Final answer:
A nurse should instruct a patient with diabetes insipidus on the prescribed frequency of desmopressin nasal spray usage, which is typically more than once a day, to control symptoms and prevent dehydration and electrolyte imbalances.
Step-by-step explanation:
A nurse providing discharge teaching to a client with diabetes insipidus who has a new prescription for desmopressin nasal spray should include instructions on how frequently to use the nasal spray. The correct schedule for desmopressin administration is specific to each patient and should be determined by the healthcare provider based on the patient's individual needs. However, it is typically used more than once a day and not merely as needed or during flare-ups. The nurse should explain that the medication is crucial for controlling the symptoms of diabetes insipidus, such as excessive thirst and urination, by helping the kidneys retain water and thereby preventing dehydration and electrolyte imbalances. The nurse should also educate the patient on the importance of adhering to the prescribed treatment regimen.