Basically scrips have to be written for a particular person. However if the supplies are on board and you need them then you use them. The EpiPen should be reserved for use by someone who has a demonstrated history of serious allergy that may need it. The most common allergies for which they are written are peanut allergy (I have seen some horrendous peanut allergy reactions and thank God have had no deaths, but they do occur) and also beestings, which can be any of a variety of stinging insect called Hymenoptera. (wasps, hornets, bees, yellowjackets etc). Note that you should also familiarize yourself with this equipment.
Please feel free to ask anything else in this line. If I can't answer it or feel I shouldn't I will let you know. None of this stuff is secret, or ought to be.