What hydrocortisone strength and dosing regimen is appropriate for a 6‑year‑old male child (approximately 20 kg)?

Hydrocortisone Dosing for a 6-Year-Old Male

For routine glucocorticoid replacement in a 6-year-old child (approximately 20 kg), use hydrocortisone 10-15 mg/m² per day divided into 2-3 doses, which translates to approximately 8-12 mg total daily dose for this child.

Routine Replacement Dosing

For maintenance therapy in adrenal insufficiency:

• Total daily dose: 10-15 mg/m²/day (approximately 8-12 mg for a 20 kg child with BSA ~0.8 m²)
• Dosing frequency: Either twice daily (BID) or three times daily (TID)
  • BID regimen: Give larger dose in morning (60-70% of total), smaller dose in evening
  • TID regimen: Divide as morning/midday/evening doses
• Available strengths: 5 mg tablets are appropriate for this age 1

Evidence Supporting Dosing Frequency

Recent research shows no significant difference in adrenal control between BID and TID dosing in prepubertal children 2. BID dosing provides similar adrenal control without impacting growth or bone age advancement, while TID dosing does not increase metabolic side effects 2. However, conventional twice-daily dosing creates supraphysiological peaks 2 hours post-dose and prolonged nadirs before the next dose 3, suggesting TID or QID regimens may better mimic physiological cortisol patterns 4.

Practical recommendation: Start with BID dosing for simplicity and adherence, but consider TID if control is suboptimal.

Stress Dosing

For Illness with Fever at Home

• Double the dose for fever 38°C
• Triple the dose for fever ≥39°C
• Continue for 2-3 days until recovery 5

For Vomiting/Unable to Take Oral Medication

• Give 50 mg hydrocortisone IM immediately (this is the standard dose for school-age children 15-25 kg) 5, 6
• Seek medical attention

For Adrenal Crisis (Emergency)

If suspected adrenal crisis with hypotension/shock:

1. Immediate bolus: 50 mg hydrocortisone IV or IM 5, 6
2. Fluid resuscitation: 20 mL/kg normal saline bolus, repeat as needed 6
3. Maintenance stress dosing: 50-100 mg/m²/day divided every 6 hours IV 5, 6
4. Check glucose hourly; if <3.5 mmol/L give 2-5 mL/kg of 10% dextrose 6

Critical Pitfalls to Avoid

• Under-dosing during stress: This is the most dangerous error and can lead to adrenal crisis. When in doubt, give stress doses 5
• Delayed treatment of suspected crisis: Give hydrocortisone immediately—do not wait for laboratory confirmation 5
• Forgetting emergency injection kit: Parents should always have IM hydrocortisone 50 mg available at home and school 6
• Inadequate patient/family education: Families must know when and how to administer emergency doses 5

Monitoring

• Assess growth, blood pressure, and general well-being every 3-4 months 5
• Watch for signs of over-replacement (weight gain, growth suppression, hypertension) or under-replacement (fatigue, poor growth, hypotension)
• Adjust doses with growth and changes in body surface area