Final answer:
The nurse should inform the client about common side effects of nasal spray, such as nasal irritation and dryness, as well as more serious ones, and advise on correct usage and when to seek medical help.
Step-by-step explanation:
The best response by the nurse when a client asks about the side effects of using nasal spray would be to provide comprehensive information about the potential side effects while ensuring to address any specific concerns the client may have. It is important for a nurse to educate the client on common side effects such as nasal irritation, dryness, sneezing, or nosebleeds, as well as rarer but more serious side effects like signs of allergic reaction, prolonged nosebleeds, or difficulty breathing. The nurse should also emphasize the importance of following the instructions for use and to consult a healthcare provider if any concerning symptoms arise.