Chloramphenicol disposition in infants and children.

We studied the pharmacokinetics of chloramphenicol following its intravenous administration as the sodium succinate ester to 54 infants and children. The mean "apparent t 1/2" of chloramphenicol clearance from the plasma was 5.94 hours (range 0.87 to 17.8 hours). The t 1/2 of patients who weighed less than 10 kg was significantly longer than that of those who weighed more than 10 kg (9.02 vs 4.55 hours; P less than 0.0001). There was a discrepancy between the plasma levels of chloramphenicol and total aromatic nitro compounds in four patients; these compounds were cleared at different rates. Repeated dosing (eight to 30 doses) did not produce a consistent effect on the t 1/2. The CSF concentrations of chloramphenicol in 13 patients were 67% (range 45 to 99%) of the simultaneous serum concentrations. We conclude that the marked individual variation in chloramphenicol pharmacokinetics in infants and children requires monitoring of blood concentrations during therapy.