Taking Expired Medications: What's the Harm?
Consumers are sometimes quick to disregard the expiration dates of their prescriptions and over-the-counter medications. These habits may be due to the rising cost of medications; negligence; lack of insurance; or unawareness of the harm in doing so.
The term "expired" is defined as something that has come to an end. Popular expressions such as an expired driver's license, passport, or even food, signify that replacements are in order or there may be consequences. The same concept applies to the use of expired medications.
To shed more light on the relevance of expiration dates, it is important to understand how drug companies determine the longevity and expiration of their products. All drugs have unique formulations consisting of active and inactive ingredients geared to treat specific diseases. Once a drug is developed, manufacturers determine the length of time a drug will last without deteriorating; this is known as the drug's shelf-life. If a medication is used within its shelf-life, maximal efficacy and safety of the drug are expected.
Efficacy and Safety
Efficacy
Efficacy is an important factor to consider because it reflects the ability of the drug to produce the desired effect; hence, the higher the efficacy, the better the results. Expired medication may not adequately treat minor conditions (for example, minor headache, cold), or serious conditions (for example, diabetes or heart disease) because of reduced efficacy. As a consequence, inadequate relief from sickness could eventually lead to longer sick days, increased absences from work/school, and lost productivity at work/school.
Safety
The safety of expired medications should also be considered. Medications may change their chemical and physical properties, as is evident when tablets disintegrate and liquids separate into layers or even change color within the dispensed bottle.
As can be seen, the big issues with expired medications are two-fold:
- drugs become weak and may potentially be unsafe.
- It is advisable to discard all expired medications. Why take the risk? Always check expiration dates posted on boxes and vials and if products are expired, check with your local pharmacy or physician's office to see if they have medication disposal receptacles.
- It is not recommended to flush unused or expired medications down the toilet as they have the possibility of contaminating the water system.
From 
Tova Alladice, M.D.
American Board of Physical Medicine & Rehabilitation