Autoinjectors.

Now they are one-use, as they were intended.
You can still change their contents with syringes before they are used.
To mitigate their one-use nature, box of them is added to medical closets and supply pack.

code/game/objects/structures/crates_lockers/closets/secure/medical.dm

@@ -13,6 +13,7 @@
 	New()
 		..()
 		sleep(2)
+		new /obj/item/weapon/storage/box/injectors
 		new /obj/item/weapon/storage/box/syringes(src)
 		new /obj/item/weapon/reagent_containers/dropper(src)
 		new /obj/item/weapon/reagent_containers/dropper(src)