PENETRATION OF RIFAMPICIN INTO THE BRAIN-TISSUE AND CEREBRAL EXTRACELLULAR-SPACE OF RATS

Rifampicin is used to treat neurosurgical shunt infections because of its excellent in-vitro activity against staphylococci and its adequate penetration into the CSF. However, nothing is known about rifampicin concentrations in the cerebral extracellular space (CES). We measured the penetration of rifampicin into the CES of anaesthetized rats by microdialysis using low-flow and equilibrium methods. Depending on the method, rifampicin concentrations in the CES were 0·3-1% of the serum concentration or 3-8% of brain tissue concentration, respectively. These experimental data in animals suggest that the recommended dose of rifampicin in man might be inadequate for treatment of some brain infections. © 1993 The British Society for Antimicrobial Chemotherapy.