Pepto-Bismol

Bismuth subsalicylate

Clinical data
Trade names	Pepto-Bismol
AHFS/Drugs.com	Multum Consumer Information
MedlinePlus	a607040
Routes of administration	Oral
ATC code	none
Legal status
Legal status	UK: P (Pharmacy medicines) US: OTC
Identifiers
IUPAC name 2-Hydroxy-2H,4H-benzo[d]1,3-dioxa-2-bismacyclohexan-4-one
CAS Number	14882-18-9 Y
PubChem CID	16682734
DrugBank	DB01294 Y
ChemSpider	17215772 Y
UNII	62TEY51RR1
KEGG	D00728 N
ChEBI	CHEBI:261649 Y
ChEMBL	CHEMBL1120 Y
ECHA InfoCard	100.035.397
Chemical and physical data
Formula	C7H5BiO4
Molar mass	362.093 g/mol
3D model (Jmol)	Interactive image
SMILES O[Bi]1OC(=O)c2ccccc2O1
InChI InChI=1S/C7H6O3.Bi.H2O/c8-6-4-2-1-3-5(6)7(9)10;;/h1-4,8H,(H,9,10);;1H2/q;+3;/p-3 Y Key:ZREIPSZUJIFJNP-UHFFFAOYSA-K Y
NY (what is this?)

Bismuth subsalicylate, sold under the brand name Pepto-Bismol, is an antacid medication used to treat temporary discomforts of the stomach and gastrointestinal tract, such as diarrhea, indigestion, heartburn and nausea. Commonly known as pink bismuth, it is also sometimes the active ingredient in Kaopectate.

Bismuth subsalicylate has the empirical chemical formula of C₇H₅BiO₄, and it is a colloidal substance obtained by hydrolysis of bismuth salicylate (Bi{C₆H₄(OH)CO₂}₃). The actual structure is unknown and the formulation is only approximate. Recent evidence dictates that it is composed of a bismuth oxide core structure with salicylate ions attached to the surface. A model structure has recently been published having the composition Bi₃₈O₄₄{C₆H₄(OH)CO₂}₂₆.

As a derivative of salicylic acid, bismuth salicylate displays anti-inflammatory and bactericidal action. It also acts as an antacid.

There are some adverse effects. It can cause a black tongue and black stools in some users of the drug, when it combines with trace amounts of sulfur in saliva and the colon to form bismuth sulfide. Bismuth sulfide is a highly insoluble black salt, and the discoloration seen is temporary and harmless.

Long-term use (greater than 6 weeks) may lead to accumulation and toxicity. Some of the risks of salicylism can apply to the use of bismuth subsalicylate.