A

Intramuscular epinephrine (adrenaline) 0.3–0.5 mg (≈0.5 mL of a 1:1000 solution) into the mid-anterolateral thigh is the first-line, lifesaving treatment for anaphylactic shock because it provides rapid systemic vasoconstriction, bronchodilation, and inhibition of mediator release with a superior safety profile compared with intravenous dosing [Simons, 2011, PMID 21549206; WAO Guidelines, 2011, PMID 21609727].