Epinephrine, anaphylaxis management

For nearly a century, epinephrine (adrenaline) has been the cornerstone of the acute management of anaphylaxis [1-6], a sudden-onset multi-systemic allergic reaction that can cause death. The World Health Organization lists epinephrine as an essential medication for anaphylaxis [7], Where national guidelines are available for the acute management of anaphylaxis, they universally recommend injection of epinephrine as the initial medication of choice [8]. 

Sicherer SH, Simons FER Quandaries in prescribing an emergency action plan and self-injectable epinephrine for first-aid management of anaphylaxis in the community J Allergy Chn Immunol 2005 115 575-583. 

These mediators can produce a number of effects including bronchiolar constriction, capillary dilatation, or urticaria (i.e., hives). In severe episodes of type I reactions a life-threatening anaphylaxis can develop in humans due to extreme bronchoconstriction and precipitate hypotension. Epinephrine is the principal drug used in the acute management of these critical effects since it achieves (1) an elevated blood pressure via activation of alpha receptors in peripheral resistance blood vessels and (2) relaxation of bronchiolar smooth muscle via activation of (32 receptors in the lung. Relief from the dermatological problem (i.e., hives) is also achieved via vasoconstriction of capillaries in the skin that reduce permeability, and, hence, fluid accumulation. Penicillin is a classic example of a drug that can cause a type I reaction. 

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