From the Research
Duration of Urea Treatment for Hyponatremia
The duration of urea treatment for hyponatremia varies depending on the study and patient response.
- A study published in 2025 1 found that a median dose of 30 g/day of urea for 4 days (interquartile range 2-7 days) increased plasma sodium from 127 to 134 mmol/L and normalized hyponatremia in 47% of treatment episodes.
- Another study from 2020 2 reported that urea was administered over a median of 5 days (range 2-10 days) to hospitalized patients with hyponatremia due to the syndrome of inappropriate antidiuretic hormone secretion (SIADH).
- A 2022 study 3 collected serum sodium levels for 4 days or until urea was discontinued, whichever occurred first, and found that median serum sodium increased 2 mEq/L per day after urea administration at a median dose of 30 g/day.
- A 2019 study 4 used urea to treat fluid restriction-refractory hyponatraemia and reported that 50 treatment episodes (64.1%) resulted in serum sodium ≥130 mmol/L at 72 hours.
Factors Associated with Treatment Duration
Several factors are associated with the duration of urea treatment for hyponatremia, including:
- Older age 1
- Lower baseline plasma sodium 1
- Higher cumulative urea dose 1
- Concurrent fluid restriction 1
- Patient tolerance and side effects, such as distaste 2, 3, 4
Treatment Outcomes
The treatment outcomes for urea in hyponatremia are generally positive, with: