Many people have questions about whether they can use expired antibiotics or not. As a general rule, most medications, including antibiotics, lose their potency and effectiveness over time and should be discarded after their expiration dates have passed. Some antibiotics, such as tetracycline and doxycycline, become toxic after they have expired.
However, some antibiotics remain relatively stable and may still work after their expiration dates have passed. For example, ibuprofen (a nonsteroidal anti-inflammatory drug available over the counter as Advil or Children’s Motrin) and some penicillins like amoxicillin, seem to keep their potency fairly well past their expiration dates. Other antibiotics, such as metronidazole and famotidine, also tend to hold up well. In fact, some liquid medications, aspirin and nitroglycerin, as well as insulin and epi-pens for severe allergic reactions, have been shown to retain their strength and efficacy for much longer than most antibiotics.
Medications, including antibiotics, are tested for their efficacy and safety up to the printed expiration date on the label. After that point, the chemical compounds begin to degrade and break down. Using a medication after its expiration date can lead to decreased or even harmful effects, including antibiotic resistance.
It’s important to remember that different bacteria cause similar-seeming infections and that the type of infection you have requires a specific antibiotic or dose. Taking the wrong medication can do more harm than good and may leave you with lasting side effects. Additionally, overuse of antibiotics kills beneficial bacteria in the body and can lead to gastrointestinal issues such as diarrhea and yeast infections or a dangerous C. difficile infection.