Cerebrospinal fluid diffusion of kanamycin in newborn infants.

Cerebrospinal fluid (CSF) diffusion of kanamycin was studied in 35 newborn infants. Five infants had bacterial meningitis and two had viral meningitis. One-half of the infants received an intramuscular injection of 7.5 mg of kanamycin per kg, whereas the other half received 12.5 mg/kg. Serum and CSF specimens were obtained 3 to 6 hr and 11 to 12 hr after injection. No significant difference was observed between serum levels of kanamycin after the 7.5 and 12.5 mg/kg doses at either sampling time. However, at 3 to 6 hr, in those infants without meningitis, there was a significantly higher concentration of kanamycin in the CSF after the larger 12.5 mg/kg dose. CSF levels of kanamycin did not rise to the desirable therapeutic range with either dose. We were unable to draw a definite conclusion regarding the CSF diffusion of kanamycin in bacterial meningitis, but our data suggest that complete confidence in intramuscular kanamycin in the treatment of gram-negative neonatal meningitis may not be justified, even in those cases with a brisk inflammatory response.