What is the appropriate prednisolone dose and dosing schedule for a 6‑year‑old male weighing 47 lb (≈21 kg)?

Prednisolone Dosing for a 6-Year-Old Male Weighing 47 Pounds

For a 6-year-old male weighing 47 pounds (21 kg), the appropriate prednisolone dose is 1-2 mg/kg/day (21-42 mg daily) given as a single morning dose, with the specific dose and duration determined by the underlying condition being treated. 1, 2, 3

Weight-Based Calculation

• Patient weight: 47 pounds = 21.3 kg
• Standard dosing range: 1-2 mg/kg/day 1, 2, 3
• Calculated dose range: 21-42 mg daily (maximum 40-60 mg/day depending on condition) 1, 3

Condition-Specific Dosing Recommendations

For Acute Asthma Exacerbations

• Dose: 1-2 mg/kg/day = 21-42 mg once daily (maximum 60 mg/day) 1, 2
• Duration: 3-10 days with no tapering needed for courses less than 7 days 4
• Administration: Single daily dose, preferably in the morning 2, 3

For Autoimmune Conditions (e.g., Autoimmune Hepatitis)

• Initial dose: 2 mg/kg/day = 42 mg once daily (maximum 60 mg/day) 1, 2
• Maintenance: Taper over 6-8 weeks to 0.1-0.2 mg/kg/day = 2-4 mg daily 1, 2
• Duration: Continue until clinical, laboratory, and histologic resolution 1

For Nephrotic Syndrome

• Initial dose: 2 mg/kg/day or 60 mg/m²/day = 42 mg once daily (maximum 60 mg/day) for 4-6 weeks 2, 5
• Maintenance: Switch to alternate-day dosing at 1.5 mg/kg/dose = 32 mg every other day for 2-5 months with gradual tapering 2, 5

Dosing Frequency and Administration

Single daily morning dosing is strongly preferred because it:

• Minimizes adrenocortical suppression 2, 3
• Mimics physiologic cortisol secretion patterns 2
• Improves medication adherence 3

Exception: If behavioral side effects (hyperactivity, emotional lability) occur, consider afternoon dosing after school 2

Tapering Protocol

For courses longer than 10-14 days, implement structured tapering 2, 4:

1. Reduce by 5 mg every week until reaching 10 mg/day
2. Then reduce by 2.5 mg/week until reaching maintenance dose
3. Finally reduce by 1 mg monthly to reach minimum effective dose

No tapering is required for short courses less than 7 days 4

Critical Monitoring Requirements

During Treatment

• Growth monitoring: Track linear growth regularly, as growth suppression is a significant concern with long-term therapy 4
• Bone health: Initiate calcium and vitamin D supplementation immediately when starting therapy 2, 4
• Steroid side effects: Monitor for Cushingoid features, weight gain, hypertension, and gastric irritation 2

For Long-Term Therapy (>30 days at ≥30 mg daily)

• Bone density testing: Baseline and annual DEXA scans of lumbar spine and hip 1, 4
• HPA axis suppression: Anticipate suppression with doses >7.5 mg daily for >3 weeks 4

Important Clinical Caveats

Dosing Adjustments

• For significantly overweight children: Calculate dose based on ideal body weight, not actual weight, to avoid excessive steroid exposure 2, 5
• Prednisolone vs. prednisone: These medications are equivalent and interchangeable at the same dosage 2, 5

Common Pitfalls to Avoid

• Divided dosing: Avoid splitting the daily dose unless behavioral side effects occur, as this increases adrenal suppression 2, 3
• Inadequate duration: For asthma, continue until peak expiratory flow reaches 80% of personal best or symptoms resolve, which typically requires 3-10 days 3
• Abrupt discontinuation: After long-term therapy, withdraw gradually rather than abruptly to prevent adrenal crisis 3

Contraindications

• Do not use systemic corticosteroids for bronchiolitis in children under 2 years, as evidence shows insufficient benefit 4

Practical Dosing Example

For this 21 kg, 6-year-old male:

• Acute asthma: Start with 30-40 mg once daily in the morning for 5-7 days 1, 2
• Severe condition requiring maximum dose: Use 40 mg once daily (approaching the 60 mg maximum) 1, 3
• Liquid formulation: If using prednisolone sodium phosphate oral solution (15 mg/5 mL), administer 10-13 mL once daily 3