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Bismuth Subsalicylate / Metronidazole / Tetracycline Dosage

Medically reviewed by Last updated on Sep 6, 2023.

Applies to the following strengths: 262.4 mg-250 mg-500 mg

Usual Adult Dose for Helicobacter pylori Infection

524.8 mg bismuth subsalicylate (chewable), metronidazole 250 mg, and tetracycline 500 mg orally four times daily for 14 days with meals and at bedtime. This therapy should be accompanied by a histamine-2 antagonist approved for the treatment of acute duodenal ulcer. The metronidazole tablet and the tetracycline capsule should be swallowed whole with a full glass of water (8 ounces).

Usual Pediatric Dose for Helicobacter pylori Infection

8 years and older: Bismuth subsalicylate 524.8 to 525 mg-metronidazole 250 mg-tetracycline 500 mg orally 4 times a day (after meals and at bedtime)

  • Duration of therapy: 14 days

Comment: An H(2) receptor antagonist approved to treat acute duodenal ulcer should be given with this drug.

Use: Eradication of Helicobacter pylori infection in patients with active or a history of duodenal ulcer

Renal Dose Adjustments

Mild to moderate renal impairment: Data not available
Severe renal impairment: Contraindicated

Liver Dose Adjustments

Mild to moderate hepatic dysfunction (Child-Pugh A and B): Use with caution.
Severe hepatic dysfunction (Child-Pugh C): Dose adjustment(s) may be required; however, no specific guidelines have been suggested. Caution recommended.



  • Metronidazole has been shown to be carcinogenic in mice and rats.
  • It is unknown whether metronidazole is associated with carcinogenicity in humans.

Safety and efficacy have not been established in patients younger than 8 years.

Consult WARNINGS section for additional precautions


Data not available

Other Comments

Administration advice:

  • This drug should be given with a full glass of water (e.g., 8 ounces), especially the bedtime dose.
  • If a dose is missed, patients should continue the normal dosing schedule; patients should not take double doses.

  • Dermatologic: Erythema/photosensitivity, signs/symptoms of cutaneous reactions
  • Hematologic: Initial and post-treatment total and differential leukocyte counts, especially in patients with evidence/history of blood dyscrasias
  • Ocular: Ophthalmologic evaluation in patients who develop visual disturbances

Patient advice:
  • Tell patients that it is important to complete the full regimen.
  • Instruct patients to seek medical attention if signs/symptoms of hypersensitivity, abnormal neurological effects, photosensitivity, or other cutaneous reactions occur.
  • Patients should be told to avoid unprotected exposure to sunlight/UV light during treatment.
  • Advise patients to speak to their healthcare provider if they become pregnant, intend to become pregnant, or are breastfeeding.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.