A 34-year-old client with central diabetes insipidus is starting desmopressin (DDAVP) intranasal spray. Which client statement indicates correct understanding of self-monitoring at home?

Desmopressin (DDAVP) is a synthetic vasopressin analogue used for central diabetes insipidus, primary nocturnal enuresis, and von Willebrand disease/hemophilia A. In central DI it replaces ADH and reduces urine output by acting on V2 receptors in renal collecting ducts. Key teaching: (1) effective therapy reduces urine to a normal range — persistent polyuria of 8 L/day means inadequate dose; (2) the principal hazard is water intoxication and dilutional hyponatremia (Na less than 135) because water is retained — daily weight, intake/output diary, and reporting headache, nausea, vomiting, confusion, lethargy, seizures, or sudden weight gain are essential; (3) drink only to thirst, not preemptively, while on therapy; (4) intranasal route requires correct technique: clear nostril, prime if new bottle, alternate nostrils, store upright; oral and SC routes are alternatives; (5) periodic serum sodium is checked; (6) do not stop abruptly because polyuria and dehydration return rapidly; (7) avoid concurrent NSAIDs, SSRIs, carbamazepine, and chlorpropamide which potentiate antidiuresis. Stopping when symptoms improve, drinking excess water, or accepting 8 L/day output are all unsafe.

The single most important DDAVP teaching point is the hyponatremia/water intoxication warning. Daily weight plus intake/output plus neurologic symptom reporting is the home monitoring trio.