ABSTRACT
Phamacokinetic study of the antibiotic concentrations in the cerebrospinal fluid was done with high pressure liquid chromatography of CSF samples from twelve patients who had various amount of continuous extra-ventricular drainage during antibiotic administration. Five patients with large amount(over 150cc/day) of drainage had decreased CSF antibiotic concentrations dramatically below the effective concentration within 4 hours after intraventricular antibiotic administration, but six patients with small(less than 150cc/day) drainage maintained CSF antibiotic level above effective concentration even 24 hours after administration. In conclusion, repeated intraventricular administration of antibiotic is necessary to maintain the effective drug level in the patient with CSF drainage over 150cc/day.