Pepto Bismol (Bismuth Subsalicylates) OTC: Review & Drug Profile.

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How does Pepto Bismol work?

Pepto Bismol (Bismuth Subsalicylates) Improves diarrhea, upset stomach, gas, and bloating. The actions include (reference)

  • Anti-secretory: It stimulates the absorption of fluid and electrolytes from your intestine and prevents its loss during diarrhea. 
  • Anti-inflammatory: Pepto Bismol coats and protects your stomach, small intestine, and colon cells. Also, Pepto Bismol absorbs toxins from your intestine. The salicylate portion of Pepto Bismol has a direct anti-inflammatory effect on the stomach and intestine wall. 
  • Anti-microbial: Pepto Bismol kills stomach bugs that cause diarrhea, such as viruses (as rotavirus and norovirus) and bacteria. Also, it can prevent harmful organisms from damaging the intestine without killing the bacteria (by inhibiting its ability to attack your intestine).
  • Anti-Nausea: Not fully understood, it may be due to its anti-inflammatory effect and the antacid effect. Also, it decreases stomach hypermotility. 
  • Antacid: Pepto Bismol has an antacid effect (neutralizes stomach acid).

When to take (indications)?

You can use Pepto Bismol for: 

  • Diarrhea (acute diarrhea such as stomach flu).
  • Sometimes, it is used for chronic diarrhea.
  • Dyspepsia (indigestion, upset stomach), gas, and bloating. 
  • Heartburn.
  • Nausea.
  • Your doctor may prescribe it as a part of h. pylori eradication treatment.
  • Treatment of traveler’s diarrhea.
  • Prophylaxis against travelers’ diarrhea. 

When NOT to take (contraindications)?

  • If you are allergic to salicylates. 
  • If you’re taking another salicylate-containing medication (as aspirin).
  • If you’ve been diagnosed with stomach or duodenal ulcer.
  • If you have a bleeding problem such as a bleeding ulcer.
  • If you’ve bloody or blackish stool before taking the medication (Pepto Bismol causes dark or blackish stool).
  • Don’t give it to children or adolescents who are recovering from chickenpox.
  • Taking drugs that interact with Pepto Bismol (see drug interactions below).

Different formulas and how to take Pepto Bismol?

Pepto Bismol is available in many formulas and products:

  1. Pepto Bismol 5 symptom relief®: Liquid, LiquiCaps, Chewables, Caplets, and Chews. It is indicated for diarrhea, gas, bloating, bleching, nausea, and upset stomach.
  2. Pepto Bismol Ultra®: Liquids and Caplets. More concentrated formula with the same indications as above.
  3. Pepto Diarrhea®: Liquid, Caplets, LiquiCaps. Indicated for diarrhea relief. 
  4. Pepto Kids®: Chewable.
  5. Pepto Herbal Blends® (with ginger and chamomile): Softgel capsules. For nausea and vomiting.
  6. Pepto Herbal Blends® (with peppermint and caraway): Softgel capsules. For indigestion, abdominal discomfort, and abdominal discomfort.

Here is how to take Pepto Bismol different formulas:

  • Liquids: shake liquids well before you drink your dose.
  • Caplets and Liquicaps: swallow with water, don’t chew.
  • Chews and Chewables: fully chew before swallowing.

What is the dose of Pepto Bismol?

The doses below are for adults and children above 12 years old.


  • Shake well before use.
  • Use the dose cup provided. 
  • Drink plenty of fluids
  • 30 mL every 30 minutes (or 60 mL once every hour) until diarrhea stops.
  • Maximum dose: 8 doses (30 mL) or 240 mL per 24 hours.
  • Maximum duration: Don’t use for more than 2 days if no response.

Ultra Liquid (2x the concentration):

  • The same as usual dose but take half the amount.
  • Take 15 mL every 30 minutes (or 30 mL every hour). 
  • The maximum dose is 8 doses (120

LiquiCaps and Caplets:

Chews and Chewables:

  • 2 tablets every 30 minutes to 1 hour as needed.
  • Don’t exceed 8 tablets in 24 hours. 
  • Chew or dissolve in your mouth.

What are the side effects?

No controlled studies assess the frequency of the side effects. However, Pepto Bismol is considered a safe drug in usual doses.

  • Grayish black stool: temporary and harmless. 
  • Headache.
  • Constipation.
  • Its use in infants and debilitated elderly and patients may cause fecal impaction. 
  • Anxiety and depression.
  • Slurred speech and confusion.
  • Muscle spasm and weakness.
  • Hearing loss.
  • Ringing of ears (tinnitus).
  • Allergic reaction (in patients who are allergic to salicylates (aspirin)).
  • In Kids and adolescents recovering from chickenpox, it can cause serious complications (Rye’s syndrome).

The above complications are relatively rare. Neurological complications often occur in very large doses (reference).

Drug interactions.

Don’t take Pepto Bismol if you’re taking any of the below medications. Call your doctor to determine the best option for you.

  • Aspirin and blood-thinning medications.
  • Drugs that lower blood glucose (Diabetes drugs).
  • Ajmaline. 
  • Ammonium Chloride.
  • ACE Inhibitor (anti-hypertensive medications).
  • Benzbromarone.
  • Bismuth subcitrate.
  • Carbonic Anhydrase inhibitors.
  • Corticosteroids.
  • Dexketoprofen.
  • Ginkgo Biloba.
  • Some Herbs such as Alfalfa, Anise, and Bilberry).
  • Hyaluronidase.
  • Influenza Virus Vaccine (liver-attenuated).
  • Diuretics such as Lasix (furosamide).
  • Non-steroidal anti-inflammatory drugs as Ibuprofen (Advil), and Diclofenac.
  • Tetracyclines.
  • Salicylates. 
  • And Others, Learn More.

Pepto Bismol during pregnancy and lactation?

Studies in pregnancy and breastfeeding have demonstrated possible harmful effects. Don’t use Pepto Bismol during pregnancy and breastfeeding without the consultation of your doctor.