An EpiPen is a medical device designed to deliver a rapid, pre-measured dose of epinephrine, a synthetic form of adrenaline, into the body. This auto-injector is primarily used for the emergency treatment of severe allergic reactions, known as anaphylaxis. Anaphylaxis is a life-threatening condition that can occur suddenly and progress rapidly, affecting multiple body systems. The epinephrine delivered by an EpiPen works quickly to counteract the severe symptoms of this reaction.
Why EpiPens Have an Expiration Date
EpiPens have an expiration date because their active ingredient, epinephrine, is chemically unstable and degrades over time. This degradation reduces its potency, meaning the medication may not be as effective in treating a severe allergic reaction.
Environmental factors can accelerate this degradation process. Exposure to light, particularly ultraviolet (UV) light, can cause epinephrine to oxidize, leading to a loss of effectiveness and a change in color, often turning pinkish or brown. Similarly, extreme temperatures, both hot and cold, can compromise the stability of the drug. For instance, prolonged exposure to temperatures above 30 degrees Celsius can affect potency, while temperatures below 15 degrees Celsius can damage the injector mechanism itself.
What Happens When an Expired EpiPen Is Used
The primary concern when using an expired EpiPen is the reduced potency of the epinephrine. Over time, the active ingredient breaks down, meaning the device may not deliver a sufficient dose to effectively reverse the severe symptoms of anaphylaxis. While not inherently harmful, an expired EpiPen might not be effective enough to stop a life-threatening allergic reaction.
Studies have shown that expired EpiPens can retain a significant portion of their labeled epinephrine concentration, even several months or years past their expiration date. For example, some studies indicate that devices may still contain at least 80% of their stated dose up to 50 months past expiration for standard EpiPens and 30 months for EpiPen Jrs. However, there is no guarantee that the medication will work as intended once it is past its expiration date.
Given the potential for reduced effectiveness, it is always recommended to use an unexpired EpiPen if available. However, in an emergency where an expired EpiPen is the only option, it should be used without hesitation. Any amount of epinephrine, even at a reduced potency, is better than no treatment at all during anaphylaxis. Following administration of an expired EpiPen, immediate medical attention by calling emergency services is necessary.
Keeping Your EpiPen Ready for Emergencies
Maintaining your EpiPen in ready-to-use condition involves several practical steps. First, regularly check the expiration date, found on the pen itself and on the medication packaging. EpiPen auto-injectors have a shelf life of 12 to 18 months, so note the expiration date on a calendar or set a reminder for timely replacement.
Proper storage conditions are also important to preserve the medication’s stability. EpiPens should be stored in their protective carrier tube at room temperature, between 20-25°C (68-77°F), with 15-30°C (59-86°F) also acceptable. It is important to protect the device from extreme heat or cold and direct light, which can degrade the epinephrine. For instance, avoid storing it in a vehicle’s glove compartment or trunk, and do not refrigerate or freeze it, as cold temperatures can damage the injector mechanism.
Before use, visually inspect the epinephrine solution through the clear window on the auto-injector. The solution should be clear and colorless; if it appears discolored (pinkish, yellowish, or brown) or contains particles, it indicates degradation and the device should be replaced. Once an EpiPen is used or expires, it requires proper disposal as a sharps container item. This can be done by returning it to the prescribing healthcare provider, a hospital, or a pharmacy with a drug take-back program that accepts sharps.