What is the first-line medication used to treat anaphylaxis?

Epinephrine is the first-line medication used to treat anaphylaxis due to its rapid action in counteracting the severe symptoms associated with this life-threatening allergic reaction. It works by stimulating alpha and beta adrenergic receptors, which leads to vasoconstriction, increased heart rate, and bronchodilation. These effects help restore normal heart function, reduce swelling, and open the airways, making it a critical treatment in emergency situations.

In anaphylaxis, the body's response to an allergen can result in significant bronchospasm, vascular collapse, and edema of the airway. Epinephrine, administered preferably via intramuscular injection, acts quickly to mitigate these severe effects, making it essential for immediate intervention. Other treatments, like antihistamines and glucocorticoids, play supportive roles in managing allergic reactions but do not address the acute symptoms as effectively as epinephrine does.