What is the dose of urea (Urea) tablets for managing hyponatremia?

Dosing of Urea Tablets for Hyponatremia Management

The recommended starting dose of urea tablets for managing hyponatremia is 30 g per day, which can be adjusted based on clinical response and severity of hyponatremia. 1

Dosing Guidelines

Initial Dosing

• Starting dose: 30 g/day for most adult patients 1
• Dose range: 0.25-0.50 g/kg/day (typically 15-45 g/day) 2
• Administration: Can be given as a single daily dose or divided into 2-3 doses

Dosing Based on Severity

• Mild hyponatremia (130-135 mEq/L): Generally does not require urea therapy unless refractory to fluid restriction 3
• Moderate hyponatremia (125-129 mEq/L): 30 g/day 1, 4
• Severe hyponatremia (<125 mEq/L): 0.5-1 g/kg/day (higher end of dosing range) 5

Dosing Adjustments

• Response monitoring: Check serum sodium levels at baseline, 24 hours, 48 hours, and 72 hours after initiation 2
• Target correction rate: Aim for serum sodium increase of 4-6 mEq/L per day, not exceeding 8 mEq/L in 24 hours 3
• Duration of therapy: Median duration is 5-6 days, but may range from 2-42 days depending on clinical response 1, 2

Clinical Considerations

Indications

• Most effective for SIADH-related hyponatremia 1, 2
• Particularly useful when fluid restriction is ineffective or not feasible 1
• Consider as second-line therapy after fluid restriction failure 2

Monitoring Parameters

• Serum sodium: Check every 24 hours initially, then adjust frequency based on response
• BUN/Creatinine: Monitor for changes in renal function
• Clinical symptoms: Assess for improvement in neurological symptoms if present

Efficacy Markers

• Approximately 64% of patients achieve serum sodium ≥130 mEq/L within 72 hours 1
• Mean increase in serum sodium is approximately 2 mEq/L per day 4

Potential Side Effects

• Common: Distaste/palatability issues (reported in 22-54% of patients) 1, 2
• Less common: Nausea, gastrointestinal discomfort
• Rare but important: Overcorrection of sodium (occurs in approximately 8% of patients) 4

Practical Administration Tips

• Mix with flavored beverages or food to improve palatability
• Can be administered via gastric tube in ICU settings 5
• Consider dividing daily dose to improve tolerability

Special Populations

• Elderly: Start at lower end of dosing range (15-20 g/day)
• Renal impairment: Use with caution and monitor renal function closely
• ICU patients: May require higher doses (0.5-1 g/kg/day) for severe hyponatremia 5

Urea therapy has demonstrated effectiveness in increasing serum sodium levels with a good safety profile when properly monitored. The key to successful treatment is appropriate patient selection, proper dosing, and careful monitoring to prevent overcorrection.