Effectiveness of urea administration for the treatment of hyponatremia in heart failure

Objectives: To assess the efficacy and safety of urea in patients with hyponatremia and heart failure (HF). Methods and results: This is a retrospective observational analytical study of patients with HF and hyponatremia (Na+ <135 mmol/l). Forty-nine patients treated with urea and 47 patients who did not receive urea, all under standard treatment (according to usual clinical practice) for HF, were included and followed up at & Aacute;lvaro Cunqueiro Hospital in Vigo between January 2013 and May 2022. The study evaluated the normalization of sodium levels (Na > 135 mmol/l). The initial natremia at the start of oral urea treatment was 127 +/- 5.22 mmol/l, at 24 h the sodium level was 128 +/- 2.47 (p < 0.009), and the mean on the day of normalization was 135.19 +/- 4.23 mmol/l (p < 0.005). The average number of days to achieve sodium normalization was 5.03 +/- 2.37 days. The initial uremia at the start of urea treatment was 73 +/- 46.93 mg/dl, and the mean on the day of Na + normalization was 116.05 +/- 63.64 mg/dl (p < 0.002). The average oral urea dose was 22.5 g/day. No relevant adverse effects were observed, nor were there significant changes in creatinine levels. Conclusions: Oral urea treatment, when added to standard treatment for short periods of time, is safe and effective in correcting natremia in patients with hypervolemic HF with hyponatremia.