In anaphylaxis, what is the first-line treatment and typical epinephrine dosing?

• A. Epinephrine 0.3-0.5 mg 1:1000 IM; may repeat every 5-15 minutes; airway/fluids; secondary meds as adjuncts.
• B. Epinephrine 0.5 mg 1:1000 IV push; rapid dosing.
• C. Albuterol inhalation first-line.
• D. Diphenhydramine only.

Answer: (A)

Epinephrine is the immediate, first-line treatment for anaphylaxis because it counteracts the life-threatening swelling, airway compromise, and circulatory collapse by providing rapid alpha-adrenergic vasoconstriction and beta-adrenergic bronchodilation. This helps reduce edema, tighten the airway, and support blood pressure while also limiting further mediator release. The standard adult dose is 0.3 to 0.5 mg of a 1:1000 epinephrine solution given intramuscularly, typically in the mid-outer thigh, and it may be repeated every 5 to 15 minutes if symptoms persist or recur. For children, the dose is usually 0.01 mg/kg per dose (up to a maximum of 0.3 mg) with the same repeat interval. While IV epinephrine can be used in severe, refractory shock, it carries a higher risk of dangerous cardiovascular effects and is reserved for monitored, advanced settings rather than initial treatment. Alongside epinephrine, secure the airway, provide supplemental oxygen, and establish IV access with fluids to support circulation. Adjuncts such as bronchodilators and antihistamines or corticosteroids may be used, but they do not replace epinephrine and are not sufficient as sole therapy—epinephrine reverses the underlying life-threatening process.