What is the recommended medical management for gastritis, including H. pylori testing and appropriate treatment options?

Medical Management of Gastritis

All patients with gastritis should be tested for H. pylori infection and, if positive, treated with 14-day bismuth quadruple therapy or concomitant non-bismuth quadruple therapy as first-line treatment, given that clarithromycin resistance now exceeds 30% in most regions 1.

Initial Diagnostic Approach

H. pylori Testing is Mandatory

Every patient with gastritis must be assessed for H. pylori infection 2. This is non-negotiable because:

• H. pylori causes chronic gastritis that progresses to atrophic gastritis, intestinal metaplasia, and gastric cancer
• Eradication cures gastritis and prevents peptic ulcer disease and gastric cancer 1, 3

Testing options include:

• Non-invasive: Urea breath test, stool antigen test (preferred for initial diagnosis)
• Invasive: Endoscopic biopsy with histology (required when endoscopy performed for other indications)
• Avoid serology for confirming eradication—it remains positive after successful treatment 2

First-Line H. pylori Eradication Regimens

The landscape has shifted dramatically due to rising antibiotic resistance. Traditional clarithromycin-based triple therapy is now obsolete in most settings 1.

Preferred First-Line Options (14 days duration):

1. Bismuth Quadruple Therapy (most recommended)

• PPI (twice daily) + Bismuth + Tetracycline + Metronidazole
• Effective even with metronidazole resistance
• Avoids clarithromycin entirely 1

2. Concomitant Non-Bismuth Quadruple Therapy (when bismuth unavailable)

• PPI (twice daily) + Amoxicillin 1000mg (twice daily) + Clarithromycin 500mg (twice daily) + Metronidazole 500mg (twice daily)
• Use only in areas with clarithromycin resistance <15% 4

Critical Treatment Principles:

• 14-day duration is mandatory—shorter courses have inferior eradication rates 1
• High-dose potent PPIs or vonoprazan (potassium-competitive acid blocker) for adequate acid suppression 4, 5
• Avoid clarithromycin-based triple therapy unless local resistance is documented <15% AND patient has no prior macrolide exposure 1

Confirmation of Eradication

Test for cure is mandatory at least 4 weeks after completing therapy using:

• Urea breath test or stool antigen test (NOT serology)
• Ensure patient off PPIs for 2 weeks and antibiotics for 4 weeks before testing 2

Second-Line Therapy (If First Attempt Fails)

Never reuse antibiotics from failed regimens 1, 4. Choose based on what was used initially:

• If bismuth quadruple therapy failed: Use levofloxacin triple therapy (PPI + Amoxicillin + Levofloxacin) for 14 days
• If concomitant therapy failed: Use bismuth quadruple therapy for 14 days
• Avoid levofloxacin if patient previously exposed or if local resistance >15% 1

Management of Atrophic Gastritis

When endoscopy reveals atrophic changes or intestinal metaplasia:

Immediate Actions:

1. Obtain topographic biopsies from body and antrum in separate jars 2
2. Test and treat H. pylori if present—eradication may halt progression 2
3. Check for autoimmune gastritis if corpus-predominant:
   • Anti-parietal cell antibodies
   • Anti-intrinsic factor antibodies
   • Vitamin B12 and iron levels 2

Surveillance Strategy:

• Advanced atrophic gastritis: Endoscopy every 3 years 2
• Autoimmune gastritis: Screen for type 1 gastric neuroendocrine tumors; surveillance every 1-2 years if NETs present 2
• All atrophic gastritis patients: Monitor for iron and B12 deficiency regardless of etiology 2

Common Pitfalls to Avoid

1. Using outdated triple therapy: Clarithromycin resistance is now >30% in most regions—this regimen fails in the majority of patients 1, 6

2. Inadequate treatment duration: 7-10 day courses are obsolete; 14 days is the evidence-based standard 1

3. Failing to confirm eradication: Approximately 20-30% of patients fail first-line therapy—always test for cure 4

4. Reusing failed antibiotics: If clarithromycin or levofloxacin failed once, resistance is confirmed—never use again 1, 4

5. Missing atrophic gastritis: Intestinal metaplasia on biopsy almost always indicates underlying atrophic gastritis requiring risk stratification and surveillance 2

6. Inadequate acid suppression: Standard-dose PPIs may be insufficient; use high-dose PPIs or vonoprazan for optimal eradication 4, 5

Special Considerations

When antimicrobial susceptibility testing should be pursued:

• After 2 failed eradication attempts
• Consider rifabutin-based triple therapy or high-dose dual amoxicillin-PPI therapy as salvage options 1, 4

Adjunctive measures:

• Probiotics may reduce antibiotic side effects and modestly improve eradication rates 4
• Ensure medication adherence through patient education about side effects and importance of completion