How is an epinephrine auto-injector administered?

How is an epinephrine auto-injector administered?

• A. Into the upper arm
• B. Auto injection into the lateral thigh
• C. Under the tongue
• D. Into the buttock

Answer: (B)

The key idea is that an epinephrine auto-injector is given as an intramuscular injection into the outer thigh. This location—the anterolateral aspect of the thigh (vastus lateralis)—has strong muscle mass and rapid blood flow, allowing the medication to be absorbed quickly to counteract anaphylaxis. The device is designed to pierce through clothing and deliver the dose into this muscle, then be held in place for a few seconds to ensure full administration. The other sites aren’t suitable for this purpose. The upper arm isn’t the recommended site because absorption can be slower or less reliable with the device design. Placing epinephrine under the tongue isn’t a valid route for the auto-injector, and injecting into the buttock yields slower, inconsistent absorption and is not used for this emergency treatment.

The key idea is that an epinephrine auto-injector is given as an intramuscular injection into the outer thigh. This location—the anterolateral aspect of the thigh (vastus lateralis)—has strong muscle mass and rapid blood flow, allowing the medication to be absorbed quickly to counteract anaphylaxis. The device is designed to pierce through clothing and deliver the dose into this muscle, then be held in place for a few seconds to ensure full administration.

The other sites aren’t suitable for this purpose. The upper arm isn’t the recommended site because absorption can be slower or less reliable with the device design. Placing epinephrine under the tongue isn’t a valid route for the auto-injector, and injecting into the buttock yields slower, inconsistent absorption and is not used for this emergency treatment.