Epinephrine, also known as adrenalin or adrenaline, is primarily a medication and hormone. As a medication it is used for a number of conditions including: anaphylaxis, cardiac arrest, and superficial bleeding. Inhaled epinephrine may be used to improve the symptoms of croup. It may also be used for asthma when other treatments are not effective. It is given intravenously, by injection into a muscle, by inhalation, or by injection just under the skin.