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Pepto-Bismol Maximum Strength Side Effects

Generic name: bismuth subsalicylate

Medically reviewed by Last updated on Jan 21, 2024.

Note: This document contains side effect information about bismuth subsalicylate. Some dosage forms listed on this page may not apply to the brand name Pepto-Bismol Maximum Strength.

Applies to bismuth subsalicylate: oral capsule liquid filled, oral suspension, oral tablet, oral tablet chewable.

Serious side effects

Along with its needed effects, bismuth subsalicylate (the active ingredient contained in Pepto-Bismol Maximum Strength) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking bismuth subsalicylate:

In some patients bismuth subsalicylate may cause dark tongue and/or grayish black stools. This is only temporary and will go away when you Stop taking bismuth subsalicylate.

For Healthcare Professionals

Applies to bismuth subsalicylate: compounding powder, oral capsule, oral suspension, oral tablet, oral tablet chewable.

Nervous system

Rare (less than 0.1%): Myoclonic encephalopathy

Frequency not reported: Weakness, fatigue, depression, anxiety, irritability, insomnia, unsteady gait, motor incoordination, loss of memory, jerky movements, mental confusion, disorientation, difficulty in walking and speaking, tremor, myoclonic jerks, incontinence[Ref]

Nervous system toxicity is a common feature of bismuth toxicity. Bismuth toxicity is characterized by the insidious onset of weakness and fatigue, depression, anxiety, irritability, insomnia, unsteady gait, motor incoordination, loss of memory, and jerky movements. Acute toxicity may result in the development of mental confusion, disorientation, difficulty in walking and speaking, tremor, myoclonic jerks, and incontinence.

Myoclonic encephalopathy has occurred in patients who have ingested bismuth for several months to years, but the incidence is very rare. Recovery of patients from bismuth encephalopathy may take several months following discontinuation of use. Bismuth encephalopathy has generally been reported in patients ingesting salts other than subsalicylate.[Ref]


Frequency not reported: Salicylism[Ref]

Salicylism has been reported in patients who chronically ingest bismuth subsalicylate. Common complaints include vertigo, diminished hearing, lethargy, CNS dysfunction, confusion, tinnitus, vomiting, and abdominal pain. Patients may present with respiratory alkalosis and metabolic acidosis, azotemia, and hypoprothrombinemia and platelet dysfunction. The elderly may be particularly vulnerable to the development of salicylism.[Ref]


Very common (10% or more): Black stool

Common (1% to 10%): Black tongue

Frequency not reported: Nausea, vomiting[Ref]

Frequently asked questions


1. Dipalma JR (1988) "Bismuth toxicity." Am Fam Physician, 38, p. 244-6

2. Gorbach SL (1990) "Bismuth therapy in gastrointestinal diseases." Gastroenterology, 99, p. 863-75

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4. Jungreis AC, Schaumburg HH (1993) "Encephalopathy from abuse of bismuth subsalicylate (Pepto-Bismol)." Neurology, 43, p. 1265

5. Weller MP (1988) "Neuropsychiatric symptoms following bismuth intoxication." Postgrad Med J, 64, p. 308-10

6. Molina JA, Calandre L, Bermejo F (1989) "Myoclonic encephalopathy due to bismuth salts: treatment with dimercaprol and analysis of CSF transmitters." Acta Neurol Scand, 79, p. 200-3

7. Bradley B, Singleton M, Po AL (1989) "Bismuth toxicity--a reassessment." J Clin Pharm Ther, 14, p. 423-41

8. Supino-Viterbo V, Sicard C, Risvegliato M, Rancurel G, Buge A (1977) "Toxic encephalopathy due to ingestion of bismuth salts: clinical and EEG studies of 45 patients." J Neurol Neurosurg Psychiatry, 40, p. 748-52

9. Malfertheiner P (1993) "Compliance, adverse events and antibiotic resistance in Helicobacter pylori treatment." Scand J Gastroenterol Suppl, 196, p. 34-7

10. (1980) "Salicylate in pepto-bismol." Med Lett Drugs Ther, 22, p. 63

11. DuPont HL (1987) "Bismuth subsalicylate in the treatment and prevention of diarrheal disease." Drug Intell Clin Pharm, 21, p. 687-93

12. Bierer DW (1990) "Bismuth subsalicylate: history, chemistry, and safety." Rev Infect Dis, 12 Suppl 1, s3-8

13. Gordon MF, Abrams RI, Rubin DB, Barr WB, Correa DD (1994) "Bismuth toxicity." Neurology, 44, p. 2418

14. Vernace MA, Bellucci AG, Wilkes BM (1994) "Chronic salicylate toxicity due to consumption of over-the-counter bismuth subsalicylate." Am J Med, 97, p. 308-9

15. Sainsbury SJ (1991) "Fatal salicylate toxicity from bismuth subsalicylate." West J Med, 155, p. 637-9

16. Cerner Multum, Inc. "UK Summary of Product Characteristics."

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.