Which medication is commonly administered for anaphylaxis in the emergency department?

Epinephrine is the first-line medication administered for anaphylaxis in the emergency department due to its ability to rapidly counteract the severe allergic reaction. It acts on both alpha and beta-adrenergic receptors, leading to multiple beneficial effects: it causes vasoconstriction, which helps to increase blood pressure, and it also relaxes bronchial smooth muscle, improving breathing. Additionally, epinephrine reduces edema and urticaria by inhibiting the release of further mediators from mast cells and basophils.

While other medications such as diphenhydramine, a histamine antagonist, and hydrocortisone, a corticosteroid, can be used as adjunct treatments, they do not act quickly enough to address the life-threatening symptoms of anaphylaxis. Aspirin is also not indicated for this acute condition, as it does not target the underlying immune response that results in anaphylactic shock. Thus, epinephrine stands out as crucial for immediate treatment of anaphylaxis, making it the appropriate choice in emergency scenarios.