For a client with diabetes insipidus on desmopressin, what symptom warrants immediate medical attention?

In the context of a client with diabetes insipidus who is receiving desmopressin, new headaches and confusion signal potential complications related to water retention and electrolyte imbalances, particularly hyponatremia (low sodium levels). Desmopressin acts as an antidiuretic hormone, promoting water reabsorption in the kidneys. When too much water is retained, it can lead to dilution of sodium in the blood, causing symptoms such as confusion and headaches. These neurological symptoms indicate that the patient's condition may be deteriorating, possibly due to water intoxication, and warrant immediate medical evaluation to adjust treatment and manage sodium levels.

Frequent thirst, increased urination, and dry mouth are more typical and manageable symptoms of diabetes insipidus and its treatment with desmopressin. While they are important to monitor, they do not indicate an urgent need for medical intervention compared to the acute symptoms of headache and confusion, which suggest a potentially life-threatening situation.