What is meant by the expiration date of medications?
It is the date by which the manufacturing company guarantees the safety and effectiveness of the drug. It is advisable not to take the medication after the date specified on the packaging.
For example, if the expiration date is July 2023, the medication should not be consumed after the 31st of July 2023.
How is the expiration date determined?
The expiration date is determined through conducting a stability test on the drug, which is carried out in the laboratories of the manufacturing company. This test involves storing the drug under various conditions, including different temperatures and levels of high and low humidity, while monitoring any significant changes over time.
Do expired medications lose their effectiveness?
Expired medications can be:
- Less effective: Such as expired antibiotics that may fail to treat infections, leading to the worsening of the illness and the development of resistance to that antibiotic.
- Potentially harmful: Some expired medications can be a risk, as they may be susceptible to bacterial growth.
So, is taking expired medication considered safe?
The U.S. Food and Drug Administration (FDA) advises against taking medications after their expiration date due to various unknown variables, such as how the medication has been stored and its chemical composition. All these factors can impact the drug's effectiveness.
However, it's acknowledged that 90% of medications remain effective and safe if used after their expiration date. Nonetheless, it is advisable not to use them, and their sale is discouraged to ensure optimal efficacy for the patient.
Additionally, there is a group of medications strictly prohibited to be taken after their expiration date. These are medications with a narrow therapeutic window, including examples such as:
- Nitroglycerin
- Digoxin
- Contraceptives
- Insulin
- Warfarin
- Phenytoin
- Valproate
Does the expiration of a medication change after opening the packaging?
The expiration date is as indicated on the medication's packaging when it is sealed. However, after opening, the stability of the drug varies. It is no longer solely influenced by storage conditions but also affected by the patient's repeated use and exposure to the external environment.
Eye and nose drops:
Their validity is 4 weeks after opening, unless otherwise stated by the manufacturer.
Syrups and external solutions:
6 months after opening, except for antibiotics, which remain effective and safe for 7 to 14 days after opening.
Ointments, creams, and gels:
3 months after opening, unless otherwise stated by the manufacturer.
Lotions:
6 months after opening, unless otherwise stated by the manufacturer.
Tablets and capsules packaged under specific conditions:
Based on the expiration date if stored under appropriate conditions.
Ampoules:
To be used upon opening and should never be stored once opened.
References:
1. Anderson L. Drug Expiration Dates - Are Expired Drugs Still Safe to Take? 2022 [Available from: https://www.drugs.com/article/drug-expiration-dates.html.
2. NHS. Why do medicines have expiry dates? 2023 [Available from: https://www.nhs.uk/common-health-questions/medicines/why-do-medicines-have-expiry-dates/.
3. FDA. Don’t Be Tempted to Use Expired Medicines 2021 [Available from: https://www.fda.gov/drugs/special-features/dont-be-tempted-use-expired-medicines.
4. FDA. Expiration Dates - Questions and Answers 2022 [Available from: https://www.fda.gov/drugs/pharmaceutical-quality-resources/expiration-dates-questions-and-answers.
5. Gikonyo D, Gikonyo A, Luvayo D, Ponoth P. Drug expiry debate: the myth and the reality. Afr Health Sci. 2019;19(3):2737-9.
6. NHS. GOOD PRACTICE GUIDANCE EXPIRY DATES FOR MEDICATION 2021 [Available from: https://www.ghc.nhs.uk/wp-content/uploads/CHST-Expiry-Dates-of-Medication.pdf.