From the Guidelines
Pepto-Bismol (bismuth subsalicylate) is known to cause several side effects, including temporary and harmless darkening of the tongue and stool, constipation, nausea, ringing in the ears (tinnitus), and headache, as well as rare allergic reactions like rash, itching, or difficulty breathing 1.
Common Side Effects
- Temporary darkening of the tongue and stool due to bismuth interacting with sulfur in saliva and digestive tract
- Constipation resulting from slowed intestinal movement
- Nausea
- Ringing in the ears (tinnitus)
- Headache
Rare but Serious Side Effects
- Allergic reactions such as rash, itching, or difficulty breathing
- Reye's syndrome, a rare but serious condition, in children and teenagers with viral illnesses
Important Considerations
- People taking blood thinners, aspirin, or medications for diabetes, gout, or arthritis should consult their doctor before using Pepto-Bismol due to potential interactions with salicylates 1
- The standard adult dose is typically two tablets or 30ml of liquid every 30-60 minutes as needed, not exceeding 8 doses in 24 hours, and treatment should generally not continue beyond 2 days without medical consultation
Dosage and Administration
- Bismuth subsalicylate can be taken as 2 tablets or 2 capsules q.i.d. 30 min before meals, as part of a bismuth quadruple therapy regimen for the treatment of certain infections 1
From the FDA Drug Label
Warnings Reye's syndrome: Children and teenagers who have or are recovering from chicken pox or flu-like symptoms should not use this product. When using this product, if changes in behavior with nausea and vomiting occur, consult a doctor because these symptoms could be an early sign of Reye's syndrome, a rare but serious illness. When using this product a temporary, but harmless, darkening of the stool and/or tongue may occur
The side effects of Pepto Bismol (bismuth subsalicylate) include:
- Reye's syndrome: a rare but serious illness that can occur in children and teenagers, especially after chicken pox or flu-like symptoms, with symptoms such as changes in behavior, nausea, and vomiting 2
- Darkening of the stool and/or tongue: a temporary and harmless side effect 2
- Allergic reactions: may occur in individuals allergic to salicylates, including aspirin 2
From the Research
Side Effects of Pepto Bismol
The provided studies do not directly discuss the side effects of Pepto Bismol. However, they do provide information on the effects of Bismuth subsalicylate, the active ingredient in Pepto Bismol.
Effects of Bismuth Subsalicylate
- Bismuth subsalicylate has been shown to have beneficial effects on chronic infantile diarrhea and selected symptoms associated with Norwalk virus-induced gastroenteritis 3.
- It has also been shown to be effective in preventing traveler's diarrhea, with a liquid preparation being 62 percent effective and a tablet formulation being 76 percent effective 3.
- A systematic review and meta-analysis found that subjects treated with bismuth subsalicylate had 3.5 times greater odds of preventing traveler's diarrhea and 3.7 times greater odds of diarrhea relief compared to those receiving placebo 4.
Lack of Information on Side Effects
There are no research papers provided that directly discuss the side effects of Pepto Bismol or Bismuth subsalicylate. Therefore, it is not possible to provide a comprehensive list of side effects based on the available evidence.