Lockett J, et al. - In patients admitted to a tertiary hospital during 2016-2017, researchers tested the premises that urea is a safe, effective treatment for fluid restriction-refractory hyponatraemia [common in hospitalized patients]. The primary endpoint consisted of a proportion of patients who achieved serum sodium ≥ 130 mmol/L at 72 hours. Urea has been used in 69 patients on 78 occasions. Seventy (89.7%) had the most common cause of hyponatraemia due to SIADH—CNS pathology (64.3%). Data reported that the median nadir serum sodium was 122 mmol/L and fluid restriction was first-line treatment in 65.4%. Investigators found that urea was used first line in 21.8% and second line in 78.2%. No patients developed hypernatremia, over-correction, or died. Overall, they suggested that in fluid restriction-refractory hyponatraemia, urea is safe and effective. In patients with SIADH and moderate to profound hyponatremia who are unable to undergo fluid restrictions, urea with an initial dose of ≥ 30 g/day was recommended.