Influence of dexamethasone on efficacy of ceftriaxone and vancomycin therapy in experimental pneumococcal meningitis.

Using a rabbit model of meningitis, we sought to determine whether concomitant use of dexamethasone affects the penetration and efficacy of ceftriaxone or vancomycin in cerebrospinal fluid. Rabbits were inoculated with a penicillin-sensitive strain of Streptococcus pneumoniae and treated with ceftriaxone or vancomycin with or without dexamethasone. In the ceftriaxone-treated groups, no statistically significant differences were seen between the group treated with dexamethasone and that without dexamethasone; however, in the vancomycin-treated groups we found statistically significant lower cerebrospinal fluid vancomycin levels at 2 h in the dexamethasone-treated rabbits and differences in bacterial killing.