EpiPen® and EpiPen® Jr. are auto-injectors containing adrenaline (epinephrine) for the treatment of allergic emergencies. The adrenaline corresponds to the body's own fast acting stress hormone and that is released when people get shocked.
The adrenaline works directly on the cardiovascular and respiratory systems. The adrenaline counteracts a potentially fatal anaphylactic shock by rapidly constricting the blood vessels, relaxing muscles in the lungs to improve breathing, reversing swelling, and stimulating the heartbeat.
In an anaphylactic shock the main problem for the body is the relaxation of the blood vessels, which in lay terms, makes room for more blood than there is in the body. The purpose of this hormone is in other words to concentrate the blood flow to the vital organs. Therefore it is also called the survival hormone.
EpiPen should be provided to patients having had a history of systemic allergic reactions towards insect stings, foods or drugs.