What are the recommended tests and treatment regimen for Helicobacter pylori infection in adults?

H. Pylori Testing and Treatment Recommendations

For treatment-naive adults with H. pylori infection, bismuth quadruple therapy (BQT) for 14 days is the preferred first-line regimen when antibiotic susceptibility is unknown. 1

Who Should Be Tested?

Testing should be offered to the following patients 2:

• Active or past gastric/duodenal ulcer disease (100% agreement, high evidence)
• Uninvestigated dyspepsia (100% agreement, high evidence)
• Gastric MALT lymphoma (100% agreement, moderate evidence)
• Family history of gastric cancer (100% agreement, moderate evidence)
• Family members in same household of patients with active H. pylori (91% agreement)
• First-generation immigrants from high-prevalence areas (82% agreement, high evidence)
• High-risk ethnic groups in the US (Latino, African American, East Asians) (91% agreement)
• Regular NSAID users being considered for long-term therapy

Diagnostic Testing Methods

Non-Invasive Tests (Preferred for Initial Diagnosis)

• Urea breath test - most frequently recommended method 3
• Stool antigen testing - equally accurate 4

Invasive Tests (When Endoscopy Performed)

• Biopsy urease test and histology with immunohistochemistry 2
• Molecular testing for antibiotic resistance detection 5

Critical Pitfall: Stop proton pump inhibitors 1-2 weeks before testing to avoid false-negative results 4. In bleeding peptic ulcer disease, confirm negative biopsy results with urea breath testing 4.

First-Line Treatment Regimens (14 Days)

Preferred: Bismuth Quadruple Therapy (BQT)

• Bismuth ~300mg QID
• Metronidazole 500mg TID (or 1.5-2g daily in divided doses) 6
• Tetracycline 500mg QID
• PPI BID
• Duration: 14 days 1, 7

Alternative First-Line Options:

1. Rifabutin triple therapy (14 days) - suitable empiric alternative in penicillin-tolerant patients 1

   • Rifabutin 150-300mg daily
   • Amoxicillin 1g BID (minimum 2g daily divided TID-QID) 6
   • PPI BID

2. Concomitant (non-bismuth) quadruple therapy (14 days) 7

   • PPI BID
   • Amoxicillin 1g BID
   • Metronidazole 500mg BID
   • Clarithromycin 500mg BID
   • Only use if local clarithromycin resistance <15% 8

3. Potassium-competitive acid blocker (PCAB) dual therapy (14 days) - newer option 1

Clarithromycin triple therapy is NOT recommended due to resistance rates now exceeding 30% in North America 9.

Second-Line/Salvage Treatment

After Failed First-Line BQT:

"Optimized" BQT for 14 days if not previously used optimally 1, ensuring:

• Adequate metronidazole dosing (1.5-2g daily) 6
• High-dose, potent PPI or PCAB 6
• Confirmed patient adherence

After Failed Optimized BQT:

Rifabutin triple therapy (14 days) is the preferred empiric salvage 1

Alternative Salvage Options:

• Levofloxacin-based triple therapy (14 days) 6
  • Levofloxacin 500mg daily
  • Amoxicillin 1g BID
  • High-dose PPI BID
  • Only use if susceptibility confirmed (resistance >30%) 9

After two failed therapies with confirmed adherence, antibiotic susceptibility testing should guide subsequent regimens 6, 1.

Key Treatment Principles

Duration

All regimens should be 14 days - longer durations provide higher eradication rates than 7-10 day courses 6, 7.

Acid Suppression

Inadequate acid suppression causes treatment failure 6. Use:

• High-dose PPIs (BID dosing)
• PPIs not metabolized by CYP2C19, or
• Potassium-competitive acid blockers when available

Amoxicillin Dosing

Minimum 2g daily divided TID or QID to avoid low trough levels 6. Consider penicillin allergy testing in patients labeled allergic (unless anaphylaxis history) to enable amoxicillin use 6.

Metronidazole Optimization

When using metronidazole regimens, dose at 1.5-2g daily in divided doses with concomitant bismuth therapy - this may overcome in vitro resistance 6.

Post-Treatment Confirmation

Universal test-of-cure is recommended for all treated patients 1. Perform urea breath test or stool antigen test at least 4 weeks after completing therapy (off PPIs for 1-2 weeks).

Common Pitfalls to Avoid

1. Using clarithromycin-based regimens empirically - resistance exceeds 30% 9
2. Treating for <14 days - significantly reduces eradication rates 7
3. Inadequate PPI dosing - use high-dose BID regimens 6
4. Testing while on PPIs - causes false negatives 4
5. Using levofloxacin empirically - resistance >30%, requires susceptibility testing 9
6. Assuming penicillin allergy without testing - many can be delisted 6