After administering the first drug for a dermatologic reaction after peg-Asparaginase, Sam starts to complain of throat tightening and he starts wheezing. The MD orders Epinephrine. What is the preferred route?

• A. PO
• B. Sub-Q
• C. IV
• D. IM

Answer: (D)

When a reaction escalates to airway involvement and bronchospasm, epinephrine is the first-line treatment because it rapidly counteracts swelling, opens the airways, and improves circulating pressure. The most reliable and fastest way to deliver this drug in an emergency is by intramuscular injection, typically into the mid-thigh. This route provides quick and predictable absorption even when perfusion is compromised, which is exactly what happens during anaphylaxis-like reactions.

Intravenous epinephrine, while lifesaving in a controlled hospital setting, carries a higher risk of dangerous blood pressure changes and arrhythmias and requires careful titration and monitoring. Subcutaneous administration is slower and can be less reliable in severe reactions when shock reduces blood flow to the subcutaneous tissues. Oral administration is not appropriate for acute, life-threatening reactions due to very poor and unpredictable absorption.

So, the intramuscular route is preferred for rapid, reliable effect in this acute setting.