The main risk of desmopressin
Desmopressin acts on the kidney's collecting ducts to retain water, replacing the vasopressin he lacks. That is how it controls his polyuria, but it also means his body holds onto water. If he keeps drinking large amounts out of habit, the retained water dilutes his blood and causes hyponatremia, which can lead to headache, nausea, confusion, seizures, and, in severe cases, water intoxication. Drinking only when thirsty and weighing daily protect against water retention and hyponatremia.
Why the correct statement works
Thirst is a reliable guide to water needs when the hormone is replaced. By drinking to thirst, he takes in roughly what his body needs. Daily weights detect water retention early: a rapid gain over a day or two suggests he is holding too much fluid, and he should contact his provider. He should also know the early signs of hyponatremia, such as headache, nausea, and unusual drowsiness, and report them promptly.
| Client statement | Effect | Correct? |
|---|
| Drink only when thirsty and weigh daily | Prevents water retention | Yes |
| Drink at least 3 liters a day, as before | Water retention and hyponatremia | No |
| Stop the drug on days without thirst | Polyuria and dehydration return | No |
| Extra dose when urine looks pale | Water intoxication risk | No |
Why the other statements are unsafe
Before treatment he drank about as much as he urinated, around 6 liters a day; continuing to force at least 3 liters while the drug holds water in the body leads to hyponatremia. Stopping the drug on days without thirst brings back heavy urination and dehydration, because his lack of vasopressin is ongoing. Taking extra doses based on how pale the urine looks is unreliable and raises the risk of water intoxication. Watch out! After starting desmopressin, the danger shifts from dehydration to water overload, and teaching must change with it.
Exam takeaway
Desmopressin teaching includes taking it as prescribed, drinking to thirst, daily weights, recognizing signs of hyponatremia, and reporting a return of heavy urination. Key point! With desmopressin, the client drinks only to thirst and weighs daily; forcing fluids or taking extra doses causes hyponatremia.