A nurse is caring for a client who has a history of allergic reactions to penicillin. The client is prescribed cefazolin for a wound infection. Which of the following actions should the nurse take before administering the medication?

Rationale: Cefazolin is a cephalosporin, which has a cross-sensitivity with penicillin. Therefore, the nurse should ask the client about any previous reactions to cephalosporins before administering the medication. This can help identify clients who are at risk of developing an allergic reaction to cefazolin.

B) is incorrect because administering an antihistamine is not a preventive measure for an allergic reaction, but rather a treatment for mild symptoms. Antihistamines do not prevent anaphylaxis, which is a life-threatening reaction that requires immediate intervention.

C) is incorrect because monitoring the client's vital signs for 15 minutes after the injection is not enough to detect an allergic reaction, which can occur up to 72 hours after exposure. The nurse should monitor the client for signs and symptoms of an allergic reaction throughout the course of therapy.

D) is incorrect because diluting the medication with normal saline does not reduce the risk of an allergic reaction, but rather the risk of phlebitis, which is inflammation of the vein. Phlebitis is a common adverse reaction to cefazolin, but it is not related to allergy.

Rationale: Epinephrine is the first-line medication for anaphylaxis, which is a severe allergic reaction that can cause bronchoconstriction, hypotension, and shock. Epinephrine acts as a bronchodilator and a vasoconstrictor, reversing the effects of histamine and other mediators released during anaphylaxis.

B) is incorrect because diphenhydramine is an antihistamine that can help relieve itching, hives, and urticaria, but it does not reverse bronchoconstriction or hypotension. Diphenhydramine can be given as an adjunct therapy after epinephrine.

C) is incorrect because albuterol is a beta2 agonist that can help relieve bronchospasm, but it does not affect blood pressure or other systemic effects of anaphylaxis. Albuterol can be given as an adjunct therapy after epinephrine.

D) is incorrect because hydrocortisone is a corticosteroid that can help reduce inflammation and prevent delayed reactions, but it does not have an immediate effect on anaphylaxis. Hydrocortisone can be given as an adjunct therapy after epinephrine.