A nurse is caring for a client who is experiencing anaphylactic shock in response to the administration of penicillin. Which of the following medications should the nurse administer first?

A. Furosemide: This is a diuretic used for fluid overload, not helpful in anaphylactic shock. B. Epinephrine: Epinephrine is the first-line treatment in anaphylaxis. It reverses airway constriction, increases blood pressure, and reduces capillary permeability. C. Dobutamine: Dobutamine is a cardiac inotrope and not the first drug of choice in anaphylaxis. D. Methylprednisolone: This corticosteroid can help reduce inflammation, but it works slowly and is not suitable for emergency reversal. Administer only after epinephrine.