Which medication should a nurse administer first if a client displays anxiety, hypotension, and dyspnea after cefazolin IV administration?

The best choice in this scenario is epinephrine, particularly due to the combination of symptoms the client is exhibiting: anxiety, hypotension, and dyspnea. These signs could suggest a serious allergic reaction, such as anaphylaxis, which requires immediate intervention. Epinephrine is the first-line treatment for anaphylactic reactions because it acts quickly to alleviate airway constriction, increase heart rate, and raise blood pressure by stimulating alpha and beta-adrenergic receptors. It essentially counteracts the severe effects of anaphylaxis by improving cardiovascular stability and respiratory function.

While diphenhydramine is an antihistamine that can help manage allergic reactions, it is not fast-acting enough to address an anaphylactic situation. Albuterol is a bronchodilator that would help with respiratory symptoms but does not address hypotension. Prednisone is a corticosteroid used for its anti-inflammatory properties, which takes hours to be effective and is not appropriate in an acute situation requiring immediate action. Therefore, administering epinephrine first is crucial to quickly stabilize the client’s condition.