Meningitis Treatment
The recommended first-line treatment for bacterial meningitis is ceftriaxone 2g IV every 12 hours or cefotaxime 2g IV every 6 hours, with additional agents based on patient age and risk factors. 1, 2
Empirical Antibiotic Therapy
Adults <60 years:
- First choice: Ceftriaxone 2g IV every 12 hours OR Cefotaxime 2g IV every 6 hours 1
- Alternative: Chloramphenicol 25 mg/kg IV every 6 hours (if cephalosporin allergy) 1
- Add if penicillin-resistant pneumococci suspected: Vancomycin 15-20 mg/kg IV every 12 hours (aim for trough levels 15-20 μg/mL) OR Rifampicin 600 mg IV/oral every 12 hours 1
Adults ≥60 years or immunocompromised:
- Base therapy: Ceftriaxone 2g IV every 12 hours OR Cefotaxime 2g IV every 6 hours 1
- Plus: Amoxicillin 2g IV every 4 hours (for Listeria coverage) 1
- Alternative: Chloramphenicol plus Co-trimoxazole 10-20 mg/kg (of trimethoprim component) in four divided doses 1
Pathogen-Specific Treatment
Streptococcus pneumoniae:
- Penicillin-sensitive (MIC ≤0.06 mg/L): Continue ceftriaxone/cefotaxime OR switch to benzylpenicillin 2.4g IV every 4 hours 1
- Penicillin-resistant but cephalosporin-sensitive: Continue ceftriaxone/cefotaxime 1
- Penicillin and cephalosporin-resistant: Ceftriaxone/cefotaxime PLUS vancomycin 15-20 mg/kg IV every 12 hours PLUS rifampicin 600 mg IV/oral every 12 hours 1
- Duration: 10 days if recovered by day 10; 14 days if not recovered or resistant strain 1
Neisseria meningitidis:
- Treatment: Continue ceftriaxone/cefotaxime OR benzylpenicillin 2.4g IV every 4 hours 1
- Duration: 5 days if clinically improved 1
- Prophylaxis: Single dose of 500 mg ciprofloxacin orally before discharge 1, 2
Listeria monocytogenes:
Adjunctive Therapy
Dexamethasone:
- Dosing: 10 mg IV every 6 hours for 4 days 2
- Timing: Start with or before first antibiotic dose (can be started up to 4 hours after first antibiotic dose) 1
- Consider discontinuation: If pathogens other than S. pneumoniae or H. influenzae are identified 1
- Caution: Dexamethasone within first 24 hours has been associated with increased mortality in Listeria meningitis 1
Special Considerations
Penicillin Resistance:
- Add vancomycin or rifampicin if patient has recently traveled to areas with high pneumococcal resistance rates 1
- For patients with both penicillin and cephalosporin resistance, triple therapy with ceftriaxone/cefotaxime, vancomycin, and rifampicin is recommended 1, 3
Pediatric Patients:
- For children with bacterial meningitis, ceftriaxone 100 mg/kg/day (not exceeding 4g daily) is recommended 4, 5
- Ceftriaxone has shown excellent CSF penetration with levels 10-100 fold higher than the MIC of common pathogens 5, 6
Monitoring and Follow-up:
- All patients should be assessed for potential long-term sequelae before discharge 2
- Hearing tests should be performed if hearing loss is suspected 2
Common Pitfalls and Caveats
Delayed antibiotic administration: Antibiotics should be given immediately after lumbar puncture, or even before if the procedure is delayed.
Inadequate dosing: Standard doses may not achieve sufficient CSF concentrations; use the higher end of dosing ranges for meningitis.
Failure to cover Listeria in at-risk populations: Always add amoxicillin for patients ≥60 years or immunocompromised.
Inappropriate discontinuation of dexamethasone: Continue for full 4 days in pneumococcal meningitis even if clinical improvement occurs.
Neglecting resistance patterns: Consider travel history and local resistance patterns when selecting empiric therapy.
Insufficient treatment duration: Ensure adequate duration based on pathogen and clinical response.
Overlooking prophylaxis: Close contacts of meningococcal meningitis patients require prophylaxis.
The treatment of bacterial meningitis requires prompt initiation of appropriate antibiotics at meningitis-specific doses to ensure adequate CSF penetration and rapid bacterial clearance, which is critical for reducing mortality and neurological sequelae.