Urea to Treat Hyponatremia Due to Syndrome of Inappropriate Antidiuretic Hormone Secretion: A Systematic Review and Meta-Analysis

The use of urea to treat hyponatremia related to the syndrome of inappropriate antidiuretic hormone secretion (SIADH) has not been universally adopted due to questions about effectiveness, safety, and tolerability. This systematic review and meta-analysis of observational studies addresses these questions. This PRISMA-guided study examined published research across 4 electronic databases. Patients with SIADH-related hyponatremia. Clinical trials and observational studies reporting at least 1 outcome related to serum sodium concentration, symptom resolution, or adverse effects after oral or nasogastric urea administration. Data extraction was performed independently by 2 reviewers using a standardized form recording study characteristics, participant demographics, intervention details, and treatment outcomes. A meta-analysis was conducted using the restricted maximum likelihood method for the random effects model to assess the effect of urea treatment on serum sodium and serum urea compared with other treatment modalities. Subgroup analyses were conducted based on treatment duration and SIADH severity. Urea treatment significantly increased serum sodium (mean difference [MD], 9.08 [95% CI, 7.64-10.52], P