What medications become toxic after expiration?

In this article, we are going to discuss medications which become toxic after expiration. We will also talk about the general risks associated with using expired medication and why you should avoid taking them.

What medications become toxic after expiration?

Some medications may become toxic after expiration, even though a majority of them become ineffective. Medications that should be avoided once they are past their expiration date include:

  • Tetracycline antibiotics
  • Ophthalmic (eye) drops
  • Certain heart medications
  • Epinephrine (a life-saving drug)

Tetracycline antibiotics

Tetracycline antibiotics, like Doxycycline, are commonly prescribed to treat various bacterial infections. However, when these medications expire, they can deteriorate and undergo chemical changes that lead to the development of harmful byproducts (1,2).

These byproducts may cause Fanconi syndrome, a rare kidney disorder that can result in kidney damage and other serious health issues (3). It’s essential to avoid using these medications after their expiration date to safeguard your kidney health and ensure you receive the proper treatment for infections.

Ophthalmic (eye) drops

Expired eye drops can lose their potency and may not effectively treat eye conditions. Additionally, sterility can be disturbed when these drops expire, increasing the risk of bacterial contamination (4). 

Using contaminated eye drops can lead to serious eye infections and even worsen existing eye conditions. When it comes to your vision and eye health, it’s essential to follow the expiration dates on ophthalmic drops and avoid using them once they have expired (4). 

This way, you can ensure the drops retain their effectiveness and help maintain your ocular health.

Certain heart medications

Some heart medications, such as Nitroglycerine, play a crucial role in managing heart conditions. Nitroglycerine is generally not stable and it starts to deteriorate earlier than other heart medications (5). 

When this medication expires, its chemical composition may change and it may become toxic for some people. Furthermore, expired Nitroglycerine may not adequately relieve chest pain (angina) or prevent a heart attack, as it should. 

Epinephrine (a life-saving drug)

Epinephrine is a vital life-saving drug used to treat severe allergic reactions (anaphylaxis). However, when Epinephrine expires, it may break down and lose its potency. It may retain its potency for some time, but there’s no easy way to tell if it’s potent enough or not (6). 

This can be extremely dangerous in emergency situations where immediate administration of epinephrine is critical to saving lives. 

To ensure its efficacy in emergencies, it’s essential to have unexpired Epinephrine and regularly check the expiration date, replacing any expired doses promptly.

Is it safe to use expired medications that do not become toxic?

Using expired medications, even if they don’t become toxic, is generally not safe and can lead to various problems. When medications expire, their chemical composition can change, making them less effective (7). 

This means that the medication may not work as intended, and you may not experience any improvement in your symptoms. Taking ineffective medications can be frustrating as it won’t provide the relief you need, and it can also affect your treatment plan (7).

If you continue to use expired medications that are no longer potent, you might mistakenly believe that the treatment is not working for your condition. This can lead to unnecessary delays in seeking appropriate medical advice or adjustments to your treatment plan. 

In some cases, your symptoms might worsen, and you could be at risk of complications if you are not receiving the proper medication for your condition.

The expiration dates on medications are there for a reason. They indicate the period during which the drug is expected to be at its highest quality and effectiveness. 

To ensure your health and well-being, it’s essential to follow the expiration dates on medications and never use them beyond that point.


In this article, we have discussed medications that become toxic once they get past their expiration dates. We have also discussed why you should avoid using expired medications, even if they don’t necessarily become toxic. Remember, proper use of meds is the only key to achieving a safe and effective therapeutic outcome. 

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Cleveland Ww, Adams Wc, Mann Jb, Nyhan Wl. Acquired Fanconi Syndrome Following Degraded Tetracycline. J Pediatr. 1965 Feb;66:333-42. doi: 10.1016/s0022-3476(65)80190-1. PMID: 14258922. https://pubmed.ncbi.nlm.nih.gov/14258922/


U.S. Food and Drug Administration. Expiration date extensions of certain lots of doxycycline hyclate capsules [Internet]. 2023 updated [cited 2022 Oct 21]. Available from: https://www.fda.gov/emergency-preparedness-and-response/mcm-legal-regulatory-and-policy-framework/expiration-date-extensions-certain-lots-doxycycline-hyclate-capsules


Keefe P, Bokhari SRA. Fanconi Syndrome. 2022 Sep 6. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–. PMID: 30521293. https://www.ncbi.nlm.nih.gov/books/NBK534872


Rauz S, Moate BJ, Jacks AS, Cumberland N, Govan JA. “In use” expiry date for eyedrops. Br J Ophthalmol. 1996 Mar;80(3):270. doi: 10.1136/bjo.80.3.270. PMID: 8703869; PMCID: PMC505442. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC505442/


Mayer GA. Instability of nitroglycerin tablets. Can Med Assoc J. 1974 Apr 6;110(7):788-9 passim. PMID: 4207612; PMCID: PMC1947477. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1947477/


Simons FE, Gu X, Simons KJ. Outdated EpiPen and EpiPen Jr autoinjectors: past their prime? J Allergy Clin Immunol. 2000 May;105(5):1025-30. doi: 10.1067/mai.2000.106042. PMID: 10808186. https://pubmed.ncbi.nlm.nih.gov/10808186/


U.S. Food and Drug Administration. Don’t Be Tempted to Use Expired Medicines [Internet]. Silver Spring (MD): U.S. Food and Drug Administration; 2021 [cited 2022 Oct 21]. Available from: https://www.fda.gov/drugs/special-features/dont-be-tempted-use-expired-medicines.