A nurse is caring for a client who reports difficulty breathing during the administration of an intermittent IV bolus of nafcillin. After stopping the infusion and notifying the provider, the nurse should anticipate a prescription for which of the following medications?

A. Deferoxamine. Deferoxamine is a chelating agent used to treat iron overload or toxicity. It has no role in managing an acute allergic reaction or respiratory distress caused by nafcillin, a penicillin-type antibiotic. B. Vitamin K. Vitamin K is used to reverse the effects of warfarin-induced anticoagulation and is not indicated for treating an allergic reaction. Anaphylaxis is not related to coagulation disturbances, making this an inappropriate intervention. C. Epinephrine. Epinephrine is the first-line treatment for anaphylaxis, which can present with difficulty breathing, bronchospasm, and hypotension. It works by stimulating alpha- and beta-adrenergic receptors, leading to bronchodilation, increased cardiac output, and vasoconstriction to counteract severe allergic reactions. Immediate administration is necessary to prevent further airway compromise and circulatory collapse. D. Prednisone. Prednisone is a corticosteroid used to reduce inflammation and prevent delayed allergic reactions. While it may be prescribed as part of long-term management, it does not provide the rapid bronchodilation and vasoconstriction needed for emergency treatment of anaphylaxis.