A client with central diabetes insipidus receives desmopressin. Which finding best indicates the intended response to therapy?

Desmopressin replaces antidiuretic activity, so effective therapy decreases excessive urine volume and produces more concentrated urine. Very low output with hyponatremia and headache suggests excessive water retention rather than the intended balanced response.

Quick answer
A lower, adequate urine output with increased urine concentration shows the intended antidiuretic response.

Why this is correct
Central diabetes insipidus causes large amounts of dilute urine because antidiuretic hormone activity is deficient. Desmopressin should reduce urine volume and increase urine osmolality or specific gravity while maintaining safe fluid and sodium balance.

Easy analogy or mental picture
Desmopressin partly closes a drain that was letting too much dilute water escape. The desired result is controlled flow, not a blocked drain, and the analogy does not replace sodium and neurologic monitoring.

Memory hook
Effective desmopressin makes urine less excessive and more concentrated without water intoxication.

NCLEX decision rule
Evaluate antidiuretic replacement by pairing urine volume with urine concentration and sodium status. Continued dilute polyuria means inadequate effect, while oliguria with hyponatremic symptoms suggests excessive effect.

Why the other choices are wrong
High dilute output shows persistent diabetes insipidus. Continued high sodium with polyuria is inadequate response, and very low output with low sodium and headache signals water intoxication.