Final answer:
Dizziness is a priority side effect to report when taking levofloxacin for pneumonia treatment.
Step-by-step explanation:
The nurse should teach the client that dizziness is a priority side effect to report to the provider when taking levofloxacin for the treatment of pneumonia. While joint tenderness, diarrhea, and difficulty sleeping can also be side effects of levofloxacin, dizziness can indicate a more serious reaction that requires immediate medical attention.