A client asks the nurse about the risk factors associated with allergic reactions to medications. Which response by the nurse is correct?

Amoxicillin is a penicillin derivative that has a high cross-reactivity with penicillin. Therefore, the nurse should hold the medication and notify the provider of the client's allergy. The provider may prescribe an alternative antibiotic that belongs to a different class, such as a macrolide or a fluoroquinolone.

A) is incorrect because administering the medication as prescribed and monitoring for signs of an allergic reaction can put the client at risk of developing a serious or life-threatening reaction, such as anaphylaxis. The nurse should not administer any medication that the client is allergic to.

C) is incorrect because asking the client about the type and severity of his allergic reaction to penicillin is not enough to prevent an allergic reaction to amoxicillin. Even if the client had a mild reaction to penicillin in the past, he may have a severe reaction to amoxicillin in the present. The nurse should avoid giving any medication that has cross-sensitivity with penicillin.

D) is incorrect because administering an antihistamine before giving the medication to prevent an allergic reaction is not a safe or effective practice. Antihistamines do not prevent anaphylaxis, which is a life-threatening reaction that requires immediate intervention. Antihistamines can also mask some signs of an allergic reaction, such as itching and hives, making it harder to detect and treat.

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.