Urea Dosage for Topical Use in Dermatology
Urea creams or lotions at 10-40% concentration treat dry skin conditions like ichthyosis, xerosis, or hyperkeratotic disorders. Apply a thin layer to affected areas 1-2 times daily, starting with lower strengths (10-20%) to avoid irritation. Increase to 30-40% for thicker plaques if tolerated. Use occlusive dressings sparingly for enhanced penetration. Moisturize afterward to prevent stinging.[1][2]
Oral Urea for Chronic Kidney Disease or Hyponatremia
For conditions like SIADH-induced hyponatremia, adults take 15-30 grams daily in divided doses (e.g., 5-10 grams every 6-8 hours), dissolved in water or juice. Titrate based on serum sodium levels, targeting 0.5-1 mmol/L rise per day. Pediatric dosing is weight-based at 0.5-1 gram/kg/day, split into 2-4 doses. Monitor electrolytes closely; duration typically short-term (days to weeks).[3][4]
Intravenous Urea for Cerebral Edema or Glaucoma
Administer 1 gram/kg IV over 1-2 hours for acute cerebral edema reduction, with a maximum of 100-200 grams per dose. For glaucoma, use 0.5-1.5 grams/kg infused slowly. Repeat every 6-12 hours if needed, but limit to 24-48 hours due to risks like dehydration. Pre-treat with antiemetics; contraindicated in renal impairment.[2][5]
Dosage Adjustments and Special Populations
Reduce doses by 50% in renal impairment (CrCl <30 mL/min). Elderly patients start at lowest effective dose due to higher dehydration risk. Pregnancy category C; use only if benefits outweigh risks. Pediatrics under 6 years: avoid topical >20% urea; oral/IV dosing requires specialist oversight.[1][3]
Common Side Effects and Monitoring
Topical: burning, itching (dose-related). Systemic: nausea, vomiting, electrolyte imbalance. Monitor serum sodium, BUN, creatinine with oral/IV use. Discontinue if severe irritation or fluid overload occurs.[2][4]
[1]: Medscape - Urea Dosing
[2]: Drugs.com - Urea Dosage Guide
[3]: UpToDate - Urea Therapy in Hyponatremia
[4]: Lexicomp - Urea Monograph
[5]: StatPearls - Urea for Cerebral Edema