What class of drugs is commonly used to treat severe allergic reactions and anaphylaxis?

Epinephrine is the primary medication used to treat severe allergic reactions and anaphylaxis because of its ability to rapidly reverse the life-threatening symptoms associated with these conditions. It acts as a potent vasoconstrictor, which helps to increase blood pressure and improve circulation during anaphylactic shock. Additionally, epinephrine relaxes the muscles around the airways, leading to bronchodilation, which alleviates breathing difficulties that often accompany severe allergic reactions.

While other classes of drugs like antihistamines and corticosteroids can be part of the management protocol for allergic reactions, they do not work quickly enough to address acute anaphylaxis. Antihistamines can help relieve milder allergic symptoms but are not effective in treating the severe life-threatening components of anaphylaxis. Corticosteroids may be used to reduce inflammation over the course of several hours to days, but they do not provide immediate relief. Beta blockers can complicate the treatment of anaphylaxis as they may inhibit the action of epinephrine, making them less favorable in emergency situations. Thus, epinephrine is the essential and first-line treatment during acute anaphylaxis for its speed and efficacy.