Oral Urea Powder Indications
Oral urea powder is indicated for the treatment of chronic hyponatremia (low serum sodium) in hospitalized and outpatient adults, where it functions as an osmotic diuretic to increase urinary water excretion and raise serum sodium levels. 1, 2
Primary Indication: Chronic Hyponatremia
Oral urea is effective and safe for treating chronic hyponatremia, particularly in patients who have failed or cannot tolerate conventional therapies such as fluid restriction or vasopressin receptor antagonists. 1
The mechanism involves osmotic diuresis—urea increases urinary water excretion without significant electrolyte loss, thereby concentrating serum sodium. 1
Recent evidence from the United States (using a novel formulation available since 2016) demonstrates efficacy in raising serum sodium levels among hospitalized patients with hyponatremia. 1
European case series since the 1980s have consistently shown oral urea to be safe and effective for chronic hyponatremia management. 1
Emerging Indication: Acute Hyponatremia
A systematic review found that oral urea supplementation was associated with increases in serum sodium concentrations among hospitalized adults with acute hyponatremia, though the evidence quality is low due to predominantly retrospective studies. 2
All eight studies reviewed (296 total patients) demonstrated increases in serum sodium levels with oral urea use. 2
Side effects were minimal—only one patient discontinued therapy due to dysgeusia (taste disturbance), indicating excellent tolerability. 2
Important Clinical Context
NOT for Topical Dermatologic Use
The FDA-approved topical urea formulation is indicated for hyperkeratotic conditions (dry skin, psoriasis, ichthyosis, eczema, calluses, nail conditions), but this is a completely different route and indication than oral urea powder. 3, 4, 5
Do not confuse oral urea for hyponatremia with topical urea for skin conditions—these are distinct therapeutic applications with different mechanisms and safety profiles.
Safety Profile for Oral Use
Oral urea appears safe and well-tolerated for hyponatremia treatment, with minimal adverse effects reported across multiple studies. 1, 2
The most common side effect is dysgeusia (altered taste), which rarely leads to discontinuation. 2
No systemic toxicity has been documented with therapeutic oral urea use for hyponatremia. 1
Clinical Pearls and Caveats
Oral urea represents an alternative when conventional hyponatremia treatments fail, cause non-adherence, produce adverse effects, or are cost-prohibitive. 1
Dosing and duration protocols vary across studies—no standardized regimen exists yet, highlighting the need for prospective controlled trials. 2
Even mild chronic hyponatremia is associated with increased morbidity and mortality, making effective treatment important despite subtle symptoms. 1
The strength of evidence for oral urea in acute hyponatremia is currently low (GRADE criteria), requiring prospective trials to establish definitive efficacy and comparative effectiveness. 2