Bismuth Subsalicylate

Approved Indications:

• Acute diarrhea (including traveler's diarrhea)
• Indigestion (dyspepsia)
• Heartburn and acid indigestion
• Nausea related to upset stomach
• Helicobacter pylori eradication (as part of combination therapy for peptic ulcer disease)

Off-label/Clinically Accepted Uses:

• Mild non-specific gastrointestinal symptoms (e.g., gas, bloating)
• Prophylaxis of traveler’s diarrhea in adults (short-term use)

Adults and Adolescents ≥12 years:

• Acute Diarrhea, Upset Stomach, Nausea, Indigestion:
• 524 mg (2 tablets or 30 mL of liquid) every 30–60 minutes as needed.
• Maximum: 8 doses (4192 mg) in 24 hours.
• Duration: Not to exceed 2 days without medical advice.
• Helicobacter pylori Eradication (in combination therapy):
• 525 mg orally 4 times daily for 14 days.

Pediatrics (<12 years):

• Not recommended due to risk of Reye’s syndrome (contains salicylate).

Elderly:

• Same as adult dose. Monitor closely for signs of salicylate toxicity.

Renal or Hepatic Impairment:

• Use with caution. Avoid prolonged use. No established dosage adjustment, but monitor for accumulation of salicylate.

Route of Administration:

• Oral (tablet or suspension)
• Shake liquid well before use.

Bismuth subsalicylate exerts its therapeutic effects through multiple mechanisms. The bismuth component has antimicrobial and mucosal protective effects. It binds to bacterial toxins, exhibits bactericidal activity (including against H. pylori), and coats ulcerated mucosa, forming a protective barrier. The salicylate portion inhibits prostaglandin synthesis, reducing gastrointestinal inflammation and hypermotility. Together, these actions relieve symptoms like diarrhea, indigestion, and nausea.

• Absorption: Minimal systemic absorption of bismuth; salicylate is well absorbed in the GI tract.
• Distribution: Salicylate is widely distributed; crosses the placenta and enters breast milk.
• Metabolism: Salicylate is metabolized in the liver to salicyluric acid and other conjugates.
• Excretion:
• Bismuth is excreted primarily in feces.
• Salicylate is excreted via urine (75%–90% as metabolites).
• Half-life: Salicylate: 2–4 hours (low doses); may be prolonged at higher doses.
• Bioavailability: Salicylate is efficiently absorbed; bismuth remains largely in the GI tract.

• Pregnancy: Not assigned a formal FDA category. Use with caution, especially in the third trimester due to risk of premature closure of ductus arteriosus and bleeding complications from salicylate.
• Lactation: Salicylate is excreted into breast milk. Avoid prolonged use while breastfeeding due to potential toxicity in infants.
• General Advice: Not recommended during pregnancy or lactation unless benefits clearly outweigh risks.

• Primary Class: Antidiarrheal and Gastrointestinal Agent
• Subclass: Gastrointestinal Protectant and Antisecretory Agent
• Other Classifications: Antiulcer agent (when used in combination for H. pylori therapy)

• Hypersensitivity to bismuth, salicylates (including aspirin), or other NSAIDs
• Active gastrointestinal bleeding or bleeding disorders
• Children and adolescents with viral infections (due to Reye’s syndrome risk)
• Severe renal impairment
• Pregnancy (especially third trimester) and breastfeeding (relative contraindications)

• Reye’s Syndrome: Avoid in children and teens with or recovering from viral illness.
• Salicylate Toxicity: Signs include tinnitus, confusion, metabolic acidosis.
• Prolonged Use: May lead to bismuth toxicity (neurotoxicity), especially with renal insufficiency.
• Black Tongue or Stool: Harmless and reversible discoloration due to bismuth.
• Drug Overlap: Avoid co-administration with other salicylates or anticoagulants.
• Monitoring: Required in patients on chronic therapy—check renal function, GI symptoms, and signs of bleeding.

Common:

• Black-colored tongue and stools (harmless)
• Constipation
• Mild nausea

Less Common:

• Tinnitus (indicative of salicylate toxicity)
• Dizziness
• Vomiting

Rare but Serious:

• Reye’s syndrome (in children)
• Neurotoxicity from chronic bismuth exposure (e.g., ataxia, confusion)
• Allergic reactions (rash, bronchospasm, anaphylaxis)

• Anticoagulants (e.g., Warfarin): Increased bleeding risk due to salicylate.
• Aspirin/NSAIDs: Additive salicylate exposure → toxicity.
• Methotrexate: Enhanced toxicity due to decreased renal clearance.
• Tetracyclines/Fluoroquinolones: Bismuth may impair absorption.
• Antidiabetic agents (sulfonylureas): Possible enhanced hypoglycemic effect.

Enzyme Systems:

• Salicylates undergo hepatic metabolism; do not primarily involve CYP450 system but may affect renal clearance of other drugs.

• Traveler’s Diarrhea Prophylaxis: CDC continues to endorse short-term prophylactic use in high-risk travelers.
• H. pylori Eradication: Remains a component in quadruple therapy regimens per updated ACG and Maastricht VI guidelines.
• Salicylate Warning Reinforcement: Emphasis on avoiding in children due to Reye’s syndrome.

• Tablets/Suspension: Store at 20°C to 25°C (68°F to 77°F).
• Protect from: Excessive heat, moisture, and light.
• Do not freeze the liquid formulation.
• Shake liquid well before each use.
• Keep out of reach of children and avoid prolonged exposure to air once opened.