How to Administer Hydrocortisone
For patients with adrenal insufficiency undergoing surgery or experiencing adrenal crisis, give hydrocortisone 100 mg intravenously at induction/onset, followed immediately by continuous IV infusion of 200 mg over 24 hours—this is the preferred method over intermittent boluses due to superior safety and more stable cortisol levels. 1
Clinical Context-Specific Administration
Adrenal Crisis (Life-Threatening Emergency)
- Immediate treatment: Hydrocortisone 100 mg IV or IM bolus immediately 2, 3
- Maintenance: Continuous IV infusion of 200 mg/24 hours OR hydrocortisone 50 mg IV/IM every 6 hours 2, 1
- Fluid resuscitation: Rapid infusion of 1000 mL isotonic saline in first hour 3
- Transition: Once stable and tolerating oral intake, switch to oral hydrocortisone at triple the usual dose (minimum 60 mg/day) divided into 3 doses, then taper over several days 4
Critical pitfall: Do NOT wait for laboratory confirmation—treat immediately if adrenal crisis is suspected, as delayed treatment can be fatal 5, 3
Surgery Under Anesthesia (Adults)
Intra-operative:
- Hydrocortisone 100 mg IV at induction
- Immediately start continuous infusion 200 mg/24 hours 1
Post-operative:
- Continue 200 mg/24 hours IV infusion while nil by mouth or vomiting
- Alternative: Hydrocortisone 50 mg IM/IV every 6 hours if continuous infusion impractical 1
- Once tolerating oral: Double usual hydrocortisone dose for 48 hours (uncomplicated recovery) or up to 1 week (major surgery) 1
Why continuous infusion is superior: Research demonstrates that continuous IV infusion is the only administration mode that persistently maintains cortisol concentrations in the range observed during major stress, whereas intermittent boluses create peaks and troughs 6. Multiple studies confirm faster shock reversal and better outcomes with continuous infusion versus boluses 7, 8, 9.
Labor and Vaginal Delivery
- Hydrocortisone 100 mg IV at onset of labor
- Immediately start continuous infusion 200 mg/24 hours 1
- Alternative: Hydrocortisone 100 mg IM followed by 50 mg IM every 6 hours 1
Pediatric Dosing
Adrenal Crisis (Children):
- Weight-based bolus:
- <15 kg (0-2 years): 25 mg
- 15-25 kg (2-6 years): 50 mg
25 kg (>6 years): 100 mg 2
- Maintenance: 50-100 mg/m²/24h divided every 6 hours OR 2 mg/kg every 6-8 hours 2, 4
Surgery (Children):
- Hydrocortisone 2 mg/kg IV at induction
- Continuous IV infusion based on weight:
- Up to 10 kg: 25 mg/24h
- 11-20 kg: 50 mg/24h
20 kg prepubertal: 100 mg/24h
20 kg pubertal: 150 mg/24h 1
Critical pediatric consideration: Children are more vulnerable to hypoglycemia—monitor blood glucose hourly and give 2-5 mL/kg of 10% glucose if <3.5 mmol/L 2, 1
Routine Replacement Therapy (Non-Stress)
Adults:
- Primary adrenal insufficiency: 15-25 mg/day hydrocortisone 4
- Secondary adrenal insufficiency: 10-20 mg/day (lower dose) 4
- Dosing schedule: Split into 2-3 doses daily, with highest dose in morning 4
Children:
- Primary AI (CAH): 10-18 mg/m²/day (higher in neonates: 20-40 mg/m²/day first month) 4
- Other primary AI: 8-15 mg/m²/day 4
- Secondary AI: 8-10 mg/m²/day 4
- Schedule: 2-3 doses daily; 3 doses recommended for infants and young children 4
Alternative Routes When IV/IM Unavailable
Subcutaneous administration: 100 mg hydrocortisone SC shows excellent pharmacokinetics with only slightly delayed cortisol increase compared to IM (time to cortisol >36 μg/dL: 22±11 min SC vs 11±5 min IM), well-tolerated, and preferred by 92% of patients 10. This is a viable emergency option when IV/IM access is difficult.
Key Clinical Pitfalls to Avoid
Never use dexamethasone alone in primary adrenal insufficiency—it lacks mineralocorticoid activity 1
Fludrocortisone is NOT needed acutely when high-dose hydrocortisone (≥50 mg/day) is given, as hydrocortisone provides sufficient mineralocorticoid effect at these doses 2, 4
Avoid abrupt discontinuation after prolonged therapy—taper gradually to prevent withdrawal and shock relapse 4
Tapering is unnecessary and potentially harmful in septic shock—associated with increased hyperglycemia and hypokalemia without reducing shock relapse 8, 11
Timing matters: Initiating hydrocortisone ≤13 hours after starting vasopressors predicts better shock reversal 8