Final answer:
The nurse should report the client's penicillin allergy to the provider before the client receives cephalexin. Cephalexin is a cephalosporin and individuals with a penicillin allergy may also be allergic to cephalosporins.
Step-by-step explanation:
The nurse should report the client's penicillin allergy to the provider before the client receives cephalexin. Cephalexin is a medication that belongs to the class of cephalosporins, which are structurally similar to penicillins. There is a cross-reactivity between penicillins and cephalosporins, meaning that individuals with a penicillin allergy may also be allergic to cephalosporins.
It is important for the provider to be aware of the penicillin allergy to avoid potential allergic reactions and to consider alternative antibiotics if necessary.