Prednisone Dosing for a 5-Year-Old Child Weighing 20 kg
For a 5-year-old child weighing 20 kg, the standard prednisone dose is 40 mg daily (calculated as 2 mg/kg/day), administered as a single morning dose, with a maximum daily dose of 60 mg.
Calculation Method
The dosing depends on the clinical indication, but the most commonly used framework for pediatric prednisone dosing follows these principles:
Weight-Based Dosing (Standard Approach)
- Standard dose: 2 mg/kg/day for most acute conditions requiring high-dose corticosteroid therapy 1, 2, 3
- For this 20 kg child: 2 mg/kg × 20 kg = 40 mg daily
- Maximum daily dose is typically 60 mg regardless of weight 1, 2
Body Surface Area-Based Dosing (Preferred by Guidelines)
- 60 mg/m²/day is the guideline-recommended dose for conditions like nephrotic syndrome 1
- Using a simplified equation for approximation: [2 × weight in kg + 8] estimates the 60 mg/m² dose 4
- For this 20 kg child: (2 × 20) + 8 = 48 mg daily
- Body surface area dosing is preferred because it parallels prednisone metabolism better and reduces the risk of underdosing in younger children 3, 4
Volume Calculation for Liquid Formulation
With prednisone 5 mg/5 mL concentration:
- For 40 mg dose: 40 mg ÷ 5 mg/mL = 8 mL (using weight-based calculation)
- For 48 mg dose: 48 mg ÷ 5 mg/mL = 9.6 mL (using BSA-based calculation)
Administration Guidelines
Timing and Frequency
- Administer as a single morning dose before 9 AM to align with physiologic cortisol rhythm and minimize hypothalamic-pituitary-adrenal axis suppression 3, 5
- Single daily dosing is superior to divided doses 1
Duration Considerations
- For courses less than 10-14 days, no tapering is required 2, 3
- For courses longer than 2 weeks, gradual tapering is essential to prevent adrenal insufficiency 2, 3, 5
- Tapering protocol: reduce by 5 mg every week until reaching 10 mg/day, then by 2.5 mg/week until reaching maintenance dose 2, 5
Critical Clinical Caveats
Weight Considerations
- For significantly overweight children, calculate dose based on ideal body weight rather than actual weight to avoid excessive steroid exposure and increased side effects 1, 2, 3
- A maximum dose of 60 mg daily should be considered, with some guidelines allowing up to 80 mg for specific severe conditions 1, 3
Condition-Specific Adjustments
- Asthma exacerbations: 1-2 mg/kg/day (maximum 60 mg/day) for 3-10 days 2, 3, 5
- Nephrotic syndrome initial episode: 60 mg/m²/day or 2 mg/kg/day (maximum 60 mg/day) for 4-6 weeks, followed by alternate-day dosing 1
- Autoimmune hepatitis: 1-2 mg/kg/day (maximum 60 mg/day) for two weeks, then taper 1, 2, 3
Monitoring Requirements
- Regular assessment for steroid-related adverse effects, particularly weight gain, cushingoid features, growth suppression, and behavioral changes 1, 2, 5
- Growth monitoring is essential for children on long-term therapy 2, 5
- Baseline and annual bone mineral density testing for long-term corticosteroid use (≥30 days at ≥30 mg daily) 1, 2, 3