The expiration date indicates the time period the prescription drug can be expected to meet the claims of the Pharmacopeial monograph (information sheet provided with a medication), that it conforms to the recommended storage conditions. These dates are usually found on the manufacturer’s container and may be included on the prescription bottle label, depending on various state requirements.
The United States Pharmacopeia also provides guidelines for “beyond-use dating,” or the appropriate time period a dispensed medication should be retained by a patient. The beyond-use date typically defines storage conditions, packaging type, specific drug characteristics, and the number of times the drug container may be opened.
While it is true that some medications may continue to work beyond their expiration dates, it is best to observe the appropriate use dates and storage conditions indicated on the label. In some instances, failing to do so can be particularly dangerous. For example, the prescription medication tetracycline can become poisonous if it is used after its expiration date or stored improperly.
The integrity or stability of a drug product can be affected by several factors, including considerations related to extreme temperatures, exposure to air, various sources of light (i.e., sunlight, ultraviolet light, artificial light), or humidity. Therefore, following recommended storage practices can help to ensure the best outcomes for medication use. Storage conditions are indicated on each prescription drug’s product information label and can be found under a section titled “storage and handling."
When in doubt, consult with a pharmacist to determine whether or not a medication should be discarded and a new prescription ordered.