Diffusion of ceftriaxone into the cerebrospinal fluid of adults.

Fourteen adults, three recovering from bacterial meningitis, were given a single 2 g dose of ceftriaxone or three 2 g doses at 12-hourly intervals. The mean per cent penetration of drug into cerebrospinal fluid (CSF) across uninflamed meninges was 1.5%. These levels, although low, are bactericidal in vitro against most pathogens causing meningitis.