Antibiotic choice is affected by complicated factors:

  • etiologic bacterial species
  • blood-brain barrier penetration
  • antibacterial activity within purulent CSF
  • drug metabolism
  • potential drug interactions
  • host defense status

The following general guidelines are well developed, however:


Organism Antibiotic
Streptococcus pneumoniae
Penicillin-sensitive Penicillin G or ampicillin
Partial penicillin-sensitive Third-generation cephalosporin
Penicillin-resistant Vancomycin + third-generation cephalosporin
Neisseria meningitidis Penicillin G or ampicillin
Haemophilus influenzae
Beta-lactamase negative Ampicillin
Beta-lactamase positive Third-generation cephalosporin
Enterobacteriaceae Third-generation cephalosporin
Pseudomonas aeruginosa Ceftazidime
Listeria monocytogenes Penicillin G or ampicillin
Staphylococcus aureus
Methicillin-sensitive Nafcillin or oxacillin
Methicillin-resistant Vancomycin
Staphylococcus epidermidis Vancomycin


Table adapted from KL Roos, AR Tunkel, WM Scheld. Acute bacterial meningitis in children and adults. In WM Scheld, RJ Whitley, DT Durack (eds), Infections of the Central Nervous System. Philadelphia: Lippincott–Raven, 1997;336–401. 
Adapted from: Goldstein MA and Harden CL. Infectious states. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;83-133. 
With permission from Elsevier ( 

Reviewed By: 
Steven C. Schachter, MD
Monday, March 1, 2004