Guideline Recommendations for Acid Suppression in Helicobacter pylori Eradication

Standard Acid‑Suppression Component

• Proton‑pump inhibitors (PPIs), not H₂‑receptor antagonists such as famotidine, are the recommended acid‑suppression agents in every current H. pylori eradication regimen according to major societies (American Gastroenterological Association, American College of Gastroenterology, Maastricht V/Florence, Toronto Consensus)【1】【2】【3】【4】【5】.
• The same societies explicitly mandate the use of PPIs in all first‑ and second‑line therapies for H. pylori eradication【1】【2】【3】【4】【5】.

First‑Line Regimens (PPIs Required)

• Bismuth quadruple therapy – PPI twice daily + bismuth 300 mg four times daily + metronidazole 500 mg three times daily + tetracycline 500 mg four times daily for 14 days【1】【3】【4】【5】.
• Concomitant therapy – PPI twice daily + amoxicillin 1 g twice daily + clarithromycin 500 mg twice daily + metronidazole 500 mg twice daily for 14 days【4】【5】【6】.
• Levofloxacin triple therapy – PPI twice daily + amoxicillin 1 g twice daily + levofloxacin 500 mg once daily for 14 days【4】【5】.

Importance of Adequate Acid Suppression

• Inadequate acid suppression is linked to higher rates of eradication failure; therefore, optimal acid control is essential for treatment success【2】【7】.
• The AGA 2021 guideline recommends:
  
  • Using high‑dose, potent PPIs【1】.
  • Selecting PPIs that are not metabolized by CYP2C19 to avoid reduced efficacy in rapid metabolizers【2】.
  • Employing potassium‑competitive acid blockers (e.g., vonoprazan) when they are available【7】.
• Concomitant use of H₂ antagonists with PPIs should be avoided because H₂ agents can interfere with PPI activation【1】【3】, a specific warning highlighted by the AGA 2021 guideline【1】【3】.

Special Populations & Alternative Strategies

• Documented PPI allergy (extremely rare) – Options include:
  
  • Bismuth quadruple therapy, where acid suppression is less critical due to the synergistic effect of bismuth【2】【3】.
  • Consideration of potassium‑competitive acid blockers if accessible【2】.
• Extensive CYP2C19 metabolizers – Recommendations are:
  
  • Increase the PPI dose【1】.
  • Use more potent PPIs such as esomeprazole or rabeprazole【7】.
  • Utilize vonoprazan where available【7】.

Role of Famotidine (H₂ Antagonist)

• No current guideline endorses a famotidine‑based regimen for H. pylori eradication【1】【2】【4】【5】【6】.
• Famotidine should be reserved only for exceptional circumstances (e.g., true PPI allergy) and administered under specialist supervision, not as a standard therapeutic approach【2】.