The expiration date on medications is the date until which the manufacturer guarantees the safety and effectiveness of the drug. After the expiration date, the medication may no longer work as intended or may even become harmful.
The specific medications that can become toxic after expiration can vary depending on the drug and how it is stored. In general, medications that break down into toxic compounds or lose their potency can be dangerous if taken after their expiration date. Here are some examples of medications that can become toxic after expiration:
1. Tetracycline antibiotics
Tetracycline antibiotics, including doxycycline and minocycline, are commonly used to treat bacterial infections such as acne, respiratory infections, and urinary tract infections. However, tetracyclines can break down into toxic compounds that can damage the kidneys when they are expired.
The breakdown of tetracyclines is caused by the formation of epianhydrotetracycline, a toxic degradation product that can cause Fanconi syndrome. This syndrome is characterized by an abnormal loss of electrolytes and other substances in the urine, which can lead to kidney damage.
A study published in the Journal of Toxicology in 1983 found that tetracycline antibiotics can break down into toxic compounds after their expiration date, particularly when they are stored in warm, humid conditions. The study also found that the toxicity of expired drugs increased over time.
2. Nitroglycerin
Nitroglycerin is a medication that is used to treat chest pain (angina) and heart failure. It works by relaxing the blood vessels and increasing blood flow to the heart. However, nitroglycerin tablets can lose their potency over time, which can be dangerous for people with heart conditions who rely on this medication.
Expired nitroglycerin tablets may not work as intended, which can increase the risk of heart attack or stroke. In addition, nitroglycerin can break down into toxic compounds such as nitric oxide and nitrogen dioxide, which can cause headaches, dizziness, and other side effects.
According to a study published in the Journal of Clinical Pharmacology in 1993, nitroglycerin tablets can lose up to 25% of their potency after six months of storage, and up to 50% after one year of storage.
3. Epinephrine
Epinephrine, also known as adrenaline, is a medication that is used to treat severe allergic reactions (anaphylaxis) and cardiac arrest. It works by constricting blood vessels and relaxing the airways, which can help to improve breathing and prevent anaphylaxis.
However, expired epinephrine may lose its potency, which can be dangerous for people who need this medication for severe allergic reactions. In addition, epinephrine can break down into inactive compounds such as metanephrine, which can reduce its effectiveness.
According to a study published in the Annals of Allergy, Asthma & Immunology in 2000, expired epinephrine may lose up to 90% of its potency after one year of storage.
4. Insulin
Insulin is a hormone that is produced by the pancreas and is used to regulate blood sugar levels in people with diabetes. It works by helping the body to absorb glucose (sugar) from the blood and use it for energy.
Expired insulin may lose its effectiveness, which can be harmful to people with diabetes who rely on this medication to regulate their blood sugar levels. Insulin can also break down into inactive compounds or form clumps that can block the insulin syringe, making it difficult to administer the medication.
According to a study published in the Journal of Diabetes Science and Technology in 2015, expired insulin can lose up to 20% of its potency after one year of storage. The study also found that expired insulin may be less effective at controlling blood sugar levels in people with diabetes.
5. Warfarin
Warfarin is a medication that is used to prevent blood clots in people with conditions such as deep vein thrombosis (DVT) and atrial fibrillation. It works by reducing the body’s ability to form blood clots.
Expired warfarin may lose its effectiveness and potency, which can increase the risk of blood clots and strokes. In addition, warfarin can break down into inactive compounds, which can reduce its ability to prevent blood clots.
According to a study published in the Journal of Clinical Pharmacology in 2006, warfarin tablets can lose up to 5% of their potency after one year of storage. The study also found that expired warfarin may be less effective at preventing blood clots in people with DVT.
Other medications that can become toxic after expiration
In addition to the medications listed above, there are other drugs that can become toxic or lose their potency after their expiration date. Here are some examples:
1. EpiPen (epinephrine auto-injector): Expired EpiPens may not work as intended, which can be dangerous for people with severe allergies who rely on this medication for emergency treatment.
2. Oral contraceptives (birth control pills): Expired birth control pills may lose their potency, which can increase the risk of unintended pregnancy.
3. Antihistamines: Expired antihistamines may lose their effectiveness, which can reduce their ability to relieve symptoms such as itching and sneezing.
4. Aspirin: Expired aspirin may lose its potency, which can reduce its ability to relieve pain and inflammation.
5. Inhalers: Expired inhalers may not work as intended, which can be dangerous for people with asthma or other respiratory conditions who rely on this medication for relief.
Conclusion
The safety and effectiveness of medications can be compromised after their expiration date, and some medications may become toxic or harmful. The specific medications that can become toxic after expiration can vary depending on the drug and how it is stored, but in general, medications that break down into toxic compounds or lose their potency can be dangerous if taken after their expiration date.
It is important to always check the expiration date on medication before taking it and to properly dispose of any expired medication. If you have any questions about the safety or effectiveness of a medication, it is important to consult with a healthcare provider.
