What are the dosages for Bismuth (Bismuth subsalicylate) quad therapy?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: October 24, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Bismuth Quadruple Therapy Dosages for H. pylori Eradication

The standard bismuth quadruple therapy regimen consists of bismuth subsalicylate 120-140 mg (or 262 mg depending on formulation) 3-4 times daily, tetracycline 500 mg 4 times daily, metronidazole 500 mg 3-4 times daily, and a proton pump inhibitor at standard dose twice daily for 14 days. 1, 2, 3

Complete Regimen Components and Dosing

  • Bismuth subsalicylate: 120-140 mg 3-4 times daily or 262 mg (depending on formulation) 2 tablets 3-4 times daily 1, 2, 3
  • Tetracycline: 500 mg 4 times daily 1, 3
  • Metronidazole: 500 mg 3-4 times daily or 400 mg 4 times daily 1, 2, 3
  • Proton pump inhibitor (PPI): Standard dose twice daily 1, 2
    • Standard PPI doses: dexlansoprazole 30 mg, esomeprazole 20 mg, lansoprazole 30 mg, omeprazole 20 mg, pantoprazole 40 mg, rabeprazole 20 mg 1

Duration of Treatment

  • The recommended duration is 14 days according to Toronto Consensus and Maastricht V/Florence Consensus 1, 2
  • American College of Gastroenterology (ACG) considers 10-14 days adequate 1, 2
  • 10-day regimens may be acceptable in regions where local efficacy has been demonstrated 2, 4

Modified Dosing Schedules

  • Recent evidence supports twice-daily dosing as an alternative to improve adherence:
    • PPI standard dose twice daily
    • Bismuth 600 mg twice daily
    • Metronidazole 500 mg twice daily
    • Tetracycline 1000 mg twice daily 5, 6
  • This twice-daily regimen has shown comparable efficacy to the standard four-times-daily regimen with eradication rates of 90-95% 5, 6

Important Considerations

  • Bismuth quadruple therapy is recommended as first-line treatment in areas with high clarithromycin resistance (>15-20%) 2, 3
  • It's also recommended as second-line therapy after failure of clarithromycin-based regimens 1
  • The addition of bismuth improves treatment efficacy, especially in the presence of metronidazole resistance 3
  • Metronidazole resistance can be partially overcome by increasing the dose and duration of treatment 3
  • Doxycycline should not be substituted for tetracycline due to inferior results 3
  • For patients with penicillin allergy, bismuth quadruple therapy is preferred over clarithromycin-based regimens 1

Optimizing Treatment Success

  • Complete the full course of treatment to maximize eradication rates 2
  • Take PPI 30 minutes before eating on an empty stomach 1
  • Avoid concomitant use of other antacids such as H2-receptor antagonists 1
  • Consider local antibiotic resistance patterns when selecting therapy 2, 3
  • After two failed therapies, H. pylori susceptibility testing should be considered 1

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.