What are the recommended antibiotics for treating H pylori (Helicobacter pylori) gastritis?

Recommended Antibiotics for H. pylori Gastritis Treatment

Bismuth quadruple therapy (PPI + bismuth + tetracycline + metronidazole) for 14 days is the recommended first-line treatment for H. pylori gastritis in regions with high clarithromycin resistance (>15-20%). 1

First-Line Treatment Options

Treatment selection should be based on regional antibiotic resistance patterns:

1. High Clarithromycin Resistance Regions (>15-20%):

   • Bismuth quadruple therapy (14 days): PPI twice daily + bismuth ~300mg four times daily + tetracycline 500mg four times daily + metronidazole 500mg three times daily 2, 1
   • Eradication rate: approximately 85% 1

2. Low Clarithromycin Resistance Regions (<15-20%):

   • Standard triple therapy (14 days): PPI twice daily + amoxicillin 1g twice daily + clarithromycin 500mg twice daily 1
   • Eradication rate: approximately 85% when used for 14 days 1

3. Alternative First-Line Option:

   • Concomitant non-bismuth quadruple therapy (14 days): PPI twice daily + clarithromycin 500mg twice daily + amoxicillin 1g twice daily + metronidazole 500mg twice daily 2, 1
   • Eradication rate: approximately 80% 1

Second-Line Treatment Options

After failure of first-line therapy:

1. After clarithromycin-based therapy failure:

   • Bismuth quadruple therapy (as described above) 1
   • Levofloxacin-based triple therapy: PPI twice daily + amoxicillin 1g twice daily + levofloxacin 500mg once daily for 10-14 days 2, 1

2. After bismuth quadruple therapy failure:

   • Levofloxacin-based therapy 1
   • Clarithromycin-based therapy (if not used previously) 1

Third-Line Treatment Options

For refractory cases with two failed therapies:

• Rifabutin-based triple therapy: PPI twice daily + rifabutin 150-300mg daily + amoxicillin 1g twice daily for 10 days 2
• High-dose dual therapy: PPI high-dose twice daily + amoxicillin 2-3g daily in 3-4 split doses for 14 days 2

Important Clinical Considerations

1. Antibiotic Resistance Testing:

   • After two failed therapies with confirmed patient adherence, H. pylori susceptibility testing should guide subsequent regimen selection 2
   • Ideally, therapy should be based on antimicrobial susceptibility testing when available 1

2. Treatment Duration:

   • Extending treatment from 7 to 14 days improves eradication success by approximately 5% 1

3. PPI Administration:

   • Optimal PPI dosing is 30 minutes prior to eating or drinking on an empty stomach 2
   • Avoid concomitant use of other antacids (e.g., H2 receptor antagonists) 2

4. Confirmation of Eradication:

   • Test for eradication at least 4 weeks after completing treatment 1
   • Use urea breath test or monoclonal stool antigen test (discontinue PPI for at least 7 days and antibiotics/bismuth for at least 4 weeks before testing) 1

5. Special Populations:

   • For penicillin-allergic patients, substitute amoxicillin with metronidazole in triple therapy regimens 3
   • Consider antibiotic history before selecting a treatment regimen to avoid previously used antibiotics 1

Common Pitfalls to Avoid

1. Using standard triple therapy in high-resistance regions: Clarithromycin resistance has increased significantly, limiting the effectiveness of standard triple therapy 1

2. Short treatment duration: 7-day regimens have lower eradication rates compared to 14-day regimens 1

3. Repeating failed antibiotic regimens: Patients should not be retreated with regimens containing antibiotics to which resistance has likely developed 1

4. Neglecting to confirm eradication: Failure to confirm eradication can lead to persistent infection and complications 1

5. Adjunctive therapies like probiotics: These are of unproven benefit for refractory H. pylori infection and should be considered experimental 2