Bismuth Subsalicylate and Warfarin


If you have suffered from an upset stomach, chances are you’ve reached for the cool chalky relief of something like the Pepto-Bismol® medication, the Kaopectate® drug or any other type of medication that can be labeled as bismuth subsalicylate. While there are a variety of products and brand names that contain bismuth subsalicylate, all of them offer the promise of relief.


Bismuth Subsalicylate and Warfarin 

Bismuth subsalicylate and its brand names belong to a class of drugs call antidiarrheals.1 The purpose of these drugs are to relieve diarrhea as well as the stomach symptoms that come with the condition including gas, heartburn, acid reflux, nausea and general stomach discomfort. While it’s uncertain exactly how bismuth subsalicylate works to relieve diarrhea and its symptoms, it is believed that the chemical element of bismuth treats with antibiotic activity while salicylate has a more antacid effect on your digestive system.1It is available in three forms: liquid, caplet and a chewable tablet form. 

People may be surprised to learn that bismuth subsalicylate is related to aspirin, a known NSAID (nonsteroidal anti-inflammatory drug). NSAID drugs affect the way platelets work, interfering with normal blood clotting and raising the risk of bleeding, particularly within the digestive tract.2 Drugs that contain bismuth subsalicylate, like the Pepto-Bismol® medication and the Kaopectate® drug, also affect the way the body absorbs the patient’s warfarin dose.3 When a patient on warfarin takes a medication containing bismuth subsalicylate, they may have an increase in their INR value which is associated with a higher risk of bleeding and increased bruising.3 If you are someone who suffers from stomach upset and take warfarin, make sure you speak with your doctor about the best bismuth subsalicylate medication to use. Your doctor may want you to test your INR more often to determine if adjustments to your dose are needed. 


  1. Wiley, F. PharmD. What is Pepto-Bismol? March 3, 2015. Retrieved from the website:
  2. Harvard Health Letter. Bad Mix: Blood Thinners and NSAIDs. Chicago Tribune. September 29, 2013. Retrieved from the website:
  3. Dartmouth-Hitchcock Communications and Marketing Department. Anticoagulation Program: Drug Interactions. 2016. Retrieved from the website: 

Pepto-Bismol is a trademark of Procter & Gamble. Alere is not affiliated or associated with the Procter & Gamble Company or the Pepto-Bismol trademark. 

Kaopectate is a trademark of Chattem, Inc., its affiliates, related companies or its licensors or joint venture partners. Alere is not affiliated or associated with Chattem, Inc., its affiliates, related companies or its licensors or joint venture partners or the Kaopectate trademark.