What is the initial treatment for gastritis?

Initial Treatment for Gastritis

The preferred initial treatment for gastritis is a 14-day quadruple therapy regimen containing a proton pump inhibitor, bismuth subsalicylate, tetracycline, and metronidazole, which has an eradication rate of 85%. 1

Diagnosis Before Treatment

Before initiating treatment, proper diagnosis is essential:

• Stop proton pump inhibitors (PPIs) for at least 2 weeks before testing to avoid false-negative results
• Use either urea breath test (UBT) or monoclonal antibody-based stool antigen test for diagnosis (sensitivity 95%, specificity 90%)
• If PPIs cannot be stopped, validated IgG serology can be performed as it's not affected by PPI use 1

Treatment Options

First-Line Treatment Regimens

1. Bismuth quadruple therapy (preferred) - 14 days:

   • Proton pump inhibitor
   • Bismuth subsalicylate
   • Tetracycline
   • Metronidazole
   • Eradication rate: 85% 1

2. Concomitant non-bismuth quadruple therapy - 14 days:

   • Proton pump inhibitor
   • Amoxicillin
   • Metronidazole
   • Clarithromycin
   • Eradication rate: 80% 1

3. Standard triple therapy - 14 days (for areas with low clarithromycin resistance <20%):

   • Proton pump inhibitor
   • Clarithromycin
   • Amoxicillin
   • Eradication rate: 85% 1

Important Treatment Considerations

• In areas with high clarithromycin resistance, bismuth-containing quadruple therapy is preferred 1
• Concomitant antacids should be given as needed for pain relief 2
• Follow-up testing should be performed at least 4 weeks after treatment completion to confirm bacterial eradication 1

Special Patient Populations

• Patients over 45 years with severe symptoms or any patients with alarm symptoms (anemia, weight loss, dysphagia, palpable mass, malabsorption) should be referred for endoscopy before treatment 1
• Younger patients (<45 years) without alarm symptoms can be managed in primary care with H. pylori testing and eradication 1
• For gastric ulcers, proton pump inhibitor therapy should be continued until complete healing is achieved 1
• For duodenal ulcers, proton pump inhibitor therapy should be continued until bacterial eradication is confirmed 1

Management of Treatment Failure

• If first-line therapy fails, use a different regimen than the initial treatment 1
• After two treatment failures, obtain antimicrobial susceptibility testing to guide further treatment 1
• For treatment-experienced patients with persistent H. pylori infection, "optimized" bismuth quadruple therapy for 14 days is preferred 1

Common Side Effects and Management

• Common side effects include diarrhea, skin rash, vomiting, nausea, metallic taste, and muscle/joint pains
• Probiotics may help reduce side effects, though evidence is limited 1
• Penicillin allergy testing should be considered in patients with a history of penicillin allergy but without anaphylaxis 1

Important Clinical Pitfalls

1. Failing to stop PPIs before diagnostic testing, leading to false-negative results
2. Using inadequate treatment duration (14 days is recommended for optimal eradication)
3. Not confirming eradication after treatment completion
4. Misdiagnosing chronic gastritis as the cause of long-standing upper abdominal complaints 3
5. Not recognizing that PPIs alone are ineffective in eradicating H. pylori (eradication rate 0% at 6 months) 4