What are the treatment guidelines for a patient with gastritis, including those with H. pylori infection?

Treatment Guidelines for Gastritis

All patients with gastritis must be tested for H. pylori infection using non-invasive methods (urea breath test or stool antigen test), and if positive, receive bismuth quadruple therapy for 14 days as first-line treatment. 1, 2

Initial Assessment and Diagnostic Testing

• Test every gastritis patient for H. pylori using urea breath test (sensitivity 88-95%, specificity 95-100%) or monoclonal stool antigen test (sensitivity 94%, specificity 92%) 3, 2
• Patients must discontinue PPIs for at least 2 weeks before testing to avoid false-negative results 2
• For patients with erosive gastritis or atrophic changes on endoscopy, check antiparietal cell antibodies and anti-intrinsic factor antibodies to evaluate for autoimmune gastritis 1, 2
• Screen for vitamin B-12 and iron deficiencies in all patients with atrophic gastritis, as failure to do so leads to inadequate management 1, 2

Treatment Algorithm Based on H. pylori Status

For H. pylori-Positive Gastritis

First-Line Treatment: Bismuth Quadruple Therapy for 14 Days 1, 2, 4

• High-potency PPI twice daily (esomeprazole 20-40 mg OR rabeprazole 20 mg) taken 30 minutes before meals 1, 4
• Bismuth subsalicylate 1, 4
• Metronidazole 500 mg twice daily 3, 4
• Tetracycline 3, 4

This regimen is preferred over clarithromycin-based triple therapy due to increasing clarithromycin resistance rates exceeding 15% in most regions 4. The 14-day duration is crucial and significantly outperforms shorter courses 4.

Avoid pantoprazole when possible due to lower potency (40 mg pantoprazole equals only 9 mg omeprazole), whereas rabeprazole 20 mg equals 36 mg omeprazole and esomeprazole 20-40 mg equals 32 mg omeprazole 1.

Second-Line Treatment if First-Line Fails 3, 4

• Levofloxacin 500 mg once daily (or 250 mg twice daily) 3
• Amoxicillin 1000 mg twice daily 3, 5
• High-potency PPI twice daily for 10-14 days 3

Approximately 15-20% of patients fail first-line therapy and require retreatment 4.

Mandatory Eradication Confirmation 2, 4

• Perform urea breath test or stool antigen test at least 4 weeks after completing antibiotics and 2 weeks after stopping PPI therapy 4
• Do not use serology to assess eradication success, as antibody titers take up to 6 months to fall by 50% 2
• Relying solely on symptom resolution without confirming eradication leads to persistent infection and complications 1

For H. pylori-Negative Gastritis

Standard PPI Therapy 2

• Esomeprazole 20-40 mg once daily OR rabeprazole 20 mg once daily OR lansoprazole 30 mg once daily for 8 weeks 1, 2, 6
• Take 30 minutes before meals for optimal effectiveness 1, 2
• H2-receptor antagonists (H2RAs) provide faster symptom relief but are less effective than PPIs for healing gastric lesions 1, 2

Special Considerations for NSAID-Induced Gastritis

Immediate Management 1, 2

• Discontinue all NSAIDs immediately if clinically feasible 1, 2
• If NSAIDs cannot be stopped, add high-dose PPI therapy indefinitely (esomeprazole 40 mg or rabeprazole 20 mg twice daily) 1, 2
• Use the lowest effective NSAID dose for the shortest duration 1

Risk Stratification for Gastroprotection 1

High-risk patients requiring intensive gastroprotection include those with:

• Previous peptic ulcer or ulcer complication 1
• Age >65 years 1
• Concurrent corticosteroid use 1
• Concurrent anticoagulation or antiplatelet therapy 1
• High-dose or multiple NSAID use 1

For high-risk patients, combine a COX-2 selective inhibitor with a PPI for maximum protection 1.

H. pylori Eradication Before Long-Term NSAID Use 1

• Eradicate H. pylori before starting long-term NSAID therapy, especially in patients with previous ulcer history 1
• In patients already on NSAIDs with H. pylori infection, both PPI therapy and eradication are necessary—eradication alone is insufficient 1

Alternative Gastroprotective Agent 1

• Misoprostol 600-800 mg daily reduces NSAID-associated gastric ulcers by 74%, but causes diarrhea and abdominal pain in ~20% of patients, limiting tolerability 1
• H2-receptor antagonists are inadequate for gastroprotection as they decrease duodenal ulcer risk but not gastric ulcer risk 1

Surveillance and Long-Term Management

For Advanced Atrophic Gastritis 1, 2

• Perform surveillance endoscopy every 3 years in patients with advanced atrophic gastritis, severe atrophy, corpus-predominant gastritis, or intestinal metaplasia 1, 2, 4
• H. pylori eradication is mandatory for gastric cancer prevention in high-risk populations, including first-degree relatives of gastric cancer patients 2

For Autoimmune Gastritis 1

• Screen for concomitant autoimmune disorders, particularly autoimmune thyroid disease 1
• Consider interval endoscopic surveillance based on individualized risk assessment 1

Critical Pitfalls to Avoid

• Inadequate PPI dosing or incorrect timing (not taking 30 minutes before meals) reduces acid suppression and eradication rates 1, 2, 4
• Premature discontinuation before 8 weeks prevents adequate mucosal healing 1, 2
• Failure to confirm H. pylori eradication allows persistent infection and cancer progression 2, 4
• Prescribing long-term PPIs without first eradicating H. pylori accelerates atrophic gastritis and increases gastric cancer risk 1, 2, 7
• Using clarithromycin triple therapy without resistance data is unreliable due to high clarithromycin resistance rates 4
• Combining multiple NSAIDs dramatically increases GI risk, especially with aspirin 1
• Using buffered or coated aspirin does not significantly decrease GI risk 1

Renal Impairment Adjustments

• For severe renal impairment (GFR <30 mL/min), adjust amoxicillin dosing to 500 mg every 12 hours for GFR 10-30 mL/min and 500 mg every 24 hours for GFR <10 mL/min 4, 5