Bismuth Subsalicylate
Bismuth subsalicylate
Brand names:Pepto-Bismol, Kaopectate, Bismatrol
A combination of bismuth and salicylate that provides antidiarrheal, antimicrobial, and antacid effects. Bismuth subsalicylate is widely used in deployment medicine for traveler's diarrhea prophylaxis and treatment, and for symptomatic relief of indigestion, nausea, and heartburn. The dark stool and black tongue effects are benign but should be expected.
Pharmacology and Actions
Bismuth subsalicylate hydrolyzes in the GI tract to bismuth oxychloride and salicylic acid. The bismuth component has antimicrobial activity against enteric pathogens including E. coli and Helicobacter pylori, and provides mucosal coating that reduces local inflammation. The salicylate component contributes to anti-inflammatory and antisecretory effects. Combined, the drug reduces both fluid secretion and intestinal motility, providing antidiarrheal effect through multiple mechanisms.
Indications
- Traveler's diarrhea prophylaxis in deployment medicine
- Mild traveler's diarrhea treatment
- Acute non-specific diarrhea
- Indigestion, nausea, and upset stomach
- Adjunct therapy for Helicobacter pylori eradication
Absolute Contraindications
- Known bismuth or salicylate allergy
- Aspirin or NSAID allergy (salicylate cross-sensitivity)
- Children and teenagers with viral illness (Reye syndrome risk from salicylate)
- Active GI bleeding or peptic ulcer disease
- Renal impairment (salicylate accumulation risk)
- Concurrent use with anticoagulants
Precautions and Side Effects
Black tongue and black stools are common benign effects from bismuth and should be expected and not mistaken for melena. Tinnitus indicates salicylate toxicity and warrants discontinuation. Constipation can occur with prolonged use. Salicylate absorption is significant; avoid combination with aspirin or NSAIDs to prevent salicylate toxicity. Encephalopathy from bismuth has been reported with prolonged high-dose use. Reye syndrome risk in pediatric viral illness contraindicates use in this population.
Adult Dosing
Pediatric Dosing
Pediatric dosing per FDA OTC labeling. CONTRAINDICATED in children and teenagers with viral illness due to Reye syndrome risk. Pediatric dosing for non-viral diarrhea is generally not recommended; use loperamide or oral rehydration therapy instead.
Pharmacokinetics
Peak Effect: PO: 1 to 2 hours
Duration: 4 to 6 hours per dose
Storage and Handling
Store tablets and liquid at controlled room temperature (15 to 30 degrees Celsius). Protect from light and freezing. Liquid formulations may darken slightly with age; this is normal.
Reconstitution:
Tablets, chewable tablets, and liquid require no reconstitution.
TCCC and TECC Role
Bismuth subsalicylate is operationally important in deployment medicine for traveler's diarrhea prophylaxis and treatment. The four-times-daily prophylactic regimen during travel is supported by evidence and is recommended by the CDC for travelers to high-risk regions when antibiotic prophylaxis is not preferred. For acute treatment of operational diarrhea, bismuth subsalicylate is generally less effective than loperamide but has the advantage of additional antimicrobial activity. The drug also addresses associated symptoms (nausea, indigestion, abdominal cramping) that loperamide does not.
Bismuth subsalicylate (Pepto-Bismol) is the deployment medicine staple for travelers' diarrhea prevention and symptomatic relief of GI complaints. The black tongue and black stools are operationally significant: educate users so they do not interpret black stools as melena and trigger unnecessary medical evacuation. The salicylate component is real; do not stack with aspirin or NSAIDs to avoid salicylate toxicity. For prevention during high-risk travel, the QID regimen is the established protocol, though many travelers find loperamide reactive use more practical than four-times-daily prophylaxis.
Mistaking the benign black stool from bismuth for melena and initiating GI bleeding workup. Educate users about the expected color change before they start the medication. The other common error is combining bismuth subsalicylate with aspirin or NSAIDs, which can produce salicylate toxicity due to additive salicylate load. Watch for tinnitus, which is the early warning sign of salicylate accumulation.
This drug profile is provided as educational reference material for trained medical providers. It is not medical advice, not a substitute for formal training, and not a substitute for current published guidelines or medical direction.
Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances are subject to additional handling, accountability, and documentation requirements per DEA and state law. Always verify dosing, indications, contraindications, and route of administration against current published guidelines and your local protocols before administration.
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Penn Tactical Solutions publishes this reference for educational purposes. PTS does not provide medical direction and does not assume responsibility for clinical decisions made in the field. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Educational reference for trained medical providers. Not medical advice. Not a substitute for formal training, current published guidelines, or medical direction. Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances require additional storage, accountability, and documentation per DEA and state law.
In a medical emergency, call 911. This reference is not a substitute for emergency medical services.
Verify dosing, indications, and contraindications against current published guidelines and your local protocols before administration. Confirm content currency against the source citation. Penn Tactical Solutions does not provide medical direction. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Bismuth Subsalicylate
| PO | Acute diarrhea or upset stomach: 524 mg (2 tablets or 30 mL liquid) PO every 30 to 60 minutes as needed, maximum 8 doses (4 g) per 24 hours. Traveler's diarrhea prophylaxis: 524 mg PO four times daily during travel and 2 days after return. (30 to 60 minutes) |