What is the recommended first-line therapy for H pylori (Helicobacter pylori) infection?

First-Line Therapy for Helicobacter pylori Infection

In areas of high clarithromycin resistance (>15-20%), bismuth-containing quadruple therapy is recommended as first-line empirical treatment for H. pylori infection. 1, 2

Treatment Selection Based on Clarithromycin Resistance

High Clarithromycin Resistance Areas (>15-20%)

• First-line therapy: Bismuth-containing quadruple therapy consisting of:

  • PPI (twice daily)
  • Bismuth subsalicylate/subcitrate (four times daily)
  • Metronidazole (500 mg three or four times daily)
  • Tetracycline (500 mg four times daily)
  • Duration: 14 days 1, 2

• If bismuth-containing regimen is not available, alternative first-line options include:

  • Sequential treatment (5-day PPI + amoxicillin, followed by 5-day PPI + clarithromycin + metronidazole)
  • Non-bismuth quadruple therapy (PPI + amoxicillin + clarithromycin + metronidazole simultaneously) 1

Low Clarithromycin Resistance Areas (<15%)

• First-line therapy options:
  • Clarithromycin-containing triple therapy: PPI + clarithromycin + amoxicillin for 14 days 1, 2
  • Bismuth-containing quadruple therapy is also an acceptable alternative 1

Optimizing Treatment Efficacy

• Use high-dose PPI (twice daily) to increase efficacy of triple therapy by 6-10% 1, 2
• Extend treatment duration to 10-14 days to improve eradication rates by approximately 5% 1, 2
• PPI-clarithromycin-metronidazole (PCM) and PPI-clarithromycin-amoxicillin (PCA) regimens have equivalent efficacy 1
• Consider adding probiotics to reduce side effects, though evidence for improved efficacy is limited 1, 2

FDA-Approved Regimens for H. pylori Eradication

• Triple therapy: 1 gram amoxicillin, 500 mg clarithromycin, and 30 mg lansoprazole, all given twice daily for 14 days 3
• Dual therapy: 1 gram amoxicillin and 30 mg lansoprazole, each given three times daily for 14 days 3

Second-Line Treatment Options

• After failure of clarithromycin-containing therapy:
  • Bismuth-containing quadruple therapy (if not used as first-line)
  • Levofloxacin-containing triple therapy (PPI + amoxicillin + levofloxacin) 1, 2, 4
• Rising rates of levofloxacin resistance should be considered when selecting second-line therapy 1, 5

Treatment Verification

• Confirm eradication at least 4 weeks after completing therapy using:
  • Urea breath test (UBT)
  • Laboratory-based validated monoclonal stool test 1, 2
• Serology is not recommended for confirming eradication 1

Special Considerations

• In patients with penicillin allergy:
  • In low clarithromycin resistance areas: PPI + clarithromycin + metronidazole
  • In high clarithromycin resistance areas: Bismuth-containing quadruple therapy 1, 2
• After failure of second-line treatment, antimicrobial susceptibility testing should guide further therapy whenever possible 1, 2

Common Pitfalls to Avoid

• Using clarithromycin-containing triple therapy in areas with high clarithromycin resistance (>15-20%) 1
• Inadequate treatment duration (less than 10-14 days) 1, 6
• Using standard-dose rather than high-dose PPI 1, 6
• Failing to verify eradication after treatment 1
• Not considering local resistance patterns when selecting therapy 1, 2