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

From the Guidelines

Bismuth quadruple therapy should be administered as 2 tablets or 2 capsules of bismuth (e.g., PeptoBismol®) q.i.d. 30 min before meals, tetracycline HCl 500 mg and metronidazole 500 mg q.i.d. 30 min after meals, plus a PPIa b.i.d. 30 min before meals and bedtime for 14 days. This regimen is based on the most recent evidence from the Annual Review of Medicine in 2022 1. The dosage of bismuth subsalicylate is crucial, and the recommended dose is 2 tablets or 2 capsules q.i.d. 30 min before meals.

• Tetracycline HCl should be taken at a dose of 500 mg q.i.d. 30 min after meals.
• Metronidazole should be taken at a dose of 500 mg q.i.d. 30 min after meals.
• A proton pump inhibitor (PPI) should be taken at a dose of b.i.d. 30 min before meals and bedtime. It is essential to note that all medications should be taken with meals and at bedtime when possible to maximize effectiveness and minimize side effects, as supported by the study 1. Patients should be advised to avoid alcohol during treatment due to potential disulfiram-like reactions with metronidazole. Additionally, tetracycline should not be taken with dairy products or antacids containing calcium, magnesium, or aluminum as these can reduce absorption.

From the FDA Drug Label

Active ingredient (in each chewable tablet) Bismuth subsalicylate 262 mg The dosages for bismuth quad therapy are not explicitly stated in the provided drug label, as it only mentions the dosage of bismuth subsalicylate in a chewable tablet.

• Bismuth subsalicylate dosage: 262 mg per chewable tablet 2

From the Research

Bismuth Quad Therapy Dosages

The dosages for bismuth quad therapy vary across different studies. Here are some of the dosages mentioned:

• Bismuth subsalicylate 300 mg four times a day, lansoprazole 30 mg twice a day, tetracycline 500 mg four times a day, and metronidazole 500 mg three times a day for 14 days 3
• Lansoprazole 15 mg twice a day, tetracycline 500 mg twice a day, metronidazole 500 mg twice a day, and swallowable Pepto-Bismol caplets (2 twice a day) for 10 days 4
• Tetracycline 1 g twice a day, metronidazole 750 mg twice a day, bismuth subcitrate 300 mg twice a day, and pantoprazole 20 mg twice a day for one week 5
• Tetracycline 500 mg four times a day, bismuth subcitrate 300 mg four times a day, metronidazole 500 mg three times a day, and pantoprazole 20 mg twice a day for one week 5

Key Considerations

Some key considerations when using bismuth quad therapy include:

• The efficacy of the therapy can be affected by metronidazole resistance 4, 3
• The dosage and frequency of administration can impact the efficacy and safety of the therapy 5
• Regional differences in effectiveness may exist due to variations in antibiotic resistance patterns and patient adherence 6