Epinephrine is a hormone that is chemically identical to the adrenaline produced by the body, and the names of the two are often used interchangeably to some extent. When produced naturally by the body, it helps us respond effectively to short-term stress. It is also used as a drug to treat cardiac arrest, asthma, and allergic reactions, especially those which could be fatal if left untreated. It was first synthesized in 1895 by a physiologist from Poland, named Napoleon Cybulski.
The term epinephrine is often used to refer to the artificially derived version of adrenaline, which the body produces naturally in the adrenal glands. It is often referred to as a fight-or-flight hormone, because it helps the body cope with perceived threats. When a threat arises, such as the threat of physical harm, this hormone prepares the body to either stay and confront the threat, or flee quickly enough to survive. It does this by restricting blood flow to certain areas of the body, while increasing blood flow to the muscles. It also dilates the pupils, opens up the airways of the lungs, and increases the heart rate and blood sugar.
Artificially derived epinephrine has saved many lives since its development. It can be used in emergency situations by those who are suffering from an asthma attack or from anaphylaxis, in order to allow breathing again. Anaphylaxis, or anaphylactic shock, is the term for a potentially fatal allergic reaction. Those who have a severe allergy to peanuts or the venom from bee stings, for example often keep a syringe of epinephrine on hand, just in case. It should only be used in emergency situations, however, because of the potential side effects, which can adversely affect the heart.
When the hormone is administered, it is usually injected into the fleshy area of the thigh, and not into a vein, which could prevent it from working properly. Injection into the hands or feet could cause a loss or reduction of blood flow to these areas, and is not recommended. One reason why epinephrine works so well to treat severe allergic reactions is that it suppresses the action of the immune system. This is important to consider, given the fact that it is also produced by the body as a response to stress, including psychological stress.
While our bodies produce adrenaline in generally smaller amounts than are administered medically, high levels of stress over long periods of time can have a very damaging effect on the immune system. Perceived threats, whether physical or psychological, cause the production of adrenaline. While in moderation it can make us more effective in these situations, chronically stressed people are likely to be much more prone to infection and illness than those with manageable stress levels.