Basic Neuroscience · Neuropharmacology
Bacterial Meningitis — Therapy & Dosing
Empirical and organism-directed antimicrobial therapy for bacterial meningitis, with the meningitis-dose antibiotic schedule. Verify doses and adjust for renal function.
Therapy by organism
| Organism | Standard therapy | Alternative |
|---|---|---|
| Neisseria meningitidis | Ceftriaxone or Cefotaxime | — |
| Streptococcus pneumoniae | Vancomycin + Ceftriaxone or Cefotaxime | Chloramphenicol |
| H. influenzae | Ceftriaxone or Cefotaxime | — |
| Enterobacterales | Ceftriaxone or Cefotaxime (if susceptible) | Meropenem (ESBL / cephalosporin-resistant); Aztreonam |
| Pseudomonas aeruginosa | Cefepime, Ceftazidime, or Meropenem | Aztreonam or ciprofloxacin; add aminoglycoside if severe |
| Streptococcus agalactiae | Ampicillin + aminoglycoside | Ceftriaxone or Cefotaxime |
| Listeria monocytogenes | Ampicillin + aminoglycoside | Cotrimoxazole |
| S. aureus (MSSA) | Nafcillin or Oxacillin | Vancomycin |
| S. aureus (MRSA) | Vancomycin | Linezolid, Daptomycin, or TMP-SMX; add Rifampin if hardware |
| S. epidermidis | Vancomycin + Rifampin | Linezolid |
Empirical therapy by age & comorbidity
| Group | Likely organisms | Empirical therapy |
|---|---|---|
| <1 month | S. agalactiae, E. coli, Listeria, Klebsiella | Ampicillin + Cefotaxime (avoid ceftriaxone in neonates) ± aminoglycoside |
| 1–23 months | S. pneumoniae, N. meningitidis, H. influenzae | Vancomycin + 3rd-gen cephalosporin |
| 2–50 years | N. meningitidis, S. pneumoniae | Vancomycin + 3rd-gen cephalosporin |
| >50 years | S. pneumoniae, N. meningitidis, Listeria | Vancomycin + 3rd-gen cephalosporin + Ampicillin |
| Basilar skull fracture | S. pneumoniae, H. influenzae, group A strep | Vancomycin + 3rd-gen cephalosporin |
Adjunctive dexamethasone: give the first dose 10–20 min before, or with, the first antibiotic — best benefit in adults with suspected/proven pneumococcal meningitis and children with H. influenzae type b.
- Dose: adults 10 mg IV q6h; children 0.15 mg/kg IV q6h — for 4 days.
- Stop if not pneumococcus (adults) or Hib (children); little benefit if started after antibiotics.
Meningitis-dose antibiotic schedule
| Antibiotic | Adult (total/day) | Child (total/day) | Interval |
|---|---|---|---|
| Amikacin | 15 mg/kg | 30 mg/kg | q8h |
| Ampicillin | 12 g | 300 mg/kg | q4h |
| Aztreonam | 6–8 g | — | q6–8h |
| Cefepime | 6 g | 150 mg/kg | q8h |
| Cefotaxime | 8–12 g | 200 mg/kg | q4–6h |
| Ceftazidime | 6 g | 150 mg/kg | q8h |
| Ceftriaxone | 4 g | 100 mg/kg | q12h |
| Chloramphenicol | 4–6 g | 100 mg/kg | q6h |
| Ciprofloxacin | 800–1200 mg | Not used | q8–12h |
| Gentamicin | 5 mg/kg | 7.5 mg/kg | q8h |
| Linezolid | 1200 mg | — | q12h |
| Meropenem | 6 g | 120 mg/kg | q8h |
| Moxifloxacin | 400 mg | — | q24h |
| Nafcillin / Oxacillin | 12 g | — | q4h |
| Penicillin G | 24 MU | 24 MU | q4h |
| Rifampin | 600 mg | 20 mg/kg | q24h |
| Tobramycin | 5 mg/kg | 7.5 mg/kg | q8h |
| TMP-SMZ | 10–20 mg/kg | — | q6–12h |
| Vancomycin | 30–60 mg/kg | 60 mg/kg | q8–12h |
Neuro.Wiki by Ahmed Koriesh, MD — Educational only, not a substitute for clinical judgement