Final answer:
Epinephrine is commonly known as Adrenalin or EpiPen and is used to counteract the effects of anaphylactic shock in severe allergic reactions.
Step-by-step explanation:
Epinephrine is commonly known by the medication names Adrenalin and EpiPen. These names refer to the same molecule, which is a hormone secreted by the adrenal medulla. In the United States, the term 'epinephrine' is preferred, while 'adrenaline' is preferred in Great Britain due to historical reasons. Epinephrine is used to counteract the effects of anaphylactic shock in severe allergic reactions.