Bismuth subsalicylate


  • Type: Anti-diarrheal
  • Dosage Forms:
  • Routes of Administration: PO
  • Common Trade Names: Pepto Bismol, Maalox

Adult Dosing

  • Diarrhea, gas, indigestion, heartburn, nausea: 524mg (2 tabs regular strength) PO q30m PRN, max 8 doses regular strength or 4 doses extra-strength daily
  • H. pylori: 524mg (2 regular-strength tablets or 1 extra-strength tablet) + 250 mg metronidazole + 500 mg tetracycline PO q6hr x14d, plus H2 antagonist

Pediatric Dosing

  • <3y: safety/efficacy not established
  • 2-6y: 87mg PO q30-60m PRN
  • 6-9y: 175mg PO q30-60m PRN
  • 9-12y: 262mg PO q30-60m PRN
  • >12y: adult dose

Special Populations

Pregnancy Rating

  • Category C, Category D in 3rd trimester

Lactation risk

  • Salicylates enter breastmilk; use with caution

Renal Dosing

  • Caution: overdose may cause nephrotoxicity

Hepatic Dosing


  • Allergy to class/drug
  • Infectious diarrhea (fever)
  • von Willebrand disease, hemorrhage, ulcer, GI bleeding, hemophilia
  • In pediatric patients; chicken pox or influenza (risk of Reye syndrome)

Adverse Reactions


  • Duodenal ulcer, GI hemorrhage
  • Neurotoxicity
  • Renal failure


  • Nausea, diarrhea, abdominal pain, constipation, anorexia, dyspepsia, flatulence, anal discomfort
  • Black stool, melena
  • URI, sinusitis
  • Asthenia
  • Discolored tongue, taste perversion
  • Headache, dizziness
  • Paresthesia
  • Anxiety, depression
  • Tinnitus
  • Muscle spasm


  • Half-life: Bismuth- 21-72 days, salicylate- 2.5h
  • Metabolism: GI tract, liver
  • Excretion: Bismuth- feces, salicylate- urine

Mechanism of Action

  • Bismuth: antimicrobial, anti-inflammatory action
  • Salicylate: antisecretory effect


See Also