Dexamethasone Dosage for Bacterial Meningitis
Recommended Dose and Duration
For adults with bacterial meningitis, administer dexamethasone 10 mg intravenously every 6 hours for 4 days, starting 15-20 minutes before or with the first dose of antibiotics. 1
For children, administer dexamethasone 0.15 mg/kg intravenously every 6 hours for 4 days (or 2-4 days depending on pathogen), starting with or before the first antibiotic dose. 1, 2
Timing of Administration
Dexamethasone must be initiated before or simultaneously with the first antibiotic dose to maximize benefit by preventing the inflammatory response from bacteriolysis. 1, 2
If antibiotics have already been started, dexamethasone can still be initiated up to 4 hours after antibiotic administration, though this is based on expert consensus rather than trial data. 1
The European Dexamethasone Study demonstrated that early dexamethasone reduced unfavorable outcomes from 25% to 15% in adults when given before or with antibiotics. 3
Pathogen-Specific Considerations
Pneumococcal Meningitis
Dexamethasone is strongly recommended for adults with pneumococcal meningitis (Grade A recommendation), reducing unfavorable outcomes from 52% to 26% and mortality by 52%. 1, 2, 3
In children with pneumococcal meningitis, evidence is less robust (Grade C-II), but dexamethasone should be considered after weighing benefits and risks. 2
H. influenzae Type b Meningitis
Dexamethasone is strongly recommended for children with H. influenzae type b meningitis (Grade A-I), with confirmed benefit in reducing hearing loss (OR 0.31). 1, 2
A 2-day regimen (0.15 mg/kg every 6 hours) appears adequate for H. influenzae meningitis in children. 4
Meningococcal Meningitis
Dexamethasone should be stopped if N. meningitidis is identified, as subgroup analyses show no effect on mortality or hearing loss, though some experts continue treatment regardless of pathogen. 1
Meningococcal meningitis patients have substantially lower event rates, making benefit assessment difficult. 1
When to Discontinue
Stop dexamethasone if bacterial meningitis is ruled out or if the causative organism is neither S. pneumoniae nor H. influenzae, though expert opinion varies. 1
Do not initiate dexamethasone in children who have already received antimicrobial therapy, as benefit is lost. 2
Clinical Outcomes
Dexamethasone significantly reduces hearing loss (OR 0.76) and neurological sequelae across all bacterial meningitis pathogens. 1, 5
The greatest benefit occurs in patients with moderate to severe disease based on Glasgow Coma Scale scores. 2
Meta-analyses show dexamethasone reduces hearing loss from 26.1% to 21.2% among survivors. 5
Important Caveats
In high-income countries, dexamethasone demonstrates clear benefit; no beneficial effects have been identified in low-income country studies. 1
Dexamethasone is not recommended for neonatal bacterial meningitis. 1
For pneumococcal meningitis patients receiving dexamethasone, consider adding rifampin to the empiric vancomycin plus third-generation cephalosporin regimen due to concerns about antibiotic penetration. 2
Gastrointestinal bleeding risk is not increased with dexamethasone (2 cases vs. 5 in placebo group in the landmark trial). 3
In patients with both meningitis and septic shock, dexamethasone cannot be unequivocally recommended, though lower doses may be reasonable. 6