Use Dexamethasone, Not Hydrocortisone, for Bacterial Meningitis
You should start dexamethasone (not hydrocortisone) for suspected bacterial meningitis in adults and children beyond the neonatal period in high-income countries, given with or immediately before the first dose of antibiotics. 1
Specific Dosing Regimen
Dexamethasone is the corticosteroid of choice for bacterial meningitis:
- Adults: 10 mg IV every 6 hours for 4 days 1
- Children: 0.15 mg/kg IV every 6 hours for 4 days 1
- Neonates: Do NOT use corticosteroids - not recommended 1
Why Dexamethasone, Not Hydrocortisone?
The evidence base for bacterial meningitis specifically supports dexamethasone, not hydrocortisone. All major randomized controlled trials and the Cochrane meta-analysis of 25 studies involving 4,121 patients used dexamethasone 1, 2. While hydrocortisone is mentioned in one UK guideline for persistent hypotensive shock (200 mg daily) 3, this is for septic shock management, not for the primary neurological benefits in meningitis.
Hydrocortisone causes significant sodium retention when used beyond 48-72 hours, which is problematic in meningitis where cerebral edema is a concern 4. The FDA labeling for hydrocortisone even recommends switching to methylprednisolone if high-dose therapy must continue beyond 48-72 hours to avoid hypernatremia 4.
Timing is Critical
Start dexamethasone before or with the first antibiotic dose - this is a Grade A recommendation 1. The mechanism is to blunt the inflammatory surge caused by bacterial lysis from antibiotics 1.
If you've already started antibiotics, you can still give dexamethasone up to 4 hours after the first antibiotic dose (Grade C recommendation based on expert consensus) 1.
Benefits Demonstrated
Dexamethasone significantly reduces:
- Hearing loss: RR 0.67 for severe hearing loss, RR 0.74 for any hearing loss 2
- Neurological sequelae: RR 0.83 2
- Mortality in pneumococcal meningitis: RR 0.84 2
These benefits apply specifically to high-income countries with advanced medical care - no benefit was demonstrated in low-income country studies 1, 2.
When to Stop Dexamethasone
Discontinue dexamethasone if:
- The patient does NOT have bacterial meningitis
- The causative organism is identified as something OTHER than S. pneumoniae or H. influenzae 1
Important caveat: Some experts recommend continuing dexamethasone regardless of the organism identified, though the guideline consensus favors stopping for organisms other than pneumococcus and H. influenzae 1. The strongest evidence for benefit is in pneumococcal meningitis (reduced mortality) and H. influenzae meningitis (reduced hearing loss) 1.
For N. meningitidis, subgroup analysis showed no significant effect, though this may reflect lower baseline event rates rather than true lack of efficacy 1.
Common Pitfalls to Avoid
- Don't delay antibiotics to give dexamethasone - give them together or dexamethasone first
- Don't use hydrocortisone as the primary corticosteroid - it's not the studied agent and has unfavorable sodium retention properties
- Don't use in neonates - insufficient evidence and potential harm 1
- Don't expect benefit in low-resource settings - all positive data comes from high-income countries 1, 2
- Don't continue beyond 4 days - the standard duration is 4 days 1
Safety Profile
Dexamethasone is safe in this context with no excess adverse effects compared to placebo, except for a modest increase in recurrent fever (RR 1.27) 2. No increased risk of gastrointestinal bleeding or other serious complications was observed 2, 5.