bismuth subsalicylate

Action and Spectrum

Actions and Spectrum: 

Bismuth subsalicylate works through multiple mechanisms. It exhibits antimicrobial effects by reducing harmful bacteria and viruses in the gastrointestinal tract. Its antidiarrheal action stems from its ability to slow intestinal motility and reduce fluid secretion, thereby decreasing the frequency of diarrhea. The anti-inflammatory effect is due to its salicylate component, which helps reduce inflammation and discomfort. Additionally, it protects the digestive lining, making it useful for treating conditions like diarrhea, indigestion, heartburn, traveler’s diarrhea, and Helicobacter pylori infection when used in combination therapy. 

Drug Interaction

Adverse Reaction

Frequency defined 

>10 % 

Nausea  

1-10% 

Diarrhea  

Abdominal pain 

Melena  

Upper respiratory tract infection  

Constipation  

Anorexia  

Vomiting  

Asthenia  

Discolored tongue  

Headache  

Dyspepsia  

Dizziness  

Stool abnormality  

Duodenal ulcer  

Sinusitis  

Taste perversion  

Flatulence  

GI hemorrhage  

Pain  

Insomnia  

Anal discomfort  

Paresthesia  

Frequency undefined 

Anxiety 

Confusion 

Depression 

Tinnitus 

Gray-black stool 

Impaction 

Muscle spasm 

Neurotoxicity

Black Box Warning

None 

Contraindication / Caution

Contraindication/Caution: 

• Allergy: bismuth subsalicylate should not be taken by anyone with a known allergy to salicylates, such as aspirin. 

• Pregnancy and breastfeeding: bismuth subsalicylate should be avoided during pregnancy and breastfeeding due to the risk of harm to the developing fetus or infant. 

• Bleeding disorders: bismuth subsalicylate can increase the risk of bleeding in people with bleeding disorders or those taking blood-thinning medications. 

• Children and teenagers: bismuth subsalicylate should not be given to children or teenagers who are recovering from a viral infection, as it may increase the risk of Reye’s syndrome, a rare but serious condition. 

• Kidney disease: bismuth subsalicylate should be used with caution in people with kidney disease, as it can accumulate in the blood and cause toxicity. 

• Interactions with other medications: bismuth subsalicylate can interact with other medications, including anticoagulants, antibiotics, and methotrexate, so it’s important to talk to your doctor before taking it if you are on any other medications. 

Pregnancy / Lactation

Pregnancy consideration:  

bismuth subsalicylate comes under the C category for the 1st and 2nd trimesters and types under the D category in the 3rd semester. 

Breastfeeding warnings: Salicylates are secreted in breastmilk; hence gestating females should consult a physician. 

Pregnancy category: 

• Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first or later trimester. 

• Category B: There is no affirmation of risk to the fetus found in animal reproduction studies, and there are not enough studies on pregnant women. 

• Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for a product in humans; Pregnant women must take care of the potential risks. 

• Category D: There is adequate data available with sufficient evidence of human fetal risk from various platforms. However, despite potential dangers may be used only in emergency cases for potential benefits. 

• Category X: Drugs listed in this category outweigh risks over benefits. The drug is not for pregnant women. 

• Category N: No data is available for the drug under this category. 

Pharmacology

Pharmacology 

Bismuth subsalicylate has multiple pharmacological actions. As an antidiarrheal, it slows gastrointestinal motility and reduces intestinal water and electrolyte secretion, helping to firm up stools. It has antimicrobial properties, exerting bactericidal and bacteriostatic effects against pathogens like E. coli, Salmonella, Shigella, and H. pylori by disrupting bacterial membranes. Its anti-inflammatory effect comes from the salicylate component, which inhibits prostaglandin synthesis. Additionally, it provides gastrointestinal protection by forming a protective coating on the mucosa, binding toxins, and promoting mucosal healing through increased mucus production. 

Pharmacodynamics 

Bismuth subsalicylate exerts multiple pharmacodynamic effects. It binds to bacterial membranes, including Helicobacter pylori, leading to membrane disruption and bacterial death. It reduces intestinal water and electrolyte secretion and slows intestinal motility, both of which help manage diarrhea. Its salicylate component provides anti-inflammatory effects by inhibiting prostaglandin synthesis. Additionally, it forms a protective barrier over the gastrointestinal lining and promotes mucus production, aiding in mucosal protection and healing. 

Pharmacokinetics 

Absorption 

It is poorly absorbed from the gastrointestinal tract, with only about 2-18% of the dose being absorbed. The absorption is affected by several factors, including the presence of food, pH of the stomach, and the presence of other drugs. 

Distribution 

It is distributed throughout the body, with the highest concentrations found in the liver, kidneys, and spleen. Bismuth does not cross the blood-brain barrier, so it does not have any central nervous system effects. 

Metabolism 

It is not metabolized by the liver or other organs. The salicylate component is hydrolyzed to salicylic acid, which is then metabolized by the liver and excreted in the urine. 

Elimination and Excretion 

It is eliminated primarily in the feces, with only a small amount being excreted in the urine. The elimination half-life of bismuth subsalicylate is long, ranging from 5 to 12 days, which allows for prolonged activity. 

Adminstartion

bismuth subsalicylate is usually administered orally as a suspension or tablet. It is recommended to take it with a full glass of water, and to shake the suspension well before using it.  

Patient Information Leaflet

Patient information leaflet 

Generic Name: bismuth subsalicylate 

Pronounced: bis-muth sub-saly-silate 

Why do we use bismuth subsalicylate? 

 bismuth subsalicylate can help reduce the frequency and severity of diarrhea by decreasing intestinal secretion, slowing intestinal motility, and binding to bacterial cell membranes. It can help treat and prevent peptic ulcers by forming a protective barrier on the surface of the gastrointestinal tract and reducing inflammation. 

bismuth subsalicylate can help alleviate the symptoms of GERD, such as heartburn and acid reflux, by neutralizing stomach acid and reducing inflammation. 

bismuth subsalicylate is used in combination with antibiotics to treat Helicobacter pylori infection, which is a common cause of peptic ulcers.