Diffusion of moxalactam into the cerebrospinal fluid in children with bacterial meningitis.

We studied the penetration of moxalactam into the cerebrospinal fluid of 16 children (age range one month to 4 1/2 years) who were being treated for bacterial meningitis. Two hours after single intravenous doses of 15 or 25 mg/kg, moxalactam was detectable in the CSF in only one of 11 instances; however, following three doses (50 mg/kg each) moxalactam was detectable in eight of 17 instances. In these eight instances CSF concentrations of moxalactam ranged between 1.5 and 18.9 micrograms/ml (mean 7.7) and the CSF/plasma ratio ranged from 2.6 to 36% (mean 17.7). There was no relation between the stage of meningitis or the CSF cell count and the diffusion of the drug into the CSF. However, the diffusion of the drug significantly correlated with the CSF protein content. In view of the unpredictability of moxalactam penetration into CSF, caution should be exercised in using it alone in the treatment of meningitis.