What is the standard adult epinephrine auto-injector dose and route for anaphylaxis?

• A. 0.3 mg IM in the lateral thigh; may repeat every 5-15 minutes as needed
• B. 0.5 mg IM in the thigh
• C. 0.15 mg IM
• D. 1.0 mg IM

Answer: (A)

The essential idea is that for adult anaphylaxis, the standard epinephrine auto-injector dose is 0.3 mg given intramuscularly into the lateral thigh, and you can repeat every 5–15 minutes if symptoms persist. This route—IM into the outer thigh—provides rapid absorption and a quick onset, which is crucial when airway swelling, low blood pressure, and bronchospasm are threats. Epinephrine counters these issues by causing vasoconstriction to raise venous return and blood pressure, and by relaxing the airways to improve breathing. The 0.3 mg dose is the typical amount for most adults; smaller doses like 0.15 mg are used for pediatric devices, while much larger doses (0.5 mg or 1.0 mg) are not standard auto-injector doses. IV administration is not preferred in the field due to higher risk of dangerous cardiovascular effects.