Central Nervous System Infections

Introduction to Antibiotic Penetration

Third-generation cephalosporins, meropenem, linezolid, metronidazole, rifampin, and trimethoprim-sulfamethoxazole are recommended for central nervous system infections due to their good blood-brain barrier penetration, as suggested by the Infectious Diseases Society of America 1, 2

The following antibiotics have good penetration into the central nervous system:
Vancomycin has limited penetration into CSF (1-5%) but is still recommended for MRSA CNS infections in combination with other agents 3

The following empiric treatments are recommended for CNS infections:
Vancomycin is recommended as first-line therapy for CNS infections caused by MRSA, despite its poor CSF penetration, with linezolid and TMP-SMX as alternatives due to their better CSF penetration 3

The French Society of Pharmacology and Therapeutics recommends CSF as the preferred sample to assess drug diffusion into the brain, with therapeutic drug monitoring (TDM) strongly recommended 4
CSF sampling for TDM should be performed 24-48 hours after treatment initiation, and TDM should be repeated after any significant change in the patient's clinical condition, as suggested by the Critical Care guidelines 4
CSF sampling specifically for TDM is not recommended unless a lumbar puncture is already indicated for clinical reasons, but may be considered in patients with external ventricular drains 4
Alternative antibiotics with better BBB penetration should be considered when appropriate based on the pathogen's susceptibility profile and the severity of the infection 4