Bismuth Subsalicylate: An Effective Medication for Gastrointestinal Discomfort

Bismuth subsalicylate is an over-the-counter medication used to manage gastrointestinal discomfort, indigestion, traveler’s diarrhea, and Helicobacter pylori infection. It has antimicrobial, anti-inflammatory, and antisecretory properties. Effective against bacterial and viral pathogens, bismuth subsalicylate does not disrupt normal gut flora.

Formulated with bismuth and an insoluble salt of salicylic acid, bismuth subsalicylate works in several ways. When broken down in the stomach, it forms salicylic acid and bismuth salts such as bismuth oxychloride, bismuth subcarbonate, bismuth phosphate, and bismuth sulfide. Salicylic acid is absorbed systemically, while only a small amount of bismuth salts are absorbed. Bismuth subsalicylate works by:

• Preventing H. pylori bacteria from binding and growing on the mucous lining, as well as inhibiting their enzyme activities that promote growth
• Inhibiting intestinal secretions and fluid loss
• Promoting fluid and electrolyte reabsorption into the bloodstream
• Reducing inflammation to aid in the healing of peptic ulcers
• Additionally, the salicylate component inhibits the synthesis of prostaglandin, an inflammation-promoting substance, by inhibiting enzymes called cyclooxygenases

Bismuth subsalicylate is commonly used to treat gas, upset stomach, indigestion, heartburn, nausea, diarrhea, traveler’s diarrhea caused by bacterial infections, H. pylori infection, and associated peptic ulcers.

Warnings

• Do not take bismuth subsalicylate if allergic to bismuth, salicylates (including aspirin), or any other components of the medication.
• Avoid bismuth subsalicylate if experiencing infectious diarrhea, high fever, bleeding disorders, hemorrhage, GI ulcers, GI bleeding with black or bloody stool, or if children/adolescents have chickenpox or flu (due to increased risk of Reye syndrome).

QUESTION

What are the side effects of bismuth subsalicylate?

Common side effects include nausea, diarrhea, abdominal pain, and dark tarry stools. Less common side effects may include constipation, vomiting, loss of appetite, indigestion, stool abnormalities, duodenal ulcer, anal discomfort, gray-black stool, discolored tongue, taste perversion, gas, gastrointestinal hemorrhage, fecal impaction, headache, dizziness, pain, weakness, upper respiratory tract infections, sinus inflammation, abnormal skin sensations, sleeplessness, anxiety, confusion, depression, ringing in the ears, hearing loss, muscle spasm, and neurotoxicity (rare).

This is not an exhaustive list of side effects. Contact your doctor for medical advice regarding serious side effects or adverse reactions. You can also report side effects or health problems to the FDA at 1-800-FDA-1088.

What are the dosages of bismuth subsalicylate?

Tablet, chewable

Caplet

Oral suspension

• 262mg/15mL
• 525mg/15mL
• 525 mg/30 mL
• 1050 mg/30 mL

Adult:

Diarrhea, Gas, Upset Stomach, Indigestion, Heartburn, Nausea

• 2 tablets (262 mg/tab) or 30 mL (regular strength) orally every 30-60 minutes as needed; maximum daily dose: 8 regular-strength doses or 4 extra-strength doses

Traveler’s Diarrhea

• 2 tablets (262 mg/tab) every 6 hours for up to 3 weeks

Helicobacter pylori infection

• 525 mg (2 regular-strength tablets or 1 extra-strength tablet) + 250 mg metronidazole + 500 mg tetracycline PO every 6 hours for 14 days, plus an H2 antagonist (Helidac Therapy pack)

Dosing Modifications

• Renal impairment: Overdose may cause nephrotoxicity

Administration

• Drink plenty of clear fluids to prevent dehydration caused by diarrhea
• Do not use for longer than 2 days
• For Helidac Therapy pack: Chew and swallow bismuth subsalicylate tablets. Do not take double doses if a dose is missed.

Pediatric:

Diarrhea, Gas, Upset Stomach, Indigestion, Heartburn, Nausea

• Children younger than 3 years: Safety and efficacy not established
• Children 3-6 years: 1/3 tablet or 5 mL (regular strength) or 2.5 mL (extra strength) orally every 30-60 minutes as needed
• Children 6-9 years: 2/3 tablet or 10 mL (regular strength) or 5 mL (extra strength) orally every 30-60 minutes as needed
• Children 9-12 years: 1 tablet or 15 mL (regular strength) or 7.5 mL (extra strength) orally every 30-60 minutes as needed
• Children older than 12 years: 2 tablets or 30 mL (regular strength) or 15 mL (extra strength) orally every 30-60 minutes as needed; maximum daily dose: 8 regular-strength doses or 4 extra-strength doses

Chronic Infantile Diarrhea

• Children younger than 2 years: 2.5 mL (regular strength) every 4 hours
• Children 2-4 years: 5 mL (regular strength) every 4 hours
• Children 4-6 years: 10 mL (regular strength) every 4 hours

Overdose

• Overdosing on bismuth subsalicylate may cause symptoms such as lethargy, drowsiness, anxiety, insomnia, tremors, and seizures.
• No specific antidote exists for bismuth subsalicylate overdose. Symptomatic and supportive care is recommended.
• If taken within two hours, activated charcoal can help eliminate unabsorbed drug in the digestive tract. Seek medical assistance or contact Poison Control in case of overdose.

Drug Interactions

Inform your doctor of all medications you take to identify possible drug interactions. Do not start, discontinue, or change medication dosage without your doctor’s recommendation.

• Severe drug interactions with bismuth subsalicylate include: dichlorphenamide, demeclocycline, doxycycline, eluxadoline, minocycline, oxytetracycline, tetracycline, and warfarin.
• Other drug interactions include: acebutolol, atenolol, benazepril, betaxolol, bisoprolol, carvedilol, celiprolol, esmolol, labetalol, metoprolol, aspirin, aspirin rectal, aspirin/citric acid/sodium bicarbonate, esomeprazole, and omeprazole.

For a more comprehensive list of drug interactions, consult the RxList Drug Interaction Checker. Inform your healthcare provider of all prescription and over-the-counter medications you use, including the dosage of each.

Pregnancy and Breastfeeding

• Use bismuth subsalicylate with caution during pregnancy when benefits outweigh potential risks. Avoid use in the third trimester unless in life-threatening situations due to potential fetal harm.
• Bismuth subsalicylate can be found in breast milk. Use with caution if breastfeeding.

Additional Information

• Follow instructions on the label when taking bismuth subsalicylate.
• Store out of children’s reach.
• Temporary discoloration of the tongue and stools may occur, which is harmless. If dark stools persist after discontinuation of the drug, seek medical help.
• Discontinue use and seek medical help if diarrhea does not stop within a few days of taking the drug or if symptoms worsen or persist for more than 14 days.
• Consult your healthcare provider before taking bismuth subsalicylate if you have a fever or mucus in the stool.

Sources:

Digestive Disorders Resources

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• Side Effects From aHUS Treatment

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Summary

Bismuth subsalicylate is an effective over-the-counter medication for managing gastrointestinal discomfort, indigestion, traveler’s diarrhea, and Helicobacter pylori infection. Common side effects include nausea, diarrhea, abdominal pain, and dark tarry stools. Use this medication with caution during pregnancy and breastfeeding. Follow the label instructions, store safely, and discontinue use if symptoms persist or worsen. Consult your doctor for any concerns.