What is an Auto-injector?
An auto-injector is a device that allows for rapid injection of pre-dosed epinephrine. The auto-injector simplifies the process of epinephrine injection, and is a user-friendly alternative to syringes and epinephrine vials. This medication is used to stop the surge of symptoms during a potentially severe allergic reaction.
Epinephrine is the only effective drug to treat anaphylaxis, the most serious and potentially fatal form of allergic reactions. This drug is a synthetic version of adrenaline, a substance naturally produced by the human body.
Auto-injectors EpiPen®, EpiPen® Jr and Allerject® 0.3 mg; 0.15 mg; 0.1 mg
Saving a child with an adult format auto-injector
A child with a food allergy should have a valid prescription for an auto-injector based on their weight. As a general rule, the child switches to the adult auto-injector when reaching a weight of 30 kg (66 lbs.). Your allergist can confirm this according to the specifics of your case.
However, if a child shows signs of an anaphylactic reaction and you only have an adult size auto-injector at hand, it is recommended to use it promptly.
If during a severe reaction the only available auto-injector is expired, some doctors and researchers stipulate that the device could still be used, as long as the solution is colorless and free of particles in suspension. For some, the potential benefits of using an expired auto-injector, despite its risks, remain greater than the absence of treatment [1,2].
 Simon, F. E., Gu, X. et Simons, K. J. (2000). Outdated Epipen and EpiPen Jr autoinjectors: Past their prime? Journal of Allergy and Clinical Immunology, 105(5):1025-1030. DOI 10.1067/mai.2000.106042
 Dubé, Dani-Elle. (2017, 9 mai). Reality check: Is it safe to use an expired EpiPen in the event of anaphylaxis? Global News.