Emergency Medicine Practice Test 2025 – Complete Exam Preparation

The initial treatment for anaphylaxis is epinephrine, which plays a crucial role in reversing the life-threatening symptoms associated with this severe allergic reaction. Epinephrine works by acting on multiple receptors in the body: it stimulates alpha-1 adrenergic receptors, causing vasoconstriction, which increases blood pressure; it stimulates beta-1 adrenergic receptors, which enhances cardiac output; and it stimulates beta-2 adrenergic receptors, leading to bronchodilation and reduced bronchospasm. This combination of effects makes epinephrine essential in managing the respiratory distress, hypotension, and other systemic effects during an anaphylactic episode.

While other treatments like diphenhydramine, glucagon, and methylprednisolone may be used in allergic reactions or anaphylaxis, they are not the first-line management. Diphenhydramine, an antihistamine, can help alleviate symptoms but does not address the acute life-threatening aspects of anaphylaxis effectively enough compared to epinephrine. Glucagon is typically reserved for patients on beta-blockers who do not respond to epinephrine, and its role is more targeted rather than as a first-line therapy. Methylprednisolone, a corticosteroid, is useful