Can I Take Pepto-Bismol and Alka-Seltzer? | Is It Safe?

A bad diarrhea and a stubborn stomach discomfort that just won’t go away is a nightmare to live in. This has prompted the formulation of some over-the-counter medications to handle cases like this. Two of these are Pepto-Bismol and Alka-Seltzer. But what happens if you take one and you still don’t get the desired relief huh? Do you combine the two?

In this article, the pharmacist gives clear explanations on whether or not you can take Pepto-Bismol and Alka-Seltzer together. We will also state how long after taking Pepto-Bismol you can take Alka-Seltzer.

Overview of Pepto-Bismol

Pepto-Bismol is an over-the-counter medication used to provide relief for a couple of stomach disturbances. It contains the active ingredient bismuth subsalicylate. A substance that shares some chemical similarities to aspirin and other drugs containing salicylate.

How Pepto-Bismol Works

The mechanism by which the Bismuth subsalicylate in Pepto-Bismol works to provide relief to upset stomach and other gastrointestinal troubles is not well understood. However, possible explanations have been given. Some of them are:

1. Increasing Fluid Absorption in the Intestines. Diarrhea often occurs when you have excess fluids in your intestine. This excess fluid is what prevents solid stool from forming, hence you passing out watery stools. Pepto-Bismol helps your intestines to absorb the excess fluid in them. Thereby causing stool to solidify, and dirarrhea to cease. 
2. Reducing Inflammation and Overactivity: Bismuth subsalicylate, the active ingredient in Pepto-Bismol belongs to the same class of drugs as aspirin called salicylates. Drugs in this class often have anti-inflammatory properties. This allows Pepto-Bismol to reduce the inflammation and overactivity in your stomach and intestines. Thereby providing a soothing relief to the symptoms of diarrhea. 
3. Preventing Prostaglandin Release: Prostaglandins are chemicals in the body that promote inflammation, pain, and fever. By blocking their release and actions, Pepto-Bismol is able to stop the effects it exerts on the body. 
4. Blocking Toxins: Bismuth Salicylate has antibacterial properties. It can stop some bacteria that produce toxins that either kickstarts or worsen diarrhea. 
5. Antacid Ability: Pepto-Bismol also has a weak antacid property. It can alleviate symptoms of heartburn, stomach upset, nausea, etc.

What It’s Used For

Pepto-Bismol is used to treat gastrointestinal disturbances like heartburn, nausea, and stomach upset. It is also used to treat diarrhea and to also prevent traveler’s diarrhea.

Doctors also prescribe it in combination with other medication for the treatment of stomach ulcers caused by the Helicobacter pylori bacteria. However, you should not use it as a self-medication for the management of persisting diarrhea or stomach ulcer without your doctor’s advice.

Overview of Alka-Seltzer

Alka-Seltzer is an effervescent tablet formulation used to treat heartburn, stomach upset, headache, and other minor body pains. It contains aspirin, sodium bicarbonate (baking soda), and anhydrous citric acid.

Aspirin(acetylsalicylic acid) is a salicylate just like the Bismuth Subsalicylate in Pepto-Bismol. It is effective in treating pain, inflammation, and fever. It is also used in the prevention of heart attack due to its ability to prevent blood clotting in blood vessels. 

Sodium bicarbonate is an anticid. It helps neutralize the excess acid in the stomach thereby relieving heartburns and gastric pain caused by the acids. It reacts with the citric acid in the formulation to give off the peculiar fizz and bubbling associated with this med.

Can You Take Pepto-Bismol And Alka Seltzer?

No, It is not advisable to take Pepto-Bismol and Alka-Seltzer together because the two drugs contain salicylates which can increase your risk of experiencing side effects like pain, inflammation, ulceration, and bleeding in your gastrointestinal tract. 

The combination of the two can make your body more susceptible to bruising and bleeding even from a not-so-serious physical contact. The aspirin in Alka-Seltzer and the Bismuth Subsalicylate in Pepto-Bismol both prevent blood clotting.

This means that if you were to injure yourself, your blood will not stick together to form a clot that will plug the wound and prevent further blood loss. 

This can be potentially fatal especially if you are already on an anticoagulant medication such as warfarin. As such, It is highly advisable not to take Pepto-Bismol if you have already taken Alka-Seltzer.

Because the two drugs have an inherent risk of irritating the gastrointestinal tract, it is recommended to take either of them with meals or after eating.

How Long After Taking Pepto-Bismol Can You Take Alka-Seltzer?

The terminal half-life of the salicylic acid produced after a single oral dose of 525 mg bismuth subsalicylate present in Pepto-Bismol has been broken down, ranges from 2 to 5 hours. This means that it will take this amount of time for half of the salicylic acid in your system to break down. 

Hence, for full elimination, it should take at least 10 hours. But that’s just for the salicylate. The bismuth on the other hand has a very terminal long ( 21 to 72 days). The concern here is not with the bismuth since there’s no bismuth in Alka-Seltzer. 

So, there will be no risk of its excessive accumulation provided you don’t exceed the recommended dose of Pepto.  But rather with the salicylate which is responsible for the majority of concerning side effects of this drug.

Instead of taking Alka-Seltzer after Pepto-Bismol, it is advisable to talk to your doctor to prescribe a substitute for the Alka-Seltzer. But if this was recommended by your doctor. To be on the safe side, you may take the Alka-Seltzer 24 hours after Pepto-Bismol. This will allow enough time for most of the salicylate to be eliminated from your system. 

If you are self-medicating yourself for stomach upset or any other discomfort, I recommend that you avoid Alka-Seltzer and ask your pharmacist to suggest a better drug that can treat your troubles without putting you at risk of adverse effects. 

Final Thoughts

References

1. National Center for Biotechnology Information. (2021). PubChem Compound Summary for CID 16682734, Bismuth subsalicylate. Retrieved November 12, 2023, from https://pubchem.ncbi.nlm.nih.gov/compound/Bismuth-subsalicylate
2. DrugBank. (2021, November 8). Bismuth subsalicylate. Retrieved November 12, 2023, from https://go.drugbank.com/drugs/DB01294
3. Drugs.com. (n.d.). Alka-Seltzer Original and Pepto-Bismol Drug Interactions. Retrieved November 12, 2023, from https://www.drugs.com/drug-interactions/alka-seltzer-original-with-pepto-bismol-258-9151-391-177.html
4. Lanas, A., & Hunt, R. (2005). Prevention of anti-inflammatory drug-induced gastrointestinal damage: Benefits and risks of therapeutic strategies. Annals of Medicine, 37(6), 415–428. doi:10.1080/07853890500371974. Retrieved November 12, 2023, from https://pubmed.ncbi.nlm.nih.gov/15804471/
5. NHS UK. (n.d.). Taking Pepto-Bismol with other medicines and herbal supplements. Retrieved November 12, 2023, from https://www.nhs.uk/medicines/pepto-bismol/taking-pepto-bismol-with-other-medicines-and-herbal-supplements/