Oral urea to raise blood sodium in SIAD when fluid restriction fails
Official title: Efficacy of Oral Urea Supplementation in Patients With SIAD Not Adequately Controlled With Fluid Restriction
Run by University of Turin, Italy · NCT07528365 · Data updated 2026-11-12
This trial tests whether taking oral urea can raise blood sodium in people with chronic SIAD whose low sodium doesn't improve with fluid restriction.
Quick facts
| Study type | Interventional |
|---|---|
| Ages | 18 Years and up |
| Sex | All |
| Enrollment | 20 (estimated) |
| Sponsor | University of Turin, Italy Academic / other |
| Locations | 1 site (Turin, Piedmont, Italy) |
| Status | Recruiting |
| Started | September 12, 2024 |
| Main results expected | November 2027 |
| Study ends | December 2027 |
| Registry record updated | April 14, 2026 |
| Trial ID | NCT07528365 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Adults with chronic, mildly symptomatic SIAD-related hyponatremia not corrected by fluid restriction (≤1500 mL/day), clinically euvolemic, with intact adrenal and thyroid function and no diuretic use in the prior 4 weeks are ideal candidates.
✕Probably not a fit
Patients with severe hypotonic hyponatremia (serum sodium <120 mmol/L), moderate-to-severe symptoms, hyponatremia from other causes, ongoing diuretic treatment, or unstable comorbidities are unlikely to benefit from this protocol.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This is a prospective interventional protocol in which patients with chronic SIAD and persistent hyponatremia despite fluid restriction receive oral urea and are followed over time for changes in serum sodium and safety. Eligible participants have a prior diagnosis of SIAD, are clinically euvolemic, and are not on recent diuretics; patients with severe symptoms or serum sodium <120 mmol/L are excluded. The study includes serial measurements of plasma sodium, neuroendocrine markers, body fluid composition, and bone metabolism to characterize physiological effects of urea therapy. The main focus is on whether urea normalizes mild, chronic hyponatremia and on documenting tolerability and downstream metabolic changes.
Why it matters
Potential benefit: If successful, oral urea could safely increase serum sodium, reduce hyponatremia symptoms, and offer an inexpensive alternative to vaptans.
How similar studies have gone: Retrospective case series and guideline recommendations support urea's safety and efficacy, but prospective controlled data are limited.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * Confirmed diagnosis of SIAD established prior to study inclusion, defined as: * Plasma sodium concentration \<135 mmol/L * Plasma osmolality \<300 mOsm/kg * Urine osmolality \>100 mOsm/kg * Urine sodium concentration \>30 mmol/L * Intact adrenal and thyroidal function and no use of diuretics in the last 4 weeks * Clinical euvolemia, defined as an absence of signs of hypovolemia (orthostasis, tachycardia, decreased skin turgor, dry mucous membranes) or hypervolemia (edema, ascites) Fulfillment of all diagnostic criteria at baseline (day 0) was not mandatory, as the diagnosis of SIAD had already been established prior to study inclusion based on overall clinical assessment. \- Written informed consent obtained Exclusion Criteria: * Chronic hypotonic hyponatremia secondary to another etiology * Presence of moderate to severe symptoms attributable to plasma hypotonicity * Severe hypotonic hyponatremia (serum sodium \<120 mmol/L) * Another ongoing drug treatment for hyponatremia (including vaptans and salt tablets) * Severe hepatic insufficiency * eGFR \<45 mL/min/1.73 m² * Pregnancy or breastfeeding * Known allergy or intolerance to urea * Patient refusal or inability to provide written informed consent
Where it's running
-
AOU Città della Salute e della Scienza
Turin, Piedmont, Italy, Italy Recruiting
Similar studies
Other studies for the same condition or treatment. Recruiting studies are listed first.
-
National Registry for Rare Kidney Diseases
This study is collecting health information from people with rare kidney diseases to help improve treatments and create better care guidelines.
-
Protein supplementation for treating low sodium levels in hospitalized patients
This study is testing if giving extra protein to hospitalized patients with low sodium levels works better and is more acceptable than limiting their fluid intake.
How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.