Oral Urea Supplementation in the Treatment of Acute Hyponatremia among Hospitalized Adults: A Systematic Review.

Overview

abstract

Hyponatremia is the most common electrolyte disturbance among hospitalized adults. Oral urea is currently recommended in Europe in the treatment of chronic hyponatremia; no published systematic review investigating oral urea for acute hyponatremia among hospitalized adults exists. An oral urea supplement became available in the United States in 2016. This was a systematic review investigating the use of oral urea in the treatment of acute hyponatremia among hospitalized adults. Pubmed, CINAHL, Scopus, Web of Science, and Cochrane databases were searched for studies published between 1998 and 2021. Risk of bias was assessed using the ROBINS-I tool; strength of the evidence was assessed using GRADE criteria. Changes in serum sodium and measures of safety and tolerance were reported. Eight studies were identified that met inclusion criteria, which included a total of 296 patients. Seven studies were retrospective. All studies found an increase in serum sodium levels associated with oral urea supplementation. Side effects were minimal; one patient discontinued urea due to a side effect (dysgeusia). Urea dose/duration varied among the studies. Based on the serious risk of bias and GRADE criteria, the strength of the evidence was considered low. Oral urea supplementation was associated with increases in serum sodium concentrations among hospitalized adults with hyponatremia, and appears to be safe and well tolerated in this population. Prospective controlled trials are needed to establish the efficacy, comparative effectiveness, and potential cost savings of this therapy.Key teaching pointsHyponatremia is associated with negative clinical outcomes among hospitalized adults.Oral urea is now available in the United States, and is currently recommended in Europe to treat chronic hyponatremia.This systematic review shows that oral urea supplementation may be associated with increases in serum sodium levels among hospitalized adults with hyponatremia, and appears safe and well-tolerated; however, the studies reviewed here are at high risk of bias and the available evidence is of low quality, making any recommendation drawn from this data weak.Prospective controlled trials are needed to establish the efficacy, comparative effectiveness, and potential cost savings of oral urea supplementation for hyponatremia.