In the allergic reaction protocol, which dose is drawn up for epinephrine?

• A. Epinephrine 1 mg
• B. Diphenhydramine 50 mg
• C. Hydrocortisone 100 mg
• D. Famotidine 20 mg

Answer: (A)

When an allergic reaction may become life-threatening, the priority is to reverse airway compromise and shock as quickly as possible. Epinephrine does this by acting on multiple body systems: it constricts blood vessels to reduce swelling and raise blood pressure, relaxes airway smooth muscle to improve breathing, and stabilizes cells that release allergic mediators. Because of its rapid, decisive effects, epinephrine is the first medication prepared and given in the acute protocol—the dose is drawn up so it can be delivered immediately.

The other drugs—an antihistamine, a corticosteroid, and an H2 blocker—are adjuncts. They can help with symptoms and may prevent biphasic reactions, but they do not reverse the life-threatening airway or circulatory problems as quickly as epinephrine does, and they have slower onset. So the epinephrine dose drawn up is the critical, prioritized element in this scenario.