In bacterial meningitis, what is the dose and duration of dexamethasone (steroid) treatment?

Dexamethasone in Bacterial Meningitis: Dosing and Duration

Dexamethasone should be given at 10 mg IV every 6 hours for 4 days in adults and 0.15 mg/kg IV every 6 hours for 4 days in children, started immediately before or with the first dose of antibiotics in suspected bacterial meningitis. 1, 2, 3

Specific Dosing Regimens

Adults

• Dose: 10 mg IV every 6 hours (total 40 mg/day) 1, 3
• Duration: 4 days 1, 3
• Timing: Must be given 10-20 minutes before or simultaneously with the first antibiotic dose 1, 2

Children (Beyond Neonatal Age)

• Dose: 0.15 mg/kg IV every 6 hours 1, 3
• Duration: 2-4 days (4 days is standard, though 2 days may be adequate for H. influenzae and meningococcal meningitis) 1, 4
• Timing: 10-20 minutes before or with first antibiotic dose 1

Neonates

• Not recommended: Insufficient evidence supports dexamethasone use in neonatal meningitis 1, 3

Critical Timing Considerations

If antibiotics have already been started, dexamethasone can still be initiated up to 4 hours after the first antibiotic dose based on European consensus. 1, 3 Some UK guidelines extend this window to 12 hours, though European guidelines are more conservative at 4 hours. 3 Beyond this timeframe, the benefit becomes uncertain as the inflammatory cascade from antibiotic-induced bacterial lysis has already been triggered. 1

Pathogen-Specific Guidance

Continue Dexamethasone for Full 4 Days:

• Streptococcus pneumoniae: Strong evidence for mortality reduction and decreased neurological sequelae 2, 5
• Haemophilus influenzae type b: Confirmed benefit for reducing hearing loss 1, 2

Discontinue Dexamethasone:

• Listeria monocytogenes: May increase mortality; stop immediately if identified 2
• Non-bacterial meningitis: Stop if bacterial meningitis is ruled out 1, 3
• Other bacterial pathogens: European guidelines recommend stopping for organisms other than S. pneumoniae or H. influenzae, though some experts continue regardless of pathogen 1, 3

Special Meningitis Types

Tuberculous Meningitis

• Adults and children ≥25 kg: 12 mg/day initially for 3 weeks, then taper over 3 weeks 6
• Children <25 kg: 8 mg/day initially for 3 weeks, then taper over 3 weeks 6
• Strong recommendation: Reduces mortality particularly in patients with decreased consciousness 6

Cryptococcal Meningitis

• Not recommended: May worsen outcomes 2

Evidence Quality and Geographic Considerations

The benefit of dexamethasone is established only in high-income countries with high standards of medical care. 1, 2 Studies from low-income countries showed no beneficial effect, likely due to differences in healthcare infrastructure, delayed presentation, HIV co-infection rates, and causative organisms. 1

The landmark European Dexamethasone Study demonstrated reduction in unfavorable outcomes from 25% to 15% in adults with bacterial meningitis. 3, 5 Meta-analyses confirm dexamethasone significantly reduces hearing loss and neurological sequelae, though the effect on overall mortality across all bacterial meningitis cases is not statistically significant. 1, 7

Common Pitfalls to Avoid

• Delayed administration: Starting dexamethasone after antibiotics have been running for >4 hours negates much of the benefit 1, 3
• Continuing in Listeria: This is potentially harmful and must be stopped 2
• Use in neonates: Lacks evidence and is not recommended 1, 3
• Assuming universal benefit: Only proven effective in high-income healthcare settings 1, 2
• Premature discontinuation: Complete the full 4-day course for pneumococcal or H. influenzae meningitis even if clinical improvement occurs earlier 1, 3