Can You Take Alka-Seltzer After Taking Nitroglycerin?
In our latest question and answer, our pharmacist discusses the safety of combining nitroglycerin and Alka-Seltzer.

Question
Can I take an Alka-Seltzer after taking a nitrogen pill?

Answered by Dr. Brian Staiger, PharmD
Medical Content Reviewed By HelloPharmacist
Staff
Last updated Apr 17, 2025
Key points
- Some Alka-Seltzer products contain aspirin, which could increase nitroglycerin levels and increase the risk of side effects.
- Most studies report this interaction as relatively minor as it appears only large doses of aspirin may have this effect and not every study has found the same results.
Answer
Thanks so much for reaching out! Your question isn't entirely clear in regard to what 'nitrogen pill' you are referring to, but I'm going to assume you are talking about nitroglycerin. If this is incorrect, please write back and let us know.
Regarding nitroglycerin, which is used to relieve chest pain, it does interact with some Alka-Seltzer products.
It is important to note here that Alka-Seltzer is a brand name, and there are several different products that use the name. I'm not sure which Alka-Seltzer product you are referring to, but there is an interaction specifically with Alka-Seltzer products that contain aspirin. Here is one example of an Alka-Seltzer product that contains aspirin:
Interaction Details
The interaction here is that aspirin (which is contained in some Alka-Seltzer products) may increase the concentrations of nitroglycerin, potentially increasing the risk of side effects, such as hypotension (i.e., low blood pressure) and increased heart rate. One study concluded the following:
We conclude that pretreatment with 1 g of aspirin increases NTG [nitroglycerin] plasma levels and therefore significantly enhances the pharmacodynamic effects of NTG.
Now, it is important to note a few things.
For one, most studies show that only high doses of aspirin (over 1 gram) are likely to cause an interaction. Alka Seltzer tablets in the product I pictured above contain only 325mg (per tablet). Additionally, not all studies have found that aspirin significantly affects nitroglycerin concentrations.
Lastly, in your question, you wanted to know about taking Alka-Seltzer after nitroglycerin, and that appears to be safe. Documented interactions have occurred when aspirin is given before nitroglycerin.
So, overall, this interaction is thought to be a relatively minor one and probably not very likely to be of significance for most people. Nevertheless, I would be cautious of using both together.
Final Words
I hope you found this helpful!
Remember that the interaction is between Alka-Seltzer products that contain aspirin. Other Alka-Seltzer products that don't aren't known to interact with nitroglycerin.
References
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Dr. Brian Staiger, PharmD
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