bismuth subsalicylate (OTC)

>10%

Nausea (12%)

1-10%

Diarrhea (7%)

Abdominal pain (7%)

Melena (3%)

Upper respiratory tract infection (2%)

Constipation (2%)

Anorexia (2%)

Vomiting (2%)

Asthenia (2%)

Discolored tongue (2%)

Headache (2%)

Dyspepsia (2%)

Dizziness (2%)

Stool abnormality (1%)

Duodenal ulcer (1%)

Sinusitis (1%)

Taste perversion (1%)

Flatulence (1%)

GI hemorrhage (1%)

Pain (1%)

Insomnia (1%)

Anal discomfort (1%)

Paresthesia (1%)

Frequency Not Defined

Anxiety

Confusion

Depression

Tinnitus

Weakness

Gray-black stool

Impaction

Muscle spasm

Neurotoxicity (rare)

Contraindications

Hypersensitivity to bismuth, aspirin, other salicylates

Infectious diarrhea, high fever, von Willebrand disease, hemorrhage, ulcer or GI bleeding with black or bloody stool, hemophilia

In pediatric patients, chicken pox or influenza (risk of Reye syndrome)

Cautions

Bismuth subcitrate potassium may cause temporary and harmless darkening of tongue and/or black stools, generally reversible within several days after treatment stopped; stool darkening should not be confused with melena

Bismuth absorbs x-rays and may interfere with x-ray diagnostic procedures of gastrointestinal tract

Cases of neurotoxicity associated with excessive doses of various bismuth-containing products reported; effects have been reversible with discontinuation of bismuth therapy

Not to be administered to children or teenagers recovering from flu-like symptoms or chickenpox; increased incidence of Reye syndrome, associated with salicylate products

Pregnancy category: C; D in 3rd trimester

Lactation: Salicylates enter breast milk; use with caution

Pregnancy Categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.

Mechanism of Action

Antimicrobial anti-inflammatory action (bismuth); antisecretory effect (salicylate)

Absorption

Bioavailability: Bismuth, <1%; salicylate, 80%

Peak plasma time: Bismuth, 1.8-5 hr

Onset: 4 hr

Distribution

Protein bound: Bismuth, 90%; salicylate, >90%

Vd: Bismuth, 170 mL/kg

Metabolism

Stomach: Bismuth subsalicylate is hydrolyzed in stomach to form slightly soluble bismuth oxychloride (BiOCl) and salicylic acid

Small intestine: Unchanged bismuth subsalicylate passes into duodenum and reacts with other anions (eg, bicarbonate and phosphate) to form bismuth subcarbonate and bismuth phosphate salts

Colon: BiOCl, bismuth subcarbonate, bismuth phosphate, and undissociated bismuth subsalicylate react with hydrogen sulfide (produced by colonic anaerobes) to form black bismuth sulfide, which is responsible for harmless darkening of stool and/or tongue

Liver: Salicylate is extensively metabolized in liver

Metabolites: Salicylate (active); BiOCl, bismuth subcarbonate, and bismuth phosphate (activity unknown)

Elimination

Half-life: Bismuth, 21-72 days; salicylate, 2.5 hr

Excretion: Bismuth, feces (99%) and urine (0.003%); salicylate, urine (95%)

Clearance: Bismuth, 50 mL/min