Prednisone Dosing for a 47-Pound Pediatric Patient
For a 47-pound (21.3 kg) child, administer prednisone 42-43 mg once daily in the morning as a single dose, calculated using the standard pediatric dosing of 2 mg/kg/day (maximum 60 mg/day). 1, 2
Dose Calculation
Weight-based calculation:
- 47 pounds = 21.3 kg
- Standard dose: 2 mg/kg/day = 42.6 mg/day 1
- Practical dose: 42-43 mg once daily (round to nearest available tablet strength)
Body surface area verification:
- Using the simplified equation [2 × W + 8] for 60 mg/m²: (2 × 21.3) + 8 = 50.6 mg 3
- This BSA-based calculation yields a slightly higher dose, but weight-based dosing at 2 mg/kg is the standard guideline recommendation 1
Critical Dosing Considerations
Maximum dose limits:
- Never exceed 60 mg/day for initial therapy 1, 2, 4
- Some guidelines suggest a maximum of 80 mg/day, but 60 mg is the standard ceiling 1, 5
Timing of administration:
- Give as a single morning dose to minimize adrenocortical suppression and mimic physiologic cortisol secretion 1, 2, 6, 4
- Exception: If behavioral side effects (hyperactivity, aggression, anxiety) develop, consider afternoon dosing after school 6, 7
Important Clinical Caveats
Weight-based vs. BSA-based dosing:
- Weight-based dosing (2 mg/kg) systematically underdoses children weighing <30 kg compared to BSA-based dosing (60 mg/m²), with a median ratio of 0.85 8
- However, weight-based dosing remains the guideline standard because it's simpler and doesn't require height measurement 1, 2
- For this 21.3 kg child, the underdosing is approximately 15-20% compared to BSA calculation 8
Overweight children:
- If this child is significantly overweight, calculate dose based on ideal body weight rather than actual weight to avoid excessive steroid exposure 1, 2, 6
Behavioral monitoring:
- Anxiety occurs in 1 in 6 children, hyperactivity in 1 in 9, and aggressive behavior in 1 in 5 at standard doses 7
- These effects are dose-dependent and twice as common at 2 mg/kg vs. 1 mg/kg 7
Duration and Tapering
Short courses (<7-10 days):
- No tapering required 2
Longer courses (>10-14 days):
- Taper by 5 mg weekly until reaching 10 mg/day 1, 2
- Then reduce by 2.5 mg weekly until reaching maintenance dose 1, 2
- Finally reduce by 1 mg monthly to minimum effective dose 2
Condition-specific duration:
- Asthma exacerbations: 3-10 days 2
- Nephrotic syndrome: 4-6 weeks daily, then alternate-day dosing 1
- Autoimmune hepatitis: 2 weeks initial, then taper over 6-8 weeks 1, 2
Monitoring Requirements
For courses >2 weeks:
- Monitor growth parameters regularly 2, 6
- Assess for steroid-related adverse effects at each visit 1, 2, 6
- Initiate calcium and vitamin D supplementation immediately 2, 6
For long-term therapy (>30 days at ≥30 mg daily):