Understanding Drug Expiration Dates

In 1979, the U.S. Food and Drug Administration (FDA) began requiring an expiration date on prescription and over-the counter medicines so it’s not surprising that the FDA strongly recommends disposing of all expired drugs. That said, in 1985 the FDA began testing medications for the Department of Defense under the Shelf Life Extension Program (SLEP) to see if it was safe for the military to stockpile medications. Continual testing shows that many Rx and OTC drugs retain full potency years beyond their expiration dates. And, current data also shows that no drugs currently in production have been shown to be toxic past their shelf life. Excluding nitroglycerin, insulin, and liquid antibiotics, most medications are as long-lasting as the ones tested by the military. That said, it’s difficult for an individual consumer to know how long a specific drug will remain active beyond it’s expiration date as it’s ingredients, type and presence of any preservatives, and storage conditions can dramatically affect the drug's potency and life expectancy. Obviously we have control of what we put into our own first aid kit but how do we, as expedition leaders and medical officers make decisions about drug use once in the field and faced with someone else’s first aid kit that contains expired medications? Below are some practical guidelines:

• Storage matters: Store medications in dry, cool spaces away from light in air-tight containers. Correctly stored, most drugs retain their full potency years beyond their expiration date.
• Solid drugs are more stable than liquid. If the physical condition of the drug remains unaltered by time, it is likely safe to use but may not have full potency. Discard any drug that shows visible degradation. This includes liquids that have changed color, become cloudy, or present with a precipitate.
• With ophthalmic drugs, the limiting factor is the continued ability of the preservative to inhibit microbial growth. With that in mind, it’s best to toss eye drops and ointments after their expiration date.
• Biologic products, insulin, and oral nitroglycerin, degrade rapidly beyond their expiration dates and should not be used. Depending on how it is stored, epinephrine can also degrade rapidly, however it remains safe to use if it is clear and free of particulates—you just may need more of it. One study showed that properly stored EpiPens 5-7 years past expiration date retained more than 70% of the original potency; many 2-3 years past their expiration date retained more than 90%.

Common sense, indicates that:

• Outfitters should check and replace all expired medications before leaving for a trip.
• You should replace medications that are required to treat a potentially life-threatening condition ideally before but definitely ASAP after their expiration date. That said, a year won't make a difference in the potency for most drugs.
• If the medication is for a minor health problem (headache, mild pain, hay fever, etc) and it’s for personal use, it’s reasonable to use it. Discontinue use—and replace it—if the drug does not yield the expected therapeutic response.
• When in doubt, consult a pharmacist before the drug expires.