What medication would you most likely administer to an anaphylaxis patient?

• A. Epinephrine
• B. Diphenhydramine
• C. Albuterol
• D. Nitroglycerin

Answer: (A)

Anaphylaxis requires immediate reversal of airway swelling, bronchospasm, and low blood pressure, so the best initial treatment is epinephrine because it works on multiple body systems at once. Epinephrine constricts blood vessels (alpha-1), which reduces swelling and helps raise blood pressure; it relaxes bronchial smooth muscle (beta-2), easing breathing; and it increases heart contractility and rate (beta-1), improving circulation. It also helps stabilize mast cells and limit further release of allergic mediators. This rapid, multi-faceted action is what makes it life-saving in anaphylaxis.

Typically given as an intramuscular injection into the thigh, the adult dose is about 0.3–0.5 mg of a 1:1000 solution, with dosing for children around 0.01 mg/kg up to 0.3 mg, and repeating every 5–15 minutes as needed while awaiting emergency care or further treatment. Auto-injectors are common for quick administration when needed.

The other medications have supportive roles but do not address the whole crisis. Diphenhydramine is an antihistamine that may help with itching and hives but won’t prevent airway obstruction or shock. Albuterol can help with bronchospasm but won’t treat hypotension or mucosal edema. Nitroglycerin would worsen low blood pressure and is inappropriate in this context.