is effective even against strains resistant to metronidazole 4
- The treatment achieves eradication rates >80% even in areas with high antibiotic resistance 4
Treatment Considerations
- High-dose PPI (twice daily) increases the efficacy of eradication therapy by reducing gastric acidity and enhancing antibiotic activity 2
- Extending treatment duration from 7 to 14 days improves eradication success by approximately 5% 2
- Smoking and short duration of treatment are predictors of eradication failure 5
- Diarrhea occurs in 21-41% of patients during the first week of H. pylori eradication therapy due to disruption of normal gut microbiota 2
- Consider adjunctive probiotics to reduce the risk of diarrhea and improve patient compliance 2
Second-Line and Rescue Therapies
- After failed first-line therapy, an alternative regimen should be selected based on prior antibiotic exposure 2
- Levofloxacin-based triple therapy (PPI + amoxicillin + levofloxacin) for 10 days is an effective second-line option with 81% per-protocol eradication rate 6
- Metronidazole-based triple therapy has shown high efficacy (96.7-100%) as second-line treatment in some populations 7
- After two failed eradication attempts, antibiotic susceptibility testing is recommended to guide further treatment 2
- Rifabutin-based triple therapy (PPI + amoxicillin + rifabutin) is recommended as a rescue option after failed first-line treatment 2
Common Pitfalls and Caveats
- Avoid repeating antibiotics to which the patient has been previously exposed, especially clarithromycin and levofloxacin 2
- In regions with clarithromycin resistance >15-20%, standard triple therapy should be abandoned due to unacceptably low eradication rates 2
- Most antibiotics are not active at low pH, which is why PPIs are a crucial component of all H. pylori treatment regimens 1
- Confirm eradication with urea breath test or monoclonal stool antigen test at least 4 weeks after completion of therapy and at least 2 weeks after PPI discontinuation 2
- The FDA has approved amoxicillin in combination with clarithromycin plus lansoprazole as triple therapy for the treatment of H. pylori infection and duodenal ulcer disease 8