Epinephrine is a synthetic form of adrenaline that is normally produced in the body. It is the active ingredient in Primatene Mist and other generic epinephrine inhalers.

The same way adrenaline helps your body in a fight-or-flight response to fear, epinephrine is used to treat asthma and other obstructive pulmonary diseases because of its ability to quickly dilate air passages.

Used during an asthma attack, epinephrine inhalers—sold commonly for asthma under the name Primatene Mist—open bronchial passages during bronchospasms and allow air to enter the lungs easier.

There is some debate among health professionals whether nonprescription epinephrine inhalers like Primatene Mist should be used because of their potential for abuse. Evidence suggests that if used as directed, epinephrine inhalers are safe for those already diagnosed with asthma.

However, beginning in 2012, Primatene Mist and other epinephrine metered-dose inhalers will no longer be made or sold following the U.S. Food and Drug Administration’s decision in 2008 to ban the use of epinephrine inhalers because they use chlorofluorocarbons, or CFCs, as a propellant. The move was due to environmental concerns because CFCs deplete the ozone layer.

Currently there are no FDA-approved, over-the-counter epinephrine inhalers on the market.

In addition to Primatene Mist, epinephrine, in other preparations, is also used to treat cardiac arrest, anaphylactic shock, and acute allergic reactions. It is also used in some local anesthetics.