BISMUTH SUBSALICYLATE

(bis'muth)
Pepto-Bismol
Classifications: gastrointestinal agent; antidiarrheal; salicylate
Pregnancy Category: C

Availability

262 mg tablets/caplets; 130 mg/15 mL, 262 mg/15 mL, 524 mg/15 mL liquid

Actions

Hydrolyzed in GI tract to salicylate, which is believed to inhibit synthesis of prostaglandins responsible for GI hypermotility and inflammation.

Therapeutic Effects

Effectiveness as an antidiarrheal also appears to be due to direct antimicrobial action and to an antisecretory effect on intestinal secretions exposed to toxins particularly of Escherichia coli and Vibrio cholerae.

Uses

Prophylaxis and treatment of traveler's diarrhea (turista) and for temporary relief of indigestion.

Unlabeled Uses

Helicobacter pylori associated with peptic ulcer disease.

Contraindications

Hypersensitivity to aspirin or other salicylates; concurrent use with aspirin; use for more than 2 d in presence of high fever or in children <3 y unless prescribed by physician; chicken pox or flu.

Cautious Use

Diabetes and gout; concurrent use with salicylates and anticoagulants; pregnancy (category C), lactation.

Route & Dosage

Diarrhea
Adult: PO 30 mL or 2 tab q30–60min prn (max: 8 doses/d)
Child: PO 3–6 y, 5 mL or ½ tab q30–60min prn (max: 8 doses/d); 6–9 y, 2/3 tab or 10 mL q30–60 min prn (max: 8 doses/d); 9–12 y, 15 mL or 1 tab q30–60min prn (max: 8 doses/d)

Traveler's Diarrhea
Adult: PO 2–4 tab or 15–30 mL q.i.d. for 3 wk

Peptic Ulcer Disease
Adult: PO 2 tablets q.i.d. with 2 additional antibiotics for 10–14 d
Child: PO <10 y, 15 mL q.i.d. times 6 wk

Administration

Oral

Ensure chewable tablets are chewed or crushed before being swallowed and followed with at least 8 oz water or other liquid.
Store at 15°–30° C (59°–86° F) unless otherwise directed.

Adverse Effects (1%)

GI: Temporary darkening of stool and tongue, metallic taste, bluish gum line; bleeding tendencies. With high doses: fecal impaction. CNS: Encephalopathy (disorientation, muscle twitching). Hematologic: Bleeding tendency. Special Senses: Tinnitus, hearing loss. Urogenital: Incontinence.

Diagnostic Test Interference

Because bismuth subsalicylate is radiopaque, it may interfere with radiographic studies of GI tract.

Interactions

Drug: Bismuth may decrease the absorption of tetracyclines, quinolones (ciprofloxacin, norfloxacin, ofloxacin).

Pharmacokinetics

Absorption: Undergoes chemical dissociation in GI tract to bismuth subcarbonate and sodium salicylate; bismuth is minimally absorbed, but the salicylate is readily absorbed.

Nursing Implications

Assessment & Drug Effects

Monitor bowel function; note that stools may darken and tongue may appear black. These are temporary effects and will disappear without treatment.
Lab tests: H. pylori breath test when used for peptic ulcers.

Patient & Family Education

Note: Bismuth contains salicylate. Use caution when taking aspirin and other salicylates. Many OTC medications for colds, fever, and pain contain salicylates.
Consult physician if diarrhea is accompanied by fever or continues for more than 2 d.
Note: Temporary grayish black discoloration of tongue and stool may occur.
Do not breast feed while taking this drug without consulting physician.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug