What is the initial intramuscular dose of Epinephrine 1 mg/mL for an adult with a severe allergic reaction?

• A. 0.15 mg IM
• B. 0.3 mg IM
• C. 0.5 mg IM
• D. 0.1 mg IM

Answer: (B)

The key point is the standard initial dose for an adult with anaphylaxis when using a 1 mg/mL (1:1000) epinephrine solution. The recommended amount is 0.3 mg, which is 0.3 mL of the solution given intramuscularly. This dose is chosen because it provides rapid bronchodilation and vasoconstriction to counter airway swelling, bronchospasm, and hypotension, with a safety profile suited to IM administration. In adults, 0.3 mg is the typical starting dose; smaller amounts are used in children or smaller adults, and higher single doses aren’t standard for the initial management in most EMS protocols. If symptoms persist, the dose can be repeated at intervals (as per protocol) up to a recommended maximum, with further medical care as needed.